News / Science & Technology

    Simulated Disasters Provide Earthquake Data

    Models could help save lives

    Lamont Research Director Heather Savage prepares a machine in the Rock Mechanics Laboratory that will simulate earthquake conditions on a micro-scale.
    Lamont Research Director Heather Savage prepares a machine in the Rock Mechanics Laboratory that will simulate earthquake conditions on a micro-scale.

    Multimedia

    Audio

    Earthquakes are among the most devastating and frequent natural disasters on the planet - and also among the least understood.

    Scientists at Columbia University’s Lamont-Doherty Earth Observatory, about 30 kilometers north of New York City, are working to change that.

    Quake dynamics

    The Rock Mechanics Laboratory is one of several specialized labs at Lamont-Doherty’s Division of Seismology, Geology and Tectonophysics, now studying the subterranean dynamics of earthquakes.   

    Research professor Heather Savage fires up a machine that simulates, in miniature, real earthquake conditions - the rubbing, slipping and sliding of the Earth’s massive plates, generating data for analysis.

    “So what we do here in our lab is put two pieces of rock that we’re interested in, say two pieces of granite, and then we put them under stress, and then load them and load them and load them until they want to slide," Savage says. "And then we look at things like how much stress did we have to put on those rocks until they started sliding? And that tells us something about how strong that fault surface is. And that tells us something about how much stress a fault in nature can take before it starts having an earthquake.”

    Significant differences

    Savage acknowledges there can be significant differences between the highly controlled mini-quakes she generates in her laboratory and those that occur in nature.

    “The problem comes in when you start to think of how complex fault zones really are. They are much bumpier than that, which can completely change your distribution of stress on the whole fault. And as soon as you start to slide things past each other, you start to break some of that roughness up and create little particles. And now your fault is no longer two pieces of rock touching each other. Now it’s got a layer of what we call ‘gouge’ in between, which is all those busted up particles of your original two surfaces. Now you’re talking about the strength of a granular material. And that opens up a whole new branch of physics which is also not well understood and that is the behavior of granular material. So there are lots of interesting things that go on in faults and a lot of different sciences that get pulled in.”

    Many of those sciences are the focus of the other labs at Lamont-Doherty Earth Observatory. Geo-chemists, for example, analyze the temperature and molecular properties of the Earth’s material. Physicists can help answer questions about how earthquake aftershocks work.

    Tremors

    For example, when plates shift or bump against each other, why isn’t there one massive shudder followed by complete rest once the tension has been relieved, rather than the series of smaller, potentially dangerous tremors that follow the collision of plates?

    One answer lies in the fact that the initial major quake only relieves some of the pent-up energy between two opposing plates. So called “aftershocks” just finish the job, as when a rock slides down a mountain, comes to rest, and is jolted into continuing its downhill course.

    Another reason for aftershocks are the “seismic waves” that earthquakes generate, which Savage likens to what happens when you jiggle the end of a loose metal spring.      

    “If you just tweak that spring, just give it a little push, you can watch a wave travel from where I pushed it and it will end up at you and then a smaller wave will come back at me, and so forth, depending on how hard I pushed it.”  

    Much of the seismological work at Lamont-Doherty is more practical than theoretical. For example, the global network of digital seismic monitoring stations it helps to manage enables scientists and governments around the world to be alerted almost immediately when an earthquake occurs.

    Because the digital information travels through cyberspace faster than seismic waves propagate through the earth, people can sometimes be warned before a quake strikes their local areas.  

    Scientists might never be able to predict the when and where of particular earthquakes. But Lamont Doherty seismologists are also working to develop mathematical earthquake probability models. The models could save lives by giving government leaders and urban planners a more accurate picture of the earthquake risk in any given area.

    You May Like

    Native Americans Ask: What About Our Water Supply?

    They say they have been facing a dangerous water contaminant for decades - uranium – but the problem has received far less attention than water contamination by lead in Flint, Michigan

    Pakistan's President Urges Nation Not to Celebrate Valentine's Day

    Mamnoon Hussain criticizes Valentine's Day, which falls on Sunday this year, as a Western import that threatens to undermine the Islamic values of Pakistan

    Mother of IS Supporter: Son Was Peaceful, 'Role Model'

    Somali-American Abdirizak Mohamed Warsame pleaded guilty Thursday to charges of conspiring to provide material support to Islamic State militants

    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.
    Two-thirds of World Faces Water Shortagei
    X
    February 12, 2016 7:31 PM
    Four billion people — or two out of every three on the planet — do not have enough water to meet their basic needs. That is far greater than previously thought, according to a new study that presents a more accurate picture of the problem. As VOA's Rosanne Skirble reports, the findings will help policymakers and the public craft solutions to address the threat.
    Video

