Alaska Glaciers

[Sigmetnow]

Mendenhall Glacier near Juneau, Alaska, has started to periodically flood the Mendenhall River on which the city sits.

As water builds up in the basin and seeks an outlet, it can actually lift portions of the glacier ever so slightly, and in that lift, the water finds a release. Under the vast pressure of the ice bearing down upon it, the water explodes out into the depths of Mendenhall Lake and from there into the river.

Glaciologists even have a name for the process, which is happening in many places all over the world as climates change: jokulhlaup, an Icelandic word usually translated as “glacier leap.”

http://www.nytimes.com/2013/07/23/us/alaska-looks-for-answers-in-glaciers-summer-flood-surges.html?_r=1&

[Sigmetnow]

OK, not exactly a glacier.  But a “frozen debris lobe” threatens the Dalton Highway to Prudhoe Bay, and even the trans-Alaskan pipeline itself, above the Arctic Circle.  And it’s moving faster lately -- about an inch a day.

http://www.alaskadispatch.com/article/20130813/only-alaska-creeping-frozen-landslide-threatens-critical-highway-and-pipeline

[Sigmetnow]

Alaska’s Glaciers Seen as Major Source of Sea Level Rise

The ice that tumbles into the ocean along Alaska’s coastline often makes for dramatic images that show one of the ravages of climate change – melting tidewater glaciers that contribute to sea level rise. But a new study finds that far more meltwater is flowing into the sea from a similar, if less frequently photographed source – inland glaciers.

Compared to their coastal counterparts, inland glaciers account for 95 percent of glacial mass loss due to climate-driven melting, a study published this month in Geophysical Research Letters shows. In fact, researchers found that Alaska’s glaciers are melting so fast that they would cover the state with a 1-foot thick layer of water every seven years.

http://www.climatecentral.org/news/alaska-glaciers-sea-level-rise-19159

[Paddy]

Out of curiosity, how many gigatons of ice do Alaska's glaciers contain?

[Tor Bejnar]

Glaciers cover about 75,000 km2 of Alaska.
If all of Alaska's glaciers melted, sea level would rise ~ 0.05 meters (about 0.16 feet).
Ocean area=165,250,000 sq km
165,250,000 x 0.05 x 10^-3 = 8,260 km^-3

Results            Unit
8260000000    kilogram
8260000000000    gram
8.26E+15    milligram
8,260,000    ton
18210197710.718    pound (lb)
41300000000000    carrat
1.2747127999495E+14    grain
4.974284874552E+36    atomic mass unit

] = 0.00826 gigatonnes

if my choice of website data, internet calculators and arithmetic skills work right (without checking my work)

[Paddy]

Thank you for that analysis!

I suppose the take home message is that Alaska is still a pretty small chunk of the total likely contribution compared to the big boys of Greenland and Antarctica...

[abbottisgone]

Thank you for that analysis!

I suppose the take home message is that Alaska is still a pretty small chunk of the total likely contribution compared to the big boys of Greenland and Antarctica...

The take home message is Glaciers are the worlds thermometers!

Complex systems are measured by indicators..

[baileyrorys]

Here's a photo of the Lamplugh Glacier at Johns Hopkins Inlet on July 22nd, 2014.

https://picasaweb.google.com/lh/photo/FIZ09Zd_a7zW5LSvuvz-a9MTjNZETYmyPJy0liipFm0?feat=directlink

[solartim27]

Lamplugh is in the news again today with a giant landslide
http://www.nytimes.com/2016/07/06/science/alaska-landslides-glaciers-melt.html?_r=2
Here is an Aqua Gif from 6/23 to 7/4

"An enormous landslide that spread rocky debris more than six miles across a glacier in southeastern Alaska last week was not the first to occur in the area, and certainly will not be the last.

The slide, first noticed by Paul Swanstrom, a sightseeing pilot, on June 28, occurred when part of a mountain gave way near Lamplugh Glacier, in Glacier Bay National Park, about 100 miles northwest of Juneau.

The slide caused seismic tremors that first registered at magnitude 2.9, , according to data from the Alaska Earthquake Center. But that magnitude was computed as if the tremors were from an earthquake. Scientists at the center later recalculated the magnitude and came up with a higher figure, 5.5."

[Tor Bejnar]

More on this landslide from Dr. Dave Petley's July 3 Landslide Blog.

[JimD]

Wow.  To have seen that live.

[skanky]

More on the above, again, from the same website: http://blogs.agu.org/landslideblog/2016/11/10/planet-labs-lamplugh/

[johnm33]

I'm beginning to wonder how many of these northern mountains are rubble held together by ice.

