Institut de Physique du Globe de Paris, Université Paris Diderot, UMR 7154, Paris, France.
Institut Universitaire de France, Paris, France.
Sci Rep. 2018 Jan 24;8(1):1555. doi: 10.1038/s41598-018-19305-1.
Surface waves emitted after large earthquakes are known to induce atmospheric infrasonic waves detectable at ionospheric heights using a variety of techniques, such as high frequency (HF) Doppler, global positioning system (GPS), and recently over-the-horizon (OTH) radar. The HF Doppler and OTH radar are particularly sensitive to the ionospheric signature of Rayleigh waves and are used here to show ionospheric perturbations consistent with the propagation of Rayleigh waves related to 28 and 10 events, with a magnitude larger than 6.2, detected by HF Doppler and OTH radar respectively. A transfer function is introduced to convert the ionospheric measurement into the correspondent ground displacement in order to compare it with classic seismometers. The ground vertical displacement, measured at the ground by seismometers, and measured at the ionospheric altitude by HF Doppler and OTH radar, is used here to compute surface wave magnitude. The ionospheric surface wave magnitude (M ) proposed here introduces a new way to characterize earthquakes observing the signature of surface Rayleigh waves in the ionosphere. This work proves that ionospheric observations are useful seismological data to better cover the Earth and to explore the seismology of the Solar system bodies observing the ionosphere of other planets.
已知大地震后发出的面波会诱发可在电离层高度使用各种技术（如高频（HF）多普勒、全球定位系统（GPS）和最近的超视距（OTH）雷达）检测到的大气次声波。HF 多普勒和 OTH 雷达对瑞利波的电离层特征特别敏感，这里使用它们来显示与 HF Doppler 和 OTH 雷达分别检测到的大于 6.2 级的 28 次和 10 次事件相关的瑞利波传播一致的电离层扰动。引入传递函数将电离层测量转换为相应的地面位移，以便与经典地震仪进行比较。这里使用由地震仪在地面测量的地面垂直位移和 HF 多普勒和 OTH 雷达在电离层高度测量的位移来计算面波震级。这里提出的电离层面波震级（M ）引入了一种新的方法来描述地震，即在电离层中观察到面波瑞利波的特征。这项工作证明了电离层观测是有用的地震学数据，可以更好地覆盖地球，并探索太阳系中其他行星的电离层的地震学。
