Magnitude-6.4 Earthquake Rocks Northern Chile
by Mark Leberfinger
A major earthquake struck early Monday morning in northern Chile.
The National Seismological Service at the University of Chile initially
listed the temblor at a magnitude-6.3. The U.S. Geological Survey listed
it as a magnitude-6.4.
The temblor's epicenter was located 48 kilometers (30 miles)
east-southeast of Putre, Chile, at a depth of 128 km (180 miles), the
USGS reported. It was near the borders with Peru and Bolivia, and
occurred at 12:51 a.m. local time.
Some landslides were reported in the region, according to Chilean
media. There was no immediate word about injuries.
Any relief efforts could be hampered by rain, AccuWeather.com Senior
Meteorologist Jason Nicholls said.
"In Putre, Chile, there is the chance for a thunderstorm each afternoon
and evening through at least Wednesday," Nicholls said. "However, much
of the time should be dry. Daytime highs will be in the lower to middle
50s (10-13C). The lower elevations in far northern Chile should stay
rain free this week, as is typical."
No tsunami was expected as a result of the earthquake, according to the
Chilean Navy Hydrographic and Oceanographic Service.
The earthquake was felt in Tacna, Peru, but it didn't affect the
electrical system, according to the USGS and Twitter users.
On April 1, 2014, a magnitude-8.2 megathrust earthquake occurred off
the Chilean coast near Iquique, Chile, with a magnitude-7.6 aftershock
one day later.
Risk of 8.0 earthquake in California rises, USGS says
by RONG-GONG LIN II AND ROSANNA XIA
Etimates of the chance of a magnitude 8.0 or greater earthquake hitting
California in the next three decades have been raised from about 4.7% to
7%, the U.S. Geological Survey said Tuesday.
Scientists said the reason for the increased estimate was because of
the growing understanding that earthquakes aren’t limited to separate
faults, but can start on one fault and jump to others. The result could
be multiple faults rupturing in a simultaneous mega-quake.
Stated another way, the chance of an 8.0 or greater quake in California
can be expected once every 494 years. The old forecast calculated a rate
of one 8.0 or greater earthquake every 617 years.
“The new likelihoods are due to the inclusion of possible multi-fault
ruptures, where earthquakes are no longer confined to separate,
individual faults, but can occasionally rupture multiple faults
simultaneously,” said USGS seismologist Ned Field, the lead author of
“This is a significant advancement in terms of representing a broader
range of earthquakes throughout California’s complex fault system.”
The report says that past models generally assumed that earthquakes
were confined to separate faults, or that long faults like the San
Andreas ruptured in separate segments.
But recent large California earthquakes showed how earthquakes can
rupture across multiple faults simultaneously. Many are in the Los
The Whittier Narrows earthquake, a magnitude 5.9, struck on the Puente
Hills thrust fault system on Oct. 1, 1987. Three days later, a magnitude
5.6 aftershock hit on a different fault. That aftershock killed one
person, twisted several chimneys and broke windows. Damage was reported
in Whittier, Pico Rivera, Los Angeles and Alhambra.
Much larger quakes also showed how this could occur, including two that
hit the Mojave Desert in the 1990s: the 1992 magnitude 7.3 Landers
earthquake and the 1999 magnitude 7.2 Hector Mine earthquake.
It also happened in the 7.2 earthquake that hit along the
California-Mexico border on Easter Sunday in 2010. Scientists said the
border quake directed tectonic stress toward Southern California,
putting the region at a higher risk for a future quake.
Data showed the April 4, 2010, quake and its aftershocks triggered
movement on at least six faults, including the Elsinore and San Jacinto
faults. Those faults run close to heavily populated areas in eastern Los
Angeles County and the Inland Empire.
At the time, scientists said the imagery gave proof that earthquakes
zipping along a fault can jump over gaps as long as seven miles.
Previously, only jumps of three miles had been observed. There was also
proof that earthquakes can reverse directions, an observation that had
never been seen before.
Dramatically, proof of earthquakes jumping fault boundaries occurred in
the massive 9.0 earthquake that hit off the Japanese coast in 2011. "The
2011 magnitude 9.0 Tohoku, Japan earthquake also violated previously
defined fault-segment boundaries, resulting in a much larger
fault-rupture area and magnitude than expected, and contributing to the
deadly tsunami and Fukushima nuclear disaster," the report said.
"As the inventory of California faults has grown over the years, it has
become increasingly apparent that we are not dealing with a few
well-separate faults, but with a vast interconnected fault system," the
report said. "In fact, it has become difficult to identify where some
faults end and others begin, implying many more opportunities for
One particular fault ripe for a massive earthquake is the southern San
Andreas, which Tuesday's forecast said was "most likely to host a large
earthquake." This section of the fault has a 19% chance of having a 6.7
or larger earthquake in the next 30 years centered in California's
The chance was lower on the northern section of the San Andreas fault
near San Francisco -- just 6.4% -- partly because of the relatively
recent 1906 earthquake. (Still, quakes are relatively ready to go on the
nearby Hayward and Calaveras faults in the Bay Area.)
The new forecast was released as part of a publication known as the
Third Uniform California Earthquake Rupture Forecast. The USGS said it
was created and reviewed by dozens of experts in seismology, geology,
paleoseismology, earthquake physics and earthquake engineering. These
predictions are factored into building codes and used by the California
Earthquake Authority to evaluate insurance premiums.
Experts say they can't predict the date and time that the next big
earthquake will come, but they're getting better at modeling the
possibilities. Tuesday's forecast considered more than 250,000
fault-based earthquakes; the last forecast considered about only 10,000.
The latest calculations use about 300 earthquake faults; the 2007
forecast relied on 200 faults, and the original 1988 report was based on
“As we’ve added more faults, we realized we’re not dealing with
separate, isolated faults but really an interconnected fault system,”
Field said in an interview.
Field said his team concluded that the previous forecast over-predicted
the rate of “moderate-sized” earthquakes like the 6.7 Northridge temblor
of 1994 “because we weren’t linking faults up.” That’s also why the
previous forecast under-predicted the rate of quakes 8.0 and larger.
“The message to the average citizen hasn’t changed. You live in
earthquake country, and you should live every day like it’s the day a
Big One could hit,” Field said. “ But what it really does help us do is
refine our estimates for those designing critical facilities: hospitals,
A higher probability of megaquakes should be a concern for those
constructing large structures.
“ If you’re dealing with a large bridge or maybe a large skyscraper
that might not even notice a small earthquake, the waves from a
magnitude-8 might be particularly problematic,” Field said.
“We are fortunate that seismic activity in California has been
relatively low over the past century. But we know that tectonic forces
are continually tightening the springs of the San Andreas fault system,
making big quakes inevitable,” Tom Jordan, director of the Southern
California Earthquake Center and a co-author of the study, said in a
Follow us on Twitter for more earthquake safety news: @ronlin and @RosannaXia
Famine threatens over 2.5mn in S Sudan
The United Nations says over 2.5 million people in South Sudan are on
the brink of famine amid the destructive civil war in the country.
UN emergency relief coordinator Valerie Amos issued the warning on
Monday during an international donor conference in the Kenyan capital
Nairobi, where the world body launched a 1.8-billion-dollar aid appeal.
The UN official referred to “the continuing widespread devastation and
destruction,” in South Sudan and called for restoration of peace in the
According to the UN, 2.5 million people – about 20 percent of South
Sudan’s population of 12 million -- are in a state of emergency or
crisis, only few steps short of famine. More than half of the country’s
population are in need of aid.
The UN predicted that the conflict would worsen in the dry season when
military vehicles could move around more easily.
Amos, who recently paid a three-day visit to the African country,
added, “The conflict has had a devastating impact on South Sudan but if
peace doesn't come quickly, it will also have a significant regional
Meanwhile, the donor nations in the conference pledged USD 529 million
(467 million euros) in aid for South Sudan.
South Sudan plunged into violence in December 2013, when fighting
erupted between troops loyal to President Salva Kiir and defectors led
by his former deputy, Riek Machar, around the capital, Juba.
The clashes left tens of thousands of South Sudanese dead, and forced
almost two million people from their homes. Seven ceasefires have so far
failed to end the clashes in the country.
South Sudan gained independence in July 2011 after its people
overwhelmingly voted in a referendum for a split from Sudan.