Notable Earthquake of the Week

Southern Chile M 9.5 Earthquake  

On May 22, 1960, the largest global earthquake recorded this century occurred along the coast of Southern Chile. The catastrophic Mw 9.5 (Ms 8.6) earthquake struck at 19:11 GMT (2:11 p.m. local time) and was centered about 480 miles south-southwest of Santiago and just off the coast of Valdivia.

The earthquake ruptured nearly a 1,000 miles of the prominent Southern Chile subduction zone a mega thrust fault where the Nazca and Pacific tectonic plates are being forced under the South American plate.

Severe shaking lasted for several minutes as the fault rupture proceeded both north and south from the focal point. Buildings toppled, soft coastal sediments liquefied, landslide swept down mountain slopes, and cliff fronts calved-off into the ocean. Given the numerous towns and cities in the effected area, it is remarkable that less than 2,300 people were killed. Hardest hit were areas around soft sediments where substantial ground settlements occurred.

The earthquake produced an enormous tsunami which impacted the entire Pacific rim. Wave heights along portions of the Chilean and Peruvian coasts were in excess of 25 m (82 ft.) and literally swept low-lying beach fronts clean of all vegetation and construction.

A robust aftershock lastered for years and producted dozens of earthquakes in the M 5.0+ range.

Images from the Steinbrugge Collection, Earthquake Engineering Research Center (EERC), University of California, Berkeley.

Seismo-Watch Earthquake Reports

Track weekly earthquake activity with the Seismo-Watch Earthquake Reports. Click here or on any of the reports below.

You can also track activity in Central California with the Brief CCA Earthquake Report, the Western Basin and Range, including the very active Mammoth Lakes region, with the Brief WGB Earthquake Report, and in Southern California with the Coachella Valley Earthquake Report.

Seismo-Watch Alert Bulletins are a great way to be informed right away when significant earthquakes occurs.