The Pichilemu Fault ( es, Falla de Pichilemu),
also referred to as the Pichilemu-Vichuquén Fault (''Falla de Pichilemu-Vichuquén''),
is a
Chile
Chile, officially the Republic of Chile, is a country in the western part of South America. It is the southernmost country in the world, and the closest to Antarctica, occupying a long and narrow strip of land between the Andes to the east a ...
an
geological fault
In geology, a fault is a planar fracture or discontinuity in a volume of rock across which there has been significant displacement as a result of rock-mass movements. Large faults within Earth's crust result from the action of plate tectonic ...
, located in
Libertador General Bernardo O'Higgins Region, some kilometers away from
Pichilemu
Pichilemu (, ), originally known as Pichilemo, is a beach resort city and commune in central Chile, and capital of Cardenal Caro Province in the O'Higgins Region. The commune comprises an urban centre and twenty-two villages, including Ciruelo ...
,
at a depth of .
The fault is long and wide.
Activity
The fault became reactivated after the
February 27, 2010, Chile earthquake, and gave rise to the
2010 Pichilemu earthquake
The 2010 Pichilemu earthquakes ( es, link=no, Terremoto de Pichilemu de 2010), also known as the Libertador O'Higgins earthquakes, were a pair of intraplate earthquakes measuring 6.9 and 7.0 that struck Chile's O'Higgins Region on 11 March 201 ...
on March 11.
At first, it was not known if it was formed during the February earthquake, or if it was just reactivated;
however, according to
University of Chile geologist José Cembrano, "
tcorresponds to a long-live fault (in a million years time) whose activity had not been detected before."
Ancient activity of the fault has been theorized to have occurred in the
Late Paleozoic
Late may refer to:
* LATE, an acronym which could stand for:
** Limbic-predominant age-related TDP-43 encephalopathy, a proposed form of dementia
** Local-authority trading enterprise, a New Zealand business law
** Local average treatment effect, ...
and
Late Mesozoic.
[ The reverse fault has a north-northeast to south-southwest strike and dips to the east.]
"This is a new record that we have found, and it explains why Pichilemu is experiencing so many tremors," the director of the Seismological Service of the University of Chile, Sergio Barrientos told ''La Tercera
''La Tercera'' ( es, The Third One), formerly known as ''La Tercera de la Hora'' ('the third of the hour'), is a daily newspaper published in Santiago, Chile and owned by Copesa. It is ''El Mercurio''s closest competitor.
''La Tercera'' is part o ...
'' on May 22, 2010. "It is not a crack nor an opening. It's a landslide," Barrientos added.
The Pichilemu Fault, along with the San Ramón Fault The San Ramón ( es, Falla de San Ramón) is a Chilean geological fault, located in eastern Santiago Metropolitan Region, passing through the eastern part of Santiago marking the boundary between the Chilean Central Valley and the Andes. As an acti ...
, was as of 2011 being studied by geologists of the University of Chile.
References
Fault
Seismic faults of Chile
Active faults
Thrust faults
Earthquakes in Chile
Geology of O'Higgins Region
Geology of the Chilean Coast Range
Coasts of O'Higgins Region
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