Study of EQLs in Lima, during the 2007 Pisco, Peru earthquake and possible explanations

The subduction of the Nazca Plate under the South American Plate is responsible for intense seismic activity along the west coast of South America. It is one of the most active areas in the world and has produced some of the strongest earthquakes known in history. The epicenter of the Mw8.0 earthquake of 15 August 2007 was located near the port of Pisco, about 150km south of the capital city of Peru, Lima. As described by Tavera et al. (2007), this event was the strongest shallow earthquake in Central Peru in the last 250 years, according to Tavera H. and Bernal I. (2008). Extensive damage occurred in the port and city of Pisco as well as in Chincha, El Carmen, Ica, Cañete, and smaller towns, leaving thousands of homeless people and producing hundreds of deaths. The seismic activity was felt along hundreds of kilometers on the Peruvian coast and very strongly in the capital city of Lima, where people were leaving work at 6:40 pm, already dark in the southern hemisphere's winter time. This explains why thousands of people along the coast, as described by Ocola L. & Torres U. (2007), and specially in the city of Lima, where only day time earthquakes had occurred at least for the last 70 years, have reported strong coseismic luminescence in the skies, and specially on the top of hills and islands on the ocean. No pre-seismic luminous activity has been reported.