Anawat Suppasri, suppasri@irides.tohoku.ac.jp Tsunami Engineering Research Division Disaster Risk Evaluation Research Field International Research Institute of Disaster Science Tohoku University
Earthquake possibility in Japan 1605 Keicho Meio  ■ ■ ■ ■ ■ ■ ■ ■ 1498 Shohei Kowa 1096 Ninna 684 Hakuhou http://www.jishin.go.jp/main/chousa/07_yosokuchizu/img/f1-3-2.jpg http://www.jma.go.jp/jma/en/Activities/earthquake.html
● Early period: → Felt a shake = tsunami is coming & No tsunami in Japan Sea side • 1896 Meiji Sanriku tsunami: tsunami-earthquake type → Small shake but large tsunami (38.2 m / 22,000 deaths) • 1933 Showa Sanriku tsunami: Outer-rise earthquake → Large shake and large tsunami (28.7 m / 3,000 deaths) • 1960 Chile tsunami: Far-field tsunami from M9.5 earthquake → No shake but large tsunami (10.7 m / 142 deaths) •   1983 Japan Sea tsunami: The first recent tsunami in Japan Sea → Warning after 14 mins but tsunami arrived after 12 mins (14.9 m / 104 deaths) • 1933 Okushiri tsunami: Just 10 years after the 1983 event → Waning after 5 mins but tsunami arrived after 2-7 mins (32.0 m / 230 deaths) • 2011 Tohoku tsunami: M9.0 never record in Japan → Large shake and large tsunami (40.5 m / 19,000 deaths)
26 Dec 2004 11 April 2012 M9.0 Dip-slip fault  M8.6 Strike-slip fault No tsunami but very serious traffic jam General tsunami
http://www.tokencon.co.jp/technology/topics/akg7b20000024ca.html Toni Hongo village: Highland residence明治三陸津波(1896)波高: 14.5m*死者: 2136人(唐丹村)流失倒壊戸数: 224戸(同上)再生形態:集団移動昭和三陸津波(1933)波高:9.3m*死者: 209人流失倒壊戸数: 101戸家屋流失倒壊区域(坪) : 25500坪*浸水家屋: 101戸再生形態:集団移動移動戸数: 101戸達成面積(坪):5637坪http://d.hatena.ne.jp/meiji-kenchikushi/19530101/p1
• 1896 Meiji-Sanriku tsunami: by individual Moving high ground • 1933 Showa-Sanriku tsunami: by country and prefecture Moving high ground + Seawall in some areas • 1960 Chile tsunami: Structural measures Seawalls, breakwaters and tsunami gates • 1993 Okushiri tsunami: Structural measures, town planning and combination with soft measures • 2011 Great East Japan tsunami: Prevention → Reduction
In 1935 http://yaplog.jp/sendai_kaze/monthly/200807/ 1. Control forest 2. Navigation canal 3. Land use management
発休で準波の激表力確認仙台で地落上子ンンホ東日本大震災で被害を受けた沿岸部や丘陵部の復旧・復興策を、地盤技術の視点から探るシンポジウムが1日、仙台市内で開かれた。地盤工学会東北支部(支部長・飛田善雄東北学院大教授)の主催で、研究者や市民ら約350人が参加した。防災林、津波軽減に効果…林野庁が再整備へ●なすめ、
Towns and villages in Edo period (1603-1868) were located outside inundation area

Level 1:
High frequency (30-200 years) but small to moderate tsunami. Community should be mostly protected by coastal defense structures. Height of coastal structures were decided by past Level 1 tsunami events
Level 2:
Low frequency (200-1,000 years) but very high tsunami. Forget about properties but secure evacuation routes for safe evacuation. Coastal structures should be strong enough even in case of the overtopping.
