Saturday, April 09, 2011

Divining Japan’s Seismic Future

 

 

 


# 5478

 

 

 

Although superstitions generally allow that bad things happen in threes – and Japan has already more than met that quota with a 9.0 earthquake, a massive tsunami, and a nuclear disaster over the past 30 days - there are concerns that another large earthquake, or perhaps a major volcanic eruption, could strike that disaster weary country.

 

While discussing such a possibility when the current crises are still unfolding seems a bit like piling on, history and science tells us that it isn’t a matter of if another seismic event will strike Japan . . .  it is just a matter of when.

 

 

This morning I received an email from Paul at Chen Qi alerting me to an article that appears in today’s (Apr 9th) International Business Times – a Hong Kong financial newspaper.

 

Japan warns of massive earthquake and volcanic explosion after the April 7 earthquake

 

You can follow the link and read the (short) article, but the gist of the story is that the massive March 11th earthquake and subsequent aftershocks may have increased the stress on adjacent fault lines and nearby volcanoes, increasing the risks of additional seismic events.

 

I’ve briefly looked for, but have not yet been able to find an announcement to this effect from the JMA (Japan Meteorological Agency). 

 

Whether the events of the past month increased the odds - or sped up the timetable - for another seismic event or not (and on that I offer no opinion), the future is nonetheless easy to predict.

 

Japan is located on the Pacific Ring Of Fire – and is a frequent host to both earthquakes and volcanic activity.

 

Future events are guaranteed. 

 

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(Mashup of an original map from USGS depicting 3 areas and 4 major earthquakes over the past year on the ring of fire)

 

There are 108 active volcanoes in Japan, and on average, they see about 15 volcanic events (including eruptions) every year.

 

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(Credit Japan Meteorological Agency (JMA))

 

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(Credit JMA Volcano Warning pamphlet)

 

Indeed, within 48 hours of the 9.0 earthquake on March 11th, the 1,421-meter Shinmoedake volcano erupted.  This particular volcano had been quiescent for 52 years, until this past January.

 

It isn’t known whether the two events are related.

 

The most widely anticipated seismic event is the Tokai Earthquake – expected to be an 8+ magnitude, and forecast to occur between the Bay of Suruga and Cape Omasezaki in Shizuoka Prefecture sometime in the near future.

 

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Major earthquakes have occurred in this region every 100-150 years, with the most recent recorded in 1498, 1605, 1707 and 1854.  

 

That puts the Tokai region 157 years since their last major quake, and in the estimation of Dr Kiyoo Mogi – Japan’s leading seismologist – well overdue for another.   In 1969, Dr Mogi began warning that the Tokai area was particularly vulnerable, and today the area is monitored continually by the JMA.

 

These concerns are taken so seriously that the city of Nogoya has produced several pamphlets for school children on the prospects of a major quake.

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For those with a desire to learn more about the Tokai earthquake prediction, Dr. Mogi produced a very readable paper for the Earth, Planets, Space Journal several years back.

 

Two grave issues concerning the expected Tokai Earthquake


Kiyoo Mogi
University of Tokyo, Japan
(Received November 7, 2003; Revised June 29, 2004; Accepted June 30, 2004)

 

Somewhat presciently Dr. Mogi raises the issue of nuclear power plants located near the focal regions of shallow earthquakes in Japan, although he expresses greatest concern over the Hamaoka nuclear power plants that are located in the Tokai region.

 

Of great concern also is the potential repeat of the great Kanto Earthquake of 1923, which devastated Tokyo, Yokohama, and the prefectures of Chiba, Kanagawa, and Shizuoka.

 

Although only a 7.9 on the Richter scale, the ensuing firestorm swept across densely populated cities claimed tens of thousands of lives.  Broken water mains, and debris, hampered attempts to fight the massive fires. 


The death toll was estimated in excess of 100,000 people, most of whom perished due to fire or asphyxiation.

 

Since 1960, September 1st is designated as Disaster Prevention Day, and is observed by nationwide disaster drills.  Historically, Tokyo sees a major earthquake about every 70 years.

 

Again, this region is feared `overdue’ for an earthquake.

 

There is an online gallery of photographs by August Kengelbacher from this horrific disaster available at http://www.japan-guide.com/a/earthquake/.

 

While Japan will no doubt face serious seismic and volcanic events in the future, it would be folly to sit back and assume the next big natural disaster will strike there instead of somewhere else in the world.

 

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Our planet’s crust is constantly in motion, and the next big quake could occur almost anywhere there are fault lines.   And that means that large parts of the United States, Canada, Europe, South America, and most of Asia are at risk.

 

Add to that the risks of severe storms, floods, and other natural hazards and the the only rational response is for families, businesses, and communities to be prepared to deal with a wide range of disaster scenarios.

 

At a bare minimum, every household should have a disaster plan, a good first aid kit (and the knowledge to use it), and emergency supplies to last a minimum of 72 hours during a disaster.

 

To become better prepared as an individual, family, business owner, or community to deal with these types of disasters: visit the following preparedness sites.

 

FEMA http://www.fema.gov/index.shtm

READY.GOV http://www.ready.gov/

AMERICAN RED CROSS http://www.redcross.org/

 

And for more on emergency preparedness, you may wish to revisit a few of my recent blogs on the subject.

 

Planning To Survive
In An Emergency, Who Has Your Back?
Inside My Bug Out Bag
Those Who Forget Their History . . .
The Gift Of Preparedness
Red Cross Unveils `Do More Than Cross Your Fingers’ Campaign