The earthquake, some 300-500 times more powerful than the magnitude 7.0 quake in Haiti Jan. 12, ruptured at the boundary between the Nazca and South American tectonic plates.
The temblor was triggered when the “subducting” Nazca plate was thrust under the South American plate, uplifting a large patch of the seafloor and prompting tsunami warnings throughout the Pacific Ocean. The two plates are converging at a rate of 80 mm per year, says Lin, “which is one of the fastest rates on Earth.”
Lin and colleague Ross S. Stein of the U.S. Geological Survey in Menlo Park, Ca., have studied the region extensively, and alerted the scientific community to a build up of stress along the interface of the two plates in a 2004 paper in the Journal of Geophysical Research.
“In 2004, we calculated that the 1960 magnitude 9.5 earthquake has caused large stress increase on both the northern and southern ends of its rupture,” said Lin. That quake, centered a few hundred kilometers south of Saturday’s earthquake, was the largest instrumentally recorded earthquake in the world. It killed 1,655 people in southern Chile and unleashed a tsunami that crossed the Pacific, killing 61 people in Hawaii and 185 in Japan. Saturday’s “quake picked up where the 1960 rupture ended in the north,” Lin said.
“This story is quite similar to the Dec. 26, 2004 magnitude-9.0 Sumatra earthquake, which was followed by a magnitude 8.7 quake on its southern end on 28 March 2005,” he said. “The only difference is that it took 50 years for the northern neighboring section of the 1960 [Chile] earthquake to rupture, while it took only 3 months for the southern adjacent segment to rupture in Sumatra.
“We do not yet have good enough science to say why one place took only 3 months and another took 50 years. But even 50 years is short enough [to fall within] in a person's lifetime. Thus, we should consider the earthquake interaction possibilities seriously.”
In Haiti, Lin pointed out that he and others have calculated that the Jan. 12 rupture has heightened stress further east along the Enriquillo Fault, thereby increasing chances of a quake in that region, which “comes within five kilometers of Port-au-Prince,” he said.
The latest Chile quake, which had killed more than 700 people as of March 1, was centered some 65 miles west-southwest of Talca, Chile, about 21.7 miles below the ocean’s surface, “relatively shallow for a subduction quake,” said Lin. It struck about 200 miles southwest of Santiago, the country’s capitol. Saturday’s earthquake had a “much longer” rupture zone—500-600 km—than that of the Haiti quake—35-50 km, Lin said.
“So why was the Haiti quake so much more catastrophic than the Chile quake?” he asked.
“First, as a nation, Chile is much better prepared for earthquakes than Haiti. People in Chile today still remember the pain of the 1960 quake,” Lin said. In addition, coastal Chile has a history of other very large earthquakes. Since 1973, there have been 13 events of magnitude 7.0 or greater. Approximately 870 km to the north of the Feb. 27 earthquake is the source region of the magnitude 8.5 earthquake of November 1922. That great quake significantly killed several hundred people and caused severe property damage. The 1922 quake generated a 9-meter local tsunami that inundated the Chile coast near the town of Coquimbo; the tsunami also crossed the Pacific, washing away boats in Hilo harbor, Hawaii.
“In contrast, the last catastrophic earthquake in Haiti was 240 years ago,” Lin said, “and thus few people were aware of a string of ‘earthquake bombs’ lying next to Port-au-Prince until Jan. 12.
“Second,” he said, “the economy of Chile is much better than that of Haiti. Thus, building codes are better developed and enforced in Chile. The contrasts between the aftermaths of the Chile and Haiti quakes reminded us, once again, that ‘earthquakes do not kill people, buildings do.’”
The Chile temblor dispatched tsunami waves onshore to Chile and across the Pacific Ocean toward Hawaii and the west coast of the US mainland, primarily California, and experts warned that tsunami waves were likely to hit Asian, Australian and New Zealand shores within 24 hours of the earthquake. Waves 6 feet (1.8 meters) above normal hit Talcahuano near Concepcion 23 minutes after the quake, and President Michelle Bachelet said a huge wave swept into a populated area in the Robinson Crusoe Islands, 410 miles (660 kilometers) off the Chilean coast. There were no immediate reports of major damage from the waves.
Though the predicted tsunami waves did reach Hawaii, California, New Zealand and other Pacific Rim regions, they proved to be relatively small and had minimal impact. “Even though the waves turned out to be not devastating”, Lin said, “it was an important opportunity for communities in coastal regions to improve the preparedness for potential greater tsunamis in the future.”
The WHOI research vessel Atlantis was operating off the coast of northern Chile when the magnitude 8.8 earthquake struck on Saturday. WHOI confirmed that R/V Atlantis and all on board are safe. There were no ill effects to R/V Atlantis or those on board from the quake or the subsequent tsunami.
R/V Atlantis has a scheduled port stop beginning on March 3, 2010, in Arica, Chile, which is on the northern coast of Chile. The WHOI Marine Operations Department is assessing the situation with their port agents to determine how or if that port stop will be affected.
A number of WHOI staff are onboard the R/V Melville, operated by Scripps Institution of Oceanography, which is conducting research at the Chile Triple Junction. WHOI received an email from an employee aboard the ship, and was told that all onboard are fine. The blog associated with this expedition (http://oceanexplorer.noaa.gov/explorations/10chile/) had not been updated on Saturday because, WHOI was told, the ship’s communication capability was being used to communicate by those onboard with family on shore.
The Woods Hole Oceanographic Institution is a private, independent organization in Falmouth, Mass., dedicated to marine research, engineering, and higher education. Established in 1930 on a recommendation from the National Academy of Sciences, its primary mission is to understand the oceans and their interaction with the Earth as a whole, and to communicate a basic understanding of the oceans' role in the changing global environment.
Media Relations | EurekAlert!
GPM sees deadly tornadic storms moving through US Southeast
01.12.2016 | NASA/Goddard Space Flight Center
Cyclic change within magma reservoirs significantly affects the explosivity of volcanic eruptions
30.11.2016 | Johannes Gutenberg-Universität Mainz
A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.
Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...
In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.
“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...
The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.
The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...
Broadband rotational spectroscopy unravels structural reshaping of isolated molecules in the gas phase to accommodate water
In two recent publications in the Journal of Chemical Physics and in the Journal of Physical Chemistry Letters, researchers around Melanie Schnell from the Max...
The efficiency of power electronic systems is not solely dependent on electrical efficiency but also on weight, for example, in mobile systems. When the weight of relevant components and devices in airplanes, for instance, is reduced, fuel savings can be achieved and correspondingly greenhouse gas emissions decreased. New materials and components based on gallium nitride (GaN) can help to reduce weight and increase the efficiency. With these new materials, power electronic switches can be operated at higher switching frequency, resulting in higher power density and lower material costs.
Researchers at the Fraunhofer Institute for Solar Energy Systems ISE together with partners have investigated how these materials can be used to make power...
16.11.2016 | Event News
01.11.2016 | Event News
14.10.2016 | Event News
02.12.2016 | Medical Engineering
02.12.2016 | Agricultural and Forestry Science
02.12.2016 | Physics and Astronomy