[M-TT43_1PM2] インフラサウンド及び関連波動が繋ぐ多圏融合地球物理学の新描像

★ [MTT43-09] 2010年Chile大地震(Mw8.8)による地殻変動から発生した長周期大気重力波

*三雲 健¹、岩国 真紀子²、新井 伸夫² (1.京都大学、2.日本気象協会)

キーワード：2010年チリ大地震, 地殻変動, 長周期大気重力波

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..