Title :
Using the Marginal Spectrum Method to Extract Spherical Free Oscillation of Strong Earthquakes
Author :
Li Jiye ; Wu Xiaojun ; Wang Qiang ; Hu Binsheng ; Ren Jianhui ; Zhang Yanji ; Sun Pengyu ; Sun Qiang ; Wu Haibo
Author_Institution :
Harbin Tech. Center of Earthquake Prevention & Disaster Reduction, Harbin, China
Abstract :
The research on earth free oscillation has become one of important methods to detect the internal structure of earth. This paper uses the marginal spectrum method based on Hilbert Huang transform for the first time, and the Tonghe station´s borehole strain data without removing solid tide, then we extracted spherical free oscillation mode that are motivated by Wenchuan M8.0 earthquake, Chile M8.8 earthquake and the east coast of Honshu of Japan M9.0 earthquake, the results are very close to the PREM mode. Among which, the Wenchuan earthquake is tested 24 spherical fundamental frequency modes, the Chile and Japan earthquakes are both 76, which consist of 0S0 and 0S2~0S76. The marginal spectrum method can effectively extract the earth free oscillation because of these strong earthquakes´ mode have spectrum divided phenomenon.
Keywords :
Earth core; Earth mantle; Hilbert transforms; earthquakes; tides; Chile earthquake; Hilbert Huang transform; Honshu east coast; Japan; PREM mode; Tonghe station borehole strain data; Wenchuan earthquake; earth free oscillation; internal earth structure; marginal spectrum method; solid tide; spherical free oscillation; strong earthquakes; Data mining; Earth; Earthquakes; Oscillators; Time-frequency analysis; Transforms; Vibrations; Hilbert Huang transform; free oscillation; the marginal spectrum; the strong earthquakes;
Conference_Titel :
Measuring Technology and Mechatronics Automation (ICMTMA), 2014 Sixth International Conference on
Conference_Location :
Zhangjiajie
Print_ISBN :
978-1-4799-3434-8
DOI :
10.1109/ICMTMA.2014.198