Support the Arctic Sea Ice Forum and Blog

Author Topic: Isostatic Rebound  (Read 3321 times)

meddoc

  • Frazil ice
  • Posts: 264
    • View Profile
  • Liked: 11
  • Likes Given: 0
Isostatic Rebound
« on: June 06, 2019, 03:03:36 PM »
So, as I haven't found any Topic dedicated to this, I think it is timely to do one.
With volcanic Activity, Earthquakes, Tsunamis, Landslides, etc ramping up.

For a Starter read about the Topic:
https://robertscribbler.com/2015/04/28/climate-changes-waking-giant-to-set-off-rash-of-volcanic-eruptions-tsunamis-earthquakes/

Then, by just simple Logic we can start connecting the Dots: Permafrost/ Ice Melt -> Tectonic Instability -> Volcanoes, Earthquakes, Tsunamis.
There's the Video Channel of Dutchsinse, with a pretty Accurate 0- 24h, Daily Foreacasts.
Unfortunately, as to the Cause, the Guy still keeps blabbering about HAARP & etc Nonsense...
However, his Forecasts turn out to be fairly accurate,

meddoc

  • Frazil ice
  • Posts: 264
    • View Profile
  • Liked: 11
  • Likes Given: 0
Re: Isostatic Rebound
« Reply #1 on: July 04, 2019, 08:44:05 PM »
Stromboli erupted yesterday

6,1 in Vancouver today
5,6 in So. California.

Only the bigger Ones reported.

sqwazw

  • New ice
  • Posts: 12
    • View Profile
  • Liked: 2
  • Likes Given: 44
Re: Isostatic Rebound
« Reply #2 on: July 05, 2019, 01:21:08 AM »
Some nice images here of the last glacial maximum in Scandinavia and England: Glacial isostatic adjustment of Scandinavia and northwestern Europe and the radial viscosity structure of the Earth's mantle

Old Ben Nevis is still slowly getting Higher.

What I find of interest to us here is Greenland. The bedrock images you see with a a large inland seas, (in the case of meltout), may be mitigated somewhat by the rebound that may already be occurring,  (has the loading decreased since LGMax?).

morganism

  • Frazil ice
  • Posts: 390
    • View Profile
  • Liked: 87
  • Likes Given: 4
Re: Isostatic Rebound
« Reply #3 on: January 09, 2021, 04:18:34 AM »
The Earth has been spinning faster lately

"Planetary scientists are not concerned about the new finding; they have learned that there are many factors that have an impact on planetary spin—including the moon's pull, snowfall levels and mountain erosion. They also have begun wondering if global warming might push the Earth to spin faster as the snow caps and high-altitude snows begin disappearing."

https://phys.org/news/2021-01-earth-faster.html

Tor Bejnar

  • Young ice
  • Posts: 4185
    • View Profile
  • Liked: 797
  • Likes Given: 661
Re: Isostatic Rebound
« Reply #4 on: January 09, 2021, 05:58:24 AM »
Isostasy (from Wikipedia)
Quote
or isostatic equilibrium is the state of gravitational equilibrium between Earth's crust (or lithosphere) and mantle such that the crust "floats" at an elevation that depends on its thickness and density.

In relation to ice sheets
Quote
isostatic post-glacial rebound is observed in areas once covered by ice sheets that have now melted, such as around the Baltic Sea and Hudson Bay. As the ice retreats, the load on the lithosphere and asthenosphere is reduced and they rebound back towards their equilibrium levels.

Lots on Post-glacial rebound in Wikipedia
Arctic ice is healthy for children and other living things.

morganism

  • Frazil ice
  • Posts: 390
    • View Profile
  • Liked: 87
  • Likes Given: 4
Re: Isostatic Rebound
« Reply #5 on: January 10, 2021, 11:23:13 AM »
I seem to recall a paper linking water evap from rain and snow during drought in California effecting earthquakes there.

can't remember if it was frequency or amplitude....

ah..
https://www.csmonitor.com/Science/2014/0514/San-Andreas-Fault-Is-California-s-thirst-triggering-earthquakes


Chinese study reveals Three Gorges Dam triggered 3,000 earthquakes, numerous landslides
""This represents a 30-fold increase in frequency over the pre-dam period," according to Patricia Adams, executive director of Toronto-based Probe International and English editor of the translated study. "The earthquake activity especially increases when the dam operators rapidly increase or decrease the level of water in the reservoir."

Most of the quakes fell under 2.9 magnitude on the Richter scale, classifying them as "microseismic" tremors. One earthquake reached magnitude 4.1 on the Richter scale. It occurred as the dam authorities were attempting to fill the reservoir to its maximum height of 175 metres above sea level. Fan Xiao, chief engineer of the Sichuan Geology and Mineral Bureau, warns that "strong earthquakes could occur in the future as the reservoir fills because the microfractures, caused by the large number of microearthquakes, could make the area dangerously prone to a strong earthquake."

Large reservoirs are known to trigger earthquakes in a phenomenon called "Reservoir-induced Seismicity (RIS)." In a report of 19 dams in China that have suffered from RIS, 15 have geological conditions similar to Three Gorges."

https://www.geologypage.com/2018/11/oil-extraction-likely-triggered-mid-century-earthquakes-in-l-a.html