Indonesia May Face a "Supercycle" of Devastating Earthquakes

By Eliza Strickland | December 12, 2008 10:30 am

coral SumatraWhile Indonesia is still rebuilding following the devastating 2004 earthquake and tsunami that killed more than 130,000 people on the island of Sumatra alone, scientists are warning that several other major earthquakes are likely to occur in the region over the next decades. A new study examined the growth records of coral reefs off the coast of Sumatra, and say they show evidence of repeated bursts of earthquakes that relieve pressure on the Sunda fault. A shock in 2007 may be the beginning of a new cycle, researchers say.

Says study coauthor Kerry Sieh: “If previous cycles are a reliable guide we can expect one or more very large west Sumatran earthquakes … within the next two decades” [Reuters]. As if to illustrate the point that the Indian Ocean is seismically active, reports are coming in that a 5.9 magnitude earthquake struck last night off the coast of Sumatra; happily, there have been no reports of casualties or damages, and authorities say there is no risk of a tsunami.

In the study, published in Science [subscription required], researchers looked at the growth patterns of coral reefs in the region over the past 700 years. When a quake occurs the seafloor rises up, effectively lowering the sea level so that shallow coral reefs are now above the surface. The reefs can’t grow upward, but their still submerged portions grow outward [The New York Times]. Researchers found evidence of this growth pattern about every 200 years, and say the changes to the coral reefs in the region weren’t caused by one single giant earthquake.

Instead, the growth patterns indicate that each cycle involves a few major earthquakes that occur over the course of several decades, in what study coauthor Aron Meltzner calls a “supercycle.” The 2007 quake originated in the southern region of the Sundra fault near the Mentawai Islands just south of Sumatra, a stretch of the fault that had been seismically calm since major quakes struck the region in 1797 and 1833, Meltzner notes…. Meltzner and his colleagues suggest that the Mentawai Islands’ September 2007 temblor is the opening salvo in a new supercycle of quakes for the region [Science News].

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DISCOVER: Did a Tsunami Wipe Out a Cradle of Civilization?

Image: Science

  • Gerald Jay


    I write from Bali Island, Indonesia

    The 2nd Best World Holiday Destination after Hawaii.

    Is it possible that some islands in Indonesia will sunken after The Great Quake ???

    How to know the sign of that big quake?!

    Looking forward for a Cooperation.


    Gerald Jay

  • http://Yahoo nita taefi

    As to 2nd Best Holiday Destination, I would have to defer to you on that but I will never forget the scenes of destruction witnessed during that last awful scene. Unfortunately, people live too close to the edge of these Islands for safety. Many beaches are being eroded just from naturally encroaching waters but where Islands exist in the Pacific, It’s wise to avoid the beaches. They are disasters waiting to happen. Stay safe!

  • http://Yahoo nita taefi

    Ritalin. Speaking of medications, it seems the whole of civilization is on some kind of mood or physical altering drugs. I’ve personally witnessed children who are medicated to the point of harming themselves or altering their appearance as a result of a Court Order when children are very active. And some parents have no alternative to stop this due to Court Orders. Now we hear television commercials advertising perscription drugs which we are to advise doctors to prescribe!

  • Bob

    Where did the Ritalin comment come from? Everyone already knows its over-prescribed and ADD is over-diagnosed. As for pull-through marketing, i see nothing wrong with that, the patient can still only get medications (legally) that a doctor prescribes – they can’t demand anything. So if someone shouldn’t be taking a medication it’s on the doctor not the drug company.

  • abeera

    hi i am doing a project at schol on the 2004 tsunami and i need basic facts on this please can u email me some on


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