Biggest recorded earthquake was brewing for four centuries

Oct 07, 2005

The earthquake that rocked Chile in 1960 - at magnitude 9.5, the biggest ever recorded - was preceded by almost 400 years of accumulating stress, according to studies of the region's buried soils and sand. Strain had been building up on the fault ever since the Spanish conquistadors were jolted by a large quake in 1575.

Seismologists had previously been confused because the region had experienced earthquakes in 1837 and 1737, making the 1960 monster difficult to explain - the fault would not have had time to become sufficiently stressed to produce the magnitude 9.5 event.

In last month's issue of the journal Nature, a team led by Marco Cisternas (Pontificia Universidad Católica de Valparaíso, Valparaíso, Chile) now reports that these earlier quakes produced little if any subsidence or tsunami in the study area near the centre of the earthquake fault, meaning that they probably did not significantly release the stress building on the fault.

By studying soils and sands laid down over the past 2,000 years, the researchers have built up a picture of how and when previous tremors occurred along the fault, which runs between the Nazca and South American plates on the continent's west coast. The 1960 event represents between 250 and 350 years' worth of motion along a 1,000-kilometre section of the fault, where the Nazca plate is grinding below the continent at a rate of some 8 metres per century.

Source: Nature

Explore further: SDO captures images of two mid-level flares

add to favorites email to friend print save as pdf

Related Stories

Impoverished North Korea falls back on cyber weapons

4 hours ago

As one of the world's most impoverished powers, North Korea would struggle to match America's military or economic might, but appears to have settled on a relatively cheap method to torment its foe.

Five ways to make your email safer in case of a hack attack

5 hours ago

The Sony hack, the latest in a wave of company security breaches, exposed months of employee emails. Other hacks have given attackers access to sensitive information about a company and its customers, such as credit-card ...

Recommended for you

SDO captures images of two mid-level flares

14 hours ago

The sun emitted a mid-level flare on Dec. 18, 2014, at 4:58 p.m. EST. NASA's Solar Dynamics Observatory, which watches the sun constantly, captured an image of the event. Solar flares are powerful bursts ...

Why is Venus so horrible?

21 hours ago

Venus sucks. Seriously, it's the worst. The global temperature is as hot as an oven, the atmospheric pressure is 90 times Earth, and it rains sulfuric acid. Every part of the surface of Venus would kill you ...

Image: Christmas wrapping the Sentinel-3A antenna

Dec 19, 2014

The moment a team of technicians, gowned like hospital surgeons, wraps the Sentinel-3A radar altimeter in multilayer insulation to protect it from the temperature extremes found in Earth orbit.

Video: Flying over Becquerel

Dec 19, 2014

This latest release from the camera on ESA's Mars Express is a simulated flight over the Becquerel crater, showing large-scale deposits of sedimentary material.

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.