Time-Lapse Photos Show Dramatic Erosion of Alaska Coast

[n2doc]

By Andrea Thompson, Senior Writer


SAN FRANCISCO — Time-lapse photography of crumbling Alaskan coastlines is helping scientists understand the "triple whammy" of forces eroding the local landscape: declining sea ice, warming ocean waters and more poundings by waves.

The erosion rates from these forces are greater than anything seen along the world's coastlines, with the coast midway between Alaska's Point Barrow and Prudhoe Bay falling into the ocean in the inland direction by up to one-third the length of a football field annually, scientists have found.

"This is pretty eye-popping," Robert Anderson of the University of Colorado at Boulder said here today at the annual meeting of the American Geophysical Union.

Time-lapse imagery and videos taken by Anderson and his team show how frozen blocks of silt and peat — that contain about 50 percent to 80 percent water ice – are toppled into the Beaufort Sea within a matter of days during the summer months as large waves and warm waters combine to attack the coast.

more, with video link
http://www.livescience.com/environment/091214-agu-arctic-climate-warming.html

[Name removed]

1. Deleted sub-thread

Sub-thread removed by moderator. Click here to review the message board rules.

[TxRider]

2. It appears to be ancient sea floor

Likely to have been eroding ever since it was raised above sea level.

But the present rate seems to be the highest rate in known history.

[n2doc]

3. nope.

It is peat. And the reason it is eroding is because
1. The sea ice that normally protects it during most of the year is disappearing, and
2. the permafrost is thawing, leaving behind a weak, waterlogged soil.

[TxRider]

4. Well...

Ice couldn't have protected it always, it was warmer than today 125,000 years ago and forests grew north of the arctic circle for thousands of years and sea level was 4-6m higher.

Is this land younger than that?

[tinrobot]

5. Ice has protected it since modern humans existed.

The peat is not comprised of trees, but mostly dead moss, along with some random shrubs and flowers that only grow for a few months in the arctic summer. It has been forming since well before the last ice age and is a huge carbon sink.

[joshcryer]

6. The ice couldn't have protected it always, of course.

But there is infrastructure and habitation here on this coastline that is increasingly threatened by AGW attributed erosion. If the ice extent wasn't retreating so quickly it would have obviously lasted longer.

[Viking12]

7. Well, it sure is gonna make it more difficult to see Russia from there

[joshcryer]

8. ROFL

:rofl:

[TxRider]

9. ROFL

Can't argue with that.

[jberryhill]

10. Oh for peat's sake.... /nt