The February 27, 2010, Mw8.8 Chile Earthquake

The 27 February 2010 mega-earthquake OFFSHORE MAULE, CHILE has ruptured the 600-km portion of the South American subduction zone between the Nazca and South American tectonic plates, which was recognized (yellow outline) as capable of producing a magnitude M8.0+ event before mid-2012 in the regular 2010a Update of the M8-MSc predictions of the Global Test of M8 (Healy et al. 1992; password protected URL The earthquake epicenter missed the reduced area of alarm (red outline) diagnosed in the second approximation by algorithm MSc. The failure of MSc algorithm is somewhat natural, taking into accout the linear extent of the event, which is about a half of the area alerted in the first approximation. (Note: The M8 algorithm provides prediction in the first approximation, and the algorithm MSc, if the data permit, narrows down the area covered by alarm. Both apply to the null approximation delivered by identifying earthquake-prone zones, e.g. «active fault zones», «D-intersections or knots», etc.)