Probing signals of atmospheric gravity waves excited by the July 29,2021 M_(W)8.2 Alaska earthquake  

作　　者：Geng Zhang Jianqiao Xu Xiaodong Chen Heping Sun Lizhuo Gong 

机构地区：[1]State Key Laboratory of Geodesy and Earth's Dynamics,Innovation Academy for Precision Measurement Science and Technology,Chinese Academy of Sciences,Wuhan,430077,China [2]University of Chinese Academy of Sciences,Beijing,100049,China

出　　处：《Geodesy and Geodynamics》2024年第3期219-229,共11页大地测量与地球动力学（英文版）

基　　金：supported by the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDB41000000);the National Natural Science Foundation of China(Grant No.42174101,41974023);the Open Fund of Hubei Luojia Laboratory(Grant No.S22H640201);(Germany)The Offshore International Science and Technology Cooperation Center of Frontier Technology of Geodesy。

摘　　要：It is commonly believed that the atmosphere is decoupled from the solid Earth.Thus,it is difficult for the seismic wave energy inside the Earth to propagate into the atmosphere,and atmospheric pressure wave signals excited by earthquakes are unlikely to exist in atmospheric observations.An increasing number of studies have shown that earthquakes,volcanoes,and tsunamis can perturb the Earth's atmosphere due to various coupling effects.However,the observations mainly focus on acoustic waves with periods of less than 10 min and inertial gravity waves with periods of greater than 1 h.There are almost no clear observations of gravity waves that coincide with observations of low-frequency signals of the Earth's free oscillation frequency band within 1 h.This paper investigates atmospheric gravity wave signals within1 h of surface-atmosphere observations using the periodogram method based on seismometer and microbarometer observations from the global seismic network before and after the July 29,2021 M_(w)8.2 Alaska earthquake in the United States.The numerical results show that the atmospheric gravity wave signals with frequencies similar to those of the Earth's free oscillations _(0)S_(2) and _(0)T_(2) can be detected in the microbaro meter observations.The results con firm the existence of atmospheric gravity waves,indicating that the atmosphere and the solid Earth are not decoupled within this frequency band and that seismic wave energy excited by earthquakes can propagate from the interior of the Earth to the atmosphere and enhance the atmospheric gravity wave signals within 1 h.

关 键 词：Atmospheric gravity modes Atmospheric gravity waves Alaska earthquake Normal modes Coupling of solid earth and atmosphere 

分 类 号：P315.7[天文地球—地震学]