[論説] 日本海沿岸における2011 年東日本地震津波と青森・秋田県沿岸の歴史地震津波

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(1)Ṕྐᆅ㟈 ➨ 29 ྕ䠄2014䠅㻌 11-16 㡫 ཷ௜᪥㻌 2013/12/26䠈㻌 ཷ⌮᪥㻌 2014/03/12. ᪥ᮏᾏἢᓊ䛻䛚䛡䜛 2011 ᖺᮾ᪥ᮏᆅ㟈ὠἼ䛸㟷᳃䞉⛅⏣┴ἢᓊ䛾Ṕྐᆅ㟈ὠἼ ⩚㫽㻌 ᚨኴ㑻. *. Behavior of the 2011 East Japan Earthquake Tsunami along Coast of the Japan Sea and Historical Earthquake Tsunamis at the Aomori-Akita Coast Tokutaro HATORI Suehiro 2-3-13䠈 Kawaguchi䠈 Saitama 332-0006䠈 Japan. The behavior of tsunami was investigated along the Japan Sea coast based on wave–heights (JMA) of the 2011 East Japan tsunami (magnitude, m =4). That was compared with the observed data of the 1952 Kamchatka, the 1960 Chile, and the 1968 Tokachi-oki tsunamis. The tsunamis propagated through the Tsugaru Straits were double– amplitude of 20-90 cm which was about 5 times smaller than those of the Pacific coast. The periods of tsunami when the maximum amplitude appeared were roughly estimated to be about 30 min. for the 2011 tsunami, 50 min. for the 1952 Kamchatka tsunami, and 70 min. for the 1960 Chile tsunami, respectively. Along the coast in the Japan Sea, the maximum tsunami amplitudes of the 2011 tsunami were observed after 10-15 hours or later since the main shock. The tsunami duration time was very long in the Japan Sea because of the reflection waves from the continental coast. The