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琵琶湖西岸断層帯南部の仮想地震による地殻変動と琵琶湖疏水 - R-Cube
Ṕྐ㒔ᕷ㜵⅏ㄽᩥ㞟 Vol. 6㸦2012 ᖺ᭶㸧 ࠙ㄽᩥࠚ ⍇⍈†すᓊ᩿ᒙᖏ༡㒊䛾௬ᆅ㟈䛻䜘䜛ᆅẆኚື䛸⍇⍈†Ỉ Seismic hazard of the Biwako-seigan fault zone and cut-off risk of the Lake Biwa Canal ᕝᓮ୍ᮁ 1࣭ᒸ⏣⠜ṇ 1࣭㐲⏣ḟ 2࣭ᑠᯇཎ㷹 3 Ichiro Kawasaki, Atsumasa Okada, Shinji Toda and Taku Komatsubara 1 ❧㤋Ꮫ≉ูᣍ⪸ᩍᤵ Ṕྐ㒔ᕷ㜵⅏◊✲ࢭࣥࢱ࣮㸦ࠛ 603-8341 ி㒔ᕷ༊ᑠᯇཎ⏫ 58㸧 Professor, Ritsumeikan University, Disaster Mitigation of Urban Cultural Heritage 2 ி㒔Ꮫᩍᤵ 㜵⅏◊✲ᡤ㸦ࠛ 611-0011 Ᏹᕷࣨᗉ㸧 Associate Professor, Kyoto University, Disaster Prevention Research Institute 3 ⏘ᴗᢏ⾡⥲ྜ◊✲ᡤ ᆅ㉁ሗ◊✲㒊㛛 ௵◊✲ဨ㸦ࠛ 305-8567 Ⲉᇛ┴ࡘࡃࡤᕷᮾ 1-1-1 ୰ኸ➨ 7㸧 Senior researcher, National Institute of Advanced Industrial Science and Technology This is a preliminary report on potential risks which would be caused by thrust-type inland earthquakes. If earthquake occurs at the Biwako seigan active fault system, the eastern half of the base of the Lake Biwa Canal could become higher than surface