Tremors Mean Antarctic Volcanism May Be Heating Up 132
The L.A. Times reports on the discovery of seismic events (nearly 1400 tremors were recorded by researchers in 2010-2011) which seem to indicate the presence of volcanic activity 15 to 20 miles beneath the surface of western Antarctica. According to the article, "The area of activity lies close to the youngest in a chain of volcanoes that formed over several million years, and the characteristics and depth of the seismic events are consistent with those found in volcanic areas of Alaska’a Aleutian Islands, the Pacific Northwest, Hawaii and Mt. Pinatubo in the Philippines, the study concludes." Volcanism isn't a new discovery (Mt. Waesche, a volcanic mountain, is the believed origin of some ash mentioned in the article), but the newly detected seismic activity may be a harbinger for local melting from below of the Antarctic ice sheet, and possibly have long-term effects on the flow patterns of the overlying ice.
Where's the link? (Score:5, Informative)
Here's the link:
http://www.latimes.com/science/sciencenow/la-sci-sn-volcano-ice-antarctica-20131115,0,6645564.story [latimes.com]
Re:It will be ok. (Score:3, Informative)
Something that gets left out when the media reports about the Antarctic caps melting are the fact that Volcano's are contributing to the melting however scientists have yet to determine how much melting is going on. There was a show on the History Channel some years ago (I believe 15-20 years ago) that showed the volcanic activity helping to melt the caps. So before you just jump to conclusions you should try and hold out, or take it into consideration, instead of knee jerk reactions when scientists and the media have yet to fully understand how the planet and how man made carbon have affected the planet.
Prepare not to be surprised (Score:5, Informative)
There's a great book covering some of the science on this topic; reviewed here on NewScientist [newscientist.com]; very much worth the read. Actually what happens is that the crust "rebounds" [wikipedia.org] in two phases. You can use the first phase to weigh the ice sheet as they are doing in Greenland [thinkprogress.org]. Then, the athenosphere (the molten layer, 15-150km deep which the crust/lithosphere sits atop) slowly slops in there and supplies extra heat and magma; generally quite a slow process, with some rebound from the last ice age still occurring.
Upshot: it's certainly possible that the events are related.
Re:So what you're telling me (Score:5, Informative)
In some ways you are correct. Depressurization is one of the 3 big ways to generate a melt (magma). Just in case you wonder, the other two ways are 1:simply add heat, and 2: add volatiles such as H2O or CO2.
But the isostatic rebound being fast enough for us to see it in our lifetime is highly doubtful, same with the resulting melt travel time to possible eruption. What they are seeing now most likely is melt from more than just a few years ago.
Disclaimer: Undergrad Geologist, not PhD yet.
Re:Prepare not to be surprised (Score:5, Informative)
...You do realize that Antarctica is a continent, not an ocean, right?
Nope, I guess you didn't.
Re:They're lying... (Score:5, Informative)
More generally, the dividing line could be said to be the prime meridian. Places whose coordinates are given using west longitude are generally part of West Antarctica. Most maps of Antarctica are oriented with the prime meridian pointing up towards England. Things on the left side of the map are West Antarctica, the right side is East. Again, this is just a general convention - a way to get yourself oriented. (Even though McMurdo Station (77.8 S 166.6 E) would be in East Antarctica by this definition, it is traditionally part of West Antarctica because it lies on that side of the Transantarctic mountains.)
This is a cartographer's convention - giving names to places - and it has a particular European bias. But everyone that works in Antarctica uses the same naming convention, so there you go.