historical earthquakes and tsunamis occurred in the period from 1694 to 1939 were also reexamined to indicate the tsunami risks at the Aomori and Akita coasts. Keywords: Wave Heights, Wave Period, Occurring Time of the Maximum Wave, Historical Earthquake Tsunamis.. 㼲㻝䠊㻌䛿䛨䜑䛻㻌 2011 ᖺ 3 ᭶ 11 ᪥ᮾ໭ᆅ᪉ኴᖹὒἈ䛷Ⓨ⏕䛧䛯ᕧ ኱ᆅ㟈䠄䠩9.0䠅䛿኱つᶍ䛺ὠἼ䜢క䛔䠈ᮾ໭ᆅ᪉ἢ ᓊ䛾㒔ᕷ䛻ቯ⁛ⓗ䛺኱⿕ᐖ䜢䜒䛯䜙䛧䛯䠊ὠἼ䛾つ ᶍ㝵⣭䜢⾲䛩䝬䜾䝙䝏䝳䞊䝗䛿 m =4 䛸䠈᭱኱⣭䛻᱁ ௜䛡䜙䜜䛯䠄⩚㫽㻘㻌 2012䠅䠊䛥䜙䛻ὠἼ䛿ὠ㍍ᾏᓙ䛻 ධᑕ䛧䠈᪥ᮏᾏഃ䛾ἢᓊྛᆅ䛷ほ䛥䜜䛯䠊୍᪉䠈㻌 ᪥ᮏᾏἢᓊ䛷䛿䠈1968 ᖺ༑຾Ἀᆅ㟈ὠἼ䜔㛗࿘ᮇ Ἴ䛜༟㉺䛧䛯 1952 ᖺ䜹䝮䝏䝱䝒䜹䠈1960 ᖺ䝏䝸ὠἼ 䛾ほ ౛䛜䛒䜛㻔⩚㫽㻘㻌1992㻕䠊㻌 ᮏ✏䛷䛿䠈Ẽ㇟ᗇ䠄2011䠅䛻䜘䜛ྛᆅ䛾Ἴ㧗ほ ್ 䜢䜒䛸䛻䠈᪥ᮏᾏഃ䛾Ἴ㧗೫ᕪ䜔ఏ᧛䛾ᵝ┦䜢ㄪ䜉䠈㻌 ኴᖹὒഃ䛾ὠἼつᶍ䛸ẚ㍑䛩䜛䠊䛥䜙䛻䛿䠈⛅⏣䞉㟷 ᳃┴ἢᓊᇦ䛾Ṕྐᆅ㟈ὠἼ㻔1694-1939㻕䜢෌᳨ウ䛧䛯䠊㻌㻌㼲㻞䠊㻌 Ἴ㧗ศᕸ㻌 ᅗ 1 䛻䛿䠈Ẽ㇟ᗇ䛻䜘䜛᳨₻グ㘓౛䠄ภ㤋䠈㓇⏣䠈 ቃ 䠈ୗ㛵ᙪᓥ䠅䜢♧䛩䠄ภ㤋䛾᣺ᖜ䝇䜿䞊䝹䛿䠈௚ ᆅⅬ䜘䜚⣙ 1/4 䛻⦰ᑻ䛥䜜䛶䛔䜛䛾䛷ὀព䠅䠊᭱኱Ἴ *. 䛾඲᣺ᖜ್䛿ภ㤋䛷 5 m 䛻㐩䛧䛯䠄⑞㊧㧗䛿ᖹᆒ₻ ఩ୖ 2.5 m䠈Ẽ㇟ᗇ䠅䠈䛧䛛䛧䠈᪥ᮏᾏἢᓊ䛷䛿 90 cm ௨ୗ䛻ῶ⾶䛧䛶䛔䜛䠊ᅗ 2 䛻 2011 ᖺὠἼ䛾඲᣺ᖜ ್ศᕸ䛸䠈1952 ᖺ䜹䝮䝏䝱䝒䜹䠈1960 ᖺ䝏䝸ὠἼ䠈 1968 ᖺ༑຾ἈὠἼ䛾᣺ᖜ್䛸ẚ㍑䛧䛶♧䛩䠊2011 ᖺὠἼ䛷䛿໭ᾏ㐨䛾⛶ෆ䛸ᑠᶡ䛷 70 cm 䛜኱䛝䛟䠈 Ώᓥ༙ᓥすᓊ䛷 50 cm 䛷䛒䛳䛯䠊䛣䛾䜋䛛ὠ㍍❳㣕䛷⣙ 1 m䠈㓇⏣䛷 80 cm䠈⯙㭯䛷 50 cm䠈ቃ 䛷 40 cm䠈὾⏣䛷 28 cm䠈ୗ㛵䛷 50 cm 䛷䛒䜛䠊㻌㻌 ୍᪉䠈1952 ᖺ䜹䝮䝏䝱䝒䜹ὠἼ䠄m =4䠅䛿඲ᅜ䛷ほ䛥䜜䠈୕㝣ἢᓊ䛻ᾐỈ⿕ᐖ䜢䜒䛯䜙䛧䛯䠄Ẽ㇟ᗇ䠈 1953䠅䠊ྛᆅ䛾඲᣺ᖜ್䛿ภ㤋䛷 100 cm 䛜✺ฟ䛧䠈 ᐑὠ䛷 43 cm䠈ቃ 䛷 20 cm䠈䛭䛾䜋䛛䛿 15 cm ๓ ᚋ䛷䛒䛳䛯䠊1960 ᖺ䝏䝸ὠἼ䛿䠈඲ᅜ䛻኱⿕ᐖ䜢䜒䛯䜙䛧䛯௦⾲ⓗ䛺㐲ᆅὠἼ䛷䛒䜛㻔Ẽ㇟ᗇ㻘㻌 1961㻧㻌䝏䝸ὠἼྜྠㄪᰝ⌜㻘㻌1961㻕䠊ภ㤋䛷 413 cm 䛜✺ฟ䛧䠈 ⩚ᖠ䛷 150 cm䠈ᚸ㊰䛸అᮌ䛷 20 cm䠈㻌 ቃ 䛷 50 cm 䛷䛒䛳䛯䠊㻌 1968 ᖺ༑຾ἈὠἼ䛷䛿䠈ภ㤋䛷 198 cm䠈䛭䛾䜋䛛䛿Ụᕪ䛸⛶ෆ䛷 15-20 cm 䛸ᑠ䛥䛔䠊㻌㻌. 䛈332-0006 ᇸ⋢┴ᕝཱྀᕷᮎᗈ 2-3-13 - 11 -.

