Magnitude 8.3 earthquake, central Chile, 16th September 2015

USGS Shakemap: available here

A great earthquake struck central Chile yesterday, with severe to extreme shaking felt in the Coquimbo region. The initial magnitude is estimated at 8.3, making this larger than the 2014 Iquique earthquake and the largest to strike Chile since the magnitude 8.8 earthquake of 2010.

The earthquake occurred along the Chilean Subduction Zone, a fault between the Nazca and South American Plates. The Nazca Plate subducts beneath South America, with the strain that accumulates over time episodically released during earthquakes. Great subduction zone earthquakes such as this are accompanied by intense shaking that may last several minutes. They also frequently generate tsunamis, which may be damaging both close to the source and across ocean basins. Wave heights of over 4m have been reported in Chile. The Pacific Tsunami Warning Centre suggests large waves are unlikely for most Pacific countries, however Chile and French Polynesia remain on alert for waves exceeding 1m.

So, what happens when a giant tsunami inundates coastal lakes?

This blog post is by Philipp Kempf, PhD student at Ghent University, who writes about his recently published Sedimentary Geology paper on tsunami deposits in coastal lakes in south central Chile. Philipp is now on twitter too, tweeting as @TsunamiPhil.