Figure 3. Unlike other sections of the Saigang fault, the portion that ruptured on March 28 was remarkably seismically quiet during the past 31 years. Further, no foreshocks greater than magnitude 4.4 struck in the preceding month. The USGS ANSS catalog is complete to magnitude 4.4 worldwide since 1994 (this means that the USGS catalog includes every earthquake greater than or equal to magnitude 4.4 that has occurred anywhere on Earth since 1994), so by plotting earthquakes from this period and magnitude threshold, the observed seismicity gaps and clusters are unlikely to be detection artifacts. Credit: Temblor, CC BY-NC-ND 4.0