http://www.pref.miyagi.jp/seisaku/sinsaihukkou/keikaku/index.htm
Assumed faults around Japan (100,000 cases) Numerical simulation results stored in Seismic Network Sea Level Network
Local Event Information 14:46 Earthquake 14:49 Mina = 11:9 IMa or        Tsunami Warning - Iwate, Miyagi and Fukushima 14:50 Tsunami  Information - Iwate: 3m, Miyagi: 6m, Fukushima: 3m, etc. (Only reads 1965, One the database 15:10 CHS bunner bun 15:14 15:14 Tsunami Warnings/Advisories extended Tsunami Information - Iwate: 6m, Miyagi: over 10m, Fukushima: 6m, etc. Tsunami hit the nearest coast 15:21 "Inde galiges ankamalabi (Usata) → 4,1m (scalerant Tsunami Warning extended 15:30 Tsunami Information- 15:31 Iwate, Miyagi, Fukushima: over 10m, etc.   16:00 17:30 Marr= 389 13th May Hayashi et al (2011) and http://www.jma.go.jp/jma/en/2011_Earthquake.html
』JAMSTEC http://www.jamstec.go.jp/jamst ec-e/maritec/donet/index.html日本海溝沿いの海底約150カ所に、地震計と津波計で構成されるケーブル式観測網が整備されます。震源の近くで地震動と海面変動を精度よく迅速に捉え、大地震と津波のモニタリング、精度の高い警報の早期伝達、地殻構造の詳しい解明等に役立てられます。日本海溝沿いに整備される海底地震津波観測網(概念図) ional Research Institute for Earth Science and Disaster Prevention http://www.bosai.go.jp/activity_special/the_third/ev/ earthvol-04.html
① The highest observed tsunami was in Sendai ② The second wave was the largest ③ Tsunami threat level was elevated from “advisory” to “warning” ④ Local runup was higher than the observed amplitude 5) Tsunami intrusion into rivers 6) Tsunami warning and broadcasting
Locations of study area, tide gauges and surveyed areas
In addition to the fault orientation, which focused the tsunami into Sendai Bay, wave reflection and refraction were other contributors. Sendai Bay is a very shallow (average water depth is less than 50 m) and wide bay. Due to this coastal topography, the waves are amplified due to wave shoaling and refraction inside the bay. Also, superposition of the incoming and reflected waves from the Fukushima coast played a role.
Status of the tsunami warnings and advisories
Change in Tsunami Warning System classification with the establishment of Emergency Warnings
T 2. When a tsunami with the height ranging from 20 cm to 1 m is expected, a tsunami advisory is issued (indicated by a yellow color; advisory). When a tsunami is expected to be between 1 m and 3 m, a tsunami warning is issued (indicated by a red color; warning). If a tsunami is expected to be greater than 3 m, a major tsunami warning is issued (indicated by a purple color; emergency warning). 3.
This phenomenon was clearly observed at Sunaoshi River in Tagajo City, where the tsunami propagated over 3 km into the river. The tsunami speed is estimated to be about 14 km/s and the maximum rising of the river level reached 0.9 m (0.6–0.7 m above the normal level).
In contrast to the calm voice used during the 2011 tsunami, terms such as “Evacuate immediately!”, “Tsunami! Evacuate!”, etc. were used to warn people to evacuate from locations expected to be hit by the tsunami. Also, some phases such as “Please remember the Great East Japan Earthquake and move to higher ground”, were used to remind the audience of the 2011 devastation. The warnings were also released in Chinese and Korean languages.
In December 2015, the UN General Assembly designated 5 November as World Tsunami Awareness Day. World Tsunami Awareness Day was the brainchild of Japan, which due to its repeated, bitter experience has over the years built up major expertise in areas such as tsunami early warning, public action and building back better after a disaster to reduce future impacts. The date for the annual celebration was chosen in honor of the Japanese story of "Inamura-no-hi", meaning the “burning of the rice sheaves”. During an 1854 earthquake a farmer saw the tide receding, a sign of a looming tsunami. He set fire to his entire harvest to warn villagers, who fled to high ground. Afterwards, he built an embankment and planted trees as a buffer against future waves.