    Video Two-thirds of World Faces Water Shortage

    Four billion people — or two out of every three on the planet — do not have enough water to meet their basic needs. That is far greater than previously thought, according to a new study that presents a more accurate picture of the problem. As VOA's Rosanne Skirble reports, the findings will help policymakers and the public craft solutions to address the threat.
    Video

    Video Gateway to Mecca: Historical Old Jeddah

    Local leader Sami Nawar's family has been in the Old City of Jeddah for hundreds of years and takes us on a tour of this ancient route to Mecca, also believed to be the final resting place of Adam's wife, Eve.
    Video

    Video New Technology Aims to Bring Election Transparency to Uganda

    A team of recent graduates from Uganda’s Makerere University has created a mobile application designed to help monitor elections and expose possible rigging. The developers say the app, called E-Poll, will make Uganda's democratic process fairer. From Kampala, VOA's Serginho Roosblad reports.
    Video

    Video As Refugees Perish, Greek Graveyards Fill

    Aid workers on the Greek island of Lesbos say they are struggling to bury the increasing number of bodies of refugees that have been recovered or washed up ashore in recent months.  The graveyards are all full, they say, yet as tens of thousands of people clamor to get out of Syria, it is clear refugees will still be coming in record numbers. For VOA, Hamada Elrasam reports from Lesbos, Greece.
    Video

    Video Russia Bristles at NATO Expansion in E. Europe

    Russian Foreign Minister Sergei Lavrov is meeting Friday with the head of NATO after the Western military alliance and the United States announced plans for the biggest military build-up in Europe since the Cold War. Russia has called NATO's moves a threat to stability in Europe. But NATO says the troop rotations and equipment are aimed at reassuring allies concerned about Russia as VOA's Daniel Schearf reports from Moscow.
    Video

    Video To Fight Zika, Scientists Target Mosquitoes

    Mosquitoes strike again. The Zika virus outbreak is just the latest headline-grabbing epidemic carried by these biting pests, but researchers are fighting back with new ways to control them. VOA's Steve Baragona takes a look.
    Video

    Video Mosul Refugees Talk About Life Under IS

    A top U.S. intelligence official told Congress this week that a planned Iraqi-led operation to re-take the city of Mosul from Islamic State militants is unlikely to take place this year. IS took over the city in June 2014, and for the past year and a half, Mosul residents have been held captive under its rule. VOA's Zana Omar talked to some families who managed to escape. Bronwyn Benito narrates his report.
    Video

    Video Scientists Make Progress Toward Better Diabetes Treatment, Cure

    Scientists at two of the top U.S. universities say they have made significant advances in their quest to find a more efficient treatment for diabetes and eventually a cure. According to the International Diabetes Federation, the disease affects more than 370 million people worldwide. VOA’s George Putic reports.
    Video

    Video NATO to Target Migrant Smugglers

    NATO has announced plans to send warships to the Aegean Sea to target migrant smugglers in the alliance's most direct intervention so far since a wave of people began trying to reach European shores.
    Video

    Video Russia's Catholics, Orthodox Hopeful on Historic Pope-Patriarch Meeting

    Russia's Catholic minority has welcomed an historic first meeting Friday in Cuba between the Pope and the Patriarch of Russia's dominant Orthodox Church. The Orthodox Church split with Rome in 1054 and analysts say politics, both church and state, have been driving the relationship in the centuries since. VOA's Daniel Schearf reports from Moscow.
    Video

    Video Used Books Get a New Life on the Streets of Lagos

    Used booksellers are importing books from abroad and selling them on the streets of Africa's largest city. What‘s popular with readers may surprise you. Chris Stein reports from Lagos.
    Video

    Video After NH Primaries All Eyes on South Carolina

    After Tuesday's primary in New Hampshire, US presidential candidates swiftly turned to the next election coming up in South Carolina. The so-called “first-in-the-South” poll may help further narrow down the field of candidates. Zlatica Hoke reports.
    Video

    Video Smartphone Helps Grow Vegetables

    One day, you may be using your smartphone to grow your vegetables. A Taipei-based company has developed a farm cube — a small, enclosed ecosystem designed to grow plants indoors. The environment inside is automatically adjusted by the cube, but it can also be controlled through an app. VOA's Deborah Block has more on the gardening system.
    Video

    Video Exhibit Turns da Vinci’s Drawings Into Real Objects

    In addition to being a successful artist, Renaissance genius Leonardo da Vinci designed many practical machines, some of which are still in use today, although in different forms. But a number of his projects were never realized — until today. VOA’s George Putic reports.