Arctic Sea Ice : Forum

Cryosphere => Glaciers => Topic started by: Lennart van der Linde on August 04, 2015, 08:36:59 AM

Title: Glaciers worldwide decline faster than ever
Post by: Lennart van der Linde on August 04, 2015, 08:36:59 AM
Zemp et al 2015:
http://www.ingentaconnect.com/content/igsoc/jog/pre-prints/content-ings_jog_15j017 (http://www.ingentaconnect.com/content/igsoc/jog/pre-prints/content-ings_jog_15j017)

Abstract
"Observations show that glaciers around the world are in retreat and losing mass. Internationally coordinated for over a century, glacier monitoring activities provide an unprecedented dataset of glacier observations from ground, air and space. Glacier studies generally select specific parts of these datasets to obtain optimal assessments of the mass-balance data relating to the impact that glaciers exercise on global sea-level fluctuations or on regional runoff. In this study we provide an overview and analysis of the main observational datasets compiled by the World Glacier Monitoring Service (WGMS). The dataset on glacier front variations (~42 000 since 1600) delivers clear evidence that centennial glacier retreat is a global phenomenon. Intermittent readvance periods at regional and decadal scale are normally restricted to a subsample of glaciers and have not come close to achieving the maximum positions of the Little Ice Age (or Holocene). Glaciological and geodetic observations (~5200 since 1850) show that the rates of early 21st-century mass loss are without precedent on a global scale, at least for the time period observed and probably also for recorded history, as indicated also in reconstructions from written and illustrated documents. This strong imbalance implies that glaciers in many regions will very likely suffer further ice loss, even if climate remains stable."
Title: Re: Glaciers worldwide decline faster than ever
Post by: Clare on August 04, 2015, 01:07:39 PM
Thanks for posting this Lennart.

"The big melt: we won't recognise our glaciers" (in New Zealand)

http://www.nzherald.co.nz/science/news/article.cfm?c_id=82&objectid=11491426 (http://www.nzherald.co.nz/science/news/article.cfm?c_id=82&objectid=11491426)
Article referring to this paper in the NZ context
+ a link to a spectacular time lapse video rom Jan 2014-Jan 2015 showing the 300m retreat of Fox Glacier on NZ's South Island's west coast:
http://www.nzherald.co.nz/science/news/video.cfm?c_id=82&gal_objectid=11491426&gallery_id=153022 (http://www.nzherald.co.nz/science/news/video.cfm?c_id=82&gal_objectid=11491426&gallery_id=153022)
Title: Re: Glaciers worldwide decline faster than ever
Post by: TerryM on August 05, 2015, 02:50:27 AM
As I understand it mountain glaciers aren't large enough to have much effect on ocean level. Those downstream however that rely on glacial melt for water will have big problems.
As coastal dwellers move inland away from rising waters and mountain/valley people move to avoid water shortages, those with a regular water supply that aren't threatened by SLR may have to fight for their traditional lands.
Exciting times ahead.
Terry
Title: Re: Glaciers worldwide decline faster than ever
Post by: Sigmetnow on August 31, 2015, 09:36:11 PM
Glaciers in Central Asia Shrinking Fast
Quote
Central Asian glaciers have melted at four times the global average since the early 1960s, shedding 27 percent of their mass, according to a recent study.

By 2050, warmer temperatures driven by climate change could wipe out half the remaining glacier ice in the Tien Shan mountain range, reported the study, published in Nature Geoscience.

At stake is a critical source of water for people in Kazakhstan, Kyrgyzstan and Uzbekistan, as well as a section of northwest China.
http://www.japantimes.co.jp/life/2015/08/29/environment/glaciers-central-asia-shrinking-fast-study/ (http://www.japantimes.co.jp/life/2015/08/29/environment/glaciers-central-asia-shrinking-fast-study/)
Title: Re: Glaciers worldwide decline faster than ever
Post by: Sigmetnow on October 07, 2015, 12:50:57 PM
Glaciers in Western Canada continue to melt at an alarming rate, with researchers recording a five-and-a-half metre ice surface loss on the Athabasca Glacier in the past year.
http://calgaryherald.com/news/local-news/western-canadas-glaciers-losing-ice-at-near-record-rates (http://calgaryherald.com/news/local-news/western-canadas-glaciers-losing-ice-at-near-record-rates)
Title: Re: Glaciers worldwide decline faster than ever
Post by: Martin Gisser on October 08, 2015, 12:53:32 AM
Since they found Ice Man Ötzi in 1991 glacial archaeology has become a field of its own with its own scientific journal: http://www.equinoxpub.com/journals/index.php/JGA (http://www.equinoxpub.com/journals/index.php/JGA) http://glacierhub.org/2014/12/12/glacier-archaeology-comes-of-age/ (http://glacierhub.org/2014/12/12/glacier-archaeology-comes-of-age/)

This is an incredible opportunity, since the artefacts found on the glaciers are so well-preserved. It might be counter-intuitive, since nobody (except Inuit) lives on the ice. But people walked it, travelling (Ötzi), hunting (Norway, Canada), making sacrifices (Peru).

Problem is, once melted out, organic stuff decomposes quickly. So this is a race against time.
Quote
“For every artifact we find, we’re losing thousands. And we’re never going to be able to replace this data,”
(...)
Thus, glacial archeologists find themselves at the start of an unprecedented but ephemeral run of discovery. “Now is the time to organize expeditions,” Hafner says. “We have 20—maybe 30—years, and then we will be finished.”
http://www.scientificamerican.com/article/melting-mummies-are-on-thin-ice-thanks-to-climate-change/ (http://www.scientificamerican.com/article/melting-mummies-are-on-thin-ice-thanks-to-climate-change/)


http://sciencenordic.com/items-lost-stone-age-are-found-melting-glaciers (http://sciencenordic.com/items-lost-stone-age-are-found-melting-glaciers)
http://www.archaeology.org/issues/105-1309/letter-from/1165-glaciers-ice-patches-norway-global-warming (http://www.archaeology.org/issues/105-1309/letter-from/1165-glaciers-ice-patches-norway-global-warming)
Title: Re: Glaciers worldwide decline faster than ever
Post by: Laurent on October 11, 2015, 09:25:04 AM
Erosion by an Alpine glacier
http://www.sciencemag.org/content/350/6257/193.short (http://www.sciencemag.org/content/350/6257/193.short)

Quote
Assessing the impact of glaciation on Earth’s surface requires understanding glacial erosion processes. Developing erosion theories is challenging because of the complex nature of the erosion processes and the difficulty of examining the ice/bedrock interface of contemporary glaciers. We demonstrate that the glacial erosion rate is proportional to the ice-sliding velocity squared, by quantifying spatial variations in ice-sliding velocity and the erosion rate of a fast-flowing Alpine glacier. The nonlinear behavior implies a high erosion sensitivity to small variations in topographic slope and precipitation. A nonlinear rate law suggests that abrasion may dominate over other erosion processes in fast-flowing glaciers. It may also explain the wide range of observed glacial erosion rates and, in part, the impact of glaciation on mountainous landscapes during the past few million years.
Title: Re: Glaciers worldwide decline faster than ever
Post by: Laurent on January 29, 2016, 08:17:15 PM
El Niño means glaciers in the Andes are melting at record rates
https://www.newscientist.com/article/2075093-el-nino-means-glaciers-in-the-andes-are-melting-at-record-rates/ (https://www.newscientist.com/article/2075093-el-nino-means-glaciers-in-the-andes-are-melting-at-record-rates/)
Quote
Tropical glaciers in the Andes are melting at their fastest rate for 12 years, thanks to the record-breaking El Niño that is warming up the area, according to new data analysed for New Scientist.

This is compounding the already high melting rates from global warming that will consign many glaciers to history within decades.

“The lower-level glaciers in the Andes, below 5500 metres, are really endangered now and probably only have a couple of decades left,” says Michael Zemp, director of the World Glacier Monitoring Service in Zurich, Switzerland. The organisation recently found that the first decade of the 21st century saw the greatest decadal loss of glacier ice ever measured, with melting rates two to three times higher than in the 20th century.
Unique record of Earth’s past

This glacier loss will lead to water and hydropower shortages, the destruction of unique habitats home to endemic species, as well as the loss of a unique record of Earth’s past recorded in layers of ice (see box, below).

Doug Hardy, a climate scientist at the University of Massachusetts, has recorded the lowest snow accumulation in the 12 years he has been monitoring the Quelccaya Ice Cap in Peru (pictured above) – the largest glacier in the tropics. “We’re seeing 40 per cent more melting than any other year since measurements started in 2002,” he says.

Similarly, the Conejeras glacier in Colombia has lost 43 per cent of its volume over the last two years, according to Jorge Luis Ceballos Liévano and his colleagues from the Hydrology, Meteorology and Environmental Studies Institute in Bogotá. More than two-thirds of that loss has taken place since the onset of the current El Niño.
Rising snowline

“2015 was particularly bad for this glacier and if losses persist it is possible that it will be extinct by 2030 or before,” says Liévano. “Conejeras is representative of what is happening elsewhere in the Andes.”

For example, the once-continuous ice mass along the crest of the Sierra Nevada del Cocuy in Colombia is now a series of broken patches. Measurements show that the snowline has risen above most of the mountain summits now. “In Colombia there is no accumulation of ice and so we anticipate that these glaciers will only have around 20 years
,” says Zemp.

The Zongo glacier in Bolivia, whose runoff feeds a hydroelectric power station supplying the capital, La Paz, also appears to be in its death throes.
Some glaciers already extinct

Some glaciers have already melted away. In 2009, the last of the ice disappeared on the 5350-metre-high Chacaltaya glacier in Bolivia – previously the world’s highest ski resort (pictured below). Similarly the ice-covered summit of Pico Espejo in Venezuela became bare rock by 2008.
QU001327

Christophe Boisvieux/Corbis

In Bolivia and Peru, which have arid summers, glaciers buffer the water supply and ensure a year-round steady flow. Last year Antoine Rabatel, from the Joseph Fourier University in Grenoble, France, and colleagues showed that during the dry season a quarter of La Paz’s water comes from glaciers. “Right now people don’t realise the urgency of the situation because the fast melting of the glaciers is providing plenty of water,” says Rabatel.

In some locations the nature of things to come is starting to become apparent. Retreat of glaciers in the Quebrada Paron mountains of Peru has reduced water flow into the lake below, which supplies a hydroelectric power plant.
Loss of ecosystems

In 2008, people living downstream in the city of Caraz found themselves short of water for irrigation and decided to take direct action in protest. “They locked access to the touristic high valley of Paron,” says Rabatel. This blocked access to the area both to tourists and scientists. “In this case it was more a problem of managing the water resource, but such problems are likely to become more important as water quantity decreases.”

