Glaciogenic Waves and
Collapsing Ice Shelves
Disintegration of the Wilkins Ice Shelf during 28-29 February, 2008, may have been a tsunamigenic process.
Simulation of shallow water waves generated by capsizing iceberg. Upper panel shows wave regime with 4 reflective boundaries common to the collapsing ice-shelf environment. Lower panel shows artificial simulation with all but the right-most reflection boundary removed. The simulation demonstrates that the region between the outward moving phalanx of initial icebergs and the intact ice shelf becomes a moshpit that creates blue ice mélange.
One of the interesting results of seismological field work on Antarctic icebergs (e.g., see the glacial seismology page) is the discovery that short-duration, impulsively created wave trains commonly propagate in the Ross Sea. We infer from these observations that these wave events are created by iceberg calving, ice-shelf rifting and other processes that are active in ice-shelf covered waters. Our goal is to determine how these waves influence the ice shelf environment (e.g., do they stimulate iceberg calving?) and whether they can be used to study such things as ice-shelf disintegration.
Schematic diagram showing how ice-shelf and iceberg processes can generate ocean waves that may be important in ice-shelf disintegration processes and useful as signals for study of ice-shelf disintegration.
Example seismogram and spectrogram from iceberg C16, Ross Sea, Antarctica, showing the arrival of a dispersed wave train (long waves arrive before short waves, following expectations for gravity wave propagation in deep water). These wave signals might be of interest in the study of ice-shelf disintegration, e.g., the Larsen B and Wilkins ice shelves that disintegrated in 2002 and 2008, respectively.
Close-up imagery of Wilkins Ice Shelf about a week after it broke up. (Imagery from NSIDC).
We have recently begun laboratory scale models of ice shelf collapse and of tipping icebergs. Here are a few videos presented at the West Antarctic Ice Sheet Workshop this Fall.