For a few hours early Saturday morning a tsunami warning was in effect for Japan’s east coast after a 7.3 magnitude earthquake struck 231 miles off the coast of Honshu Island.The quake hit about 3:10 am in Japan and was felt up to 300 miles away in Tokyo. The tsunami warning did not include the west coast of the United States or to any other areas around the Pacific Rim. After waves about three feet high hit three Japanese cities, the warning was cancelled. This time around, Japan dodged the bullet.
While the tsunami warning was in effect however, Japanese officials warned residents to “get out of the water” and “leave the coast immediately.” Workers around the Fukishima Dai-ichi nuclear power plant were preparing for a coming typhoon, but were quickly evacuated from the area. The plant was struck by a tsunami in 2011 that led to meltdowns and radiation leaks.
Some may consider this a knee jerk reaction, but Japan and other countries in the South Pacific have had their share of disasters triggered by deep sea earthquakes.
The word tsunami literally means “harbor wave” but in modern vernacular has come to denote any large wave or waves that hit along the coast. Tsunamis are caused by earthquakes, volcanic eruptions and other underwater explosions. This also includes explosions under water as one might see from the detonation of a nuclear device. Landslides, glacier calvings (ice falling off into the water) and meteorite impacts can also create enough displacement to trigger a large wave.
Tsunamis have a longer wavelength than normal sea or ocean waves and run deeper under water. Also called tidal waves, tsunamis do not appear as a breaking wave, looking more like a rising tide. Tsunamis arrive in a series, with period of minutes to hours between each wave, creating what has been called a “wave train”. Waves can be as low as three feet and as high 50 feet, as recorded in 2004.
The Indian Ocean tsunami that year hit over 11 countries from Asia to Africa. The waves were caused by an earthquake that measured 9.0 magnitude under the Indian Ocean that created a rupture about 600 miles long that displaced about 10 yards horizontally. Although that does not seem like much, the energy released by the India plate sliding under a section of the Burma tectonic plate was enormous.
NationalGeographic News.com reports trillions of tons of rock moved along hundreds of miles in the biggest quake recorded in the last 40 years. US Geological Service (USGS) estimated the force of the quake was equal to the energy of 23 thousand “Hiroshima-type atomic bombs.”
This tsunami was one of the most destructive disasters in history, killing an estimated 150,000 people. Waves reached up to six miles inland and swept homes and businesses out to sea. Boats were beached on roads and debris was left cluttering neighborhoods struck by the towering waves.
With the impact of the 2004 tsunami, officials began to push to implement a better global detection system. Underwater wi-fi stations were set up and may have helped detect Saturday’s earthquake and trigger the tsunami warning. A team of researchers from University of Buffalo in New York tested the system that uses sound waves that “work better than radio waves.” The test was performed earlier this month at Lake Erie.
There is a system of buoys in place to detect underwater earthquakes and possible tsunamis but most of the system is still using radio wave technology. Since 2004, upgrades have been put in place to relay information more quickly between sites.
At the moment there is no standard method of underwater communication, thus making it harder to share information when disturbances are detected by the various stations around the world’s oceans.
The acoustic system is already in use by the US National Oceanic and Atmospheric Administration (NOAA) but because of the lack of standardization, they are currently unable to share information with the U. S. Navy as quickly as they would like. The underwater sound wave system is working towards a worldwide method of measuring and detecting ocean-floor quakes so the time between detection and warning can be significantly reduced.
Once fully implemented this sound wave “deep ocean wi-fi” can also help detect smugglers in submarines and help locate oil deposits underwater.
The Saturday morning earthquake in Japan set off a tsunami warning that ended up far less destructive than it otherwise could have been.This time around, the resulting tsunami was minimal. The evacuations would have saved thousands of lives if the threat had become more dire. In the future, detection and warning systems will be crucial to ensuring inhabited coastal areas are cleared in time to prevent the massive loss of life seen in 2004.
By: Brandi Tasby
Tsunami Warning Cancelled