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I read about the earthquake that took place in Japan in 2011, led to some small calving events in Antarctica (link). So, it makes me think if there is a big earthquake near or in Antarctica, can it lead to big calving events, like loosing a whole floating ice shelf (event comparable to the Larsen ice shelf collapse)? Such an event can be very important, as ice shelves control the flow of ice from the various ice streams. And losing one leads to a significant speed up in the ice loss from the antarctic ice sheet.

Or the somewhat plastic nature of ice makes it much resistant to a big Tsunami or earthquake, to the point that we don't need to consider it as a possibility at all.

I did some background study, and found there are not many active seismic regions near Antarctica as such. But there had been some big quakes in the nearby region in the past few decades.

UPDATE: Found a recent news article "Faraway Earthquake Triggered Antarctica Icequakes". It doesn't answers the question, but provides more insight to the topic. You can also listen to this very cool audio Antarctic Icequakes Triggered By Earthquake in Chile

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  • $\begingroup$ Your question is unclear. The NASA video presents evidence that tsunami waves triggered ice shelf calving in Antarctica. But there was no evidence that a tsunami was involved with the Larsen ice sheet collapse. A large tsunami is evidently not necessary for calving to happen $\endgroup$ – Mark Rovetta Aug 9 '14 at 16:16
  • $\begingroup$ I didn't say that the Larsen event has anything to do with a tsunami or an earthquake. I used the Larsen event just as a scale for a big calving event. $\endgroup$ – Vikram Aug 11 '14 at 8:20
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There are two ways in which earthquakes could affect the Antarctic ice sheet, either by occurring on the Antarctic continent or by occurring elsewhere and sending tsunami-type waves towards the ice sheet/continent.

Seismic activity occurs all the time on Antarctica. Particularly the West-Antarctic Ice Sheet (WAIS) is located over seismically active zones although such occur under the East Antarctic Ice Sheet (EAIS) as well. In the case of WAIS, subglacial volcanoes have been inferred from geophysical measurements. It is possible that such activity but also elevated geothermal heat fluxes, typical of seismically active areas, contribute to making the subglacial thermal regime temperate (at the melting temperature). This means the ice flow can, at least partially decouple from the bed and slide causing larger ice fluxes. Such behaviour is known from WAIS but is observed to be a part of the dynamic setup of the ice sheet and does not seem to change fluxes on time frames that we can observe directly or through investigations of indirect evidence of past flow variations. In short, there is no clear evidence that seismic activity in Antarctica directly causes major changes in ice loss.

Tsunamis reaching Antarctica could conceivably cause break off of larger ice bergs or larger numbers of ice bergs at the fringes of the ice sheet. Ice berg calving in Antarctica is largely through ice shelves, which are floating parts of the ice sheet. These ice shelves are part of the natural way in which the ice sheet looses mass so a momentary acceleration due to tsunami-type waves is conceivable. But, the main question will be of this momentary acceleration of calving simply causes ice that would calve anyway within some period is shed more quickly resulting in a period of quiescence as the shelf recuperates and resumes normal "operations*. This is unclear because we are dealing with processes that have to be seen over long time spans. The loss of an immense ice berg, such as occasionally reported in media, may not have that much significance in the long-term.

There are studies indicating larger ice fluxes out from specific outlets in Antarctica. How these may be influenced by direct or indirect seismic activity has not been investigated. Ice in glaciers and ice sheets behaves plasticly, which means it can accommodate external forcing to some extent by plastic deformation, and also elastically. As an example, lake ice may bend when waves propagate in the underlying water but can also cause breakage under certain circumstances (wave amplitude and frequency). It is hence conceivable that increased breakage can occur if circumstances are just right but it is not at all clear that such activity would cause anything but momentary acceleration of processes that would be shadowed by the longer term trends caused by climatic forcing.

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    $\begingroup$ I really like the nuance of this answer. +1 $\endgroup$ – Neo Aug 13 '14 at 20:16
  • $\begingroup$ @Peter. Thanks for you answer. So, in short you agree to the possibility that seismic activity can contribute to antarctic ice loss and possible ways, but then you also highlighted that we don't have enough data as evidence to prove how significant it can be. You also brought the topic of volcanic activities, from which i think you are referencing to this study. phys.org/news/… Correct me if wrong, but can you please include the reference in the answer? Just so that interested people can dig deeper easily. $\endgroup$ – Vikram Aug 14 '14 at 8:56
  • $\begingroup$ My aim was to get more insight into this topic, and your answer contributed a lot. But considering the nature of the topic, i think there is a possibility of learning and exploring even more. So, i will wait a little and see if we get any more answers, if not, i will accept your answer. Thanks again! $\endgroup$ – Vikram Aug 14 '14 at 8:57
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    $\begingroup$ To respond to your earlier comment. Ice is continually lost from Antarctica, the rate has natural fluctuations so when you say loss, you need to decide over what perspective, i.e. if it is a temporary fluctuation that is compensated over time (and over what time) or if the loss is an irreparable addition to the longer term trend. Your question totally lacks the important time perspective. $\endgroup$ – Peter Jansson Aug 14 '14 at 9:09
  • $\begingroup$ I agree. I'm thinking from the perspective of current climate change scenario, the role of antarctica and how it will affect us in future. So when i said loss, i was thinking of time frame of decades to a few centuries, not more. $\endgroup$ – Vikram Aug 14 '14 at 12:49

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