The first-ever quantitative Global Seismic Hazard Map, issued on December 16, provides updated seismic hazard values for nearly half of the world's nations. The map also adjusts hazard values along some politically charged international boundaries where different methods for determining seismicity had led to dissimilar values on either side of a border.
Eight percent of Earth's land mass falls within a range of high or very high seismic hazard zones on the map. That hazard is defined as a 10% or greater probability of violent shaking— which is 25% or more acceleration of gravity— within the next 50 years. About 70% of the land mass lies in a low hazard range.