News / Science & Technology

    Scientists: Subtle Seismic Activity Hints at Predicting Large Quakes

    The 2011 quake and resulting tsunami waves killed an estimated 18,000 people and triggered the meltdowns of three nuclear reactors in Fukushima, Japan. (S. Herman/VOA)
    The 2011 quake and resulting tsunami waves killed an estimated 18,000 people and triggered the meltdowns of three nuclear reactors in Fukushima, Japan. (S. Herman/VOA)

    The ability to accurately predict earthquakes is a holy grail of geology. Now, a group of researchers says it has found a previously unrecognized pattern just before larger earthquakes, observed with the devastating magnitude-9.0 tremor in northeastern Japan in 2011.

    This “has the potential to help refine time-dependent earthquake forecasts,” according to an article published Friday in the journal Science.

    “Although it will be a long way to make earthquake predictions that are useful for society, I believe this is a significant step toward that,” lead author Naoki Uchida, an assistant professor at Tohoku University’s Research Center for the Prediction of Earthquakes and Volcanic Eruptions, told VOA.

    But several prominent scientists told VOA they had issues with the methodology and did not see this as a major breakthrough.

    Slips prior to quake

    Uchida, two Japanese colleagues and two University of California-Berkeley scientists have outlined data they said reveals that subtle slips began accelerating a few days before the massive quake on March 11, 2011, which unleashed a devastating tsunami.

    The massive quake on March 11, 2011, unleashed a devastating tsunami upon Japan. (S. Herman/VOA)
    The massive quake on March 11, 2011, unleashed a devastating tsunami upon Japan. (S. Herman/VOA)

    The quake and resulting tsunami waves killed an estimated 18,000 people and triggered the meltdowns of three nuclear reactors in Fukushima, Japan.

    The offshore quake was the largest ever known to hit the seismically active island nation.

    Uchida and his colleagues analyzed the data of more than 6,000 seismic moments over a period of 28 years to detect slip-rate fluctuations in northeastern Japan.

    “The results suggest the possibility of an earthquake is larger when slow slips are occurring,” Uchida told VOA. “By taking account of such relationships, the probability forecast of earthquakes can be improved.”

    Slow (or aseismic) slips displace rocks much more slowly than earthquakes and without generating seismic waves. But these slow slips can increase stress in adjacent areas and may trigger damaging earthquakes.

    The analysis done by Uchida and his colleagues revealed that intervals of slow slips range from one to six years — often coinciding with clusters of large magnitude earthquakes, according to the paper published Friday.

    Some have doubts

    There are doubts among others, however, that detecting these slow slips can lead to reliable quake forecasting.

    “I think the best we could hope for from slow-slip events would be the same sort of modest probability gain,” said David Jackson, professor emeritus of Earth and space sciences at the University of California-Los Angeles.

    Until scientists make testable predictions, however, “they have an interesting anecdote, not a fundamental discovery,” said Philip Stark, a professor of statistics at California-Berkeley who was not involved in the research.

    Stark, speaking to VOA, also criticized the lack of “statistical care” in the Science paper, adding “the periodic slip model clearly does not fit the data well, but it's treated as ground truth.”

    Looking backward

    A prominent critic of quake prediction theories asserted that after big quakes it is easy to retrospectively say a particular movement was a foreshock.

    “Despite 100 years of work, no one has ever found a way [going forward] to distinguish foreshocks from random small quakes,” said Robert Geller, a geophysics professor at Tokyo University. “So, unless you issue an alarm after every small quake, there's no way to use possible foreshocks to reliably predict big quakes.”

    Hundreds or thousands of false alarms for every successful alarm is not something the public would tolerate, Geller told VOA.

    Jackson at UCLA said he “agrees fully” with Stark and Geller.

    “Readers will be drawn to the idea of earthquake prediction, but they will be much better informed if they are led to the logical constraints on the problem,” Jackson told VOA. “Meanwhile, let's wait for a track record of successful statements about future location, time and size limits for earthquakes after their predictions.”


    Steve Herman

    A veteran journalist, Steve Herman is VOA's Southeast Asia Bureau Chief and Correspondent, based in Bangkok.