level of the Lake Biwa by uplift at hanging wall side in lower reaches and subsidence at footwall side in the upper reaches. Keywords: Lake Biwa Canal, Biwako-seigan fault zone, 1185 Genryaku earthquake, crustal deformation 䠍䠊䛿䛨䜑䛻 2011 ᖺᮾ᪥ᮏ㟈⅏࡛ࡣࠊ∻㮵༙ᓥࡽ▼ᕳࡢἢᓊ㒊ࡀᗈᇦⓗ㸯㹫௨ୖࡶࡢỿ㝆ࡀ⏕ࡌࠊἢᓊࡢఫᏯᆅ ࡣ‶ࡕ₻ࡢᗘᐃᖖⓗᾏỈ㠃ୗ࡞ࡾࠊఫẸࡀ㛗ᮇࢃࡓࡗ࡚ⱞࡋࡵࡽࢀ⥆ࡅ࡚࠸ࡿࠋᆅ㟈㜵⅏࡛ࡣᆅ㟈 ືࡼࡿ⅏ᐖࡢࡳὀ┠ࡀ㞟ࡲࡾࡀࡕ࡛࠶ࡿࡀࠊ∻㮵༙ᓥ୍ᖏࡢ⌧≧ࡣࠊᆅẆኚືࡀࡁ࡞⅏ᐖせᅉ࡞ࡿ ࡇࢆዴᐇ♧ࡋࡓࠋᮏሗ࿌ࡣࠊ㏆␥ᆅ᪉୰ኸ㒊࠾ࡅࡿᆅẆኚື⅏ᐖࡢ࠶ࡾ࠺ࡿࡋ࡚ࠊ⍇⍈†すᓊ ᩿ᒙᖏ⍇⍈†Ỉࡢሙྜࢆ᳨ウࡍࡿࠋ 䠎䠊⍇⍈†すᓊ᩿ᒙᖏ༡㒊䛾ᆅ㟈䛻䜘䜛ᐃᆅẆኚື ⍇⍈†すᓊ᩿ᒙᖏࡣࠊ➨㸯ᅗࡢࡼ࠺ࠊࡣ㈡┴㧗ᓥᕷ࣐࢟ࣀ⏫ࡢ⚟┴ቃ㏆ࡃࡽ༡ࡣὠᕷᅜศ ㏆⮳ࡿࠊ㉮ྥᮾ࣮༡༡すࠊ㛗ࡉ⣙ 60km ࡢすୖࡀࡾࡢ㏫᩿ᒙ࡛࠶ࡿࠋ㐣ཤࡢάືᮇࡢ㐪࠸ࡽࠊᏳ ᕝ㏆ࡃ࡛⣙ 23km ࡢ᩿ᒙᖏ㒊⣙ 38km ࡢ༡㒊ศࡅࡽࢀ࡚࠸ࡿࠋ ᆅ㟈ㄪᰝጤဨ㸦2009㸧㸯㸧ࡢά᩿ᒙホ౯࡛ࡣࠊ⍇⍈†すᓊ᩿ᒙᖏ༡㒊ࡓ࠸ࡋ࡚ࠊ㛗ࡉ 38kmࠊᖜࡣ᫂ࠊ ୖ➃ࡢ῝ࡉ 0kmࠊ㉮ྥ N20Eࠊഴᩳࡣᆅ⾲ࡽ῝ࡉ 3km ࡲ࡛ 40 rࠊ῝ࡉ 3-5km ࡛ 35 rࠊ5km ௨῝ࡣ᫂ࠊ 㸯ᅇࡢࡎࢀࡢ㔞 6-8m㸦ୖୗᡂศ㸧 ࠊM7.4 ᐃࡋ࡚࠸ࡿࠋ௨ୗࡢィ⟬࡛ࡣࠊά᩿ᒙホ౯࡛ࡣ᭕࡞ࣃ࣓࣮ࣛ ࢱ࣮ࡸ࠼ࡽࢀ࡚࠸࡞࠸ࣃ࣓࣮ࣛࢱ࣮ࡣࠊᖜ 30kmࠊ᩿ᒙ㠃ࡑࡗࡓࡾ㔞㸦᩿ᒙ㠃࡛ྥ࠸ྜ࠺ᒾ┙ࡀ㣗 ࠸㐪࠺ࡁࡉ㸧11mࠊ㉮ྥ N25Eࠊഴᩳ 40 r௬ᐃࡋࡓࠋഴᩳ 40 rࡢ᩿ᒙ㠃ἢࡗ࡚ୖ┙ୗ┙ࡀ 11m ࡿࠊ᪉ྥవᘻࡢୖୗᡂศࡣࠊᆅ㟈ㄪᰝጤဨࡢᐃ 6-8m㸦ୖୗᡂศ㸧ࡢᖹᆒ 7m ࡞ࡿࠋ ➨㸰ᅗࡣࠊࡇࢀࡽࡢࣃ࣓࣮ࣛࢱ࣮ࢆධຊࡋࠊOkada㸦1992㸧㸰㸧ࡢࣉࣟࢢ࣒ࣛࢆࡗ࡚ 1km ࢢࣜࢵࢻ࡛ィ −97− Ṕ㜵 ࢩ࣏ࣥ ⍇⍈† Ỉ 