Wednesday, 2 April 2014

The 1877 and 2014 earthquakes

We provided a brief introduction to the 1st April 2014 Iquique earthquake earlier. It's struck the Northern Chilean (or Iquique) seismic gap, an area that hasn't ruptured in a major megathrust earthquake since 1877 (though a magnitude 7.7 earthquake did rupture a deeper section of the interface in 2007). GPS data published in 2004 suggested the Nazca and South American plates were fully coupled, with none of the plate convergence being offset by slip between the plates. An update just last year identified three zones of high coupling - the Camarones, Loa and Paranal segments - separated by weaker zones. Potentially any of these segments would individually be capable of producing an earthquake of the size of the one seen yesterday. The authors

Magnitude 8.2 earthquake north of Iquique, Chile, April 2014

A major earthquake struck the north of Chile yesterday (1st April 2014), with intense shaking felt in the cities of Iquique and Arica. Less intense shaking was also felt across northern Chile and in Bolivia, Peru, Brazil and Costa Rica..The USGS maintains 'did you feel it?' pages, where anyone can report shaking that they have experienced. Here's the page for the 1st April earthquake: Did you feel it?. Initial reports placed the magnitude in the region of 8.0, with subsequent analysis upgrading this to 8.2. This USGS page will continue to be updated as further information on the earthquake becomes available. For comparison, the 2010 Maule (Chile) earthquake measured 8.8, the 2011 Tohoku (Japan) earthquake registered