[skanky]

Alaskan landslides and glacial melting: http://blogs.agu.org/landslideblog/2016/12/07/icy-bay-landslide/

[Aporia_filia]

I was very surprised when a knowledgable person told me about a >500 meters wave recorded in the 50s. I could not completely believe it till I read this (some in the wiki as well);

http://geology.com/records/biggest-tsunami.shtml

[Bruce Steele]

Thirty two years ago I traveled to Prince William sound to participate in a dive fishery for a herring roe
on kelp fishery about this time of year.  A bush pilot who my wife and I hired took us on a joyride after my wife had gotten the pictures she needed for a magazine article she was writing . He took us to the base of Columbia Glacier and throttled up as he put the small plane just above the water / floating ice field.  He headed straight into a fissure and we were flying inside the Columbia glacier with ice walls a on either side of the wings. He pulled back on the stick and we exited vertically out of the glacier , did a hammerhead and shot straight back into another fissure.  We then exited the glacier back at deck level over the water/ floating ice field.
 It wasn't the craziest thing I did during that fishing season but 14 hour dives in 36 degree water are fishing stories. Maybe this all sounds like a fish story . Anyway the Columbia doesn't calf into the sound like it did back in 1984.  The Prince William Sound herring fishery has only been a small artisanal effort in the decades after the Valdez hit Bligh Rock in 1986.  I read recently a course change to avoid a iceberg field, with origins from Columbia Glacier, was causative in the tankers grounding. The collapse of the herring fishery, the collapse / retreat of the Columbia Glacier, the oil spill and the oil from the North Slope all play interactive parts in this story.

[solartim27]

Mendenhall Glacier near Juneau, Alaska, has started to periodically flood the Mendenhall River on which the city sits

Nice drone footage from the area

[solartim27]

Insane footage from Ruth Glacier
https://www.instagram.com/p/BXgNgIFjIr1/

natgeoVideo by @renan_ozturk @sanctityofspace collection // A phenomenon of the Ruth Glacier Alaska. While filming on the glacier @freddiewilkinson noticed a couple hundred ft wide bubbling pool about a mile away from the terminus of the main glacier. The Ruth Glacier is among the thickest glaciers on earth at around 4000ft but is melting fast with the effects of climate change. We have asked a few friends but are still unsure if this is natural or abnormal. The forces seem accelerated these days as water is drawn down 'moulins' or shafts in the glacier only to emerge in such a startling high volume pool so far down valley. The inner workings are a bit of a mystery and scientific study waiting to happen but I can't help but think of it as one of my favorite places bleeding out under a warming planet. For more images of the Alaska range see @renan_ozturk @sanctityofspace. ~ Aerial DP's @camp4collective @ansonfogel @zatzworks

[Sigmetnow]

Global warming is causing an Alaskan glacier to melt at the fastest pace in 400 years

One of the USA's tallest glaciers is melting at the fastest pace in 400 years, a new study reports.

The study said melting on Mount Hunter in Alaska’s Denali National Park can be linked mainly to rising summer temperatures in the region.

"We have not seen snow melt like this in at least four centuries,” said study lead author Dominic Winski, a glaciologist at Dartmouth College.

New ice cores taken from the top of Mt. Hunter show summers there now are least 2 to 3 degrees Fahrenheit warmer than they were during the 18th, 19th and early 20th centuries. Specifically, the ice core record shows 60 times more snow melt occurs today than did 150 years ago. ...

https://www.usatoday.com/story/news/nation/2018/04/11/global-warming-causing-alaskan-glacier-melt-fastest-pace-400-years/506549002/

[Sigmetnow]

“Melting time lapse of the Mendenhall Glacier near Juneau. Over just 7 years. credit to James Balog @EarthVisionInst ”
https://twitter.com/ClimateHuman/status/985305766109167617

Video at the link.

[oren]

Great video. The rate of change is scary.

[solartim27]

Another cool video

Alaska CASC (@Alaska_CASC) Tweeted:
Watch: A dramatic calving event surprised researchers at Suicide Basin, a glacier-dammed lake adjoining Mendenhall Glacier in Juneau, when a section of ice 1/5th of a mile wide separated ice in the basin from the main #glacier

https://t.co/k70hcnCs1E @NWSAPRFC @uafairbanks @USGS https://t.co/kM4BrjZcu8 https://twitter.com/Alaska_CASC/status/1012854506491502593?s=17

[ReverendMilkbone]

Google Earth Engine shows a lot of these glaciers receding;

Mendenhall Glacier in Alaska;

https://earthengine.google.com/timelapse/#v=58.43448,-134.5559,11.03,latLng&t=1.30

Columbia Glacier in Alaska;

https://earthengine.google.com/timelapse/#v=61.14667,-146.91079,8.019,latLng&t=0.61

Barnes Ice Cap (Remnant of last ice age, also Canada but whatever) melting away...;

https://earthengine.google.com/timelapse/#v=70.0137,-74.1739,7.193,latLng&t=0.80