The 2nd Annual Meeting of the Strategic Cooperative Program:Seismic Hazard Assessment for the Next Generation Map,October. 29 - 31, 2012, in Jeju Island, Korea

Cyclic Pattern of Nankai Trough Earthquakes
and the Tasks in its Modeling- Primary Uncertainty in Earthquake Hazard/Risk Model -Toshihiro YAMADAOYORMS Corporation, Japan

Outline•It is concerned that the “Nankai trough Earthquake” and the“Metropolitan Earthquake” will occur in the near future (see Page 3) .
– Losses by those earthquakes are estimated larger than the Tohoku Earthquake (see Page 4) .
– Some fear that those earthquakes are triggered by the Tohoku Earthquake.

•The Central Disaster Prevention Council of Japan studied theNankai trough Earthquake of Magnitude 9 after the Tohoku
Earthquake (see Page 3) .
– Recently, site surveys, such as a survey of inland tsunami deposit or trace of liquefaction, areused for specifying the damaged area by an earthquake besides historical literature research.
– Recent research indicates that Tokai, To-Nankai and Nankai earthquakes are likely occur
within a short span or at the same time (see Page 5).

•Based on the above background, we tried to visualize the cyclic
pattern of Nankai Trough Earthquakes with surrounding
earthquakes using Usami catalog.
Ⓒ 2012 OYO RMS Corporation, All Right Reserved.

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Focal Region of the EarthquakesⒸ 2012 OYO RMS Corporation, All Right Reserved.

3

Comparison of Historical/Scenario Earthquake

Buildings(residence, office, factory,machine and equipment etc.)

Lifeline(water supply, electric power, city
gas etc.)

Infrastructure(highway, river, port, sewer, etc.)

Other

Agriculture,Forestry andFisheries

OtherDirect Loss
Indirect Loss
Total

Historical Earthquake
TohokuKobeEarthquake
Earthquake

Scenario Earthquake
Nankai Trough
Metropolitan
Earthquake (2003) Earthquake (2005)2011 Great East
Japan Earthquake

1995 Great HanshinAwaji Earthquake

Tokai, To-Nankai, Nankai

Cabinet Office

National Land Agency¥ 10.4 trillion¥ 6.3 trillion¥ 1.3 trillion¥ 0.6 trillion

Central Disaster
Prevention Council

Tokyo Bay North
Earthquake (M7.3)
Central Disaster
Prevention Council¥ 55.2 trillion

Updating¥ 2.2 trillion¥ 1.9 trillion¥ 1.1 trillion¥ 16.9 trillion¥ 2.2 trillion¥ 0.5 trillion¥ 9.6 trillion¥ 40～60 trillion¥ 13～21 trillion¥ 53～81 trillionⒸ 2012 OYO RMS Corporation, All Right Reserved.

¥ 66.6 trillion¥ 45.2 trillion¥ 112 trillion
4Historical Nankai Trough Earthquakes
東海 Tokai
東南海
東海To-Nankai
Tokai
1944
Not Occurred

Name of an Era

南海Nankai

昭和 Showa

1946

安政 Ansei
宝永 Hoei

1854 (Next Day)

1854

1854

(simultaneous occurrence)

1707

1707

1707

慶長 Keicho

1605

1605

?

明応 Meio1498 (Date unknown)

1498

1498

正平 Shohei
永長・康和
Eicho-Kowa
仁和 Nin-na

1361

?

?

1099 (Kowa)

1096 (Eicho)

1096 (Eicho)

887? ⇒▲?⇒▲

白鳳 Hakuho

684?⇒▲?⇒▲?＝Occurrence is not recorded in the literature▲＝tsunami deposit was found by the site investigationⒸ 2012 OYO RMS Corporation, All Right Reserved.

5684 Hakuho EQ - 887 Nin-na EQⒸ 2012 OYO RMS Corporation, All Right Reserved.

6887 Nin-Na EQ – 1099 Kowa EQⒸ 2012 OYO RMS Corporation, All Right Reserved.

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1099 Kowa EQ – 1361 Shohei EQⒸ 2012 OYO RMS Corporation, All Right Reserved.

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1361 Shohei EQ – 1498 Meio EQ

It is pointed out that thelarge earthquake occurred
at Sagami Bay in 1495？

Ⓒ 2012 OYO RMS Corporation, All Right Reserved.

91498 Meio EQ – 1605 Keicho EQⒸ 2012 OYO RMS Corporation, All Right Reserved.

101605 Keicho EQ – 1707 Hoei EQⒸ 2012 OYO RMS Corporation, All Right Reserved.

111707 Hoei EQ -1854 Ansei Tokai/Nankai EQⒸ 2012 OYO RMS Corporation, All Right Reserved.

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Ansei Tokai/Nankai EQ – Showa To-Nankai/Nankai EQⒸ 2012 OYO RMS Corporation, All Right Reserved.

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After Showa To-Nankai/Nankai EQ？

Ⓒ 2012 OYO RMS Corporation, All Right Reserved.

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Summary•18 years after 869 Jogan Earthquake, 887 Nin-na Earthquakeoccurred.
•During 887 Nin-na Earthquake and 1605 Keicho Earthquake,there are few records of large earthquakes around Tohoku andKanto regions.
•After 1611 Keicho Sanriku Earthquake, 1677 Off-Boso
Earthquake, 1703 Genroku Earthquake and 1707 Hoei
Earthquake occurred in order.
•After 1896 Meiji Sanriku Earthquake, 1923 Kanto Earthquake,
1944 Showa To-Nankai and 1946 Showa Nankai Earthquake
occurred in order.
•Between a series of Nankai Trough Earthquakes, large
earthquake often occurred around Tohoku region.
•Space-time relation among earthquakes will be considered in
the “future” Generation Map.
Ⓒ 2012 OYO RMS Corporation, All Right Reserved.

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