And it isn’t just people who will be affected. Previous research has found that between 11 and 38 per cent of species could be lost in an area following the disappearance of a glacier. Specialist species such as the meltwater stonefly, whose larvae rely on glacial streams, are likely to start vanishing when half the glacial cover in a region is lost. And slow-growing alpine cushion plants, along with many other species of plant and animal that depend on these mossy pillows, will suffer under increasing temperatures. Even though cushion plants prefer to colonise newly deglaciated land, they will struggle to keep up with the pace of melting. The only bird known to nest on a glacier – the white-winged diuca finch (Diuca speculifera) – may have to keep moving higher to build its nests, until eventually it will run out of places to go.
Race to capture the soul of dying glaciers

Several teams of glaciologists are rushing to drill into remaining glaciers to preserve a sample called an ice core, and with it record of our planet's past.

"Some of these glaciers contain 20,000 years' worth of atmospheric data and right now melting is wiping this record out," says Antoine Rabatel from the Joseph Fourier University in Grenoble, France.

"We need to preserve these cores now, so that scientists of the future can still extract this information," says his colleague Patrick Ginot, who is leading a UNESCO-supported project - Saving Ice in Danger - to collect and store glacial ice cores at the Concordia Research Station in Antarctica.

Lonnie Thompson, from the Ohio State University, and his team have been hauling their specialist solar-powered drilling rigs up to some of the most inaccessible places in the world since 1983. Just last month they returned with ice cores from the Guliya ice cap in north-west Tibet, which they then store in a specialist unit at the university.

"This freezer facility is the only place that the ice from some of these glaciers still exists," says Thompson. These glacial ghosts include lost ice fields on Mount Kilimanjaro in East Africa and those from the rapidly melting Northwall Firn glacier on the slopes of Puncak Jaya in Indonesia.

Much of our understanding of global climate is based on the high-resolution record of past atmosphere that only ice cores can provide.

The cores from the Quelccaya Ice Cap in Peru, for example, show the medieval warm period when the Vikings settled in Greenland. "You can see the onset of the Little Ice Age in the early 1500s that contributed to the demise of the Vikings," says Thompson. "And you can see the warming in the 20th century."

"We hope soon to be able to reconstruct the evolution of things like bacteria and viruses through time by using the ice archive," says Thompson.
Title: Re: Glaciers worldwide decline faster than ever
Post by: Sigmetnow on February 17, 2016, 03:12:45 PM
Xinjiang Region of China Bans Glacier Tourism, Citing Risk to Ecosystem
Quote
BEIJING — Glaciologists in China and elsewhere have said for years that climate change is the main cause of glacier erosion, which threatens the water sources of much of humanity.

Officials in the far northwestern Chinese region of Xinjiang now say another factor is putting the fragile glaciers at risk: tourism.

The Xinjiang government announced this month that it was banning tourism on glaciers across the region, which is one-sixth of the Chinese land mass. Many glaciers are found in Xinjiang, and in the Tianshan range in particular, which runs east-west through the middle of the vast region.

Officials want to ensure that tourists observe the glaciers from a distance, not atop the glaciers themselves, according to a report published on Thursday by Xinhua, the state news agency.
...
The report said that “global warming, grazing, mining and tourism have accelerated destruction of the glaciers, and led to water shortages in several areas.”

It quoted Chen Xi of the Chinese Academy of Sciences as saying that glaciers in the Tianshan range have receded 15 to 30 percent in the last three decades.
http://www.nytimes.com/2016/02/17/world/asia/china-xinjiang-glacier-tourism.html (http://www.nytimes.com/2016/02/17/world/asia/china-xinjiang-glacier-tourism.html)
Title: Re: Glaciers worldwide decline faster than ever
Post by: Sigmetnow on March 13, 2016, 04:41:28 AM
Witness the collapse of the Perito Moreno Glacier in Argentina's Los Glaciares National Park.
https://twitter.com/weatherchannel/status/708812675531157509
Title: Re: Glaciers worldwide decline faster than ever
Post by: abbottisgone on April 26, 2016, 09:47:19 AM
As I understand it mountain glaciers aren't large enough to have much effect on ocean level. Those downstream however that rely on glacial melt for water will have big problems.
As coastal dwellers move inland away from rising waters and mountain/valley people move to avoid water shortages, those with a regular water supply that aren't threatened by SLR may have to fight for their traditional lands.
Exciting times ahead.
Terry
It is more that it is an indicator of Climate Change.
Title: Re: Glaciers worldwide decline faster than ever
Post by: DoomInTheUK on April 26, 2016, 11:38:28 AM
The estimates I've seen are around 1 meter of sea level rise from all the land based glaciers, and about the same agian from thermal expansion.
So not a lot in comparison to Greenland and Antarctica, but still enough to count.
Title: Re: Glaciers worldwide decline faster than ever
Post by: Xulonn on April 26, 2016, 09:07:26 PM
Although mountain glaciers are not that important with respect to SLR, they have their own set of serious consequences coming for human civilization.  I don't think that many people - even those who accept the reality of rapid AGW/CC - realize the dire implications of mountain glacier melt and average snowpack reduction as in California's Sierra Nevada mountains. 

I have not found a paper or study with a detailed analysis of world-wide human dependency on these water sources and the implications of the dynamics of the involved hydrology  trends.  However, a post at the the Seametrics blog (http://www.seametrics.com/blog/climate-change/),although without citation, states that: 

"More than one-sixth of the world population relies on glaciers and seasonal snow packs for water resources." 

That's more than one billion people! 

The origin and primary flow of water for many South American and Asian rivers depends on Andes and Himalayan glaciers respectively, although countries in the lower elevation rain-forest regions of some watersheds can be lightly to heavily supplemented by monsoonal and other tropical rainfall patterns. 

In a warming world, river flow in some regions will likely increase as glacial melt increases, but eventually decrease as glaciers shrink  - lose volume - past a certain point.  The temporary increase will encourage population growth and development, but then slam the affected areas later with water shortages.  Coupled with "water grabs" via new dams on rivers such as the Mekong, permanent and irreversible flow reductions may already be happening, especially in places such as  in China, Pakistan, India, and SE Asia. 

With a significant increase in atmospheric moisture content capacity with each degree rise in average global temps (7%?), and a likely shift to more frequent heavy regional precipitation events alternating with droughts that are likely to be severe and extended, we may be on the threshold of some serious civilization-impacting weather events and short-term climate changes.     

Although SLR will be easy for everyone to see as it kicks into high gear, the quantification of glacier melt on river flows, coupled with the impacts of weather patterns and drought cycles, will be much more difficult to quantify and assign attribution. 

(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fwww.cartoonistgroup.com%2Fproperties%2Fanderson%2Fart_images%2Fcg5716b4876d397.jpg&hash=9e637b8e945d08207bc8e3a282ef3f62)
Title: Re: Glaciers worldwide decline faster than ever
Post by: abbottisgone on June 21, 2016, 07:33:06 AM
The estimates I've seen are around 1 meter of sea level rise from all the land based glaciers, and about the same agian from thermal expansion.
So not a lot in comparison to Greenland and Antarctica, but still enough to count.
Glaciers act as indicators of climate change: before sea level rise will be global panic in more than the economy. Where are the Syrians going to run once the Europeans realise the situation in the deserts of the world is being taken advantage of...?

Eventually the penny drops once the forecasters come to agree that too many indicators line up to tell only one story. Then people rush to secure their food and drink and everything else supplies. It's geo-politics!!
Title: Re: Glaciers worldwide decline faster than ever
Post by: AbruptSLR on September 04, 2016, 12:30:42 AM
The linked article is entitled: "Melting Glaciers Are Wreaking Havoc on Earth's Crust":

http://www.smithsonianmag.com/science-nature/melting-glaciers-are-wreaking-havoc-earths-crust-180960226/?no-ist (http://www.smithsonianmag.com/science-nature/melting-glaciers-are-wreaking-havoc-earths-crust-180960226/?no-ist)
Title: Re: Glaciers worldwide decline faster than ever
Post by: budmantis on September 04, 2016, 06:17:32 AM
Great article ASLR.
Title: Re: Glaciers worldwide decline faster than ever
Post by: AbruptSLR on December 13, 2016, 06:45:22 PM
The linked reference (& associated article) provide statistical evidence gather from 37 mountain glaciers for the past approximately 100-years indicating that climate change is real:

Gerard H. Roe, Marcia B. Baker & Florian Herla (2016), "Centennial glacier retreat as categorical evidence of regional climate change", Nature Geoscience, doi:10.1038/ngeo2863

http://www.nature.com/ngeo/journal/vaop/ncurrent/full/ngeo2863.html (http://www.nature.com/ngeo/journal/vaop/ncurrent/full/ngeo2863.html)

Abstract: "The near-global retreat of glaciers over the last century provides some of the most iconic imagery for communicating the reality of anthropogenic climate change to the public. Surprisingly, however, there has not been a quantitative foundation for attributing the retreats to climate change, except in the global aggregate. This gap, between public perception and scientific basis, is due to uncertainties in numerical modelling and the short length of glacier mass-balance records. Here we present a method for assessing individual glacier change based on the signal-to-noise ratio, a robust metric that is insensitive to uncertainties in glacier dynamics. Using only meteorological and glacier observations, and the characteristic decadal response time of glaciers, we demonstrate that observed retreats of individual glaciers represent some of the highest signal-to-noise ratios of climate change yet documented. Therefore, in many places, the centennial-scale retreat of the local glaciers does indeed constitute categorical evidence of climate change."

See also the following article entitled: "Mountain glaciers are showing some of the strongest responses to climate change".
http://phys.org/news/2016-12-mountain-glaciers-strongest-responses-climate.html (http://phys.org/news/2016-12-mountain-glaciers-strongest-responses-climate.html)

Extract: "Overall, the results show that changes in the 37 glaciers' lengths are between two and 15 standard deviations away from their statistical means. That represents some of the highest signal-to-noise ratios yet documented in natural systems' response to climate change.

