Fig. 1
From: Visualizing heterogeneities of earthquake hypocenter catalogs: modeling, analysis, and compensation
Smoothed magnitude differences of earthquakes from JMA and USGS PDE catalogs from July 1965–1990 (a, c). The original version of the JMA catalog was revised in September 2004. The smoothed magnitude difference of earthquakes in the revised catalog and the original catalog is shown in panel b. Panel a compares the magnitude of the original JMA hypocenter catalog and c uses the revised JMA catalog. Contours show equidistance of 0.1 difference magnitude unit in the smoothed surface. Higher JMA magnitudes than USGS magnitudes are shown in purple. Light blue is used to show the opposite. The vertical red dotted line denotes 1977, when the significant change of the original JMA magnitude difference pattern in the range between mb 3.5–5