(2) 㼲㻟䠊㻌 ྛᆅ䛾Ἴ㧗೫ᕪ㻌 ᅗ 3 䛻䛿䠈ὠἼ䝬䜾䝙䝏䝳䞊䝗䛾ุᐃᅗ䜢♧䛩䠊⦪ ㍈䛻䛿᪥ᮏᾏἢᓊྛᆅ䛾᭱኱Ἴ䛾∦᣺ᖜ್䜢䛸䜚䠈 1952 ᖺ䜹䝮䝏䝱䝒䜹䠈1968 ᖺ༑຾ἈὠἼ䛾ほ ್䛸 ẚ㍑䛧䛶♧䛩䠊ᶓ㍈䛻䛿䠈㟈ኸ䛛䜙ほ Ⅼ䜎䛷䛾㊥㞳䜢䛸䜛䠊㻌㻌 ὠἼ䛾つᶍ䝇䜿䞊䝹䛿䠈Ἴ㧗䛜㟈ኸ㊥㞳䂴-䠍/2 䛷 ῶ⾶䛩䜛䛸䛧䛶䠈2.24 ಸ䛾้䜏䛷༊ศ䛧䛶䛒䜛䠊䛭䛾 ⤖ᯝ䠈2011 ᖺὠἼ䛷䛿᣺ᖜ್䛜 m =2 䛻㞟䜎䜚䠈ኴ ᖹὒഃ䛾Ἴ㧗䝕䞊䝍䛷ᚓ䛯 m ್䜘䜚 2 㝵⣭㻔᣺ᖜ್ 䛻䛧䛶⣙ 1/5㻕ୗᅇ䜛䠊⛶ෆ䞉㓇⏣䞉ୗ㛵䛾᣺ᖜ್䛜䜔䜔኱䛝䛔䠊1952 ᖺ䜹䝮䝏䝱䝒䜹ὠἼ䛷䛿䠈1 㝵⣭㻔᣺ ᖜ್䛻䛧䛶⣙ 1/2㻕ୗᅇ䛳䛶 m =3 䛻䛺䜛䠊㛗࿘ᮇἼ䛷䛒䛳䛯䛾䛷ῶ⾶䛜ᑠ䛥䛟䠊㛗᫬㛫⥅⥆䛧䛯䠊1968 ᖺ༑ ຾ἈὠἼ䠄m =2.5䠅䛷䛿䚸᣺ᖜ್䛜㢧ⴭ䛻ῶ⾶䛧䛶䛔䜛䠊㻌㻌 ᅗ 4 䛻䛿䠈3 ౛䛾ὠἼ㻔ᮾ᪥ᮏ䠈䜹䝮䝏䝱䝒䜹䠈䝏䝸㻕䛻䜘䜛ྛ ‴䛾᭱኱Ἴ䛾࿘ᮇ䛸඲᣺ᖜ䛾 2 ஌್䛸䛾㛵ಀ䜢♧䛩䠊2011 ᖺὠἼ䛷䛿䠈1983 ᖺ᪥ᮏᾏ୰㒊 ᆅ㟈ὠἼ䛻䛚䛡䜛᭱኱Ἴ䛾࿘ᮇ㻔Ẽ㇟ᗇ㻘㻌 1984㻕䜢ཧ ↷䛧䛯䠊ほ ್䛿䝞䝷䛴䛟䛜䠈࿘ᮇ 30 ศ䛒䛯䜚䛜䝢䞊䜽䛻䛺䜛䠊䛺䛚䠈ኴᖹὒഃ䛾ほ ್䛷䛿䠈44 ศ䛸 69 ศ䛾࿘ᮇ䛜༟㉺䛧䛯㻔㜿㒊㻘㻌 2011㻕䠊䛭䛾䜋䛛䜹䝮䝏䝱䝒䜹ὠἼ䛷 50 ศ䠈䝏䝸ὠἼ䛷 70 ศ䛻᣺ᖜ䛾䝢䞊䜽䛜䜏䜙䜜䜛䠊㻌㻌㼲㻠䠊㻌 ᭱኱Ἴ䛾ฟ⌧᫬㛫㻌 Ẽ㇟ᗇ䛾ほ䛻䜘䜜䜀䠈ᆅ㟈ᚋ䛾ὠἼఏ᧛᫬㛫㻔᫬䠖ศ㻕䛿䠈ὠ㍍ᾏᓙ䛾ภ㤋䠄1:29䠅䠈❳㣕㻔1:16㻕䛷䛒䛳䛯䠊᪥ᮏᾏἢᓊ䛷䛾ὠἼึື䛿䝜䜲䝈䛸㔜䛺䜚䠈୙ ᫂䛺ᆅⅬ䛜ከ䛔䠊ᆅ㟈ᚋ䠈᭱኱Ἴ䛾ฟ⌧᫬㛫䛿኱ ᖜ䛻㛗䛟䠈ὠ㍍ᾏᓙ䛛䜙༡໭䛻 10-15 ᫬㛫䛻䛺䜛㻔ᅗ 5㻕䠊䛥䜙䛻ᑠᶡ䞉᯽ᓮ䞉㔠ἑ䛜ఙ䜃䠈⯙㭯䠄44:54䠅䛻䛺䛳䛶䛔䜛䠊㻌㻌䛥䛝䛻➹⪅㻔⩚㫽㻘㻌1992㻕䛿䠈ภ㤋㉳Ⅼ䛾᪥ᮏᾏ䛾ὠ Ἴఏ᧛ᅗ䜢♧䛧䛯䛜䠈2011 ᖺὠἼ䜒ྛᆅ䛾᭱኱Ἴ䛾 ฟ⌧᫬㛫䛿ึື䛛䜙኱ᖜ䛻ఙ䜃䛶䛔䜛䠊౛䛘䜀䠈໭ ᾏ㐨すᓊ䜔໭㝣䡚ᒣ㝜㛫䛷䝏䝸䞉䜹䝮䝏䝱䝒䜹ὠἼ 䛾᭱኱Ἴ䛿 12 ᫬㛫௨㝆䛷䛒䛳䛯䠊㐲ᆅὠἼ䛿㛗࿘ ᮇἼ䜢཯ᫎ䛧䠈ὠἼ䛾⥅⥆᫬㛫䛜䛝䜟䜑䛶㛗䛔䠊ຍ 䛘䛶䠈᪥ᮏᾏ䛜㛢䛦䛥䜜䛯ᙧ䜢䛧䛶䠈኱㝣䛛䜙䛾཯ᑕ Ἴ䛜⧞䜚㏉䛥䜜䛶䛔䜛㻔⩚㫽㻘㻌1986㻕䠊㻌㻌㼲㻡䠊㻌㟷᳃䞉⛅⏣┴ἢᓊ䛾Ṕྐᆅ㟈ὠἼ㻌 1694-1939 ᖺ㛫䛻䠈㟷᳃䞉⛅⏣┴ἢᓊ௜㏆䛷Ⓨ⏕ 䛧䛯䠈⿕ᐖᆅ㟈䠄䠩6.8-7.2䠅䛾᥎ᐃ㟈※ᇦ䜢ᅗ 6 䛻♧ 䛩䠄⩚㫽㻘㻌 1987䠅䠊ྛᆅ㟈䛿ὠἼ䜢క䛳䛯䠊㟈※ᇦ䛿䠈㟈ᗘ䠄5-6 䛾⠊ᅖ䠅䠈ὠἼศᕸ䛚䜘䜃ᆅẆኚື䛾グ㘓䛛䜙䠈ἢᓊ䛻ἢ䛔㛗䛥 30-50㻌㼗㼙䛸᥎ᐃ䛧䛯䠊ྛᆅ䛾 ὠἼ䛾㧗䛥䛿⌧ᆅㄪᰝ䛷᳨ウ䛧䠈ὠἼ䝬䜾䝙䝏䝳䞊䝗 m ್䛿 ǻ-H ᅗ䠄ᅗ 7䠅䛷ุᐃ䛧䛯䠊䛴䛞䛻Ⓨ⏕㡰䛻䠈. ᆅ㟈䛾ᴫせ䜢♧䛩䠊㻌㻝㻕㻌 1694 ᖺ 6 ᭶ 19 ᪥䠄ඖ⚘୐䠅⬟௦ᆅ㟈䠖⡿௦ᕝὶ ᇦ䛜㟈ᗘ 6 䛻㐩䛧䠈⬟௦䛷඲ቯ 1,132 ᡞ䛻䛾䜌䛳䛯䠊 M7.0 䛸᥎ᐃ䠊ඵ㑻₲໭ᮾᓊ䛜ᖸୖ䛜䜚䠈Ἑཱྀ䛾Ỉ఩ 䛜పୗ䛧䛶ᆅ┙㝯㉳䛧䛯䠊ᑠὠἼ䛜క䛳䛯ྍ⬟ᛶ䛜䛒䜚䠈m =-1 䛸᥎ᐃ䠊㻌㻞㻕㻌 1704 ᖺ 5 ᭶ 27 ᪥䠄ᐆỌඖ䠅ᒾ㤋ᆅ㟈䠖⬟௦䡚῝ ᾆ㛫 60 km 䛾⠊ᅖ䛜㟈ᗘ 6 䛷 M7.0 䛸᥎ᐃ䠊㟷᳃䞉 ⛅⏣┴ቃ䛾ᾏᓊ䛷 1.5-2 m ᆅ┙㝯㉳䛧䛯䠊῝ᾆ䡚⁪ 䝜㛫䛾ᾏᓊ䛷₻䛜ᩘ୎ᘬ䛝䠈ὠἼ㧗䛿㪛䞄ἑ䛷 1.0 m䠈 ῝ᾆ䛷 1 m䠈ᒾᓮ䛷 1.2 m䚸኱㛫㉺䛷 1.4 m䠈ᒾ㤋䛸 ⬟௦䛷 1.3 m 䛷䛒䜚 m =0 䛸᥎ᐃ䠊㻌㻌㻟䠅㻌 1793 ᖺ 2 ᭶ 8 ᪥䠄ᐶᨻᅄ䠅㪛䞄ἑᆅ㟈䠖῝ᾆ䡚㪛䞄ἑ㛫䛷㟈ᗘ 6 䛻㐩䛧 M7.2 䛸᥎ᐃ䠄⌮⛉ᖺ⾲㻌 M6.9-7.1䠅䠊኱ᡞ℩ᓮ䛷 2.2 m 㝯㉳䛧䛯䠊⌧ᅾᗈ䛔㝯㉳ᾏᗋ䛿䠈䡞༓␚ᩜ䡟䛸࿧䜀䜜䜛ほගᆅ䛸䛺䛳䛶䛔䜛䠊 ὠἼ㧗䛿⯙ᡞ䛷 3.3 m䠈㪛䞄ἑ䛷 2.8 m䠈㉥▼䛷 5-6 m䠈῝ᾆ䛷 3.2 m䠈䜐䛴኱‖䛷 0.3 m 䛷䛒䜚 m =1 䛸᥎ ᐃ䠊㻌㻠㻕㻌 1810 ᖺ 9 ᭶ 25 ᪥䠄ᩥ໬୐䠅⏨㮵ᆅ㟈䠖ඵ㑻₲ᮾ ᓊ䛷㟈ᗘ 6-7䠊ᐙᒇ䛾඲ቯ 1,003䠈Ṛ⪅ 57 ே䠈1939 ᖺ⏨㮵ᆅ㟈䜘䜚⿕ᐖᩘ䛿 2 ಸ௨ୖ䜒ከ䛔䠊M7.0 䛸᥎ ᐃ㻔⌮⛉ᖺ ⾲㻌 M6.5㻕䠊ඵ㑻₲䛻ᾏ Ỉධ䜚䛂ᑠ㨶➼ ရ䚻Ṛὶ䛃䛸䛒䜛䠊ὠἼ㧗䛿 20-30 cm 䛷䛒䜚䠈m =-1 䛸 ᥎ᐃ䠊㻌㻌㻡䠅㻌 1939 ᖺ 5 ᭶ 1 ᪥䠄᫛࿴ 14䠅⏨㮵ᆅ㟈䠖⏨㮵༙ᓥ 䛷㟈ᗘ 6 䛷䛒䜚ᓴᔂ䜜䛜ከⓎ䛧䛯䠊༙ᓥす㒊䛷᭱኱ 44 cm 㝯㉳䛧䛯䠊㻌 M6.8 䛸᥎ᐃ䠊᳨₻グ㘓䛻䜘䜜䜀䠈 ඲᣺ᖜ䛿ᅵᓮ䛷 27 cm䠈㪛䞄ἑ䛷 10 cm䠈㓇⏣䛷 15 cm 䛷䛒䜚 m =-1.5 䛸᥎ᐃ䠊㻌㻌㼲㻢䠊㻌䜐䛩䜃㻌 Ẽ㇟ᗇ䛾Ἴ㧗ほ ್䜢䜒䛸䛻䠈᪥ᮏᾏἢᓊ䛷䛾 2011 ᖺὠἼ䛾つᶍ䜔ఏ᧛䛾ᵝ┦䜢ㄪ䜉䠈1952 ᖺ䜹䝮䝏䝱䝒䜹䞉1960 ᖺ䝏䝸ὠἼ䛺䛹䛾ほ ್䛸ẚ㍑᳨ウ䛧䛯䠊᭱኱Ἴ䛾඲᣺ᖜ್䛿 90 cm ௨ୗ䛷䛒䜚䠈ኴᖹ ὒഃ䛾ほ ್䛛䜙ᚓ䛯ὠἼ䝬䜾䝙䝏䝳䞊䝗䠄m =4䠅䜘䜚 2 㝵⣭ୗᅇ䛳䛯䠊⛶ෆ䞉㓇⏣䛾᣺ᖜ್䛜ẚ㍑ⓗ኱ 䛝䛟䠈᭱኱Ἴ䛾࿘ᮇ⣙ 30 ศ䛾 ‴䛜䝢䞊䜽䛻䛺䜛䠊 ᭱኱Ἴ䛿ᆅ㟈ᚋ 10 ᫬㛫௨㝆䛻ほ䛥䜜䠈᪥ᮏᾏ䛾 ὠἼ䛿㛗᫬㛫⥅⥆䛩䜛䛾䛜≉ᚩⓗ䛷䛒䜛䠊1939 ᖺ ௨㝆䠈㟷᳃䞉⛅⏣┴ἢᓊᇦ䛷䛿䠈㛗ᮇ㛫㟼✜ᮇ䛜⥆ 䛔䛶䛚䜚䠈⏒኱䛺ἢᓊᇦᆅ㟈䛾⊛ጾ䛻␃ព䛧䛯䛔䠊㻌㻌 ᑐ㇟ᆅ㟈䠖2011 ᖺᮾ᪥ᮏᆅ㟈䠈1952 ᖺ䜹䝮䝏䝱䝒䜹 ᆅ㟈䠈1960 ᖺ䝏䝸ᆅ㟈䠈1968 ᖺ༑຾Ἀᆅ㟈䠈1694 ᖺ ⬟௦ᆅ㟈䠈1704 ᖺᒾ㤋ᆅ㟈䠈1793 ᖺ㫏䞄ἑᆅ㟈䠈 1810 ᖺ⏨㮵ᆅ㟈䠈1939 ᖺ⏨㮵ᆅ㟈㻌㻌㻌㻌. - 12 -.

