Japan’s Earthquake Japan’s Earthquake &Tsunami 2011&Tsunami 2011

(REUTERS)

Images courtesy of the US Geological Survey

Magnitude 9.0 NEAR Magnitude 9.0 NEAR THE EAST COAST THE EAST COAST OF HONSHU, JAPANOF HONSHU, JAPAN

Friday, March 11, Friday, March 11, 2011 at 05:46:23 2011 at 05:46:23 UTC UTC

The earthquake occurred 130 km (80 miles) east of Sendai and 373 km (231 miles) northeast of Tokyo.

This is one of the largest earthquakes that Japan has ever experienced.

Part of houses swallowed by

tsunami burn in Sendai, Miyagi

Prefecture (state) after Japan was

struck by a strong earthquake off its

northeastern coast Friday, March 11,

2011.

New York Times

In downtown Tokyo, large buildings shook violently. Elsewhere severe flooding occurred due to a tsunami

generated by the earthquake.

Tsunami waves swept away houses and cars in northern Japan and pushed ships aground.

The earthquake caused some damage – The earthquake caused some damage – but the tsunami was devastatingbut the tsunami was devastating

The tsunami waves traveled far inland, the wave of debris racing across the farmland, carrying boats and houses with it.

CNN reported “The quake rattled buildings and toppled cars off bridges and into waters underneath. Waves of debris flowed like lava across farmland, pushing boats, houses and trailers toward highways.”

A number of fires broke out including one at an oil refinery which was burning out of control.

Giant fireballs rise from a burning oil refinery in Ichihara, Chiba Prefecture (state) after Japan was struck by a strong earthquake off its northeastern coast Friday, March 11, 2011.

Los Angeles Times

Fires after earthquakes are often caused by broken gas pipelines Fires after earthquakes are often caused by broken gas pipelines

Let’s take a look at tsunami as it hits the Let’s take a look at tsunami as it hits the east coast of Japaneast coast of Japan

http://www.bbc.co.uk/news/world-asia-http://www.bbc.co.uk/news/world-asia-pacific-12725646pacific-12725646

Globally, this is the 5th largest earthquake since 1900 (or 4th depends on M).

Chile 1960

Alaska 1964

Sumatra 2004

Chile 2010

Japan 2011

Russia 1952

Ecuador 1906Alaska 1965

What is a Tsunami?(harbor wave)

Seismic sea waves (NOT tidal waves)Large ocean wave or series of ocean waves generated by an earthquake, volcanic eruption, submarine landslide or meteor impact

How do EQs cause a tsunami?How do EQs cause a tsunami?

http://geology.com/articles/tsunami-geology.shtml

http://sese.asu.edu/teacher-resources

Tsunami causesTsunami causes Unless there is an underwater landslide, strike-

slip EQ WILL NOT cause tsunami Most tsunami generated by subduction zones

• Chile Alaska Japan Cascadia Philippines Caribbean New Zealand

Tsunami wavelength and Tsunami wavelength and speedspeed

Long wavelengths (over 100 km)Long wavelengths (over 100 km) Travel at high speeds : 450 to 650 mph Travel at high speeds : 450 to 650 mph

316,800 ft = 60 miles

Nearby the earthquake there are only minutes to evacuate. However, in many other regions there is advance warning.How long before the tsunami reaches Los Angeles?

Projected travel times for the Projected travel times for the arrival of arrival of

tsunami waves across the Pacifictsunami waves across the Pacific

What happens when What happens when tsunami gets near shore?tsunami gets near shore?

Tsunami slows down (shallower water)Tsunami slows down (shallower water) Wave gets taller Wave gets taller

Tsunami nears shoreTsunami nears shore

As wave gets into shallow water bottom of As wave gets into shallow water bottom of wave drags along ocean floorwave drags along ocean floor

Top of wave still moving fast: causes Top of wave still moving fast: causes cresting of wave, and breaking onto shorecresting of wave, and breaking onto shore

Tsunami warningTsunami warning

Receding of coastal waters ( 5 - 15 minutes before Receding of coastal waters ( 5 - 15 minutes before the strike ).the strike ).

Approaching tsunamis are almost always Approaching tsunamis are almost always heralded by a noticeable fall of coastal heralded by a noticeable fall of coastal waters.waters.

Water may recede several hundreds of Water may recede several hundreds of meters. If you are on the beach, and you see meters. If you are on the beach, and you see water suddenly receding, exposing the water suddenly receding, exposing the ocean floor, it means that you have minutes ocean floor, it means that you have minutes before the tsunami strikes.before the tsunami strikes.

What do you do?What do you do?

Run for high ground!Run for high ground!

Let’s take a look at what Japan looks like Let’s take a look at what Japan looks like before and afterbefore and after

http://www.abc.net.au/news/specials/http://www.abc.net.au/news/specials/japan-quake-2011/japan-quake-2011/

Detecting a tsunamiDetecting a tsunami

Pressure recorder on Pressure recorder on bottom of oceanbottom of ocean

Buoy to communicate Buoy to communicate readings via satellitereadings via satellite

Tsunami Warning Tsunami Warning Centers issue warningCenters issue warning

Tsunami Warning CentersTsunami Warning Centers Hawaii and AlaskaHawaii and Alaska When EQ considered capable of When EQ considered capable of

generating tsunami, send warning with generating tsunami, send warning with estimated arrival timeestimated arrival time

Once tsunami hits Once tsunami hits somewhere, tsunami somewhere, tsunami watch established to watch established to monitor tide gauges monitor tide gauges and ocean buoysand ocean buoys

Tsunami Monitoring SystemsTsunami Monitoring Systems

Locations of NOAA’s National Data Buoy Center (NDBC) DART stations comprising the operational network.

Tsunami WarningTsunami Warning

When warning is issued – low lying When warning is issued – low lying areas are evacuatedareas are evacuated

U.S. Coast guard issues warnings over U.S. Coast guard issues warnings over marine frequenciesmarine frequencies

Some places have sirensSome places have sirens