"Even though the scientific analysis arguably hasn't always been there, it now turns out that it really is true—we can look at these glaciers all around us that we see retreating, and see definitive evidence that the climate is changing," Roe said. "That's why people have noticed it. These glaciers are stunningly far away from where they would have been in a preindustrial climate." "
Title: Re: Glaciers worldwide decline faster than ever
Post by: skanky on December 14, 2016, 10:13:37 AM
Mapping glacier speeds:

http://earthobservatory.nasa.gov/IOTD/view.php?id=89261&eocn=home&eoci=iotd_title (http://earthobservatory.nasa.gov/IOTD/view.php?id=89261&eocn=home&eoci=iotd_title)
Title: Re: Glaciers worldwide decline faster than ever
Post by: Archimid on May 08, 2017, 01:21:06 PM
The Glaciers are Going

http://blogs.ei.columbia.edu/2017/05/05/the-glaciers-are-going/ (http://blogs.ei.columbia.edu/2017/05/05/the-glaciers-are-going/)

Extract:
Quote
As can be seen above, the Waggonwaybreen glacier in Svalbard, Norway, has retreated substantially since 1900. Svalbard’s glaciers are not only retreating, they are also losing about two feet of their thickness each year. Glaciers around the world have retreated at unprecedented rates and some have disappeared altogether. The melting of glaciers will affect people around the world, their drinking water supplies, water needed to grow food and supply energy, as well as global sea levels.
Title: Re: Glaciers worldwide decline faster than ever
Post by: Archimid on May 11, 2017, 03:41:37 PM
US Glacier national park losing its glaciers with just 26 of 150 left

https://www.theguardian.com/environment/2017/may/11/us-glacier-national-park-is-losing-its-glaciers-with-just-26-of-150-left (https://www.theguardian.com/environment/2017/may/11/us-glacier-national-park-is-losing-its-glaciers-with-just-26-of-150-left)

Extract:
Quote
Warming temperatures have rapidly reduced the size of 39 named glaciers in Montana since 1966, according to comparisons released by the US Geological Survey (USGS) and Portland State University. Some have lost as much as 85% of their expanse over the past 50 years, with Glacier national park, site of 37 of the surveyed glaciers, set to lose all of its eponymous ice formations within the next few decades. Of the 150 glaciers that existed in the park in the late 19th century, only 26 remain.
Title: Re: Glaciers worldwide decline faster than ever
Post by: RoxTheGeologist on May 15, 2017, 04:09:52 PM

https://weather.com/science/environment/news/climate-central-glacier-national-park-montana-melt

An interesting read on Glacier National Park.
Title: Re: Glaciers worldwide decline faster than ever
Post by: Sigmetnow on August 15, 2017, 03:50:36 AM
Glacier National Park is overcrowded. Thanks, climate change.
Quote
A record-breaking 1 million people visited Glacier in July, up 23 percent from last year. Park officials are stuck dealing with overcrowded parking lots, more medical emergencies, and a shortage of open campsites.

While the number of visitors has fluctuated in past decades, it’s been on the rise over the past five years. Some attribute the park’s popularity to low gas prices (perfect for road trips!) and all the envy-inducing photos making their way to Instagram, while others blame our old pal climate change: All but 26 of the 150 glaciers that existed in Glacier National Park in the late 1800s have melted away, and scientists say it’s “inevitable” we’ll lose the rest. Such predictions have prompted a wave of “doomsday tourists” who want to catch a glimpse of climate change in action.

“People tell us they want to see glaciers before they’re gone,” Pamela Smith, a Glacier campground volunteer, told the Missoulian. “They have come here to see the impacts of climate change for themselves.”
http://grist.org/briefly/glacier-national-park-is-overcrowded-thanks-climate-change/ (http://grist.org/briefly/glacier-national-park-is-overcrowded-thanks-climate-change/)
Title: Re: Glaciers worldwide decline faster than ever
Post by: solartim27 on October 21, 2017, 05:45:55 PM
China has restricted tourism, and shut down industrial plants trying to save these glaciers.  Good story, though could easily be posted in Places becoming less livable thread.
http://www.npr.org/sections/parallels/2017/10/21/554271726/impossible-to-save-scientists-are-watching-chinas-glaciers-disappear
Title: Re: Glaciers worldwide decline faster than ever
Post by: TerryM on October 22, 2017, 07:35:36 PM
China has restricted tourism, and shut down industrial plants trying to save these glaciers.  Good story, though could easily be posted in Places becoming less livable thread.
http://www.npr.org/sections/parallels/2017/10/21/554271726/impossible-to-save-scientists-are-watching-chinas-glaciers-disappear (http://www.npr.org/sections/parallels/2017/10/21/554271726/impossible-to-save-scientists-are-watching-chinas-glaciers-disappear)
Karez, the name for the underground channels bringing glacial water to dry regions is a new word to me. Reminiscent of the ancient qanat from Libya that inspired Qaddafi to build the Great Man-Made River that brought water to so many. It's recent destruction wasn't an accident.


A few posts up is a piece about the tourist uptick at Glacier National Park, strange how different governments respond to similar stimuli.


Sad
Terry
Title: Re: Glaciers worldwide decline faster than ever
Post by: gerontocrat on March 21, 2018, 06:03:35 AM
https://www.carbonbrief.org/global-warming-to-date-could-obliterate-third-glacier-ice

N.B. The study excludes the "baked-in" melt of the Greenland and Antarctic ice-sheets.

Global warming to date could ‘obliterate’ a third of glacier ice

Quote
The warming the world has already experienced could be enough to melt more than a third of the world’s glaciers outside Antarctica and Greenland – regardless of current efforts to reduce emissions.

Future changes
Of course, it is impossible that global temperatures would just stop rising overnight. Therefore, the researchers looked at the different rates of glacier melt, according to scenarios of how quickly CO2 emissions are reduced over the course of this century.

You can see these scenarios in the charts below, which show projections for global temperature rise (upper chart), rate of glacier change (middle) and total glacier mass (lower). The different colour lines indicate four future greenhouse gas scenarios known as “Representative Concentration Pathways” – and two extra scenarios that specifically represent the 1.5C and 2C long-term temperature goals of the Paris Agreement.
Title: Re: Glaciers worldwide decline faster than ever
Post by: gerontocrat on April 18, 2018, 05:21:12 PM
Well worth a read.

https://www.theguardian.com/environment/climate-consensus-97-per-cent/2018/apr/18/glacier-loss-is-accelerating-because-of-global-warming

+ Links to :-
world glacier monitoring service (http://wgms.ch/) and the report:-
http://wgms.ch/latest-glacier-mass-balance-data/

But that is not all:- Guardian article also links to:-
https://agupubs.onlinelibrary.wiley.com/doi/epdf/10.1002/2017JD027539?referrer_access_token=qnIinv_kzq0W9zfebzS-sk4keas67K9QMdWULTWMo8O4PZcJK-h8pDGMGxmLWPhbGyqPG0GCkA6-uyR6lkkdfj7kQ1D6vIizytNqgv26T3Ma7rrUFBeohpyP-iIhuvz4

Quote

Plain Language Summary

Warming in mountainous areas affects glacier melt, water resources,and fragile ecosystems, yet we know relatively little about climate change in alpine areas, especially a thigh latitudes. We use ice cores drilled on Mt. Hunter, in Denali National Park, to develop a record of summer temperatures in Alaska that extends 400 years into the past, farther than any other mountain record in the North Pacific region. The ice core record shows that 60 times more snow melt occurs today than 150 years ago. This corresponds to roughly a 2°C increase in summer temperature, which is faster than summertime warming in Alaska near sea level. We suggest that warming of the tropical Pacific Ocean has contributed to the rapid warming on Mt. Hunter by enhancing high-pressure systems over Alaska. Our ice core record indicates that alpine regions surrounding the North Pacific may continue to experience accelerated warming with climate change, threatening the already imperilled glaciers in this area
Title: Re: Glaciers worldwide decline faster than ever
Post by: mitch on April 18, 2018, 05:32:04 PM
At some point the glacier mass loss will drop. Unfortunately that comes about because the total glacier volume has decreased to a small number. Do you know of any site that is trying to track alpine glacier volume?
Title: Re: Glaciers worldwide decline faster than ever
Post by: Susan Anderson on August 02, 2018, 07:16:15 PM
EarthObservatory is a terrific collection of satellite images; I've been wanting to put this somewhere so here goes. But there is lots else there. I found it here: https://earthobservatory.nasa.gov/Topic/ImageoftheDay (https://earthobservatory.nasa.gov/Topic/ImageoftheDay) but suspect that's not specific enough: I chose topic Snow and Ice and More

Here's the particular one I've been wanting to share: https://earthobservatory.nasa.gov/images/92325/losing-ice-in-svalbard (https://earthobservatory.nasa.gov/images/92325/losing-ice-in-svalbard) Losing Ice in Svalbard, dated 25 June. I've copied it here, but the link is better because it provides a dandy little image comparison, and source material, as well as leading to other interesting content.

(https://eoimages.gsfc.nasa.gov/images/imagerecords/92000/92325/svalbard_tm5_1990232.jpg)

(https://eoimages.gsfc.nasa.gov/images/imagerecords/92000/92325/svalbard_oli_2017231.jpg)

Quote
Mauri Pelto, an environmental scientist at Nichols College, has a go-to analogy for describing what a glacier needs to survive. “People need to consume the same number of calories as they expend to stay alive,” he said. Similarly, glaciers needs to accumulate at least as much snow and ice as they lose. “For glaciers, they need more than 50 percent of their area in the accumulation zone, which is the upper part of a glacier where snow persists year round.”

The mass a mountain glacier loses to evaporation, melting, or iceberg calving in the ablation zone cannot surpass the mass it adds near the top. Any imbalance causes glaciers to shrink over time, growing thinner, covering less area, and seeing their lowest edge (terminus) draw back toward the accumulation zone—a process scientists describe as retreat.

While other satellite sensors are needed to measure the thickness of glaciers, the natural- and infrared light imagers on the Landsat satellites excel at monitoring changes in glacial extent, snow lines and the positions of termini. Pelto has analyzed several decades of Landsat imagery for glaciers around the world and describes many of them on his blog From a Glacier’s Perspective.

One area Pelto has focused on is the Hornsund Fjord region in Svalbard, a remote Norwegian archipelago in the Arctic Ocean. The shallow fjord nearly divides the large island of Spitsbergen into two separate islands. Fourteen tidewater glaciers flow into the fjord, and all of them have retreated substantially during the past three decades. The Thematic Mapper (TM) on Landsat 5 captured a image (top) of Hornsund Fjord on August 20, 1990. The second image shows the same area on August 19, 2017, as observed by the Operational Land Imager (OLI) on Landsat 8.

Many of the glaciers have seen their termini retreat by several kilometers. One of the largest and fastest changing was Storbreen. “In Storbreen’s case, in 1990, 2013, and 2015, the snow line left only 20 percent of the glacier in the accumulation zone,“ explained Pelto. “This cannot sustain the other 80 percent. Storbreen will continue to lose mass until this equation balances or the glacier is lost.”