(3) ᩥ㻌 ⊩㻌㻌㜿㒊㑥᫛㻘㻌2011㻘㻌DART ὠἼグ㘓䛛䜙 2011 ᖺᮾ໭ᆅ ᪉ኴᖹὒἈᆅ㟈ὠἼ䛾༟㉺࿘ᮇ㻘㻌 ᪥ᮏᆅ㟈Ꮫ ఍ㅮ₇ண✏㞟㻘㻌 ⛅Ꮨ኱఍㻘㻌A31-11㻚㻌䝏䝸 ὠ Ἴ ྜ ྠ ㄪ ᰝ ⌜ 㻔 ௦ ⾲䠖㧗 ᶫ 㱟 ኴ 㑻㻕㻘㻌 1961㻘㻌 1960 ᖺ 5 ᭶ 24 ᪥䝏䝸ᆅ㟈ὠἼ䛻㛵䛩䜛ㄽᩥཬ 䜃ㄪᰝ㻘㻌 ᮾ኱ᆅ㟈◊✲ᡤ㻘㻌397 pp㻚㻌 ⩚㫽ᚨኴ㑻㻘㻌 1986㻘㻌 ᪥ᮏᾏὠἼ䛻䛚䛡䜛኱㝣䛛䜙䛾 ཯ᑕἼ㻘㻌 ᆅ㟈◊✲ᡤᙡሗ㻘㻌61㻘 329-338㻚㻌 ⩚㫽ᚨኴ㑻㻘㻌 1987㻘㻌すὠ㍍䞉⏨㮵㛫䛻䛚䛡䜛Ṕྐᆅ 㟈䠄1694-1810䠅䛾㟈ᗘ䞉ὠἼㄪᰝ㻘ᆅ㟈◊✲ᡤ ᙡሗ㻘㻌62㻘㻌133-147㻚㻌㻌㻌㻌㻌. ⩚㫽ᚨኴ㑻㻘㻌 1992㻘㻌 ὠ㍍ᾏᓙ䛛䜙᪥ᮏᾏ䛻ఏ᧛䛩䜛 ὠἼ䛾ᵝ┦㻘㻌 ᆅ㟈 2㻘㻌45㻘㻌169-176㻚㻌 ⩚㫽ᚨኴ㑻㻘㻌 2012㻘㻌 2011 ᖺᮾ໭ᆅ᪉ኴᖹὒἈᆅ㟈 ὠἼ䛾つᶍ㻘㻌 ὠἼᕤᏛ◊✲ሗ࿌㻘㻌29㻘㻌1-6㻚㻌 Ẽ㇟ᗇ㻘㻌 1953㻘㻌䜹䝮䝏䝱䝒䜹ᆅ㟈ㄪᰝሗ࿌㻘㻌㦂㟈᫬ ሗ㻘㻌18㻘㻌48 pp㻚㻌 Ẽ㇟ᗇ㻘㻌1961㻘㻌 ᫛࿴ 35 ᖺ 5 ᭶ 24 ᪥䝏䝸ᆅ㟈ὠἼㄪ ᰝሗ࿌㻘㻌 Ẽ㇟ᗇᢏ⾡ሗ࿌㻘㻌8㻘㻌389 pp㻚㻌 Ẽ㇟ᗇ㻘㻌 1984㻘㻌 ᫛࿴ 58 ᖺ㻔1983 ᖺ㻕᪥ᮏᾏ୰㒊ᆅ㟈ㄪᰝሗ࿌㻘㻌 Ẽ㇟ᗇᢏ⾡ሗ࿌㻘㻌106㻘㻌251 pp㻚㻌 Ẽ㇟ᗇ㻘㻌2011㻘㻌 ᖹᡂ 23 ᖺ䠄2011 ᖺ䠅ᮾ໭ᆅ᪉ኴᖹὒ Ἀᆅ㟈㻘㻌 ᖹᡂ 23 ᖺ 3 ᭶ᆅ㟈䞉ⅆᒣ᭶ሗ㻔㜵⅏ ⦅㻕㻚㻌. 㻌 ᅗ 1㻌 2011 ᖺᮾ᪥ᮏὠἼ䛻䜘䜛ภ㤋㻘᪥ᮏᾏἢᓊ䛾᳨₻グ㘓䠄Ẽ㇟ᗇ䛻䜘䜛䠅㻌 Fig. 1 Tide gauge records of the 2011 E. Japan tsunami at Hakodate and the Japan Sea coasts (JMA). - 13 -.

