Study of the atmospheric pressure change as a n excitation source of ground motion by the co-located array of microbarographs and broadband seismographs

利用微气压计和宽带地震仪共置阵列研究大气压力变化作为地震动激励源

• 批准号: 15540404
• 负责人: WATADA Shingo
• 金额: $ 2.5万
• 依托单位: The University of Tokyo
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2003
• 资助国家: 日本
• 起止时间: 2003 至 2004
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-15540404/
• 关键词: microbarogram; Tokachi-Oki earthquake; ground motion; Atmospheric pressure change; Acoustic waves; Acoustic coupling; Rayleigh waves; Surface waves

Small but clear atmospheric pressure changes associated with the 2003 Tokachi-Oki earthquake with M 8.3 were recorded by the microbarographs installed along Japanese Island ; at Enoshima in Miyagi, Tsukuba in Ibaragki, Nokogiriyama in Chiba, Kirishima in Miyagaki, Muroto in Kochi, Sugeno in Yamashina, and Nakaizu in Shizuoka. The pressure change starts at the arrival of seismic waves and reaches its maximum amplitude at the arrival of Rayleigh waves. The ground motion is about 5 mm/sec and pressure change is about 2 Pa. The dominant period in the pressure record is about 10 to 15 seconds. The propagation speed of the waves in barograms and seismograms are both about 3.2 km/sec. The transfer function between the vertical ground motion and the pressure change for periods between 10 sec through 50 sec is constructed from the co-locating barograph and seismograph records. The transfer function reveals that the pressure change is propotinal to the vertical ground velocity. Comparison of the observed transfer function with the theoretical one including the finite frequency and wavelength effects for a gravitationally stratified isothermal atmosphere confirms that the observed amplitude and phase of the pressure change is explained by the acoustic coupling between the atmosphere and the ground just beneath the sensors.

安装在日本岛上的微气压计记录了与 2003 年十胜冲 8.3 级地震相关的微小但明显的气压变化；宫城县江之岛、茨城县筑波县、千叶县能古切山县、宫崎县雾岛县、高知县室户县、山科县须野县、静冈县中海津县。压力变化在地震波到达时开始，并在瑞利波到达时达到最大振幅。地面运动约为5毫米/秒，压力变化约为2帕。压力记录的主导周期约为10至15秒。气压图和地震图中波的传播速度均为约 3.2 公里/秒。 10 秒到 50 秒期间的垂直地面运动和压力变化之间的传递函数是根据并置的气压计和地震仪记录构建的。传递函数表明压力变化与垂直地面速度成正比。将观测到的传递函数与理论传递函数（包括重力分层等温大气的有限频率和波长效应）进行比较，证实观测到的压力变化的幅度和相位可以通过大气与传感器下方地面之间的声学​​耦合来解释。

项目成果

Array observation of background atmospheric waves in the seismic band from 1mHz to 0.5Hz

1mHz～0.5Hz地震频段背景大气波阵列观测

• 期刊: Geophysical Journal International (印刷中)
• 作者: Nishida;et al.
• 通讯作者: et al.

2003年十勝沖地震に伴う微気圧変動

与 2003 年十胜冲地震相关的微压力波动

• 发表时间: 2005
• 期刊: 月刊地球 49
• 作者: 錦田辰吾

Microbarographic change associated with the 2003 Tokachi-Oki earthquake

与 2003 年十胜冲地震相关的微气压变化

• 发表时间: 2005
• 期刊: Gekkan chikyuu(In Japanese) 49
• 作者: 錦田辰吾;Nishida et al.;Shingo Watada
• 通讯作者: Shingo Watada

Array observation of background atmospheric waves in the seismic band from 1mHz to 5mHz

1mHz~5mHz地震频段背景大气波阵列观测

• 发表时间: 2005
• 期刊: Geophysical Journal International 162
• 作者: 錦田辰吾;Nishida et al.
• 通讯作者: Nishida et al.

Array Observation of background atmospheric waves in the seismic band from 1mHz to 10mHz

1mHz~10mHz地震频段背景大气波阵列观测

• 发表时间: 2005
• 期刊: Geophysical Journal International 162
• 作者: 錦田辰吾;Nishida et al.;Shingo Watada;K.Nishida et al.
• 通讯作者: K.Nishida et al.