| 研究実績の概要 |
Recent dramatic retreat and mass-loss of glaciers is one of the most evident consequences of the climate change. Among the least understood elements of glacier dynamics, related to mass-loss of fast flowing ocean-terminating glaciers, are difficult-to-access englacial / basal processes, and evolution of ice fractures ultimately leading to major iceberg collapse and thus to further retreat of glaciers. Sound waves produced by some of these processes and propagating through ice/rock and air can be monitored and used to understand otherwise unreachable rapid phenomena. Such in situ records were obtained during a comprehensive international expedition to the Bowdoin Glacier, Greenland in 2015. Analysis revealed the mechanisms of tide-modulated seismicity (as a proxy for ice fracturing temporary patterns) and were recently published [Podolskiy et al., GRL, 2016]. We also note, that in order to accommodate new circumstances of the fellow and a possibility of an early termination of the fellowship for starting a new job as an Assistant Professor in Dec 2015, the geographical location of the initially proposed glacier had to be changed from Patagonia to Greenland. Otherwise it would be impossible to conduct summer field work before the early end of the fellowship (summer campaign in southern hemisphere was supposed to take place in Jan-Feb 2016; while for Greenland it was possible to held in Jul-Aug 2015). Despite this change, objectives of the study remained principally intact and were focused on seismic observations for understanding glacier dynamics, as initially proposed.
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