    You May Like

    US-Russia Tensions Complicate Syria War

    With a shared enemy and opposing allies, Russia and the US are working to avoid confrontation

    Video Re-opening Old Wounds in Beirut's Bullet-riddled Yellow House

    Built in neo-Ottoman style in 1920s, it is set to be re-opened in Sept. as ‘memory museum’ - bullet-riddled walls and bunkered positions overlooking city’s notorious ‘Green Line’ maintained for posterity

    Cambodian-Americans Lobby for Human Rights Resolution

    Resolution condemns all forms of political violence in Cambodia, urges Cambodian government to end human rights violations, calls for respect of press freedom

    This forum has been closed.
    Comments
         
    There are no comments in this forum. Be first and add one

    Featured Videos

    Your JavaScript is turned off or you have an old version of Adobe's Flash Player. Get the latest Flash player.
    Brexit Vote Plunges Global Markets Into Uncharted Territoryi
    X
    June 24, 2016 9:38 PM
    British voters plunged global markets into unknown territory after they voted Thursday to leave the European Union. The results of the Brexit vote, the term coined to describe the referendum, caught many off guard. Analysts say the resulting volatility could last for weeks, perhaps longer. Mil Arcega reports.
    Video

    Video Brexit Vote Plunges Global Markets Into Uncharted Territory

    British voters plunged global markets into unknown territory after they voted Thursday to leave the European Union. The results of the Brexit vote, the term coined to describe the referendum, caught many off guard. Analysts say the resulting volatility could last for weeks, perhaps longer. Mil Arcega reports.
    Video

    Video Orlando Shooting Changes Debate on Gun Control

    It’s been nearly two weeks since the largest mass shooting ever in the United States. Despite public calls for tighter gun control laws, Congress is at an impasse. Democratic lawmakers resorted to a 1960s civil rights tactic to portray their frustration. VOA’s Carolyn Presutti explains how the Orlando, Florida shooting is changing the debate.
    Video

    Video Tunisian Fishing Town Searches for Jobs, Local Development Solutions

    As the European Union tries to come to grips with its migrant crisis, some newcomers are leaving voluntarily. But those returning to their home countries face an uncertain future.  Five years after Tunisia's revolution, the tiny North African country is struggling with unrest, soaring unemployment and plummeting growth. From the southern Tunisian fishing town of Zarzis, Lisa Bryant takes a look for VOA at a search for local solutions.
    Video

    Video 'American Troops' in Russia Despite Tensions

    Historic battle re-enactment is a niche hobby with a fair number of adherents in Russia where past military victories are played-up by the Kremlin as a show of national strength. But, one group of World War II re-enactors in Moscow has the rare distinction of choosing to play western ally troops. VOA's Daniel Schearf explains.
    Video

    Video Experts: Very Few Killed in US Gun Violence Are Victims of Mass Shootings

    The deadly shooting at a Florida nightclub has reignited the debate in the U.S. over gun control. Although Congress doesn't provide government health agencies funds to study gun violence, public health experts say private research has helped them learn some things about the issue. VOA's Carol Pearson reports.
    Video

    Video Trump Unleashes Broadside Against Clinton to Try to Ease GOP Doubts

    Recent public opinion polls show Republican Donald Trump slipping behind Democrat Hillary Clinton in the presidential election matchup for November. Trump trails her both in fundraising and campaign organization, but he's intensifying his attacks on the former secretary of state. VOA National Correspondent Jim Malone reports.
    Video

    Video Muslim American Mayor Calls for Tolerance

    Syrian-born Mohamed Khairullah describes himself as "an American mayor who happens to be Muslim." As the three-term mayor of Prospect Park, New Jersey, he believes his town of 6,000 is an example of how ethnicity and religious beliefs should not determine a community's leadership. Ramon Taylor has this report from Prospect Park.
    Video

    Video Internal Rifts Over Syria Policy Could Be Headache for Next US President

    With the Obama administration showing little outward enthusiasm for adopting a more robust Syria policy, there is a strong likelihood that the internal discontent expressed by State Department employees will roll over to the next administration. VOA State Department correspondent Pam Dockins reports.
    Video

    Video Senegal to Park Colorful ‘Cars Rapide’ Permanently

    Brightly painted cars rapide are a hallmark of Dakar, offering residents a cheap way to get around the capital city since 1976. But the privately owned minibuses are scheduled to be parked for good in late 2018, as Ricci Shryock reports for VOA.
    Video

    Video Florida Gets $1 Million in Emergency Government Funding for Orlando

    The U.S. government has granted $1 million in emergency funding to the state of Florida to cover the costs linked to the June 12 massacre in Orlando. U.S. Attorney General Loretta Lynch announced the grant Tuesday in Orlando, where she met with survivors of the shooting attack that killed 49 people. Zlatica Hoke reports.
    Video

    Video How to Print Impossible Shapes with Metal

    3-D printing with metals is rapidly becoming more advanced. As printers become more affordable, the industry is partnering with universities to refine processes for manufacturing previously impossible things. A new 3-D printing lab aims to bring the new technology closer to everyday use. VOA's George Putic reports.
    Video

    Video Big Somali Community in Minnesota Observes Muslim Religious Feast

    Ramadan is widely observed in the north central US state of Minnesota, which a large Muslim community calls home. VOA Somali service reporter Mohmud Masadde files this report from Minneapolis, the state's biggest city.

    Special Report

    Adrift The Invisible African Diaspora