Summary of predicted risk of Tokyo Earthquake

Summary of Predicted Earthquakes and the Damage

TOKAI  EARTHQUAKE

Massive Earthquake with an epicenter in Nankai Trough (shallow trench) that would trigger Tokai/Tonankai/Nankai Earthquakes (Cabinet Office Review Board)　

The scale of an earthquake that causes Tsunami is M 9.1.  The estimated height of Tsunami in Kuroshio-Machi, Kochi Prefecture is 34 meters.  The areas where Japanese scale of 7 will be experienced are now 20 times more than previous estimation.  These are much more than we have anticipated before.  In Kanto region, the height of Tsunami is 29.7 meters in Nijima Island in Tokyo and 9.2 meters in Kamakura City in Kanagawa Prefecture.  The height of Tsunami expected at Hamaoka Nuclear Power Plant of Chubu Electric Company in Shizuoka, which is now shut down, is 21 meters.  That is much higher than previously predicted and it is now urgently necessary to revise the safety measures. 

The estimated 21 meter-high Tsunami at Hamaoka Nuclear Power Plant which is located within the predicted epicentral area of Tokai Earthquake is more than the standardized emergency safety measures (15 meters) which have been directed to each electric company by the Nuclear and Industrial Safety Agency at Ministry of Economy, Trade and Industry after the Great East Japan Earthquake.  That is higher than the level that is being built currently at the said Nuclear Power Plant (18 meters) and it would flood the Power Plant.  The fundamental review of the safety measures is now most urgently necessary.  If Hamaoka Nuclear Power Plant explodes, the radiation will reach the Greater Tokyo Area in 6 hours.  

Tokai Earthquake has been occurring regularly in 100 to 150 year cycle.  The last one was Ansei Tokai Earthquake in 1854 and it’s been 157 years since.  Tokai Earthquake can occur any time.  Tokai earthquake may trigger the eruption of Mt. Fuji.

Earthquake in Greater Tokyo Area

This has been concluded by the special project research of the Ministry of Education, Culture, Sports, Science and Technology.  The research team has concluded the magnitude 7 inland earthquake can occur any minute.  They have also publicly announced that the scale of Tokyo Bay Northern Area Earthquake which is one of the possible earthquakes of Greater Tokyo Area Inland Earthquake is predicted to be intensity scale of 7, more than the previously anticipated intensity scale 6 upper.  This was due to the recently discovered fact that the boundary of the sinking Philippine Sea Plate and the continental plate was approximately 10 kilometers shallower than previously believed.   The Japanese scale 7 is expected to be experienced in the bay area, and the mouth of Tama River.   The probability of Greater Tokyo Area Inland Earthquake is 70% within the next four years.* (Preliminary calculation by Tokyo Univ. Research Center  11: 24  1/23/12  Sankei  News [Earthquake, Tsunami, Geoscience])  * Later lowered to 50%.  28% in the next 5 years according to the research of Kyoto University.

Greater Tokyo Area Earthquake Damage Prediction　（In case of Tokyo Bay Northern Area Earthquake,announced as of the date of April 18, 2012 by Tokyo City Government）

　□The death toll is predicted to be maximum of 9,700  (11,000 according to the Cabinet Office) people

　□Totally collapsed buildings, Approx. 304,300 　(850,000 due to fire and collapse)

　□Evacuees 3,390,000　(At the peak, a day after the earthquake) *Ten times more than Tohoku

　□Stranded commuters 5,170,000 (6,500,000 according to the Cabinet Office) people

　□People who are locked in the elevators, 9200 elevators and 12,500 people (apartment buildings

    and office buildings)

  □The height of Tsunami at Tokyo Bay Coastal area is expected to be maximum of T.P. 2.61m at

    full tide (Shinagawa Ward)

　　This takes into account ground level subsidence.  (T.P. = average Tokyo Bay water surface levels)

　□Economic Damage：112 Trillion Yen         

                                   (Reported by Tokyo Metro government office on April 18, 2012)

　　　In addition, damage from liquefaction is expected in Tokyo Bay area.  And individual fires may result in firestorms. 

In case of the Greater Tokyo area earthquake, there will be stranded people in high-rise buildings (people stranded in high rise apartments and office buildings), stranded commuters (6,500,000 people), displaced evacuees (there would be shortage of space equivalent to 12 Tokyo Domes)