Since the water where Storbreen terminates is quite shallow, Pelto is confident that the glacier is retreating because rising air temperatures are driving the snow line higher up the glacier. In 1990, the snow line sat at an elevation of 400 meters. In 2013, 2014 and 2015, it has averaged about 500 meters. The center of Storbreen’s terminus has retreated nearly 6 kilometers (4 miles).
Title: Re: Glaciers worldwide decline faster than ever
Post by: bluesky on August 02, 2018, 09:30:50 PM

"The European mountain cryosphere: a review of its current state, trends, and future challenges"
Martin Beniston et al , 2018
https://archive-ouverte.unige.ch/unige:103006/ATTACHMENT01

Abstract:

"The mountain cryosphere of mainland Europe is
recognized to have important impacts on a range of environmental
processes. In this paper, we provide an overview on
the current knowledge on snow, glacier, and permafrost processes,
as well as their past, current, and future evolution.
We additionally provide an assessment of current cryosphere
research in Europe and point to the different domains requiring
further research. Emphasis is given to our understanding
of climate–cryosphere interactions, cryosphere controls
on physical and biological mountain systems, and related
impacts. By the end of the century, Europe’s mountain
cryosphere will have changed to an extent that will impact the
landscape, the hydrological regimes, the water resources, and
the infrastructure. The impacts will not remain confined to
the mountain area but also affect the downstream lowlands,
entailing a wide range of socioeconomical consequences. European
mountains will have a completely different visual appearance,
in which low- and mid-range-altitude glaciers will
have disappeared and even large valley glaciers will have experienced
significant retreat and mass loss. Due to increased
air temperatures and related shifts from solid to liquid precipitation,
seasonal snow lines will be found at much higher
altitudes, and the snow season will be much shorter than today.
These changes in snow and ice melt will cause a shift
in the timing of discharge maxima, as well as a transition of
runoff regimes from glacial to nival and from nival to pluvial.
This will entail significant impacts on the seasonality of
high-altitude water availability, with consequences for water
storage and management in reservoirs for drinking water,
irrigation, and hydropower production. Whereas an upward
shift of the tree line and expansion of vegetation can
be expected into current periglacial areas, the disappearance
of permafrost at lower altitudes and its warming at higher
elevations will likely result in mass movements and process
chains beyond historical experience. Future cryospheric research
has the responsibility not only to foster awareness of
these expected changes and to develop targeted strategies to
precisely quantify their magnitude and rate of occurrence but
also to help in the development of approaches to adapt to
these changes and to mitigate their consequences. Major joint
efforts are required in the domain of cryospheric monitoring,
which will require coordination in terms of data availability
and quality. In particular, we recognize the quantification
of high-altitude precipitation as a key source of uncertainty
in projections of future changes. Improvements in numerical
modeling and a better understanding of process chains affecting
high-altitude mass movements are the two further fields
that – in our view – future cryospheric research should focus
on."

extract from the conclusion:
"Within a few decades, these impacts will have a bearing on ecosystems and
the services provided by them and on a number of economic
sectors, including hydropower, agriculture, and tourism. The
management of natural hazards will equally be affected, and
a need for adaptation to climate change will arise.
"
Title: Re: Glaciers worldwide decline faster than ever
Post by: gerontocrat on August 02, 2018, 09:44:20 PM
Why do they always say "by the end of the century" when it is happening now and will get worse a long time before then?
Title: Re: Glaciers worldwide decline faster than ever
Post by: bluesky on August 03, 2018, 01:49:49 PM
Why do they always say "by the end of the century" when it is happening now and will get worse a long time before then?

Agree
This was written by 25 scientists from 19 research institutions and 7 countries in Europe, therefore I presume this paper is a common ground between realistic scientists and conservative scientists/ institution. But surely climate change and environmental damage is already impacted the Alpes, and Scandinavian mountains right now.
Something astonishing mentioned in the article:
"In Switzerland, ski slope areas employing artificial snowmaking
equipment have tripled (from 10 to 33 %) from 2000
to 2010 (Pütz et al., 2011). In the French Alps, 32%of the ski
slope area was equipped with snow-making facilities in 2014,
and this proportion is likely to reach 43% by 2020 (Spandre
et al., 2015). In Austria, this share is about 60 %, mainly due
to the lower average elevations of the Austrian ski areas, and
in the Italian Alps almost 100% of the ski areas are equipped
(Rixen et al., 2011)."
Anyway, qs temperature continues to increase, artificial snow will be useless in most areas as it requires below freezing temperatures for several days for artificial snow to efficiently cover the slope. A glimpse of it happened in December 2015 when average temperature over part of the Alps were more than 4°C above average…

Below the glaciers surface mass balance dropping to rock bottom especially in the Alps (2015 and 2017 are not on the charts, they were disastrous years, close to 2003, 2018 should not be as bad as there was record snow height - more than 4 meters at 3000 meters in the French Alps-, but the melting season started from mid April -extremely early- with a slight pause mid May, meaning that the 4 meters have melted away by now, and some glaciers -not all- as the one at Les Deux Alpes (summer ski) already seem in poor state)
Second chart below is the snow height at Bellecote at 3000 meters (a small galcier at the top of La Plagne ski resort, source: meteofrance.com)
http://m.webcam-hd.com/2alpes/2alpes_restaurant-les-glaciers
(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2F&hash=35d7d5d7526c9897dfb55501e320295a)

Title: Re: Glaciers worldwide decline faster than ever
Post by: litesong on August 08, 2018, 02:25:43 AM
..... few posts up is a piece about the tourist uptick at Glacier National Park, strange how different governments respond to similar stimuli.
Oh!!! The fed gov't determines tourist destination numbers? Is that a "don't rump" policy?
Title: Re: Glaciers worldwide decline faster than ever
Post by: litesong on August 08, 2018, 02:44:32 AM
qs temperature continues to increase, artificial snow will be useless in most areas as it requires below freezing temperatures for several days for artificial snow to efficiently cover the slope.
  You.... you... you mean they won't be able to keep the "kiddy hill" in snow? Does that mean the hiking season will by 12 months a year....... 'cept during forest fires?
Title: Re: Glaciers worldwide decline faster than ever
Post by: Tor Bejnar on August 08, 2018, 04:11:54 PM
Villagers ‘Living Between Life and Death’ as Pakistan’s Glaciers Melt (http://floodlist.com/asia/villagers-living-between-life-and-death-as-pakistans-glaciers-melt) August 8, 2018 Floodlist.com (http://floodlist.com)
Quote
BADSWAT, Pakistan, Aug 6 (Thomson Reuters Foundation) – When a glacial lake burst in Pakistan’s northern Gilgit-Baltistan province in July, Sher Baz watched helplessly as the waters swept away his family home.
...
Pakistan has more glaciers than any other country outside the polar region – more than 7,200 in the Karakoram, Himalayan and Hindu Kush ranges, according to the Pakistan Meteorological Department (PMD).

They feed the Indus River system, the country’s water lifeline. But data gathered over the last 50 years shows that all but about 120 of the glaciers exhibit signs of melting, due to rising temperatures, meteorological officials said.

As the glaciers retreat, they leave behind lakes supported by ice dams or accumulations of rock and soil. Inherently unstable, these dams often burst, sending huge volumes of water rushing into the villages below them.
...
Title: Re: Glaciers worldwide decline faster than ever
Post by: Tor Bejnar on August 08, 2018, 04:25:32 PM
Alpine Glacier-BAMS State of the Climate 2017  (https://blogs.agu.org/fromaglaciersperspective/2018/08/01/alpine-glacier-bams-state-of-the-climate-2017/)
August 2018 - From a Glacier's Perspective - AGU Blogosphere (https://blogs.agu.org/fromaglaciersperspective/)
Not as bad as 2003, but the trend is clear.  Article has regional details and several references to  recent publications, including this gem: "Huss and Hock (2018) indicate that approximately half of 56 glaciated watersheds globally have already passed peak glacier runoff."
[image changed to PNG]
Title: Re: Glaciers worldwide decline faster than ever
Post by: sidd on September 19, 2018, 10:33:04 PM
An icecap in Russia has accelerated hugely due to bed turning slippery:

" where rates of motion accelerated to 9125 ± 354 m/y ..."

"These results show that up until 2013 the glacier was strongly supported by the bed. By 2015, the bed can no longer support the driving stresses, which are predominantly supported by longitudinal stress gradients and lateral drag. An extraordinary transition from a high friction bed to a near frictionless bed has taken place over just two years."

"There is, however, a general acceptance that ice caps in the polar regions will only respond slowly to a warming climate and changes in boundary conditions. Our observations indicate this assumption should be questioned, especially when glaciers can advance over low friction sediments. We show polar glaciers that have bed elevations above sea level can rapidly collapse."

I shudder to think of something like Thwaites doing this.

doi: 10.1016/j.epsl.2018.08.049

https://phys.org/news/2018-09-unprecedented-ice-loss-russian-cap.html

sidd
Title: Re: Glaciers worldwide decline faster than ever
Post by: Richard Rathbone on September 23, 2018, 06:14:54 PM
An icecap in Russia has accelerated hugely due to bed turning slippery:

" where rates of motion accelerated to 9125 ± 354 m/y ..."

"These results show that up until 2013 the glacier was strongly supported by the bed. By 2015, the bed can no longer support the driving stresses, which are predominantly supported by longitudinal stress gradients and lateral drag. An extraordinary transition from a high friction bed to a near frictionless bed has taken place over just two years."

"There is, however, a general acceptance that ice caps in the polar regions will only respond slowly to a warming climate and changes in boundary conditions. Our observations indicate this assumption should be questioned, especially when glaciers can advance over low friction sediments. We show polar glaciers that have bed elevations above sea level can rapidly collapse."

I shudder to think of something like Thwaites doing this.

doi: 10.1016/j.epsl.2018.08.049

https://phys.org/news/2018-09-unprecedented-ice-loss-russian-cap.html

sidd

This is the sort of acceleration that would result in a 1m/decade sea level rise if repeated everywhere that is losing ice at the moment.
Title: Re: Glaciers worldwide decline faster than ever
Post by: gerontocrat on September 23, 2018, 10:20:19 PM
Presumably IceSat2 will be able to produce data for a relief map for every glacier on the planet?
Title: Re: Glaciers worldwide decline faster than ever
Post by: litesong on October 01, 2018, 03:48:36 AM
https://insideclimatenews.org/news/26092018/climate-change-mountains-landslide-hazard-thawing-permafrost-rockfall-extreme-weather-glaciers-global-warming

Mountains destabilize & are collapsing for several reasons: 1) mountainous regions are warming faster than general AGW warming, 2) increasing underlying "permafrost" thaws are no longer able to resist the downslope force of gravity. Quoted in the article, "....global warming is dissolving the glue that holds mountains together", 3) increases in warm rainfall cause great leaps in de-stabilized mountain slopes. "A 633-foot-high wave that surged down a remote fjord in Alaska in 2015 was caused by 180 million tons of rock falling into the water. The massive quantities of unstable loose rock had been exposed as the Tyndall Glacier retreated over the past 50 years."
Title: Re: Glaciers worldwide decline faster than ever
Post by: Stephan on November 22, 2018, 08:25:10 PM
In which part of Russia (probably on one of its Arctic Sea islands ?) is this Vavilov glacier/ice cap located?
Title: Re: Glaciers worldwide decline faster than ever
Post by: Tor Bejnar on November 22, 2018, 09:12:48 PM
(https://www.researchgate.net/profile/Martin_Siegert/publication/273239292/figure/fig1/AS:395286049509377@1471254946276/Map-of-Severnaya-Zemlya-showing-the-locations-of-the-Vavilov-Pioneer-and-Academy-of.png)
from here (https://www.researchgate.net/figure/Map-of-Severnaya-Zemlya-showing-the-locations-of-the-Vavilov-Pioneer-and-Academy-of_fig1_273239292)
Title: Re: Glaciers worldwide decline faster than ever
Post by: Stephan on November 22, 2018, 10:27:15 PM
Thanks!!
Title: Re: Glaciers worldwide decline faster than ever
Post by: sidd on January 22, 2019, 10:24:14 PM
N. American glacier mass waste increases fourfold in ten years:

"We observe a fourfold increase in mass loss rates between 2000–2009 [ 2.9 ± 3.1 Gt yr 1 ] and 2009–2018 [ 12.3 ± 4.6 Gt yr 1 ]"

Thats a doubling period of about 9 yr.

