Tsunami around Japan North American plate...Tsunami around Japan Eurasian plate Philippine plate Pacific plate North American plate 1611 Keichou Sanriku Tohoku Sanriku Ria coast V-shape

1854 Toukai, Nankai 1896 Meiji Sanriku1933 Showa Sanriku1944 Tounankai1946 Nankai1960 Chile1983 Japan Sea 1993 Okushiri2011 Tohoku

Tsunami around Japan

Eurasian plate

Philippine plate

Pacific plate

North American plate

1611 Keichou Sanriku

SanrikuTohoku Ria coastV-shape bay

103km

fault motion

L

h at most4000m

100/1/ Lh

long waves

Tsunami generated at subduction zone

plate

Large water pressure in deep water

JapanUSA

Meiji Sanriku1896/06/1520:00 pmM8.2～8.5(tsunami Eq.)

Showa Sanriku1933/03/03M8.12:30am

Keicho Sanriku1611

Chilean Tsunami1960/05/24

地震調査委員会の図に加筆

Historical Earthquakes

Aftershockscompiled by JMA

5.3m Eastward1.2m subsidence

Ground displacement

阿部・菅野・千釜（1990）Minoura・Nakaya(1991)

Satake, Namegaya,Yamaki（2008）

Jougan Tsunami（869）

・old document・tsunami sedimentsonce in 1000yrs

All data plotted with the past eventsThe 2011 Tohoku Earthquake Tsunami Joint Survey Grouphttp://www.coastal.jp/ttjt/

data as of Apr 30, 2011

The 2011 Tohoku Earthquake Tsunami Joint Survey Grouphttp://www.coastal.jp/ttjt/

data as of Apr 30, 2011

Kuji

Kuji by Japan Self‐Defence Force 

Taro

田老

15

居住者 死者 行方不

明者

割合

A地区（二重堤に守ら

れている地域）

1610 63 9 4.5%

B地区 566 19 36 9.7%

C地区 278 12 5 6.1%

Taken by Japan Self‐Defence Force

Mainichi News Paper（15/May）

OotsuchiRiver

Kozuchi River

JR Railway

Iwate Prefecture

Seawall

岩手県提供

T.P.+13m

Death 726, Missing 978, as of May 1, 2011

Collapsed Seawalls

Kamaishi

Rikuzentakada1km far from coast line

Rikuzentakada

Kesennuma

Onagawa

No.2

No.3

Natural Breakwaters Matsushima

１０．３ｍ

４．５ｍ

Failure of Katsura Island at the Ocean  Side

10.3m

Huge Tsunami in Sanriku CoastLarger than Meiji & Showa events

Attack in wide subsided areas in short timeOnce in 100 to 1000 years

Damages on flat plain formed around rivermouthTsu-nami affected not only ‘tsu’, ports and harbors, but also flat plains

2011 Tohoku Tsunami