Magnitude

The NEIC (National Earthquake Information Center) of the USGS reports earthquakes, by year, with magnitude. These statistics shows an increase in magnitude 7.9 or greater, the magnitude used as a threshold by Troubled Times on their Quake Watch pages. A magnitude of 7.9 was used as the threshold as it was noted that the USGS downgraded quake magnitude slightly, from the magnitude originally reported in the news. Since 8.0 is used by the USGS to include a quake in their "major" quake category, including 7.9 avoids any statistical manipulation.