Caveats:

"Our estimated rate of WNA mass change for the early period ( 2.9 ± 3.1 Gt/yr ) is considerably less negative than the rate ( 14 ± 3 Gt/yr) previously reported for the period 2003–2009 (Gardner et al., 2013)."

"Using available SMB measurements for 14 glaciers in WNA (supporting information S1), we calculate an average mass change of 874 ± 100 kg m^2/yr over the period 2000–2017. When multiplied by the total glacierized area of WNA, this value yields an annual mass loss of 13.6 ± 4.3 Gt/yr , close to the value (14 ± 3 Gt/yr ) calculated by Gardner et al. (2013) using a similar approach. These values are twice as large as those based on our trend analysis. This discrepancy suggests that glaciers chosen for long-term monitoring programs are losing mass more rapidly than the region as a whole."

Open access, read all about it: Menunos et al doi:10.1029/2018GL080942  . Pelto is an author as might be suspected.

sidd

Title: Re: Glaciers worldwide decline faster than ever
Post by: Klondike Kat on January 22, 2019, 10:35:25 PM
N. American glacier mass waste increases fourfold in ten years:

"We observe a fourfold increase in mass loss rates between 2000–2009 [ 2.9 ± 3.1 Gt yr 1 ] and 2009–2018 [ 12.3 ± 4.6 Gt yr 1 ]"

Thats a doubling period of about 9 yr.

Caveats:

"Our estimated rate of WNA mass change for the early period ( 2.9 ± 3.1 Gt/yr ) is considerably less negative than the rate ( 14 ± 3 Gt/yr) previously reported for the period 2003–2009 (Gardner et al., 2013)."

"Using available SMB measurements for 14 glaciers in WNA (supporting information S1), we calculate an average mass change of 874 ± 100 kg m^2/yr over the period 2000–2017. When multiplied by the total glacierized area of WNA, this value yields an annual mass loss of 13.6 ± 4.3 Gt/yr , close to the value (14 ± 3 Gt/yr ) calculated by Gardner et al. (2013) using a similar approach. These values are twice as large as those based on our trend analysis. This discrepancy suggests that glaciers chosen for long-term monitoring programs are losing mass more rapidly than the region as a whole."

Open access, read all about it: Menunos et al doi:10.1029/2018GL080942  . Pelto is an author as might be suspected.

sidd

Can you comment on that caveat, because it appears that there is no change between the two time periods, using the rates calculated by Gardner, et. al.
Title: Re: Glaciers worldwide decline faster than ever
Post by: oren on January 23, 2019, 02:28:51 AM
Can you comment on that caveat, because it appears that there is no change between the two time periods, using the rates calculated by Gardner, et. al.
It seems Gardner used less accurate methods than those available now.
Quote
A global assessment of glacier mass change by Gardner et al. (2013) included an estimate of WNA glacier mass loss of 14 ± 3 Gt yr−1 for the period 2003–2009 based on the extrapolation of sparse in situ surface mass balance (SMB) measurements (Cogley, 2009). Other approaches to estimate glacier mass change, such as satellite laser altimetry and satellite gravimetry employed by Gardner et al. (2013) for other glacierized regions, have so far proven unsuccessful for WNA due to sparse repeat‐track spacing at lower latitudes and challenges associated with deconvolving competing mass change signals (groundwater, seasonal snow, reservoir volumes and glacio‐isostatic adjustment). Such methods perform particularly poorly for lower‐latitude mountain ranges with disperse glacier coverage, such as those that characterize WNA (Gardner et al., 2013; Jacob et al., 2012).

Repeat mapping of surface elevation through stereophotogrammetry provides an additional approach to measure glacier thickness change on a regional scale that can circumvent spatial and temporal biases imposed by using SMB observations to estimate regional mass change. Geodetic surveys exist for many glacierized regions of WNA (e.g., Basagic & Fountain, 2011; Schiefer et al., 2007), but no study samples all of these regions in a systematic fashion. Novel methods to infer elevation change from medium resolution satellite imagery (Brun et al., 2017) coupled with automated processing of both medium and very high resolution optical satellite imagery (Noh & Howat, 2017; Shean et al., 2016) provide new opportunities to improve global estimates of glacier mass change.

The primary motivation of our paper is to provide the first, regionally complete estimate of glacier mass change for WNA for the period 2000–2018. We then use these data to (i) quantify the contribution of WNA glaciers to sea level rise over the last 18 years, (ii) determine the reliability and representativeness of existing WNA in situ SMB records, and (iii) assess the climatic drivers that affect mass change at the subregional scale.
Title: Re: Glaciers worldwide decline faster than ever
Post by: Stephan on January 23, 2019, 09:28:00 PM
Are comparable values available for the 1990s or even the 1980s?
If the acceleration were constant through the last 40 years, the mass los rate should have been around 0.7 Gt/y in the 90s and around 0.17 Gt/y in the 80s.
Title: Re: Glaciers worldwide decline faster than ever
Post by: vox_mundi on February 13, 2019, 05:23:45 PM
Glacial Ice Volume Calculated Anew
https://www.eurekalert.org/pub_releases/2019-02/ez-ivc021219.php

Researchers have provided a new estimate for the glacier ice volume all around the world, excluding the Greenland and Antarctic ice sheets. Their conclusion: previous calculations overestimated the volume of the glaciers in High Mountain Asia.

Led by ETH Zurich and the Swiss Federal Institute for Forest, Snow and Landscape Research WSL, an international team of glaciologists used a combination of different numerical models to calculate the ice thickness distribution and the ice volume of some 215,000 glaciers around the world. The researchers excluded sea ice and glaciers that are connected to the Greenland and Antarctic ice sheets from their calculations.

According to the study, the combined ice volume of all considered glaciers currently amounts to some 158,000 cubic kilometres (km3). The last available estimate - dating a few years ago - was around 18 percent higher. The largest glacier ice masses (some 75,000 km3) are found in the Arctic and account for almost half of the global glacier ice volume. They include glaciers in both the Canadian and the Russian Arctic - such as those found on Baffin Island and the Novaya Zemlya archipelago - as well as glaciers along the Greenland coast and the Norwegian island of Spitsbergen.

Quote
... "In light of these new calculations, we have to assume that glaciers in High Mountain Asia might disappear more quickly than we thought so far," says Daniel Farinotti, Professor of Glaciology at the Laboratory of Hydraulics, Hydrology and Glaciology (VAW) at ETH Zurich and at the WSL.

Previously, researchers had estimated that the area covered by glaciers in this region would halve by the 2070s.This is now expected to happen in the 2060s - with perceptible consequences for local water supplies. The glaciers of High Asia, in fact, feed into large rivers, including the Indus, the Tarim and rivers feeding into the Aral Sea. Hundreds of millions of people depend on them.

For the above regions and depending on the model, researchers expect summer meltwater volumes to be as much as 24 percent lower by the end of the century as they are today. “This difference is unsettling.

A consensus estimate for the ice thickness distribution of all glaciers on Earth (https://www.nature.com/articles/s41561-019-0300-3)
https://www.nature.com/articles/s41561-019-0300-3
Title: Re: Glaciers worldwide decline faster than ever
Post by: bligh8 on March 17, 2019, 12:38:08 AM
Receding Chilean glacier a sign of accelerating climate change



"In the space of just two weeks, two large icebergs broke off the Grey Glacier in Chilean Patagonia—a sign of accelerating climate change, experts say.

The Grey Glacier is one of the main sights in the Torres del Paine national park popular with tourists and hikers.
A giant iceberg the size of six football pitches—8.8 hectares (22 acres)—broke away from the glacier on February 20 and another six hectare piece detached on March 7.
It marks the first time two icebergs of such great size have broken off in such quick succession.
The 270 square kilometer (104 square mile) glacier receded by 500 meters (550 yards), more than half the amount lost over the previous decade.
A smaller iceberg detached in 2017 but Ricardo Jana, a scientist at the Chilean Antarctic Institute, said "the loss of mass over the previous years was definitely smaller than this year."
Scientists following the glacier's evolution say it lost around two kilometers in the last 30 years.
A United Nations study in 2018 found that 95 percent of Chile's 24,100 glaciers had receded.
Scientists say that unusually warm summer temperatures—up to 31 degrees Celsius in Patagonia—and high rainfall weakened the glacier's walls.
"The receding of the glaciers coincides with the increased temperatures that we've noticed in the region," said Inti Gonzalez, a glaciologist at the Cequa Foundation that studies geology in Patagonia and the Antarctic.
Higher rainfall also accelerates the glacier melt while raising the level of the eponymous lake where the glacier is found.


Read more at: https://phys.org/news/2019-03-receding-chilean-glacier-climate.html#jCp


Title: Re: Glaciers worldwide decline faster than ever
Post by: Klondike Kat on March 21, 2019, 05:09:04 PM
This is not big by Grey standards.  In 2017, a chunk measuring over 13 hectares broke off. This glacier may be returning to the time of glacial recession and large iceberg calving of the 1990s, when the glacier was losing mass and receding.  Since 2000, the Grey glacier has experienced a net mass balance gain, with no large calvings.
Title: Re: Glaciers worldwide decline faster than ever
Post by: vox_mundi on March 23, 2019, 01:35:55 AM
Mount Everest: Melting Glaciers Expose Dead Bodies
https://www.bbc.com/news/science-environment-47638436

Expedition operators are concerned at the number of climbers' bodies that are becoming exposed on Mount Everest as its glaciers melt.

Nearly 300 mountaineers have died on the peak since the first ascent attempt and two-thirds of bodies are thought still to be buried in the snow and ice.

"Because of global warming, the ice sheet and glaciers are fast melting and the dead bodies that remained buried all these years are now becoming exposed," said Ang Tshering Sherpa, former president of Nepal Mountaineering Association.

