Japan Geoscience Union Meeting 2014

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Oral

Symbol M (Multidisciplinary and Interdisciplinary) » M-TT Technology & Techniques

[M-TT43_1PM2] Brand-new scope of coupling geophysics being established by infrasound and associated waves

Thu. May 1, 2014 4:15 PM - 6:00 PM 311 (3F)

Convener:*Masa-yuki Yamamoto(Department of systems engineering, Kochi University of Technology), Nobuo Arai(Japan Weather Association), Chair:Masa-yuki Yamamoto(Department of systems engineering, Kochi University of Technology)

5:30 PM - 5:45 PM

★ [MTT43-09] Atmospheric Gravity Waves from the 2010 Maule, Chile earthquake (Mw8.8)

*Takeshi MIKUMO1, Makiko IWAKUNI2, Nobuo ARAI2 (1.Kyoto University, 2.Japan Weather Service)

Keywords:2010Maule, Chile earthquake, Mw=8.8, low-frequency, Atmospheric gravity waves

Atmospheric pressure waves were recorded after the 2010 Maule, Chile earthquake (Mw=8.8) by microbarographs at seven International Monitoring System (IMS) stations in the distance range up to 7,680 km. By applying bandpass-filtering, we extracted low frequency gravity waves, removing atmospheric noise and higher-frequency acoustic modes, and then estimated their phase velocities around 332-341 m/s. To compare with these observations, we constructed synthetic waveforms, referring to the source dimension and coseismic vertical ground displacements based on geodetic measurements (Moreno et al., 2012), and incorporating a standard atmospheric sound velocity structure up to a height of 220 km. The comparison between the observed and synthetic waveforms provides generally satisfactory agreement, and suggests the time constant of ground displacements between 2 and 3 min in the northern and southern segments of the entire source region extending for about 500 km..