Background and Scope - Tohoku, Japan Earthquake and Tsunami of 2011 - page 3

also received attention. In the U.S., standard design methodology for stone and armor
unit revetment structures typically does not account for tsunami wave characteristics
but given the large number of similar structures used along the U.S. Pacific coast,
understanding of the performance of these structures in tsunamis takes on urgency.
Team members included (in alphabetical order)
Lesley Ewing (Co-Leader), California Coastal Commission
Bryan Jones, Ocean and Coastal Consultants, a COWI Company
Haruyuki Kojima, Kyushu Kyoritsu University
James Marino, Taylor Engineering (formerly with Coastal Tech)
Yoshitaka Matsuzaki, PARI
Ron Noble, Noble Consultants
Catherine Petroff, LP4 Associates
Kijiro Suzuki, PARI
Shigeo Takahashi (Co-Leader), PARI
Yoji Tanaka, PARI
1.3 Event Summary and Consequences
The Great East Japan earthquake that occurred on March 11, 2011 precipitated a
complex series of events with global consequences. The earthquake's magnitude of
9.0 placed it as the fourth largest in the world since 1900, and the largest in Japan
since the use of modern instruments began recording earthquake magnitude 130 years
ago. The waves generated in this event caused the third highest number of tsunami-
related fatalities in Japan's long recorded history of such disasters. Concurrent
damage to housing, infrastructure, and commerce not only affected the country's
internal economy but also impacted countries around the world that rely on the steady
exchange of goods, resources, and finances with Japan. In addition, the tsunami
damage contributed to another problem: the continuing grave situation at the
Fukushima nuclear power plants.
1.3.1EarthquakeandTsunamiWarningSystems
Japan, the U.S., and a number of other countries operate warning centers in the event
of earthquakes and tsunamis. The operations of these centers differ between nations.
The Japan Meteorological Agency (JMA) serves as the country's earthquake and
tsunami warning center. JMA also acts as an interim tsunami warning center for the
Western Pacific and Indonesia, as the NorthWest Pacific Tsunami Advisory Center
(NWPTAC). In addition to receiving global seismic information, JMA maintains a
national network of seismic stations that trigger local earthquake and tsunami
warnings. The intent of the system is to issue an early earthquake warning within 30
seconds of a seismic event and a tsunami warning within three minutes. In case of a
local earthquake, dedicated telephone lines transmit real time seismic data to JMA
headquarters and to district centers to activate the earthquake early warning system.
After preliminary calculations of an earthquake's magnitude and location, JMA