Seismic source of the earthquake of Camana Peru 2001 (Mw 8.2) from joint inversion of geodetic and tsunami data

Abstract

On June 23, 2001 at 15:33 local time (20:33 UTC), a strong earthquake of magnitude Mw 8.2 shook the southern region of Peru, causing considerable material damage and the loss of 74 human lives. The epicenter was located in the sea near the city of Atico (Arequipa). As a coseismic effect, a local tsunami was generated, which after 15 min, caused the flood and destruction of the beach resorts of Camana and resulted in the death of 25 people and 62 missing persons. Another coseismic effect was the subsidence of the coastal zones in the source region, evidenced by geodetic observations. We have conducted a joint inversion of tsunami and geodetic data with a fault plane of variable dip to obtain the slip distribution. The main asperity (slip = 12.6 m) was located offshore Camana, this explains the great damage in this city. The seismic moment was calculated in 2.72×10²¹ Nm and the corresponding moment magnitude was Mw 8.2. The subfaults near the trench have a null slip, therefore there is a high potential for the generation of a tsunamigenic earthquake in the updip of the fault plane near the trench.