2012-06-01.jtd 1 12/06/08 ⟬ࡋࠊࣉࣟࢵࢺࡋࡓ㟼ⓗኚࡢࣃࢱ࣮࡛ࣥ࠶ࡿࠋ᩿ᒙ⥺すഃ ୖ┙࡛᭱ 5.98mࠊி㒔ᕷෆ࡛㸯 m ⛬ᗘࡢ㝯㉳࡞ࡾࠊ᩿ ᒙ⥺ᮾഃୗ┙࡛᭱ 69cmࠊ⍇⍈†ᶫ௨༡ࡣ 50cm ࡢ ỿ㝆࡞ࡿࠋ࡞࠾ࠊ㟼ⓗኚࡣࠊᆅ㟈ືࡀ㏻ࡾ㐣ࡂ࡚⾜ࡗ ࡓᚋṧࡿ௨๓ࡢ⨨ࡽࡢࡎࢀ࡛࠶ࡿࠋ㟼ⓗኚࡣࠊᆅ㟈 ィ࡛ࡣ ࢀࡎࠊ 㔞ࡸ GPS ࡞ࡢ ᆅᏛⓗᡭἲࡼࡗ࡚ィ ࡉࢀࡿࡢ࡛ࠊᆅẆኚືゝ࠸⩦ࢃࡉࢀ࡚࠸ࡿࠋ ☜ᐃせ⣲ࡣከ࠸ࠋࡑࡢ୍ࡘࡣ᩿ᒙ㠃ࡢഴࡁ࡛࠶ࡿࠋά᩿ ᒙホ౯࡛ࡣ 5km ௨῝ࡣ᫂ࡉࢀ࡚࠸ࡿࡀࠊᚤᑠᆅ㟈ࡶ ࢇⓎ⏕ࡋ࡚࠾ࡽࡎࠊᚤᑠᆅ㟈ࡢศᕸࡽ᩿ᒙ㠃ࢆỴࡵࡿ ࡇࡣ࡛ࡁ࡞࠸ࠋࡇࡇ࡛ࡣࠊ௬ࠊ᩿ᒙ㠃ࢆ 70 r㧗ゅ ኚ࠼࡚㸦ࡾ㔞ࢆ 8m㸧ィ⟬ࡋࡓࡢࡀ➨㸱ᅗ࡛࠶ࡿࠋ᩿ᒙ㠃 ࡢഴᩳࡀ 40 rࡢሙྜ㸦➨㸰ᅗ㸧ࡣࠊࡁ࡞ᆅẆኚືࡀ㉳ࡇ ࡿࡢࡣ᩿ᒙ㠃ࡢୖ┙ഃ೫ࡿࡀࠊ㧗ゅ㸦➨㸱ᅗ㸧࡞ࡿࠊ ୖ┙ഃࡢᆅẆኚືࡣ⦰ᑠࡋࠊ᭱㝯㉳ࡣ 4.35m ࡞ࡿࠋ㏫ ࠊୗ┙ഃࡢỿ㝆ᇦࡣᣑࡋࠊ᩿ᒙ┤㏆࡛ 2.22mࠊ㏆Ụඵᖭ ࡛ 50cm ࡽ 100cm ࡞ࡿࠋ ࡶ࠺୍ࡘࡢ☜ᐃせ⣲ࡣࡾ㔞࡛࠶ࡿࠋM7 ࢡࣛࢫࡢෆ㝣 ➨㸯ᅗ ⍇⍈†すᓊ᩿ᒙᖏࡢ⨨ࠋ ᆺᆅ㟈ࡢሙྜࠊ1943 ᖺ㫽ྲྀᆅ㟈࡛ࡣ 2m ࡽ 3mࠊ1948 ᖺ⚟ ᆅ㟈ㄪᰝጤဨ㸦2009㸧㸯㸧ࡼࡿࠋ ᆅ㟈ᆅ㟈࡛ࡣ 2m ࡽ 3mࠊ1995 ᖺරᗜ┴༡㒊ᆅ㟈࡛ࡣ 2m ࡽ 3mࠊ2007 ᖺ⬟Ⓩ༙ᓥᆅ㟈ࡣ 2m ࡽ 3m ࡞ࡢࡢࡼ࠺ࡁࡃ࡚ࡶ 5m ࢆ㉺࠼࡞࠸ࠋᚑࡗ࡚ࠊ᩿ᒙ㠃 ἢࡗ࡚ࡢ㏻ᖖࡢព࡛ࡢࡾ㔞 8m㸦ഴᩳゅ 40 rࡢሙྜ㸧ࡽ 11m㸦ྠ 40 r㸧ࡣࠊM7 ࢡࣛࢫࡢෆ㝣ᆺᆅ 㟈ࡋ࡚ࡣࡁࡍࡂࡿࡼ࠺ᛮࢃࢀࡿࠋࡓࡔࡋࠊࡾ㔞ࡢᐃࢆ 1/3 ࡢ 2.5m ࡽ 3.5m ⛬ᗘࡋ࡚ࡶࠊ➨㸰 ᅗ➨㸱ᅗࡢࢥࣥࢱ࣮ࡢ್ࢆ 1/3 ࡍࡿࡔࡅ࡛ࠊ✵㛫ศᕸࡢࣃࢱ࣮ࣥࡣኚࢃࡽ࡞࠸ࠋ୕ࡘ┠ࡢ☜ᐃせ⣲ࡣࠊ ィ⟬ࡢ㒔ྜୖࠊ᩿ᒙ㠃ࡣ㸯ᯛࡢ㛗᪉ᙧࡢᖹ㠃࡛ࠊࡾ㔞ࡣ᩿ᒙ㠃య࡛ྠࡌ್ࡋࡓࡇ࡛࠶ࡿࠋᐇ㝿ࡢᆅ 㟈ࡢሙྜࡣࠊࡾ㠃ࡣ᩿ᒙ㠃ୖࡢሙᡤࡼࡗ࡚ࡁࡃኚࢃࡿࠋ➨㸰ᅗ➨㸱ᅗࢆࡳࡿሙྜࡣࠊࡇࢀࡽࡢ☜ ᐃせ⣲ࡀᏑᅾࡍࡿࡇὀពࡍࡿᚲせࡀ࠶ࡿࠋ ࡇࡢᵝ࡞☜ᐇせ⣲ࡢᏑᅾࡶ㛵ࢃࡽࡎࠊḟࡢࡇࡣᣦ࡛ࡁࡿࠋ 