How commonly do “great” earthquakes happen around the world?
Over the entire Earth, the number of earthquakes with magnitudes of 8 and greater is less than one each year. However, each year there are about 10 earthquakes of magnitude 7 or greater and 100 earthquakes of magnitude 6 or greater. No matter where they occur, these earthquakes are all powerful enough so that they are recorded by all or mostly all of the world’s sensitive seismograph stations, such as UTIG’s station HKT. Each year there are probably also about 1,000 earthquakes of magnitude 5 or more, 10,000 of magnitude 4 or more, etc. However, these smaller earthquakes are only recorded by seismograph stations if they are situated sufficiently near the epicenter; thus, many such earthquakes which occur in remote areas on Earth are never recorded, located, or catalogued. Q: Can earthquakes occur anywhere? A: Earthquakes have occurred in all 50 of the United States. Even in so-called ‘inactive’ regions like the Gulf Coast of Texas most locations will experience small (M ~ 3.0) earthqua