(https://upload.wikimedia.org/wikipedia/commons/thumb/8/89/Green_Boots.jpg/280px-Green_Boots.jpg)
Green Boots
Title: Re: Glaciers worldwide decline faster than ever
Post by: Sebastian Jones on March 25, 2019, 02:45:14 PM
A multi- year glacier monitoring program conducted by an environmental studies class in Iceland provides a record of glacier retreat.
https://www.hakaimagazine.com/news/glacier-lessons-as-a-glacier-lessens/ (https://www.hakaimagazine.com/news/glacier-lessons-as-a-glacier-lessens/)
Title: Re: Glaciers worldwide decline faster than ever
Post by: kassy on June 05, 2019, 01:26:39 PM
Melting small glaciers could add 10 inches to sea level by 2100

According to a new analysis, glaciers worldwide are projected to lose anywhere from 18 to 36 percent of their mass by 2100, resulting in almost 10 inches (25 cm) of sea level rise. That’s without any contribution from melting of the vast Greenland and Antarctic ice sheets, which were not included in the study. According the researchers, the behavior of smaller glaciers requires modeling methods unlike those for the major ice sheets.

https://earthsky.org/earth/melting-small-glaciers-sea-level-rise
Title: Re: Glaciers worldwide decline faster than ever
Post by: ArcticMelt2 on June 09, 2019, 04:13:18 PM
The general picture of the melting glaciers in the world (for some reason it is believed that the glaciers on Kerguelen Islands in the Southern Ocean will be good).

https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2018EF001139

(https://wol-prod-cdn.literatumonline.com/cms/attachment/01d86c01-155a-428b-b35b-937113a8a995/eft2520-fig-0001-m.jpg)

(https://wol-prod-cdn.literatumonline.com/cms/attachment/7af04763-2679-491b-80ae-195f6d06a642/eft2520-fig-0003-m.jpg)
Title: Re: Glaciers worldwide decline faster than ever
Post by: ArcticMelt2 on June 09, 2019, 04:34:41 PM
Melting small glaciers could add 10 inches to sea level by 2100

According to a new analysis, glaciers worldwide are projected to lose anywhere from 18 to 36 percent of their mass by 2100, resulting in almost 10 inches (25 cm) of sea level rise.
https://earthsky.org/earth/melting-small-glaciers-sea-level-rise

In this work, the total volume of remaining mountain glaciers is estimated much less (only 40 cm of sea level rise).

https://www.nature.com/articles/s41586-019-1071-0

Quote
Glaciers distinct from the Greenland and Antarctic ice sheets cover an area of approximately 706,000 square kilometres globally1, with an estimated total volume of 170,000 cubic kilometres, or 0.4 metres of potential sea-level-rise equivalent2

Quote
Here we use an extrapolation of glaciological and geodetic observations to show that glaciers contributed 27 ± 22 millimetres to global mean sea-level rise from 1961 to 2016.

The greatest losses are due to Alaska:

(https://pbs.twimg.com/media/D3uP3feW0AAH542.png)
Title: Re: Glaciers worldwide decline faster than ever
Post by: ArcticMelt2 on June 09, 2019, 04:40:35 PM
https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2018EF001139

Interestingly, it turns out that 80% total mass of the remaining mountain glaciers are located on the mountains of southern Alaska.

This is strange, considering that the oldest mountain ice is found in Tibet.
Title: Re: Glaciers worldwide decline faster than ever
Post by: mitch on June 09, 2019, 06:14:08 PM
That most of the alpine glacier mass is in Alaska makes sense, since it sets next to a relatively warm water mass (the North Pacific), so has a major water source.  However, significant parts of the new deposition melt out every summer. Now that the temperatures have warmed, there is net loss along the glaciers.
Title: Re: Glaciers worldwide decline faster than ever
Post by: ArcticMelt2 on June 09, 2019, 06:24:20 PM
That most of the alpine glacier mass is in Alaska makes sense, since it sets next to a relatively warm water mass (the North Pacific), so has a major water source.  However, significant parts of the new deposition melt out every summer. Now that the temperatures have warmed, there is net loss along the glaciers.

I agree, apparently there is very high ice mobility. Ice in the cores of Alaska has an age at best of several hundred years. For comparison, some Alpine glaciers are supposed to be 10 thousand years old or more.

https://www.the-cryosphere.net/10/2779/2016/tc-10-2779-2016.pdf

Quote
In the western Alps, an ice core extracted from Colle Gnifetti (4450 m, Monte Rosa, Italian–Swiss border) provided evidence for more than ∼ 10 kyr-old ice in its lower section (Jenk et al., 2009), suggesting a continuous glaciation of at least the highest locations of the western Alps throughout the Holocene.

Or maybe Alaska has been studied much worse than the Alps, and it is also possible to find the oldest ice there.

P.S. Managed to find evidence of millennial ice in Alaska.

https://www.alaskapublic.org/2019/02/25/climate-warming-demonstrated-in-ice-core-samples-of-the-alaska-range/

Quote
The bottom 8 inches of the first 682-foot ice core (of two) collected from Mt. Hunter. Imbedded pebbles and discolored ice indicate that this represents the bottom of the glacier in contact with underlying rock. This ice is at least 5,000 years old, and most likely 20,000 years old. Analyses of this deepest portion of the ice core, representing thousands of years or time, are ongoing. (Photo courtesy of Mike Waszkiewicz)

Osterberg, an Associate Professor of Earth Sciences at Dartmouth College, and his colleagues have been conducting field research on Mt. Hunter since 2008 to capture climate history preserved in ice core samples. In 2013, two separate 700-foot-long ice cores were collected at an ideal location on Mt. Hunter’s summit plateau.
Title: Re: Glaciers worldwide decline faster than ever
Post by: Klondike Kat on June 09, 2019, 08:11:14 PM
https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2018EF001139

Interestingly, it turns out that 80% total mass of the remaining mountain glaciers are located on the mountains of southern Alaska.

This is strange, considering that the oldest mountain ice is found in Tibet.

I haven’t had the chance to read this yet, but I suspect that they are not including the glaciers ofTibet
Title: Re: Glaciers worldwide decline faster than ever
Post by: ArcticMelt2 on June 09, 2019, 08:25:28 PM
https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2018EF001139

Interestingly, it turns out that 80% total mass of the remaining mountain glaciers are located on the mountains of southern Alaska.

This is strange, considering that the oldest mountain ice is found in Tibet.

I haven’t had the chance to read this yet, but I suspect that they are not including the glaciers ofTibet

They write that the amount of ice in Alaska is 10 times greater than in Tibet.

For example, Alaska has the thickest mountain glacier in the world.

https://en.wikipedia.org/wiki/Taku_Glacier

Quote
Using radio-echo soundings and seismic reflections, we measured cross-sections of Taku Glacier, near Juneau, Alaska, to resolve inconsistencies in previous measurements and to understand better the glacier’s dynamics. The maximum thickness is about 1477 m and the minimum bed elevation is about 600 m below sea level, which establishes Taku Glacier as the thickest and deepest temperate glacier yet measured.
Title: Re: Glaciers worldwide decline faster than ever
Post by: ArcticMelt2 on June 09, 2019, 08:40:32 PM
In general, the discovery of the most ancient ice in Tibet in 1987 year was later questioned.

https://www.researchgate.net/publication/324453299_Age_of_the_Tibetan_ice_cores

Shallower wells (100–200 meters versus 300 meters) on neighboring glaciers gave an age of less than 100 thousand years.

In this connection, a new well was drilled at Guliya Ice Cap in 2015. And she fully confirmed that this Tibetan ice is the oldest of those found outside of Antarctica.

https://news.osu.edu/researchers-capture-oldest-ice-core-ever-drilled-outside-the-polar-regions/

Quote
December 04,2017

Researchers capture oldest ice core ever drilled outside the polar regions

New Orleans—The oldest ice core ever drilled outside the polar regions may contain ice that formed during the Stone Age—more than 600,000 years ago, long before modern humans appeared.

Researchers from the United States and China are now studying the core—nearly as long as the Empire State Building is tall—to assemble one of the longest-ever records of Earth’s climate history.

What they’ve found so far provides dramatic evidence of a recent and rapid temperature rise at some of the highest, coldest mountain peaks in the world.

At the American Geophysical Union meeting on Thursday, Dec. 14, they report that there has been a persistent increase in both temperature and precipitation in Tibet’s Kunlun Mountains over the last few centuries. The change is most noticeable on the Guliya Ice Cap, where they drilled the latest ice core. In this region, the average temperature has risen 1.5 degrees Celsius (2.7 degrees Fahrenheit) in the last 50 years and the average precipitation has risen by 2.1 inches per year over the past 25 years.

Lonnie Thompson, Distinguished University Professor in the School of Earth Sciences at The Ohio State University and co-leader of the international research team, said that the new data lend support to computer models of projected climate changes.

“The ice cores actually demonstrate that warming is happening, and is already having detrimental effects on Earth’s freshwater ice stores,” Thompson said.

“The water issues created by melting ice on the Third Pole, along with that from the Arctic and Antarctica, have been recognized as important contributors to the rise in global sea level. Continued warming in these regions will result in even more ice melt with the likelihood of catastrophic environmental consequences,” Yao noted.Earth’s largest supply of freshwater ice outside of the Arctic and Antarctica resides in Tibet—a place that was off limits to American glaciologists until 20 years ago, when Ohio State’s Byrd Polar and Climate Research Center (BPCRC) began a collaboration with China’s Institute of Tibetan Plateau Research. There, glaciologist Yao Tandong secured funding for a series of joint expeditions from the Chinese Academy of Sciences.

The name “Third Pole” refers to high mountain glaciers located on the Tibetan Plateau and in the Himalaya, in the Andes in South America, on Kilimanjaro in Africa, and in Papua, Indonesia—all of which have been studied by the Ohio State research team.

Of particular interest to the researchers is a projection from the Intergovernmental Panel on Climate Change that future temperatures on the planet will rise faster at high altitudes than they will at sea level. The warming at sea level is expected to reach 3 degrees Celsius by the year 2100, and possibly double that, or 6 degrees Celsius, at the highest mountain peaks in the low latitudes.

“The stable isotopic records that we’ve obtained from five ice cores drilled across the Third Pole document climate changes over the last 1,000 years, and contribute to a growing body of evidence that environmental conditions on the Third Pole, along with the rest of the world, have changed significantly in the last century,” Thompson said. “Generally, the higher the elevation, the greater the rate of warming that’s taking place.”

Around the world, hundreds of millions of people depend on high-altitude glaciers for their water supply. The Guliya Ice Cap is one of many Tibetan Plateau ice caches that provide fresh water to Central, South, and Southeast Asia.

“There are over 46,000 mountain glaciers in that part of the world, and they are the water source for major rivers,” Thompson said.

In September and October of 2015, the team ventured to Guliya and drilled through the ice cap until they hit bedrock. They recovered five ice cores, one of which is more than 1,000 feet long.

The cores are composed of compressed layers of snow and ice that settled on the western Kunlun Mountains year after year. In each layer, the ice captured chemicals from the air and precipitation during wet and dry seasons. Today, researchers analyze the chemistry of the different layers to measure historical changes in climate.

Based on dating of radioactive elements measured by scientists at the Swiss research center ETH Zurich, the ice at the base of the core may be at least 600,000 years old.

The oldest ice core drilled in the Northern Hemisphere was found in Greenland in 2004 by the North Greenland Ice Core Project and was dated to roughly 120,000 years, while the oldest continuous ice core record recovered on Earth to date is from Antarctica, and extends back 800,000.

Over the next few months, the American and Chinese research teams will analyze the chemistry of the core in detail. They will look for evidence of temperature changes caused by ocean circulation patterns in both the North Atlantic and tropical Pacific Oceans, which drive precipitation in Tibet as well as the Indian monsoons. For instance, one important driver of global temperatures, El Niño, leaves its chemical mark in the snow that falls on tropical glaciers.

Ultimately, researchers hope the work will reveal the linkages that exist between ice loss in tropical mountain glaciers and climate processes elsewhere on the planet. Thompson, Yao, and German ecologist Volker Mosbrugger are co-chairing a Third Pole Environment Program to focus on basic science and policy-relevant issues.

“The more we study the different components of the environment of the Third Pole, the better we understand climate change and its linkages among Earth’s three polar regions,” Yao said.

