On the generation and decay of the long-period coda energy of large earthquakes |
| |
Authors: | Xinyu Jiang Xiaodong Song Han H.Xia Richard L.Weaver |
| |
Affiliation: | 1.Institute of Theoretical and Applied Geophysics, School of Earth and Space Sciences, Peking University, Beijing 100871, China2.Hebei Hongshan Geophysical National Observation and Research Station, Peking University, Beijing 100871, China3.Institute of Geophysics and Geodynamics, School of Earth Science and Engineering, Nanjing University, Nanjing 210023, China4.Department of Physics, University of Illinois at Urbana-Champaign, USA |
| |
Abstract: | Seismic coda wave is the tail portion of the earthquake record after main arrivals. Studies on the coda usually focus on high-frequency data within several hours after regional events and attribute them to the scattering effect of the heterogeneities inside the earth. Here, we use records of seven large earthquakes at globally distributed seismic stations to examine the decay of long-period (100 s to 300 s) coda in the time window of 10,000 s to 140,000 s after the origin time and fit it with a statistical model. The geometric spreading effect in the estimated initial energy and a location-independent equivalent attenuation coefficient indicate that the long-period coda energy is less affected by the heterogeneity-induced scattering effect than that of shorter-period coda. The coda energy can reach the earth's inner core and can be explained by a 1D earth model, making it more effective for constraining the global attenuation model. It also has the potential to determine the magnitudes of large earthquakes and to explore the interior of planetary bodies. |
| |
Keywords: | long-period coda waves large earthquakes geomet-ric spreading attenuation scattering |
本文献已被 万方数据 ScienceDirect 等数据库收录! |
| 点击此处可从《地震科学(英文版)》浏览原始摘要信息 |
|
点击此处可从《地震科学(英文版)》下载免费的PDF全文 |
|