It could provoke a major earthquake at any time, which would strike Santiago de Chile full force: the San Ramon fault has recently been placed under increased surveillance by the authorities, in this country which is one of the most seismic in the world.
No one can predict exactly when this will happen, but the history of the earthquakes recorded over the last few thousand years shows that “enough tectonic effort has been accumulated to generate another large earthquake” from one moment to another, Explains to Gabriel Vargas, geologist, and director of the project of follow-up of the fault of San Ramon, planned to last until 2019.
The scientist, however, tries not to be too alarmist: “It could happen in the next few minutes or it could be in the next 100 or 1,000 years,” he said.
But the threat is real. A massive earthquake would directly affect Santiago, the capital of seven million people.
At least 30 kilometers long, this fault can cause earthquakes “at least two or three times stronger than what was felt during the 2010 earthquake”, which had reached a magnitude of 8.3 to Santiago, and 8.8 at its epicenter, in the region of Bio Bio (south).
The first results of the monitoring of the fault have shown that it is currently active, generating earthquakes of a magnitude which do not, for the time being, exceed the two degrees.
n Chile, a country struck during the last seven years by three earthquakes of more than eight degrees, seismological monitoring is crucial.
With a network of more than 80 stations and a 24-hour monitoring center, Chile is ready to immediately detect and report the characteristics of dozens of earthquakes occurring every day.
But the San Ramon fault is another challenge.
The authorities have just installed eleven underground monitoring stations and are preparing to put a 12th one in order to prevent any seismic activity at the moment it occurs.
This new network “serves us to know the characteristics of the fault, the potential of earthquakes that can be caused, the greatest earthquake that can occur, and whether or not it activates the whole fault,” says AFP Mario Pardo, deputy director of the National Seismological Center.