科研之友
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摘要
China has a nearly 3000-year-long earthquake record listed in various Chinese earthquake catalogs. The magnitudes in those catalogs are expressed in surface-wave magnitude M-s. However, modern seismic-hazard analysis prefers earthquake catalogs in moment magnitude M-w. Here, we compile a homogeneous M-w-based historical earthquake catalog based on three Chinese earthquake catalogs and three global Mw catalogs. For post-1900 earthquakes, we compare the common events with M-s in Chinese catalogs and with M-w in global catalogs, and derive M-s-M-w regression relationships using a constrained general orthogonal regression method. The regressions are performed separately over two magnitude ranges (5: 5 <= M-s < 7: 0 and M-s >= 7: 0) and three time periods (1900-1965, 1966-1975, and 1976-2015) because earthquake monitoring capabilities in China varied over those magnitudes and time ranges. We use the regression results to convert M-s magnitudes in the Chinese catalog to M-w magnitudes. For pre-1900 events, we apply the regression results of the 1900-1965 period because the M-s values of the pre-1900 events were converted from shaking intensity, and the M-s-intensity relationships were derived from the post-1900 earthquakes. We also add earthquakes from other catalogs to obtain a more complete M-w-based catalog for China. The final catalog has about 15,700 earthquakes of M-w >= 4: 0: The catalog is more complete for eastern China than western China because eastern China has a much longer history of human settlement.
- 出版日期2017-10
- 单位FM Global; 中国地震局
