An Mw‐Based Historical Earthquake Catalog for Mainland China

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 $Ms$⁠. However, modern seismic‐hazard analysis prefers earthquake catalogs in moment magnitude $Mw$⁠. Here, we compile a homogeneous $Mw$‐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 $Ms$ in Chinese catalogs and with $Mw$ in global catalogs, and derive $Ms–Mw$ regression relationships using a constrained general orthogonal regression method. The regressions are performed separately over two magnitude ranges (⁠$5.5≤Ms<7.0$ and $Ms≥7.0$⁠) 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 $Ms$ magnitudes in the Chinese catalog to $Mw$ magnitudes. For pre‐1900 events, we apply the regression results of the 1900–1965 period because the $Ms$ values of the pre‐1900 events were converted from shaking intensity, and the $Ms$‐intensity relationships were derived from the post‐1900 earthquakes. We also add earthquakes from other catalogs to obtain a more complete $Mw$‐based catalog for China. The final catalog has about 15,700 earthquakes of $Mw≥4.0.$ The catalog is more complete for eastern China than western China because eastern China has a much longer history of human settlement.