Destructiveness of Japan's Tsunami Explained

NASA and Ohio State University researchers found it was a "merging tsunami," where two wave fronts merged to create a double-high wave front far out to sea that could travel long distances without losing power.

Researchers from NASA and Ohio State University gave a briefing Dec. 5 during the American Geophysical Union meeting in San Francisco in which they explained why the March 2011 tsunami that devastated parts of northeastern Japan was so powerful. It was "a long-hypothesized 'merging tsunami'" produced when two wave fronts merged.

They based this on data from three NASA and European radar satellites that showed at least two wave fronts that day. These merged to form a double-high wave far out at sea that could travel long distances without losing power; ocean ridges and undersea mountain chains pushed the waves together along certain directions from the tsunami's point of origin. The discovery helps to explain how tsunamis cause major damage at some locations while leaving others unharmed, and it may help in tsunami forecasting.

Research scientist Y. Tony Song of NASA's Jet Propulsion Laboratory in Pasadena, Calif., and Professor C.K. Shum of Ohio State gave the briefing, according to NASA's news release. "It was a one in 10 million chance that we were able to observe this double wave with satellites," said Song, the principal investigator in the NASA-funded study. "Researchers have suspected for decades that such 'merging tsunamis' might have been responsible for the 1960 Chilean tsunami that killed about 200 people in Japan and Hawaii, but nobody had definitively observed a merging tsunami until now. It was like looking for a ghost. A NASA-French Space Agency satellite altimeter happened to be in the right place at the right time to capture the double wave and verify its existence."

"We can use what we learned to make better forecasts of tsunami danger in specific coastal regions anywhere in the world, depending on the location and the mechanism of an undersea quake," Shum said.

Download Center

  • Safety Metrics Guide

    Is your company leveraging its safety data and analytics to maintain a safe workplace? With so much data available, where do you start? This downloadable guide will give you insight on helpful key performance indicators (KPIs) you should track for your safety program.

  • Job Hazard Analysis Guide

    This guide includes details on how to conduct a thorough Job Hazard Analysis, and it's based directly on an OSHA publication for conducting JHAs. Learn how to identify potential hazards associated with each task of a job and set controls to mitigate hazard risks.

  • A Guide to Practicing “New Safety”

    Learn from safety professionals from around the world as they share their perspectives on various “new views” of safety, including Safety Differently, Safety-II, No Safety, Human and Organizational Performance (HOP), Resilience Engineering, and more in this helpful guide.

  • Lone Worker Safety Guide

    As organizations digitalize and remote operations become more commonplace, the number of lone workers is on the rise. These employees are at increased risk for unaddressed workplace accidents or emergencies. This guide was created to help employers better understand common lone worker risks and solutions for lone worker risk mitigation and incident prevention.

  • EHS Software Buyer's Guide

    Learn the keys to staying organized, staying sharp, and staying one step ahead on all things safety. This buyer’s guide is designed for you to use in your search for the safety management solution that best suits your company’s needs.

  • Vector Solutions

OH&S Digital Edition

  • OHS Magazine Digital Edition - June 2022

    June 2022

    Featuring:

    • SAFETY CULTURE
      Corporate Safety Culture Is Workplace Culture
    • HEAT STRESS
      Keeping Workers Safe from Heat-Related Illnesses & Injuries
    • EMPLOYEE HEALTH SCREENING
      Should Employers Consider Oral Fluid Drug Testing?
    • PPE FOR WOMEN
      Addressing Physical Differences
    View This Issue