(4) 㻌 ᅗ 2㻌 ᪥ᮏᾏἢᓊ䛻䛚䛡䜛ኴᖹὒᇦὠἼ䛾඲᣺ᖜ್ศᕸ㻌 Fig. 2 Distribution of double wave heights of the Pacific tsunamis 㻌. 㻌 ᅗ 3㻌 ὠἼ䝬䜾䝙䝏䝳䞊䝗䞉䝇䜿䞊䝹䛷༊ศ䛧䛯Ἴ㧗೫ᕪ㻌 Fig. 3 Tsunami height deviations divided by tsunami magnitude scale. - 14 -.

(5) 㻌 ᅗ 4㻌 ྛ ‴䛾᭱኱Ἴ䛾࿘ᮇ䛸Ἴ㧗䠎஌್䛸䛾㛵ಀ㻌 Fig. 4 Relation between period of maximum wave and square of double amplitude 㻌. 㻌 ᅗ 5㻌㻞㻜㻝㻝 ᖺᮾ᪥ᮏὠἼ䛻䛚䛡䜛Ⓨ㟈᫬ᚋ䛾᭱኱Ἴ䛾ฟ⌧᫬㛫ศᕸ㻌 Fig. 5 Time distribution of peak amplitude after the main shock. - 15 -.

(6) 㻌. ᅗ 6㻌㟷᳃䞉⛅⏣┴ἢᓊ䛾Ṕྐᆅ㟈䛾᥎ᐃ㟈※ᇦ㻚㻌 Ⓨ⏕ᖺ䛻ᆅ㟈䛸ὠἼ䛾䝬䜾䝙䝏䝳䞊䝗್㻘㻌㻹㻛䡉䜢 ♧䛩㻚㻌 ᕥୖᅗ䠖ά᩿ᒙศᕸ㻌 Fig.6 Estimated source areas of historical earthquakes (1694-1939). Earthquake and tsunami magnitudes, M/m are shown 㻌㻌. ᅗ 7㻌 ὠἼ㧗䛸㟈ኸ㊥㞳䛾㛵ಀ㻚㻌 ὠἼ䝬䜾䝙䝏䝳䞊䝗䛷༊ศ㻚㻌 Fig. 7 Relation between tsunami heights and distance classified by tsunami magnitude scale㻌. 㻌. - 16 -.

(7)