The 2010 Chile earthquake (Spanish: Terremoto del 27F) occurred off the coast of central Chile on Saturday, 27 February at 03:34 local time (06:34 UTC), having a magnitude of 8.8 on the moment magnitude scale, with intense shaking lasting for about three minutes. It was felt strongly in six Chilean regions (from Valparaíso in the north to Araucanía in the south), that together make up about 80 percent of the country's population.
3 miles) southwest of the town of Pelluhue and at a point approximately 100 km (62 miles) away from the following four provincial capitals: Talca (to the north-east), Linares (to the east), Chillán (to the south-east) and Concepción (to the south). Chile's Seismological Service located the quake's epicenter at about 34 km (21 miles) off the coast of Ñuble Province in the Biobío Region. This is 60 km (37 miles) north of Concepción and 170 km (110 miles) south-west of Talca.
6 followed within an hour of the initial quake. The USGS said that a large vigorous aftershock sequence can be expected from this earthquake. By 6 March UTC, more than 130 aftershocks had been registered, including thirteen above magnitude 6.0.
Shortly after the mainshock seismologists installed a dense network of seismometers along the whole rupture area. This network captured 20.000 aftershocks in the 6 months after the mainshock and shows a detailed picture of the structure of the Chilean margin. Seismicity is focused in the depth range 25–35 km and in a deeper band of between 45 and 50 km depth.
Around 10.000 aftershocks occurred in the region of two large aftershocks in the Pichilemu region. A 6.9-magnitude offshore earthquake struck approximately 300 kilometers southwest of, and less than 90 minutes after, the initial shock; however, it is not clear if that quake is related to the main shock.
A separate earthquake of magnitude 6.3 occurred in Salta, Argentina, at 15:45 UTC on 27 February, at a depth of 38.2 km (23.7 mi); two people were injured and one died in Salta.
This earthquake was followed on 1 March, at 06:32 UTC by a magnitude 4.9 aftershock. Four other earthquakes above M5.0, some possible aftershocks, also occurred near the border in Argentina following the Chile earthquake; a magnitude 5.
0 earthquake occurred in Mendoza on 28 February, a M5.3 earthquake in Neuquen and a M5.2 in San Juan on 2 March, and a M5.1 quake in Mendoza on 4 March.
Another strong earthquake occurred on 4 March, at 22:39 UTC in Antofagasta in northern Chile, with a magnitude of 6.3.Minor quakes generated by the main one could be felt as far away as São Paulo, Brazil, located about 3,000 km (1,900 mi) away from Concepción. Since the major earthquake, and as of 15 March, at least four to forty >M5.
0 earthquakes have been recorded daily in the vicinity of the main earthquake, including four above magnitude 6.0 between 3 March and 6 March.On 5 March, two aftershocks above M6.0 were reported.
The first was a 6.3-magnitude off the coast of the Biobío Region. The second was near the epicenter of the original quake at 08:47 local time with a magnitude of 6.6.
On 11 March, the March 2010 Chile earthquake (magnitude 6.9, treated by some as an aftershock of the February 2010 earthquake) was reported, followed quickly by further aftershocks measuring 6.7 and 6.0.
The epicenter of the 6.9 quake was in Pichilemu, O'Higgins Region.On 15 March, two aftershocks of the February 2010 earthquake were reported, one at magnitude 6.1 at 08:08:28 local time offshore Maule, and another at magnitude 6.
7 with the epicenter located offshore the Biobío Region, near Cobquecura, at 23:21:58 local time. This tremor was followed by two minor aftershocks, one occurring 45 minutes later, measuring M5.5. No tsunami was reported and there were no tsunami warnings issued.
On 17 March, at 14:38:37 local time, an earthquake of magnitude 5.2 was recorded in Aisén, in Southern Chile. Another magnitude 5.2 earthquake was recorded in Los Lagos the next day.
On 26 March, at 10:52:06 local time, a magnitude 6.2 earthquake hit the Atacama region, in Northern Chile. The Biobio Region of Chile has had strong aftershocks of this earthquake. The first one was a magnitude 6.
7 MW earthquake that struck off the coast of Biobío, Chile, at 23:21 on 15 March 2010 at the epicenter, at a depth of 18 kilometres (11 mi). The second earthquake struck on land in the region at 22:58 (UTC) on 2 April 2010 at 5.9 MW and at a depth of 39 km. The third struck on 10:03 (UTC) on 23 April 2010 at 6.
2 MW. The Pacific Tsunami Warning Center said that historical data indicates that this quake will not generate a tsunami but still advised of the possibility. On 3 May, at 19:09 a 6.4 MW earthquake magnitude struck off Biobío, Chile, at the epicenter, at a depth of 20 kilometres (12 mi).
The epicenter was 55 kilometres (34 mi) south of Lebu. On 14 July 2010, another 6.5 magnitude earthquake occurred in the area.
Chile has been at a convergent plate boundary that generates megathrust earthquakes since the Paleozoic era (500 million years ago). In historical times the Chilean coast has suffered many megathrust earthquakes along this plate boundary, including the strongest earthquake ever measured, which is the 1960 Valdivia earthquake. Most recently, the boundary ruptured, causing the 2007 Tocopilla earthquake in northern Chile. The segment of the fault zone which ruptured in this earthquake was estimated to be over 700 km (430 mi) long with a displacement of almost 10 meters, or 120 years of accumulated plate movement.
It lay immediately north of the 1,000 km (620 mi) segment which ruptured in the great earthquake of 1960. Preliminary measurements show that the entire South American Plate moved abruptly westward during the quake. A research collaborative of Ohio State and other institutions have found, using GPS, that the earthquake shifted Santiago 28 cm (11 in) to the west-southwest and moved Concepción at least 3 metres (10 ft) to the west. The earthquake also shifted other parts of South America from the Falkland Islands to Fortaleza, Brazil.
For example, it moved Argentina's capital of Buenos Aires about 2.5 cm (1 in) to the west. Several cities south of Cobquecura were also raised, by up to 3 meters. The maximum recorded peak ground acceleration was at Concepcion, with a value of 0.
65 g (6.38 m/s2).