Collaborators on the project include Ellen Mosley-Thompson, Distinguished University Professor of Geography at Ohio State and Director of BPCRC; Mary E. Davis, Emilie Beaudon, Stacy E. Porter, Ping-Nan Lin, M. Roxana Sierra-Hernández and Donald V. Kenny, all of Ohio State; Guangjian Wu and Baiqing Xu of the Institute of Tibetan Plateau Research; and Ninglian Wang of Northwest University and Keqin Duan of Shaanxi Normal University, both in Xian, China.

Funding for the Guliya project was provided by a grant from the National Science Foundation’s Paleo Perspectives on Climate Change Program, the Strategic Priority Research Program of the Chinese Academy of Sciences, and the Frontier Research of the Chinese Academy of Sciences.

Title: Re: Glaciers worldwide decline faster than ever
Post by: ArcticMelt2 on June 09, 2019, 08:43:01 PM
In general, as you can see, even in the place with the oldest ice Northern Hemisphere (at least half a million years!) intensive melting is now underway.

This clearly proves the unprecedented modern warming in the geological history of the Earth.
Title: Re: Glaciers worldwide decline faster than ever
Post by: ArcticMelt2 on June 09, 2019, 09:29:59 PM
https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2018EF001139

Interestingly, it turns out that 80% total mass of the remaining mountain glaciers are located on the mountains of southern Alaska.

This is strange, considering that the oldest mountain ice is found in Tibet.

I haven’t had the chance to read this yet, but I suspect that they are not including the glaciers ofTibet

They write that the amount of ice in Alaska is 10 times greater than in Tibet.

For example, Alaska has the thickest mountain glacier in the world.

https://en.wikipedia.org/wiki/Taku_Glacier

Quote
Using radio-echo soundings and seismic reflections, we measured cross-sections of Taku Glacier, near Juneau, Alaska, to resolve inconsistencies in previous measurements and to understand better the glacier’s dynamics. The maximum thickness is about 1477 m and the minimum bed elevation is about 600 m below sea level, which establishes Taku Glacier as the thickest and deepest temperate glacier yet measured.

Interestingly, 5 years ago it was believed that the mass and area of glaciers in Tibet is almost comparable to Alaska.
https://www.the-cryosphere.net/7/141/2013/tc-7-141-2013.pdf

But in recent years there has been a radical revaluation.
https://www.the-cryosphere.net/13/325/2019/

(https://www.the-cryosphere.net/13/325/2019/tc-13-325-2019-t06-web.png)

Quote
Table 6 Percentage ice volume loss, relative to the initial volume (ΔV), and ice loss in millimetres of sea level equivalent (SLE) for the end of the century (2097).
Title: Re: Glaciers worldwide decline faster than ever
Post by: ArcticMelt2 on June 09, 2019, 09:58:26 PM
The table predicts that by the end of this century, Tibet will lose up to 90% of all its ice. Those. It is highly probable that the most ancient ice of the Northern Hemisphere will be destroyed already in this century.

And we will only photos of this amazing place:

(https://www.researchgate.net/publication/322532251/figure/fig1/AS:583584263970816@1516148739006/Study-area-map-showing-the-locations-of-the-Chongce-and-Guliya-ice-caps-the-Kesang-cave.png)

https://byrd.osu.edu/research/groups/ice-core-paleoclimatology/projects/china/guliya

Quote
Guliya resembles a "polar" ice cap, is surrounded by vertical 30 to 40 meter ice walls (see photographs).

(https://byrd.osu.edu/sites/byrd.osu.edu/files/styles/full_width/public/cliff.gif?itok=dbyLzaJo)

(https://byrd.osu.edu/sites/byrd.osu.edu/files/styles/full_width/public/gulobel.gif?itok=2F3Dtm9C)
Title: Re: Glaciers worldwide decline faster than ever
Post by: Tom_Mazanec on June 19, 2019, 05:58:31 PM
Glacier National Park to be icefree 2013:
https://www.csmonitor.com/Environment/2019/0618/Glacier-National-Park-s-name-will-outlive-its-glaciers
Title: Re: Glaciers worldwide decline faster than ever
Post by: Tor Bejnar on June 19, 2019, 07:24:00 PM
Typo, Tom:  "before 2030".
Their conclusion is in conflict with the recent From A Glacier's Perspective post on Varied Snowcover Extent Diagnostic of Glacier NP Glacier Climate Response (https://blogs.agu.org/fromaglaciersperspective/2019/06/14/varied-snowcover-extent-diagnostic-of-glacier-np-glacier-climate-response/) - June 14, 2019
Quote
[That] Three of the glaciers that retain significant snowcover indicates these glaciers are not as vulnerable to warming and will continue to persist until 2050 at least.
(edit for grammar's sake)
Title: Re: Glaciers worldwide decline faster than ever
Post by: gerontocrat on June 19, 2019, 08:43:29 PM
Typo, Tom:  "before 2030".
Their conclusion is in conflict with the recent From A Glacier's Perspective post on Varied Snowcover Extent Diagnostic of Glacier NP Glacier Climate Response (https://blogs.agu.org/fromaglaciersperspective/2019/06/14/varied-snowcover-extent-diagnostic-of-glacier-np-glacier-climate-response/) - June 14, 2019
Quote
[That] Three of the glaciers that retain significant snowcover indicates these glaciers are not as vulnerable to warming and will continue to persist until 2050 at least.
(edit for grammar's sake)
Reminds me of "Mars Attacks" after the Martians have wiped out Congress. The President (Jack Nicholson)  addresses the Nation sort of like this..
"Yes, we've lost Congress. But we've still got The Executive and The Judiciary... and two out of three ain't bad".

"No, we ain't gonna lose all the glaciers by 2030.. three might last 'til 2050". Whoopee.
Title: Re: Glaciers worldwide decline faster than ever
Post by: vox_mundi on June 19, 2019, 09:34:05 PM
Melting of Himalayan Glaciers has Doubled in Recent Years
https://phys.org/news/2019-06-himalayan-glaciers-years.html

A newly comprehensive study shows that melting of Himalayan glaciers caused by rising temperatures has accelerated dramatically since the start of the 21st century. The analysis, spanning 40 years of satellite observations across India, China, Nepal and Bhutan, indicates that glaciers have been losing the equivalent of more than a vertical foot and half of ice each year since 2000—double the amount of melting that took place from 1975 to 2000. The study is the latest and perhaps most convincing indication that climate change is eating the Himalayas' glaciers, potentially threatening water supplies for hundreds of millions of people downstream across much of Asia.

... Maurer and his colleagues analyzed repeat satellite images of some 650 glaciers spanning 2,000 kilometers from west to east. Many of the 20th-century observations came from recently declassified photographic images taken by U.S. spy satellites. The researchers created an automated system to turn these into 3-D models that could show the changing elevations of glaciers over time. They then compared these images with post-2000 optical data from more sophisticated satellites, which more directly convey elevation changes.

They found that from 1975 to 2000, glaciers across the region lost an average of about 0.25 meters (10 inches) of ice each year in the face of slight warming. Following a more pronounced warming trend starting in the 1990s, starting in 2000 the loss accelerated to about half a meter (20 inches) annually. Recent yearly losses have averaged about 8 billion tons of water, or the equivalent 3.2 million Olympic-size swimming pools, says Maurer. Most individual glaciers are not wasting uniformly over their entire surfaces, he noted; melting has been concentrated mainly at lower elevations, where some ice surfaces are losing as much as 5 meters (16 feet) a year.

Some 800 million people depend in part on seasonal runoff from Himalayan glaciers for irrigation, hydropower and drinking water. The accelerated melting appears so far to be swelling runoff during warm seasons, but scientists project that this will taper off within decades as the glaciers lose mass. This, they say, will eventually lead to water shortages.

(https://advances.sciencemag.org/content/advances/5/6/eaav7266/F1.large.jpg)
Fig. 1 Map of glacier locations and geodetic mass balances for the 650 glaciers.
Circle sizes are proportional to glacier areas, and colors delineate clean-ice, debris-covered, and lake-terminating categories. Insets indicate ice loss, quantified as geodetic mass balances (m w.e. year−1) plotted for individual glaciers along a longitudinal transect during 1975–2000 and 2000–2016. Both inset plots are horizontally aligned with the map view. Gray error bars are 1σ uncertainty, and the yellow trend is the (area-weighted) moving-window mean, using a window size of 30 glaciers.


Open Access: J.M. Maurer el al., "Acceleration of ice loss across the Himalayas over the last 40 years, (https://advances.sciencemag.org/content/5/6/eaav7266)" Science Advances (2019).
Title: Re: Glaciers worldwide decline faster than ever
Post by: Tor Bejnar on June 19, 2019, 11:48:04 PM
Quote
"No, we ain't gonna lose all the glaciers by 2030.. three might last 'til 2050". Whoopee.
I agree with the sentiment, although on these threads we are often 'arguing' about when the first BOE will occur (for example), with a difference of opinion within a decade or so. These Montanan glaciers, albeit minor players in the scheme of things (unless you are in Glacier National Park or down stream), have scientists disagreeing on more than 2 decades.
Title: Re: Glaciers worldwide decline faster than ever
Post by: Tor Bejnar on June 20, 2019, 04:04:24 PM
More from From a Glacier's Perspective (https://blogs.agu.org/fromaglaciersperspective):
Arnesenbreen, Svalbard Retreat, Separation and Surge (https://blogs.agu.org/fromaglaciersperspective/2019/06/20/arnesenbreen-svalbard-retreat-separation-and-surge/)  -  June 20, 2019
Quote
Blaszczyk et al’s (2009) analysis identified 163 Svalbard glaciers that are tidewater with the total length calving ice−cliffs at 860 km for the 2001-2006 period. They observed that 14 glaciers had retreated from the ocean to the land over the last 30–40 year period.
Most of the article is about a pair of glacial fronts that, since 1990, retreated, then surged, then retreated again.

My summary (interpretation/generalization) of the piece I quoted: nearly 8% of Svalbard's glaciers that terminated in the ocean in 1970 no longer terminated in the ocean in 2009.
Title: Re: Glaciers worldwide decline faster than ever
Post by: gerontocrat on June 20, 2019, 04:19:23 PM
Quote
"No, we ain't gonna lose all the glaciers by 2030.. three might last 'til 2050". Whoopee.
I agree with the sentiment, although on these threads we are often 'arguing' about when the first BOE will occur (for example), with a difference of opinion within a decade or so. These Montanan glaciers, albeit minor players in the scheme of things (unless you are in Glacier National Park or down stream), have scientists disagreeing on more than 2 decades.
Those Montanan glaciers are not going to have a good summer according to the weather people.
Nor will the Alaskan Glaciers or those lumps of ice on land on the islands of the CAA.
Title: Re: Glaciers worldwide decline faster than ever
Post by: vox_mundi on July 23, 2019, 06:11:04 PM
Climate Change Has Claimed Its First Icelandic Glacier
https://www.popularmechanics.com/science/environment/a28470046/okjokull-glacier/

The latest climate change victim is Okjökull, more commonly known as 'Ok,' an Icelandic glacier which scientists from Iceland and Rice University in Houston will memorialize in August with a heartbreaking plaque reading:

Quote
... "Ok is the first Icelandic glacier to lose its status as a glacier. In the next 200 years all our glaciers are expected to follow the same path. This monument is to acknowledge that we know what is happening and what needs to be done. Only you know if we did it."

