Magnitude 8.8 - OFFSHORE MAULE, CHILE

2010 February 27 06:34:14 UTC

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Earthquake Details

Magnitude8.8
Date-Time
Location35.909°S, 72.733°W
Depth35 km (21.7 miles) set by location program
RegionOFFSHORE MAULE, CHILE
Distances95 km (60 miles) NW of Chillan, Chile
105 km (65 miles) NNE of Concepcion, Chile
115 km (70 miles) WSW of Talca, Chile
335 km (210 miles) SW of SANTIAGO, Chile
Location Uncertaintyhorizontal +/- 6.2 km (3.9 miles); depth fixed by location program
ParametersNST=391, Nph=391, Dmin=987.2 km, Rmss=1.17 sec, Gp= 14°,
M-type=teleseismic moment magnitude (Mw), Version=8
Source
  • USGS NEIC (WDCS-D)
Event IDus2010tfan
  • This event has been reviewed by a seismologist.
  • The U.S State Department has set up a number for Americans to call if they are looking for infomation about relatives and friends: 1-888-407-4747. This line will receive a high number of calls however so you may hear a recording.
  • Did you feel it? Report shaking and damage at your location. You can also view a map displaying accumulated data from your report and others.

Earthquake Summary

Small globe showing earthquakeSmall map showing earthquake

Earthquake Summary Poster

Felt Reports

At least 507 people killed, many injured and at least 200,000 houses damaged by the earthquake and tsunami in the Concepcion-Valparaiso area. Felt in much of Chile and Argentina. Also felt in parts of Bolivia, southern Brazil, Paraguay, Peru and Uruguay. A Pacific-wide tsunami was generated and caused minor damage to boats and a dock in the San Diego area, California.

Tectonic Summary

The earthquake was generated at the gently sloping fault that conveys the Nazca plate eastward and downward beneath the South American plate. The two plates are converging at 7 meters per century. The fault rupture, largely offshore, exceeded 100 km in width and extended nearly 500 km parallel to the coast. The rupture began deep beneath the coast and spread westward, northward, and southward. As it spread, the fault slip generated earthquake shaking. The fault slip also warped the ocean floor, setting off the tsunami along the fault-rupture area.

The written history of very large plate-boundary earthquakes between Valparaíso and Concepción probably begins with a shock near Concepción in 1562. Another earthquake eight years later set off a tsunami that led Spaniards to rebuild Concepción on higher ground. A 1730 earthquake probably centered near Valparaíso generated a tsunami that caused flooding and damage in Japan, as did the great Concepción earthquake of 1751. Charles Darwin and Robert FitzRoy observed the next major Concepción earthquake in 1835. The northern part of the 2010 rupture overlaps with the probable source area of the 1906 Valparaíso earthquake of magnitude 8.2. The tsunami associated with the 1906 earthquake produced damage in Hawaii, with reported run-up heights as great as 3.5 m.

Other parts of Chile’s coast have also produced notable earthquakes. South of Concepción, the source of the 2010 earthquake adjoins a fault rupture nearly 1,000 km long that produced the largest 20th-century earthquake worldwide – the giant 1960 earthquake of magnitude 9.5 An estimated 1600 lives were lost to the 1960 earthquake and tsunami in Chile, and the 1960 tsunami took another 200 lives among Japan, Hawaii, and the Philippines. At Valparaíso, a plate-boundary earthquake of magnitude 8.0 occurred in 1985. North of Valparaíso, a magnitude 8.5 earthquake in 1922 generated a Pacific Ocean tsunami that reached heights of 9 m on the Chilean coast near Coquimbo and washed away boats in Hilo harbor, Hawaii. Still farther north along the coast of Chile and Peru, great earthquakes with trans-Pacific tsunamis occurred are known from 1586, 1687, 1868, and 1877. Overall along the Chilean coast there have been 13 earthquakes of magnitude 7.0 or greater since 1973.

This map shows the spatial relationship among instrumentally located earthquakes since 1900. Those before 1964 are of M6.5 or larger; those since 1964-present, M5.5 or larger. and the 2010/02/27 M8.8 Chile earthquake and its associated aftershocks. Since the beginning of the 20th century there have been M8.2 earthquakes in 1906, 1943 and 1960 and an M8.0 in 1985. The M8.2 1960 earthquake was a foreshock that occurred the previous day to the great M9.5 Chilean earthquake. The point of initial rupture for the M8 or larger earthquakes are shown, while the estimated rupture zones of the 1922 M8.5 and 1960 M9.5 earthquakes are also identified. These rupture zones were defined by the areal extent of aftershocks and/or geological and macroseismic observations. 


Since the middle of the 16th century, there is a comprehensive written record of other large damaging earthquakes throughout the region. Notable likely mega-thrust earthquakes prior to 1900 include earthquakes in 1868 and 1877 offshore southern Peru and northern Chile. In the vicinity of the 2010 earthquake, damaging earthquakes were reported in 1751, near Concepcion, and one further to the north in 1730. Tsunamis from the 1730, 1751, 1868, and 1877 earthquakes produced Pacific-wide tsunamis as evidenced from detailed records of flooding and damage in Japan. An 1835 Concepcion earthquake is notable because the great Explorers Charles Darwin and Robert FitzRoy provided observations and comments.

Does the recent earthquake activity in Chile, Haiti, the western Pacific, and the Indian Ocean mean that one earthquake is triggering the next? Probably not. Instead, as illustrated at right, the global rate of earthquake energy release shows little if any difference between times when very large earthquakes have been common and times when they have not. The graphs and the map above them show the temporal and spatial distribution of earthquakes with a magnitude of M >= 8 since 1900. On the global map, earthquake locations are denoted by red stars, and the largest five are labeled with their location names and year of occurrence. Below this map, earthquakes are displayed in graphic format; first as a bar graph of earthquake magnitude through time, and next as cumulative energy release (seismic moment) through time. As on the global map, the largest five earthquakes are labeled on the bar graph. These graphs show that while the largest earthquakes of the last 70 years occurred close together in time – first during the 1950’s and 1960’s and again since 2000 – there has been no appreciable increase in the rate of energy release between these large events, as indicated by the parallel red dashed lines.

A statistical analysis of the same data shows no meaningful, statistically significant clustering of M>=8 earthquakes in time. In this analysis, not presented here, synthetic histories of randomly recurring earthquakes commonly include clusters similar to those of the last 70 years.

  • Aftershock Report

    In the time period since the earthquake's origin at 2010-02-27 06:34 to 2010-04-02 21:00 UTC, the USGS NEIC has located 280 aftershocks of magnitude 5.0 or greater. Nineteen of these aftershocks have magnitudes of 6.0 or greater. See Aftershock Map

  • Earthquake Information for Chile

    Earthquake Information for South America

    Predecessors of the giant 1960 Chile earthquake - Brian Atwater, Nature 437, 404-407 (15 September 2005)




    Poster of the Seismicity of the Nazca Plate and South America

    Educational slides for the M7.0 January 12, 2010 and M8.8 February 27, 2010 Chile earthquakes.

    Educational slides for the M7.0 January 12, 2010 and M8.8 February 27, 2010 Chile earthquakes (with notes)