Seismological Research Letters; July/August 2008; v. 79; no. 4;
p. 510-515; DOI: 10.1785/gssrl.79.4.510
© 2008 Seismological Society of America
The Pisco (Peru) Earthquake of 15 August 2007
Hernando Tavera and
Isabel Bernal
Dirección de Sismología, Instituto
Geofísico del Perú
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INTRODUCTION
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The seismic activity in Peru has its origin in the convergence process
between the Nazca and South American plates. Such convergence takes place at
an average speed on the order of 7–8 cm/year
(DeMets et al. 1980;
Norabuena et al.
1999). This process is responsible for the offshore earthquakes
with depths smaller than 60 km that take place off the coast of Peru
(Dorbath et al. 1990;
Tavera and Buforn 2001), which
are all associated with seismogenic contact. Moderate to large earthquakes
occur on average at a rate of more than 60 per year and usually affect the
towns near their epicenters. Earthquakes of larger magnitude (Mw >
7.0) have produced significant damage over broad areas, such as the event that
occurred in southern Peru on 23 June 2001 (Mw = 8.2), which affected
an area of 370 x 70 km2 between the towns of Atico (Arequipa)
and Ilo (Moquegua) (Tavera et al.
2006).
The earthquake that is the subject of this article occurred on 15 August
2007 with a magnitude of Mw 7.9 and was named "the Pisco
earthquake" because its epicenter was located 60 km west of Pisco city.
The earthquake produced significant damage in Pisco city (approximately 80% of
all structures) and minor damage in nearby towns, and it was assigned an
approximate intensity of VII–VIII on the Modified Mercalli Intensity
(MMI) scale in Pisco city. The epicenter of the Pisco earthquake and its
aftershocks were located between the rupture areas of the 1974 Lima earthquake
(Mw 7.5) and the 1996 Nazca earthquake (Mw 7.7). The earthquake also produced
a tsunami, which originated south of the epicenter in the Paracas Peninsula.
Focal mechanisms for these earthquakes generally correspond to reverse motion
with nodal planes oriented in a . . . [Full Text of this Article]
Instituto Geofísico del Perú
Calle Badajoz
169
Urb. Mayorazgo IV Etapa
ATE, Lima,
Peru
hjtavera@geo.igp.gob.pe
(H.T.)
Copyright © 2009 by Seismological Society of America