The plaque—written by a Icelandic author, Andri Snær Magnason—also reads "415 ppm CO₂," indicating the amount of carbon dioxide in the atmosphere as of May this year. The memorial is a somber reminder of what's to come as we continue emitting high levels of greenhouse gases. Temperatures will continue to soar, summers will be hotter, and we can expect even more glacial melt.

(https://img-s-msn-com.akamaized.net/tenant/amp/entityid/AAEGLQw.img?h=448&w=624&m=6&q=60&o=f&l=f)
Title: Re: Glaciers worldwide decline faster than ever
Post by: vox_mundi on July 26, 2019, 12:16:25 AM
Underwater Glacial Melting is Occurring at Higher Rates Than Modeling Predicts
https://phys.org/news/2019-07-underwater-glacial-higher.html

Researchers have developed a new method to allow for the first direct measurement of the submarine melt rate of a tidewater glacier, and, in doing so, they concluded that current theoretical models may be underestimating glacial melt by up to two orders of magnitude.

... Most previous research on the underwater melting of glaciers relied on theoretical modeling, measuring conditions near the glaciers and then applying theory to predict melt rates. But this theory had never been directly tested.

To test these models in the field, the research team of oceanographers and glaciologists deployed a multibeam sonar to scan the glacier's ocean-ice interface from a fishing vessel six times in August 2016 and five times in May 2017.

The sonar allowed the team to image and profile large swaths of the underwater ice, where the glacier drains from the Stikine Icefield. Also gathered were data on the temperature, salinity and velocity of the water downstream from the glacier, which allowed the researchers to estimate the meltwater flow.

"We measured both the ocean properties in front of the glacier and the melt rates, and we found that they are not related in the way we expected," Jackson said. "These two sets of measurements show that melt rates are significantly, sometimes up to a factor of 100, higher than existing theory would predict."

The research team found that submarine melt rates were high across the glacier's face over both of the seasons surveyed, and that the melt rate increases from spring to summer.

D.A. Sutherland atUniversity of OregoninEugene, OR el al., "Direct observations of submarine melt and subsurface geometry at a tidewater glacier," (https://science.sciencemag.org/content/365/6451/369  ) Science (2019)
Title: Re: Glaciers worldwide decline faster than ever
Post by: vox_mundi on August 14, 2019, 06:07:51 PM
New Insight Into Glaciers Regulating Global Silicon Cycling
https://phys.org/news/2019-08-insight-glaciers-global-silicon.html

A new review of silicon cycling in glacial environments, led by scientists from the University of Bristol, highlights the potential importance of glaciers in exporting silicon to downstream ecosystems.

This, say the researchers, could have implications for marine primary productivity and impact the carbon cycle on the timescales of ice ages.

This is because silica is needed by primary producers, such as diatoms (a form of algae that account for up to 35 percent of all marine primary productivity), and these primary producers remove significant amounts of carbon dioxide from the atmosphere, transporting it to the deep ocean.


Open Access: Jade E. Hatton et al, Silicon isotopes in Arctic and sub-Arctic glacial meltwaters: the role of subglacial weathering in the silicon cycle (https://royalsocietypublishing.org/doi/10.1098/rspa.2019.0098), Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences (2019).
Title: Re: Glaciers worldwide decline faster than ever
Post by: vox_mundi on August 15, 2019, 04:55:33 PM
Heatwave Shuts Down Dog Sled Tours Early on a Glacier Near Skagway, Alaska
https://www.alaskapublic.org/2019/08/14/heatwave-shuts-down-dog-sled-tours-early-on-a-glacier-near-skagway/

Record-breaking temperatures are searing the globe. One spot where the evidence of that heatwave is especially apparent is on a glacier near Skagway. Icefield Expeditions operates a sled dog tour on Denver Glacier above the city. Their hopes for a full season melted in the heat wave ⁠— the snow was gone before August.

“Precipitation and snow pack conditions across Southeast Alaska has been below normal,” said Aaron Jacobs, Senior Hydrologist for the National Weather Service in Juneau. He says regionally the snow pack is less than half of normal.

“But the bigger thing, I think is the temperatures,” Jacobs said. “The trend over the last 10, 20 years is that temperatures have been rising.”

Another piece of the puzzle locally is the pollen that swept through the Upper Lynn Canal this year. A lot of it blew up to the glacier. The dark matter of the pollen absorbs sunlight and it accelerated snow melt.

He has seen low snow years before, but nothing like this. This year, conditions pushed the camp off the Denver glacier altogether. The season that usually runs through September ended in July.

... “We just move way farther up in elevation,” Hayashida said. (... you're going to run out of that elevation thingy pretty soon)
Title: Re: Glaciers worldwide decline faster than ever
Post by: Tom_Mazanec on September 11, 2019, 09:07:40 PM
Swedish mountain loses highest peak title due to global heating
https://www.theguardian.com/world/2019/sep/06/sweden-kebnekaise-mountain-loses-highest-peak-title-global-heating
Quote
The mountain peak known to Swedes as their country’s highest can no longer lay claim to the title due to global heating, scientists have confirmed, as the glacier at its summit shrinks amid soaring Arctic temperatures.

“This is quite a symbol,” said Gunhild Ninis Rosqvist, a Stockholm University geography professor who has been measuring the glacier annually for several years. “A very obvious, very clear signal to everyone in Sweden that things are changing.”
Title: Re: Glaciers worldwide decline faster than ever
Post by: kassy on October 16, 2019, 11:02:58 AM
A Two-Century-Long Advance Reversed by Climate Change
Mauri Pelto
15 October 2019

In 2008 and 2012, JIRP was at the terminus, creating the map below. There was no change at the east and west side of the margin since 2008, with 55 to 115 m of advance closer to the center. The glacier did not advance significantly after 2013 and did not retreat appreciably until 2018. The Taku Glacier cannot escape the result of three decades of mass losses, with the two most negative years of the record being 2018 and 2019. The result of the run of negative mass balances is the end of a 150+ year advance and the beginning of retreat. Sentinel images from 2016 and 2019 of the two main termini Hole in the Wall Glacier (right) and Taku Glacier (left). The yellow arrows indicate thinning and the expansion of a bare rock trimline along the margin of the glacier. The Hole in the Wall terminus has retreated more significantly with an average retreat of about 100 m.  The Taku main terminus has retreated more than 30 m along most of the front.

...

All other outlet glaciers of the Juneau Icefield have been retreating, and are thus consistent with the dominantly negative alpine glacier mass balance that has been observed globally (Pelto 2017).  Now, Taku Glacier joins the group unable to withstand the continued warming temperatures. Of the 250 glaciers I have personally worked on, it is the last one to retreat. That makes the score: climate change 250, alpine glaciers 0.

https://glacierhub.org/2019/10/15/a-two-century-long-advance-reversed-by-climate-change/

Title: Re: Glaciers worldwide decline faster than ever
Post by: Tor Bejnar on October 22, 2019, 05:54:05 PM
A 'perfect example' of a glacier retreating "faster than ever":
Nordenskjold Glacier, South Georgia Retreat Accelerates  (https://blogs.agu.org/fromaglaciersperspective/2019/10/18/nordenskjold-glacier-south-georgia-retreat-accelerates/)
From a Glacier's Perspectiv (https://blogs.agu.org/fromaglaciersperspective/)e - October 18, 2019
Quote
In 1989 the glacier terminated at approximately the same location as in 1957. Vegetation extended quite close to the terminus with a minimal trimline or recently deglacated zone evident. ... By 1993 there has been a limited retreat exposing some newly deglaciated unvegetated terrain adjacent to the shoreline and glacier terminus. There was limited additional retreat up to 2000. This is unusual as the neighboring glaciers had all retreated substantially by 2000. By 2016 the glacier had retreated substantially, ~900 m.
(https://blogs.agu.org/fromaglaciersperspective/files/2019/10/norden-map.jpg)
(https://www.polarcruises.com/sites/default/files/Map_Ioffe_FalklandSouthGeorgiaAntarctica.jpg)
Title: Re: Glaciers worldwide decline faster than ever
Post by: Klondike Kat on October 24, 2019, 01:26:42 PM
A Two-Century-Long Advance Reversed by Climate Change
Mauri Pelto
15 October 2019

In 2008 and 2012, JIRP was at the terminus, creating the map below. There was no change at the east and west side of the margin since 2008, with 55 to 115 m of advance closer to the center. The glacier did not advance significantly after 2013 and did not retreat appreciably until 2018. The Taku Glacier cannot escape the result of three decades of mass losses, with the two most negative years of the record being 2018 and 2019. The result of the run of negative mass balances is the end of a 150+ year advance and the beginning of retreat. Sentinel images from 2016 and 2019 of the two main termini Hole in the Wall Glacier (right) and Taku Glacier (left). The yellow arrows indicate thinning and the expansion of a bare rock trimline along the margin of the glacier. The Hole in the Wall terminus has retreated more significantly with an average retreat of about 100 m.  The Taku main terminus has retreated more than 30 m along most of the front.

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All other outlet glaciers of the Juneau Icefield have been retreating, and are thus consistent with the dominantly negative alpine glacier mass balance that has been observed globally (Pelto 2017).  Now, Taku Glacier joins the group unable to withstand the continued warming temperatures. Of the 250 glaciers I have personally worked on, it is the last one to retreat. That makes the score: climate change 250, alpine glaciers 0.

https://glacierhub.org/2019/10/15/a-two-century-long-advance-reversed-by-climate-change/

Over 150 years of advance, followed by a mere two years of retreat?  I would like to see this sustained before I make this type of judgment call.
Title: Re: Glaciers worldwide decline faster than ever
Post by: kassy on October 24, 2019, 02:09:28 PM
Quote
Of the 250 glaciers I have personally worked on, it is the last one to retreat.

I guess the other 249 probably figured in his judgement call and he knows about the local conditions and trends.
Title: Re: Glaciers worldwide decline faster than ever
Post by: Tor Bejnar on October 24, 2019, 03:12:45 PM
Quote
The Taku Glacier cannot escape the result of three decades of mass losses
The professional opinion is partially based on mass-loss evidence.  Not all arm-less and leg-less knights (https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=11&cad=rja&uact=8&ved=2ahUKEwj0j9yE_LTlAhUiTt8KHbfPBhcQwqsBMAp6BAgJEAQ&url=https%3A%2F%2Fwww.youtube.com%2Fwatch%3Fv%3DzKhEw7nD9C4&usg=AOvVaw388WmoQT3rzxOSn93DVYCP) fight on.
Title: Re: Glaciers worldwide decline faster than ever
Post by: kassy on October 24, 2019, 03:44:21 PM
He might still be able to bite the legs of but the cowards retreat too fast. How apt.  :)