Infrasound signals in Antarctica reflect physical interaction in the surface environments around the recorded area. In December 2015, an infrasound array by three sensors in the detectable frequency range of 0.1 - 200...Infrasound signals in Antarctica reflect physical interaction in the surface environments around the recorded area. In December 2015, an infrasound array by three sensors in the detectable frequency range of 0.1 - 200 Hz, combined with one broadband barometer was deployed at Jang Bogo Station, Terra Nova Bay, Antarctica. The two years of data by the broadband barometer contain characteristic signals that caused by surface environment nearby the station, mixing with local noises such as katabatic winds. Clear continuous signals by oceanic swells (microbaroms) were recorded with a predominant frequency of around 0.2 s. Variations of frequency context and amplitudes in the Power Spectral Density were considered as affected by sea-ice dynamics surrounding the Terra Nova Bay. Monitoring of microbaroms could contribute to understanding ocean wave climate, with other oceanographic, cryospheric and geophysical data in Antarctica. Infrasound data in Terra Nova Bay might be a new proxy for estimating environmental variations affected by global warming, cryosphere dynamics, together with volcanic eruptions in Victoria Land.展开更多
Majority areas of Antarctica and Greenland are under the thick ice sheet and characterized by evolving cryosphere surroundings. In the polar region, associated with the recent trend on climate change such as global wa...Majority areas of Antarctica and Greenland are under the thick ice sheet and characterized by evolving cryosphere surroundings. In the polar region, associated with the recent trend on climate change such as global warming, glacier relating earthquakes are increasing during this 21</span><sup><span style="font-family:Verdana;">st</span></sup><span style="font-family:Verdana;"> century. In this paper, a decade of progress in “Cryoseismology” at bi-polar regions is re-viewed by focusing on the contribution from Japanese researchers. In particular, the specific cryoseismic events are treated, which occurred in the coastal area of East Antarctica, around the L</span><span style="color:#4F4F4F;font-family:Verdana;">ü</span><span style="font-family:Verdana;"></span><span style="font-family:Verdana;">tzow-Holm Bay, together with the coast and whole inland area of Greenland. As the major scientific results, frequency-overtone signals in the harmonic cryoseismic tremors were analyzed by assuming constant sources, suggesting inter-glacial asperities that generate characteristic tremors. Infrasound source locations were also determined by using the array deployment at the coastal regions in the Antarctic. In contrast, characteristics of glacial earthquakes and seismic interferometry approach have been conducted so as to achieve the fine structure of the Greenland Ice Sheet (GrIS) in particular the basal condition beneath the ice sheet.展开更多
文摘Infrasound signals in Antarctica reflect physical interaction in the surface environments around the recorded area. In December 2015, an infrasound array by three sensors in the detectable frequency range of 0.1 - 200 Hz, combined with one broadband barometer was deployed at Jang Bogo Station, Terra Nova Bay, Antarctica. The two years of data by the broadband barometer contain characteristic signals that caused by surface environment nearby the station, mixing with local noises such as katabatic winds. Clear continuous signals by oceanic swells (microbaroms) were recorded with a predominant frequency of around 0.2 s. Variations of frequency context and amplitudes in the Power Spectral Density were considered as affected by sea-ice dynamics surrounding the Terra Nova Bay. Monitoring of microbaroms could contribute to understanding ocean wave climate, with other oceanographic, cryospheric and geophysical data in Antarctica. Infrasound data in Terra Nova Bay might be a new proxy for estimating environmental variations affected by global warming, cryosphere dynamics, together with volcanic eruptions in Victoria Land.
文摘Majority areas of Antarctica and Greenland are under the thick ice sheet and characterized by evolving cryosphere surroundings. In the polar region, associated with the recent trend on climate change such as global warming, glacier relating earthquakes are increasing during this 21</span><sup><span style="font-family:Verdana;">st</span></sup><span style="font-family:Verdana;"> century. In this paper, a decade of progress in “Cryoseismology” at bi-polar regions is re-viewed by focusing on the contribution from Japanese researchers. In particular, the specific cryoseismic events are treated, which occurred in the coastal area of East Antarctica, around the L</span><span style="color:#4F4F4F;font-family:Verdana;">ü</span><span style="font-family:Verdana;"></span><span style="font-family:Verdana;">tzow-Holm Bay, together with the coast and whole inland area of Greenland. As the major scientific results, frequency-overtone signals in the harmonic cryoseismic tremors were analyzed by assuming constant sources, suggesting inter-glacial asperities that generate characteristic tremors. Infrasound source locations were also determined by using the array deployment at the coastal regions in the Antarctic. In contrast, characteristics of glacial earthquakes and seismic interferometry approach have been conducted so as to achieve the fine structure of the Greenland Ice Sheet (GrIS) in particular the basal condition beneath the ice sheet.