(Mashup of an original map from USGS depicting 3 areas and 4 major earthquakes over the past year on the ring of fire)
# 6095
Just before noon on September 1, 1923 a massive - and by all reports long-duration - 7.9 magnitude earthquake struck beneath Sagami Bay devastating Tokyo, the port city of Yokohama, and several nearby prefectures.
The timing of the quake, at lunchtime, meant many people were cooking when it struck, and that – combined with winds from an offshore typhoon – contributed to the firestorm that swept Tokyo.
Estimates vary, but more than 100,000 people are believed to have perished.
Since 1960, September 1st has been designated as an annual "Disaster Prevention Day" in Japan.
With the horrific events from last year’s Tohoku 9.0 earthquake, tsunami, and resultant nuclear crisis still fresh, the prospect of Japan enduring another great quake continues to haunt.
The Japanese government has stated that there is a 70% of a strong earthquake striking the capital over the next 30 years, but some academics see the threat as being much closer in time.
Over the past year, seismologists have detected an increase in the number of small quakes in and around the nation’s capital. A scenario not unlike what was seen in the lead up to last year’s massive quake.
This from the Tokyo Times.
The “Big One” was preceded by 1,000 smaller quakes
Monday, January 23, 2012
More than a thousand small, repeating earthquakes migrated towards the epicenter of the 2011 Tohoku Quake in the month before the disaster, scientists have learned.
Today, the news wires are filled with stories on a report issued from researchers at the University of Tokyo that claims the likelihood of a strong (7+) Tokyo quake is greater than the government has maintained.
Major Tokyo quake more likely than government says: academics
(Reuters) - A major earthquake is far more likely to hit Tokyo in the next few years than the government predicts, researchers at the University of Tokyo said on Monday, warning companies and individuals to be prepared for such an event.
There is a 70 percent chance a magnitude 7 quake will jolt the southern part of the Tokyo metropolitan area in the next four years, the university's Earthquake Research Institute said.
As I wrote last year in Divining Japan’s Seismic Future, Japan does not lack for devastating earthquake potential.
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.
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.
Which is why the Prime Minister of Japan called upon Chubu Electric to shut down its No. 4 and No. 5 reactors at the Hamaoka nuclear plant last May, located roughly 200 km south-west of Tokyo.
As for the seismic threat to the Tokyo region, Shinichi Sakai - associate professor at the earthquake research institute - is quoted today as saying:
"The government, individuals and corporations should make preparations for that now"
For more on earthquakes, you may wish to revisit:
UN Agency Warns On Global Seismic Risks
The Great Central U.S. Shakeout:2012
NPM11: Are You Earthquake Prepared?
