2010 Pichilemu earthquakes

6.9 and 7.0 MW intraplate earthquakes 2010 in Chile

A 6.9 earthquake occurred on March 11, 2010, 40 kilometers southwest of Pichilemu, O'Higgins Region, Chile .[2][3][4][5][6] A tsunami warning was made by the Pacific Tsunami Warning Center Pacific-wide, although they warned of the possibility of local tsunamis within 100 kilometers of the epicenter (between San Antonio and Concepción).[7]

2010 Pichilemu earthquakes
Terremoto de Pichilemu de 2010
House damaged by the Pichilemu earthquake, in the epicentre town, as seen on 16 April 2011.
Above: House damaged by the Pichilemu earthquake, in the epicentre town, as seen on 16 April 2011. Below: Pichilemu earthquake shakemap produced by the United States Geological Survey
UTC timeDoublet earthquake:    
 2010-03-11 14:39:43
 2010-03-11 14:55:27
ISC event 
 14554049
 14400686
USGS-ANSS 
 ComCat
 ComCat
Local date11 March 2010 (2010-03-11)
Local time 
 11:39 UTC-3
 11:55 UTC-3
Magnitude 
 6.9 Mw
6.3 ML
 7.0 Mw
Depth33.1 kilometres (20.6 mi)
EpicenterPichilemu, Chile
34°18′04″S 72°07′48″W / 34.301°S 72.13°W / -34.301; -72.13
Areas affectedChile
Argentina
Max. intensityMM X
Peak acceleration0.086g (Curicó, Maule)[1]
TsunamiYes
Casualties1 killed

Although news media first reported the earthquake as an aftershock of the February earthquake,[5][8] the initial geological summary given by the United States Geological Survey [9] said it was a different earthquake. Though unchained by the regional stress caused by the February 27 earthquake, the March event was not a fast adjustment to February's thrust fault rupture between the Nazca and South American plates, but it was caused by normal faulting inside one of those plates. However, it has not been positively decided in which plate the earthquake occurred.

Within 6 hours, 10 aftershocks took place, of these 2 were of magnitude 6 or greater and 7 between magnitude 5 and 6.[10]

The earthquake took place shortly before the new president, Sebastián Piñera, was sworn in, at about 12:15 PM local time (15:15 UTC), at the Chilean congress in Valparaíso, where the shaking was clearly felt. The presidents of Bolivia, Paraguay, and Ecuador were present when the earthquake occurred, however, the television footage showed that the inauguration was not interrupted.[11]

Damage reported by the Chilean news media include a collapsed pedestrian crossing over Chile Highway 5, north of Rancagua.[12] The most affected place by the earthquake was Pichilemu, the epicentre of the earthquake. It destroyed the Ross Park, most of the Agustín Ross Cultural Centre and many houses in Espinillo and Rodeillo.[13]

May 2, 2010 aftershock

change

The May, 2 2010 Pichilemu earthquake was a magnitude 6.0 MW earthquake that struck off Pichilemu, Chile, at 10:52 AM on May 2, 2010 at the epicenter, at a depth of 31 kilometres (19 mi). USGS described the epicenter as 70 kilometres (43 mi) south-southwest of San Antonio, 105 kilometres (65 mi) west Regional capital of Rancagua, 105 kilometres (65 mi) northwest of Curicó and 140 kilometres (87 mi) southwest of the Chilean capital of Santiago.[14]

After almost exactly three hours later a second quake happens in the same area with an intensity of 4.8 MW[15]

More than 10 aftershocks happened on May 2 and 3.

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References

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  1. "Station Lists". United States Geological Survey. 2010. Archived from the original on 25 February 2013. Retrieved 20 May 2012.
  2. Magnitude 6.9 - LIBERTADOR O'HIGGINS, CHILE, U.S. Geological Survey, March 11, 2010, archived from the original on 2012-04-20, retrieved 2017-08-30
  3. Doce réplicas con epicentro en Pichilemu, El Carabobeño, March 11, 2010, archived from the original on July 16, 2011, retrieved March 14, 2010
  4. El Mayor Fue de 7,2° Richter, Chile.com, March 11, 2010, archived from the original on March 15, 2010, retrieved March 14, 2010
  5. 5.0 5.1 "New Chile quake as Pinera sworn in as president". BBC News. 11 March 2010.
  6. "24 Horas - Televisión Nacional de Chile". Archived from the original on 2012-02-27. Retrieved 2010-03-14.
  7. Tsunami Information Bulletin, Pacific Tsunami Warning Center, March 11, 2010, archived from the original on 2012-04-20, retrieved 2010-03-14
  8. "Chile president vows to rebuild". www.aljazeera.com.
  9. "Geological summary by the USGS". Archived from the original on 2012-04-20. Retrieved 2017-08-30.
  10. USGS list of earthquakes. Retrieved March 12. Archived 2011-03-12 at the Wayback Machine
  11. "Three strong earthquakes strike Chile in quick succession - CNN.com". www.cnn.com.
  12. El Mercurio online Archived 2010-03-14 at the Wayback Machine, March 11
  13. Pichilemu devastado Archived 2012-03-18 at the Wayback Machine, Canal 13 (Chile), March 16, 2010.
  14. "Magnitude 6.0 - LIBERTADOR O'HIGGINS, CHILE". USGS. 2010-05-02. Archived from the original on 2010-05-05. Retrieved 2010-05-02.
  15. "Magnitude 4.8 - OFFSHORE LIBERTADOR O'HIGGINS, CHILE". USGS. 2010-05-02. Archived from the original on 2010-05-05. Retrieved 2010-05-02.