Tsunami Science: Reducing the Risk

Fear the Future Tsunami?

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Another conventional tsunami-measuring technique is through tide gauges, plastic tubes installed vertically near shorelines. As water fills the tube, a computerized sensor records the sea level. But tide gauges are problematic. Many must be physically accessed to retrieve the data. Also, the topography of shorelines can reduce or amplify a tsunami’s wave height, leaving researchers unable to predict how that same wave may affect coasts far away. Tide-gauge data oftentimes come too late to be useful, and the tsunami can wash away the tubes.

“When you measure offshore, deep-ocean pressures with a tsunameter, you can see what the energy means for specific communities,” says Meinig. “Our goal is to have site-specific forecasts just like we’re able to do for a hurricane. But the challenge is that we don’t have three days to do it. We have three hours.”

The New Wave

After the tsunameter measures the wave, it relays the digital data acoustically to the floating buoy. The buoy transmits the information to a satellite, which beams it to ground-based scientists who incorporate the data into community-specific computer model forecasts. The modelers then send their predictions to local emergency managers. All these steps can be completed within 15 minutes.

Improving tsunami monitoring and warning in the Indian Ocean means installing better seismometers, tsunami-appropriate tide gauges, and of course, DART systems. PMEL is now working to adapt the DART technology for the challenges of the tropical climate. “Alaska has freezing rain and monster waves,” says Meinig. “The tropics have instead tremendous bioproductivity. The buoys will be covered with things like mussels and gooseneck barnacles.” Also, the Indian Ocean is among the most-pirated seas in the world. Vandalism, boat tie-offs, and even gunshots will threaten any buoys placed there.

NOAA is also working on increasing the U.S. monitoring system to 39 buoys by mid-2007. As technology improves and scientific understanding of tsunamis matures, monitoring them will become more akin to weather forecasting, predicts Meinig. “We’re getting better and better weather forecasts all the time,” he says. “We’ll also get better and better tsunami forecasts to benefit people all over the world.”