Cryoseismologic Studies for Polar Environment—Recent Progress of Japanese Contribution

Document pages: 17 pages

Abstract: Majority areas ofAntarctica and Greenland are under the thick ice sheet and characterized byevolving cryosphere surroundings. In the polar region, associated with therecent trend on climate change such as global warming, glacier relatingearthquakes are increasing during this 21st century. In this paper,a decade of progress in “Cryoseismology” at bi-polar regions is re-viewed byfocusing on the contribution from Japanese researchers. In particular, thespecific cryoseismic events are treated, which occurred in the coastal area ofEast Antarctica, around the Lützow-Holm Bay, together with the coast and wholeinland area of Greenland. As the major scientific results, frequency-overtonesignals in the harmonic cryoseismic tremors were analyzed by assuming constantsources, suggesting inter-glacial asperities that generate characteristictremors. Infrasound source locations were also determined by using the arraydeployment at the coastal regions in the Antarctic. In contrast,characteristics of glacial earthquakes and seismic interferometry approach havebeen conducted so as to achieve the fine structure of the Greenland Ice Sheet(GrIS) in particular the basal condition beneath the ice sheet.