㸦ၥ㢟Ⅼ㸯㸧⍇⍈†すᓊ᩿ᒙᖏ༡㒊ࡣࠊὠ࡛⍇⍈†Ỉࢆᶓษࡗ࡚࠾ࡾࠊࡶࡋᆅ㟈ࡀ㉳ࡇࢀࡤࠊࡓ࠼ᆅ 㟈ືࡼࡿ◚ቯࢆචࢀ࡚ࡶࠊὶ㊰ࡣ᩿⤯ࡍࡿࠋࡇࡇ࡛ࡣࡑࢀࢆ⍇⍈†Ỉ᩿Ỉၥ㢟ࡪࡇࡍࡿࠋ 㸦ၥ㢟Ⅼ㸰㸧⍇⍈†༡㒊ࡀᆅ㟈ྠᮇࡋ࡚ỿ㝆ࡍࡿࡢ࡛ࠊ㒊ࡢ†Ỉࡀ༡ὶࡋࠊ⍇⍈†༡㒊ࡢ†ᓊࡣὠἼ ➨㸰ᅗ 㛗ࡉ 38kmࠊᖜ 30kmࠊୖ➃ࡢ῝ࡉ 0kmࠊ㉮ ྥ N25Eࠊഴᩳす 40° ࡢ㏫᩿ᒙࠊࡎࢀࡢ㔞 11m ௬ᐃࡋ࡚㟼ⓗኚࡢୖୗᡂศࠋᇶᅗࡣࠊᅜᅵᆅ⌮㝔ࡢ ᅜᅵᇶᮏᅗࠋࢹࢪࢱࣝᅗࡣ࢝ࢩ࣑࣮ࣝ 3D ࢆ⏝࠸ࡓࠋ ➨㸱ᅗ ➨㸰ᅗࡢሙྜ࡛ࠊ᩿ᒙ㠃ࡢഴࡁࢆ 70° ࡾ 㔞ࢆ 8m ኚ࠼ࡓሙྜࡢ㟼ⓗኚࡢୖୗᡂศࠋࡣࡍ ࡚➨㸰ᅗྠࡌࠋ −98− Ṕ㜵 ࢩ࣏ࣥ ⍇⍈† Ỉ 2012-06-01.jtd 2 12/06/08 くࢃࢀࡿࠋሀ⏣᩿ᒙ௨ࡀືࡃࡼ࠺࡞ᆅ㟈ࡔ℩⏣ᕝὙሖ㸦ᪧ༡㒓Ὑሖ㸧ࡣỿ㝆ᇦእ࡞ࡾࠊὠἼࡣ⍇⍈† ࡢ୰␃ࡲࡿࠋ㏫ࠊሀ⏣᩿ᒙࡼࡾ༡ࡢẚཿ᩿ᒙࡸ⮃ᡤ᩿ᒙࡀືࡃᆅ㟈ࡔ℩⏣ᕝὙሖࡶྠỿ㝆ࡋࠊὠ Ἴࡣ℩⏣ᕝὙሖࢆࡇ࠼࡚℩⏣ᕝࡽᏱᕝὶࢀୗࡿࠋ ᮏㄽ࡛ࡣࠊ 㸦ၥ㢟Ⅼ㸯㸧ࡢࡳࢆᑐ㇟ࡋࠊ 㸦ၥ㢟Ⅼ㸰㸧ࡣࡘࡢᶵㆡࡾࡓ࠸ࠋ 䠏䠊⍇⍈†Ỉ ➨㸲ᅗࡣ⍇⍈†Ỉࡢὶ㊰ᅗ࡛࠶ࡿࠋỈࡣ㸰ὶ㊰ ࠶ࡾࠊ➨㸯Ỉࡣࠊ1890 ᖺ㸦᫂ 23 ᖺ㸧 ࠊỈ㐨⏝ỈࡸⓎ 㟁ࢆ┠ⓗసࡽࢀࡓࠋࡑࢀࡣࠊὠᕷࡢὠ㛮㛛ࡽࡣ ࡌࡲࡾࠊ㛗ࡰ 8km㸦┤⥺㊥㞳࡛ 6km 㸧ࡢ㊥㞳 ࢆ 5m ࡢⴠᕪ㸦ഴࡁࡰ 2000 ศࡢ㸯㸧࡛ὶࢀࡓ࠶ࠊ ㋾ୖ࡛ࣥࢡࣛࣥࡢࡑࡤࢆഴࡁ 15 ศࡢ㸯࡛ி㒔┅ᆅ ὶࢀୗࡿࠋ➨㸰Ỉࡣࠊ1912 ᖺ㸦ṇ 3 ᖺ㸧ᡂࠊ ➨㸲ᅗ ⍇⍈†Ỉࡢὶ㊰ᅗࠋி㒔ᕷୖୗỈ㐨ᒁࡢ ⍇⍈†ἢᓊ㒊ࡢྲྀỈཱྀ࡛┤ࡕᆅୗࢺࣥࢿࣝ࡞ࡾࠊ➨ HP ࡢᅗࢆಟṇࠋ 㸯Ỉྠᵝ㋾ୖࡽி㒔┅ᆅὶࢀୗࡿࠋ➨㸰Ỉ ࡣࠊ1996 ᖺࠊ⍇⍈†ࡢỈ㠃పୗᑐᛂࡍࡿࡓࡵࠊྲྀ ࡾධࢀཱྀࡽࡓࡔࡕ 20m ࢆ㉺࠼ࡿ⦪✰ධࡾࠊᒣ⛉ ┅ᆅ࡛ඖࡢ➨㸰Ỉᡠࡿ㐃⤡ࢺࣥࢿࣝࡀ㐀ࡽࢀࡓࠋ ࡇࢀࡽࡣࠊி㒔ࡢⓎᒎࡁ࡞ᙺࢆᯝࡓࡋ࡚ࡁࡓࠋ ⌧ᅾ࡛ࡣࠊ➨㸰Ỉࡀࠊ140 ி㒔ᕷẸࡢ㣧ࡳỈࡢ ࢇᥦ౪ࡋ࡚࠾ࡾࠊி㒔ࡢ⥘࡞ࡗ࡚࠸ࡿࠋ ၥ㢟ࡣࠊ⍇⍈†すᓊ᩿ᒙᖏ༡㒊ࡀẚཿᒣᮾ㯄ࡢᒣᆅ ᖹ㔝㒊ࢆ༊ษࡗ࡚㉮ࡗ࡚࠾ࡾࠊ⍇⍈†Ỉࢆᶓษࡗ ࡚࠸ࡿࡇ࡛࠶ࡿࠋ➨㸰ᅗࡢሙྜࡋࢁࠊ➨㸱ᅗࡢሙ ྜࡋࢁࠊ➨㸳ᅗ㯮ᐇ⥺ࡢ┤ᚄ⣙㸲 m ࡢὶ㊰ࡣࠊᆅ㟈 ᚋࡣྠᅗ㉥◚⥺ࡢࡼ࠺࡞ࡾࠊ᩿ᒙ㒊࡛ୖୗࡰ 7m ࡎࢀ࡚᩿⤯ࡍࡿࠋᮾᐤࡾᩘ km ࡢỈᗏ㠃ࡣ⍇⍈† ࡢᖹᆒỈ㠃ࡼࡾ㧗ࡃ࡞ࡿࠋࡾࡢࡁࡉࢆ 1/3 ࡍࡿ ᩿ᒙࡢୖୗࡎࢀࡶ 1/3㸦ᅗࡢᆅ㟈๓ᆅ㟈ᚋࡢᕪࡀ 1/3㸧࡞ࡾࠊỈࡢᗏ㠃ࡀ⍇⍈†ࡢᖹᆒỈ㠃ࡼࡾ㧗ࡃ ➨㸳ᅗ ⍇⍈†Ỉࡢὶ㊰ࡢᆶ┤ᅗࠋỈᖹ᪉ྥẚ ࡞ࡿ㊥㞳ࡣ▷ࡃ࡞ࡿࠋ࠸ࡎࢀࡏࡼࠊ௬ᆅ㟈ືࡼ ࡚ୖୗ᪉ྥࡣࡰ㸯ಸᣑࡉࢀ࡚࠸ࡿࠋ㯮ᐇ ࡿ◚ቯࢆචࢀ࡚ࡶࠊᩘ km Ώࡗ࡚Ỉᗏ㠃ࡀ⍇⍈† ⥺ࡣᆅ㟈๓ࡢὶ㊰ࠊ㉥◚⥺ࡣᆅ㟈ᚋࡢὶ㊰ࠋ ࡢᖹᆒỈ㠃ࡼࡾ㧗ࡃ࡞ࡾࠊி㒔┅ᆅ㣧ᩱỈࡸᾘⅆ⏝ Ỉࢆ౪⤥ࡍࡿࡇࡣྍ⬟࡞ࡿࠋᪧᕤࡣ㛗ᮇཬࡧࠊி㒔ᕷẸࡣఱࣨ᭶ࡶࠊ࠶ࡿ࠸ࡣఱᖺࡶỈࡢᴟ➃ ஈࡋ࠸⏕άࢆᙉ࠸ࡽࢀࡿࡶ▱ࢀ࡞࠸ࠋ 䠐䠊 1185 ᖺඖᬺᆅ㟈 㝔ᨻࡢᮎᮇࡽ※ᖹࡢྜᡓ⮳ࡿᮇࡣ⅏གྷࡢᮇ࡛࠶ࡗࡓࠋ1177 ᖺ㸦Ᏻඖ୕ᖺ㸧ࠊⅆࡼࡗ࡚ෆࢆ ྵࡴඵ┬㝔ࡣ↝ኻࡋࡓࠋ1179 ᖺ㸦ᢎ୕ᖺ㸧ࡣᖹΎ┒ࡢࢡ࣮ࢹࢱ࣮ࡼࡗ࡚㝔ᨻࡀṆࡉࢀࠊḟࡢᖺࡣ ௨ோ⋤ࡢᐉ᪨ࡼࡗ࡚ࡀᅜᣑࡋࡓࠋᖹᏳிࡣᖺ㈉ࡀ㞟ࡲࡽ࡞ࡃ࡞ࡾࠊ㣴ࡢ㣚㤡㸦1181 ᖺࡽ 1182 ᖺ㸧㝗ࡗࡓࠋ࡞࠾ࠊ1181 ᖺ㸦ᢎᖺ㸧ᖹẶᨻᶒࡼࡗ࡚㣴ᨵඖࡉࢀࡓࡀࠊᖹẶ⁛ஸᚋࡣ ᢎࡀ⥅⥆ࡋࡓࡶࡢࡋ࡚ᢅࢃࢀ࡚ࡿࠋ㣚㤡ࡢ୰࡛※ᖹࡢத࠸ࡀ⥆࠸ࡓࡀࠊ1184 ᖺධࡗ࡚ᒁ㠃ࡣᛴᒎ㛤ࡋࠊ ᮌ᭯⩏௰ࡀᚋⓑἙἲ⋤ࢆᨷࡵࡓἲఫᑎྜᡓ㸦1 ᭶ 3 ᪥㸧 㸪⩏௰ࡀ⁛ࡰࡉࢀࡓ㏆Ụ⢖ὠྜᡓ㸦3 ᭶ 5 ᪥㸧㸪ᦤὠ ୍ࣀ㇂ྜᡓ㸦3 ᭶ 20 ᪥㸧㸪ࢃࡎ㸱ࣨ᭶ࡢ㛫ᖹᏳிࡣ⧞ࡾ㏉ࡋᡓሙ࡞ࡗࡓࠋḟࡢᖺ㸪ᒇᓥࡢᡓ࠸㸦1185 ᖺ 3 ᭶ 22 ᪥㸧ቭࣀᾆࡢᡓ࠸㸦4 ᭶ 25 ᪥㸧࡛ᖹᐙࡣ⁛ࢇࡔࠋࡑࡢ㸱ࣨ᭶ᚋ㸦7 ᭶ 9 ᪥㸧ඖᬺᆅ㟈ࡀ㉳ࡇ −99− Ṕ㜵 ࢩ࣏ࣥ ⍇⍈† Ỉ 2012-06-01.jtd 3 12/06/08 ࡗࡓࠋ 㧘ᶫ㸦2012㸧㸱㸧ࡣࠊᒣᵘグ㸦୰ᒣᛅぶࡢ᪥グ㸧ࡢグ㏙ࡽࠊඖᬺᆅ㟈ࡢࠊⓑἙ㸦⌧ᅾࡢᒸᓮ࿘㎶㸧ἲ ᑎࡢ㧗ࡉࡰ 80m ࡢ㔜ሪࡀࠊᚰᰕࡇࡑಽቯࡣචࢀࡓࡀࠊሪ㡬ࡢ┦㍯ࡣᢡࢀⴠࡕࠊྛᒙࡢᒇ᰿ࡣᜳࡃⴠࡕࠊ ึ㔜ࡽඵ㔜ࡲ࡛ࡣ↓ࡁࡀࡈࡁ↓࡞≧ែ࡞ࡗࡓࡋࡓࠋࡢᑎ㝔ࡢ⿕⅏ࡶྜࢃࡏ⪃࠼ࢀࡤࠊⓑἙ࠾ ࡅࡿᆅ㟈ືࡀ⃭Ⅿ࡛࠶ࡗࡓ㐪࠸࡞࠸ࠋࡉࡽࠊᮾす᪉ྥ㛗࠸ᘓ≀ࡼࡾࠊἲᑎ㜿ᘺ㝀ᇽࡸᚓ㛗ᑑ㝔༓య ᇽ࡞༡㛗࠸ᘓ㐀≀ࡢ⿕ᐖࡢ᪉ࡀከࡗࡓࡢ࡛ࠊᆅ㟈ືࡣᮾす᪉ྥࡀ༟㉺ࡋ࡚࠸ࡓ᥎ ࡋࡓࠋ ၥ㢟ࡢ㸯ࡘࡣࠊ㟈※᩿ᒙࡀⰼᢡ᩿ᒙᖏ༡㒊࡛࠶ࡗࡓࡢࠊ⍇⍈†すᓊ᩿ᒙᖏ༡㒊࡛࠶ࡗࡓࡢ࡛࠶ࡿࠋ ᮾ㒓࣭㸦1997㸧㸲㸧ࡣ㸪ⰼᢡ᩿ᒙᖏ➃ࡢ㏵୰㇂㸦㈡┴㧗ᓥᕷ㸧ࢺࣞࣥࢳⓎ᥀ㄪᰝࡽ㸪1185 ᖺࡢᆅ 㟈ࡢࡁⰼᢡ᩿ᒙᖏࡀື࠸ࡓྍ⬟ᛶࢆ♧၀ࡋࡓࠋࡋࡋ㸪ி㒔ᕷෆࡢྜྷ⏣ᒣす㯄ࡢฟᕝ㏻ࡾࢺࣞࣥࢳⓎ ᥀ㄪᰝ࡛ࡣ 1185 ᖺື࠸ࡓ㊧ࡣぢ࠸ࡔࡉࢀ࡞ࡗࡓ㸦ྜྷᒸ࣭㸪1998㸧㸳㸧ࠋὠᕷᮏሀ⏣ࡢሀ⏣᩿ᒙࡢ ࢪ࢜ࢫࣛࢧ࣮࣮࣎ࣜࣥࢢࡽࡣ㸪⍇⍈†すᓊ᩿ᒙᖏ࡛ 12 ୡ⣖ᚋ༙ᆅ㟈ࡀ㉳ࡗࡓྍ⬟ᛶࡀ♧ࡉࢀࡓ 㸦Kaneda et al, 2008㸧㸴㸧ࠋά᩿ᒙᏛⓗࡣࠊ㟈※᩿ᒙࡣ⍇⍈†すᓊ᩿ᒙᖏ༡㒊⪃࠼࡚㛫㐪࠸࡞ࡉࡑ࠺࡛࠶ ࡿࠋ すᒣ㸦2001㸧㸵㸧ࡣࠊⓑἙࡢ⿕ᐖࡀ⏒࡛࠶ࡗࡓࡇࠊᕥி㸦ᙜࡣ㬞ᕝすഃ㸧ࡢ⿕ᐖࡀࡁࡗࡓࡇࠊ ẚཿᒣ࡛ࡶ⿕ᐖࡀ࠶ࡗࡓࡇࠊ ࠕ⳹㡬せ␎ࠖ 㸦ி㒔㟷ⶈ㝔ࡢᑎㄅ㸧ࡼࡿὠࡽᆏᮏ࡛ࡶ⿕ᐖࡀ࠶ࡗࡓࡇ ࠊ୍᪉ࠊ ཎ୕༓㝔࡞ࡢ⿕⅏ࡢグ㘓ࡀṧࡉࢀ࡚࠸࡞࠸ࡇࠊோᑎࡸἲ㔠๛㝔ࡢ࠶ࡿ⾰➟ࡸၿᓟᑎࡢ ⿕ᐖࡀᑠࡉࡗࡓࡇ࡞ࡽࠊ⿕ᐖศᕸ㸦➨㸴ᅗཧ↷㸧ࡢどⅬࡽࡶ⍇⍈†すᓊ᩿ᒙᖏ༡㒊ㄝࡀጇᙜ⤖ ㄽࡋࡓࠋ ࡋࡋࠊẚཿᒣࡢ⿕ᐖࡘ࠸࡚ࡣ㸪㧘ᶫ㸦2005㸧㸷㸧ࡣࠕពእᑠࡉ࠸ࠖ࠸࠺༳㇟ࢆ㏙࡚࠸ࡿࡋ㸪ࡑࡶ ࡑࡶ㸪ᘏᬺᑎࡣ㸪ⰼᢡ᩿ᒙᖏࡽࡶ⍇⍈†すᓊ᩿ᒙᖏࡽࡶ㊥㞳ࡣ࠶ࡲࡾ㐪ࢃࡎ㸪ⰼᢡ᩿ᒙᖏ⍇⍈†すᓊ ᩿ᒙᖏࢆᕥྑࡍࡿᮦᩱࡣ࡞ࡽ࡞࠸ࡢ࡛ࡣ࡞࠸ࡔࢁ࠺ࠋࡲࡓ㸪 ோᑎࡸἲ㔠๛㝔ࡢ࠶ࡿ⾰➟ࡸၿᓟᑎ ࡢ⿕ᐖࡀᑡ࡞࠸ࡢࡣᆅ┙ࡀࡼ࠸ࡽࡶ⪃࠼ࡽࢀࡿࠋὠࡽᆏᮏࡢ⿕ᐖࡘ࠸࡚ࡶࠊỤᡞ௦ࡢᩥ⊩࡛࠶ ࡿࠕ⳹㡬せ␎ࠖࡣ⪃࠼࡞࠸ࡇࡍࡿࠊඖᬺࡢᆅ㟈ࡢࡁࡢὠࡽᆏᮏࡢ⿕ᐖࡣ᫂ࡋ࡚࠾࠸ࡓ࠺ ࡀࡼ࠸ࠋ ࡇࡇ࡛╔┠ࡋࡓ࠸ࡢࡣࠊி㒔ᕷ➨㸱ḟ⿕ᐖᐃ 㸦2003㸧㸯㸮㸧ࡢ㟈ᗘண 㸦➨㸵ᅗ㸧ඖᬺᆅ㟈ࡢ⿕ᐖ ศᕸ㸦➨㸴ᅗ㸧ࡢᑐᛂࠊⓑἙ㸦⌧ᅾࡢᒸᓮ㸧㏆㞄 ࡢά᩿ᒙࡢ⨨㛵ಀ࡛࠶ࡿࠋ⌧ᅾ 800 ᖺ๓ࡢ≧ἣ ࡣࡁࡃ␗࡞ࡿࡢ࡛ࠊி㒔ᕷ⿕ᐖᐃࢆࡑࡢࡲࡲ㐺ᛂ ࡍࡿࡇࡣ࡛ࡁ࡞࠸ࡋ࡚ࡶࠊᒁⓗࡣཧ⪃࡞ࡿ ࡛࠶ࢁ࠺ࠋி㒔ᕷ⿕ᐖᐃ࡛ࡣࠊ᱈ᒣ࣭㮵ࣨ㇂᩿ᒙࢆ ᐃ᩿ᒙࡋࡓሙྜࠊ㟈ᗘ㸵࡞ࡿࡢࡣᮾᒣす⦕㒊ࡢ ▱ᜠ㝔ࡽఅぢ✄Ⲵࡲ࡛ᒣ⛉┅ᆅ୰ኸ㒊࡛ࠊⓑἙࡣ 㟈ᗘ㸴࡛࠶ࡿࠋᙜᮾᒣす⦕㒊Ꮡᅾࡋࡓᆺᘓ㐀≀ ࡣභἼ⨶➨ἲఫᑎ㸦⌧ᅾࡢᅜ❧༤≀㤋୕༑୕㛫ᇽ ㏆㸧࡛࠶ࡿࡀࠊᆅ㟈ࡢ๓ࠊභἼ⨶➨ࡣᖹᐙ㒔ⴠࡕ ࡢᚋ↝ኻࡋࠊἲఫᑎࡣἲఫᑎྜᡓ࡛↝ኻࡋࡓࡢ࡛ཧ⪃ ࡞ࡽ࡞࠸ࠋᒣ⛉ࡢ⿕ᐖࡣ㟈ᗘண ㄪⓗ࡛࠶ࡿࠋ 㒔ᕷᅪά᩿ᒙᅗࠕி㒔ᮾ㒊ࠖ 㸦ᒸ⏣࣭ࠊ1996㸧㸯 㸯㸧 ࡼࢀࡤࠊᒸᓮࡣࠊⰼᢡ᩿ᒙᖏ༡➃㸦ྜྷ⏣ᒣす㯄㸧 ᱈ᒣ᩿ᒙ➃㸦▱ᜠ㝔す➃㸧ࡢ㛫⨨ࡋ࡚࠸ࡿࠋ ➨ 㸴 ᅗ 1185 ᖺ ඖ ᬺ ᆅ 㟈 ࡢ ⿕ ᐖ ศ ᕸ ࠋ ᑠ ᯇ ཎ ୧⪅ࡀᆅୗ῝㒊࡛⧅ࡀࡗ࡚₯ᅾ᩿ᒙ࡞ࡗ࡚࠸ࡿࡍ 㸦2011㸧㸶㸧ࡼࡿࠋ ࡿࠊⓑἙࡣ₯ᅾ᩿ᒙ┤ୖ࡛࠶ࡾࠊἲᑎࡢ㔜ሪࡣ ୖ┙⨨ࡍࡿࡇ࡞ࡾࠊ⏒࡞⿕ᐖࡶᛮ㆟࡛ࡣ࡞࠸ࠋ⍇⍈†すᓊ᩿ᒙᖏࡀ㟈※࡛࠶ࡗࡓࡍࡿ㸪ⓑ Ἑࡣ➨㸵ᅗྑࡢࡼ࠺㟈ᗘ㸴ᙅࡋ࡞ࡽࡎࠊ⃭⏒࡞⿕ᐖࡣㄝ᫂ᅔ㞴࡛࠶ࢁ࠺ࠋ ࣐ࢢࢽࢳ࣮ࣗࢻࡀ M7.4 ࡁ࡞ぢ✚ࡶࡾ࡞ࡗ࡚࠸ࡿࡓࡿཎᅉࡣࠕ᪂᪥ᮏᆅ㟈ྐᩱࠖ㸦ᮾிᏛᆅ㟈 ◊✲ᡤࡼࡗ࡚㞟ࡵࡽࢀࡓṔྐᆅ㟈ྐᩱ㸧࡛୕Ἑ࡛᭷ឤࡉࢀ࡚࠸ࡿࡇ࡛࠶ࡿࡀࠊ㧘ᶫ㸦2005㸧㸶㸧ࡣࠊ Ṕ㜵 ࢩ࣏ࣥ ⍇⍈† Ỉ 2012-06-01.jtd −100− 4 12/06/08 ➨㸵ᅗ ி㒔ᕷ➨㸱ḟ⿕ᐖᐃ㸦2003㸧㸯㸮㸧࠾ࡅࡿᐃ㟈ᗘࠋ ࠕ᪂᪥ᮏᆅ㟈ྐᩱࠖࡢඖ࡞ࡗࡓឡ▱┴⨾㒆ࡢࠕᖖගᑎᖺ௦グࠖࡢᖖගᑎࡀ 15 ୡ⣖ࡢ㛤࡞ࡢ࡛ྠ ௦ྐᩱ࡛ࡣ↓ࡃࠊドᣐ࡞ࡽ࡞࠸ࡋ࡚࠸ࡿࠋ᭷ឤ⠊ᅖࡀி㒔┅ᆅ࿘㎶࡞ࡽࡤࠊ㟈※᩿ᒙࡀ᱈ᒣ᩿ᒙ࠸ ࠺ 10km つᶍࡢά᩿ᒙ࡛ࡶᕪࡋᨭ࠼ࡣ࡞࠸ゝ࠼ࡼ࠺ࠋ㧘ᶫ㸦2005㸧㸶㸧ࡣࠊ ࠕ㝔ᨻᮇࡣࠊ㏆⮧ཷ㡿ᒙࡢዊ ࡼࡾࠊࡉࡲࡊࡲ࡞ᅵᮌᘓ⠏ᴗࡀࠊ⢒〇℃㐀࠸ࡗ࡚࠾ࡋࡃ࡞࠸ࡼ࠺࡞㏿ᗘᩘ࡛ࠊḟࠎ㐙⾜ࡉࢀ ࡚࠸ࡗࡓࠋࡇࡢ⤖ᯝࠊᡂࡋ࡚࠶ࡲࡾࡀࡓࡓ࡞࠸࠺ࡕࠊ᪩ࡃࡶ③ࡳࡀ⾲ࢀ࡚ࡃࡿࠖࡇࡀ⿕ᐖࢆࡁࡃ ࡋࡓྍ⬟ᛶࡶᣦࡋ࡚࠸ࡿࠋ ௨ୖࡢ㆟ㄽࢆ⪃៖ࡍࢀࡤ㸪➹⪅ࡋ࡚ࡣ㸪᱈ᒣ᩿ᒙ㸦₯ᅾ᩿ᒙࡋ࡚ⓑἙࡢ㒊ศࡶྵࡴ㸧ࢆ㑅ᢥ⫥ࡢ୍ࡘ ࡋ࡚ṧࡋ࡚࠾ࡁ㸪 ࠕ᪤Ꮡࡢ㈨ᩱࡢ⠊ᅖෆ࡛ࡣࡕࡽࡶỴࡵࡽࢀ࡞࠸ࠖࡋ࡚࠾࠸ࡓ᪉ࡀ㈼᫂ᛮ࠼ࡿࠋ ࠶ࡿ࠸ࡣࠊᚋ㏙ࡢ㆟ㄽࡶྵࡵࠊ ࠕⰼᢡ᩿ᒙᖏ༡㒊ࠊ⍇⍈†すᓊ᩿ᒙᖏ༡㒊ࠖ࠸࠺ၥ㢟タᐃ࡛ࡣ࡞ࡃࠊ ࠕ᱈ᒣ᩿ᒙ㸦ⰼᢡ᩿ᒙᖏ༡㒊ࡢᨭ᩿ᒙࡢ㸯ࡘ㸧ࠊሀ⏣᩿ᒙࠖ࠸࠺ၥ㢟タᐃࡋࡓ᪉ࡀⰋ࠸ࡶゝ࠼ࡑ ࠺࡛࠶ࡿࠋᝎࡲࡋ࠸ࡢࡣࠊά᩿ᒙᏛⓗ࡞ドᣐ㸦ሀ⏣᩿ᒙࡢᧉ᭤ࡢ 6-8m ࡢୖୗᕪ㸧ࠊⓑἙ࠾ࡅࡿ⏒࡞ ⿕ᐖࡀ୧❧ࡋࡑ࠺ࡶ↓࠸ࡇ࡛࠶ࡿࠋ 䠑䠊⍇⍈†すᓊ᩿ᒙᖏ༡㒊 ⍇⍈†Ỉ᩿Ỉၥ㢟ࡢษ㏕ᛶࡣࠊ⍇⍈†すᓊ᩿ᒙᖏ༡ 㒊࡛ᆅ㟈ࡀ࠾ࡇࡿษ㏕ᛶࡗ࡚࠸ࡿゝ࠼ࡼ࠺ࠋ ➨㸶ᅗࡣࠊ㏆␥ᆅ᪉୰ኸ㒊ࡢᚤᑠᆅ㟈ศᕸ࡛࠶ࡿࠋⰼ ᢡ᩿ᒙᖏࡶ⍇⍈†すᓊ᩿ᒙᖏࡶࠊἼᒣᆅ␗ᖖᆅẆάື ᇦࡢᮾ➃⨨ࡋ࡚࠸ࡿࠋࡋࡋࠊ୧᩿ᒙᖏἢ࠸ࡢᆅ㟈 άືࡣᑡ࡞ࡃࠊᚤᑠᆅ㟈ศᕸࡽ᩿ᒙࡢഴࡁ࡞ࢆ᥎ᐃ ࡍࡿࡇࡣྍ⬟࡛࠶ࡿ㸦∦ᑿࠊ2005㸧㸯㸱㸧ࠋ 2006 ᖺ 10 ᭶ࠊி㒔Ꮫ㜵⅏◊✲ᡤᮾிᏛᆅ㟈◊ ✲ᡤࡼࡗ࡚ࠊἼᒣᆅࡽ⍇⍈†ࢆᶓ᩿ࡋ࡚⃰ᑿᖹ 㔝࠸ࡓࡿ⣙ 100 km ࡢ ⥺㸦➨㸷ᅗ㸧࡛ᑕἲᆅ㟈᥈ ᰝࡀ⾜ࢃࢀࡓ㸦బ⸨࣭ࠊ2008㸧㸯㸲㸧ࠋ➨ 10 ᅗࡣࡑࡢ⤖ ᯝゎ㔘࡛࠶ࡿࠋᅗ୰ኸࡢኴ᭤⥺㸦῝ࡉ 0m ࡽ 1000m㸧 ࡼࡾ῝࠸ࡇࢁࡀ㹎Ἴ㏿ᗘ 5km/s ࢆࡸࡸ㉺࠼ࡿⰼᓵᒾ㉁ Ṕ㜵 ࢩ࣏ࣥ ⍇⍈† Ỉ 2012-06-01.jtd −101− ➨㸶ᅗ 2007ᖺ㹼2011ᖺࡢ5ᖺ㛫ࡢ㏆␥ᆅ᪉୰ኸ㒊 ࡢᚤᑠᆅ㟈ᆅ㟈ศᕸࠋ∦ᑿ㸦⚾ಙ㸧ࡼࡿࠋ 5 12/06/08 ᒙࡢᇶ┙࡛࠶ࡿࠋᇶ┙ࡣࠊሀ⏣᩿ᒙ࡛ᮾ ഃࡀࡰ 300m ⴠࡕ㎸ࢇ࡛࠸ࡿࠋࡑࡇ ࡽ㕥㮵ᒣ⬦す⦕⮳ࡿᮾすᖜࡰ 10km ࡢὸ㒊ࢆ㹎Ἴ㏿ᗘ 2.1km/s ࡽ 2.3km/s ࡢሁ✚ᒙࡀᇙࡵ࡚࠸ࡿࠋ ሀ⏣᩿ᒙࡽすྥࡗ࡚ 20 r⛬ᗘ ࡢపゅ࡛すྥࡗ࡚ഴᩳࡍࡿ᩿ᒙ㠃ࢆ ᥎ᐃ࡛ࡁࡿࡀᚲࡎࡋࡶ᫂░࡛ࡣ࡞࠸ࠋ⍇ ⍈†᭱῝㒊ࡽపゅ࡛ᮾྥࡗ࡚ᘏࡧ ➨㸷ᅗ 2006 ᖺᑕἲ᥈ᰝࡢഃ⥺ࠋబ⸨࣭㸦2008㸧㸯㸰㸧ࡢᅗ ࡿ᩿ᒙ㠃ࡶᏑᅾࡍࡿࡀࠊࡑࡢ⣲ᛶࡣ᫂ ຍ➹ࠋ ࡛࠶ࡿࠋ ᆅ㟈ㄪᰝጤဨ㸦2009㸧㸯㸧ࡢά ᩿ᒙ㛗ᮇホ౯࡛ࡣࠊ⍇⍈†すᓊ᩿ᒙ ᖏ༡㒊࡛ࡢᆅ㟈Ⓨ⏕㛫㝸ࡣ 4500 ᖺ ࡽ 6000 ᖺࠊ๓ᅇࡢᆅ㟈ࡣ 1185 ᖺ M7.4 ඖᬺᆅ㟈ࠊࡋࡓࡀࡗ࡚ḟࡢᆅ 㟈ࡢ 30 ᖺⓎ⏕☜⋡ࡣࡶࡕࢁࢇࠊ300 ᖺⓎ⏕☜⋡ࡲ࡛ࡶࡰ㸮㸣࡛࠶ࡿࠋ ඖᬺᆅ㟈ࡢ㟈※᩿ᒙࢆ⍇⍈†すᓊ ᩿ᒙᖏ༡㒊ࡋࡓ᰿ᣐࡣࠊሀ⏣᩿ᒙ ➨ 10 ᅗ 2006 ᖺᑕἲ᥈ᰝࡼࡗ࡚ᚓࡽࢀࡓᆅẆὸศࡢᵓ㐀᩿㠃ᅗࠋబ ࡢࢪ࢜ࢫࣛࢧ࣮ㄪᰝࡼࡗ࡚ࠊ12 ୡ⣖๓ᚋ⏕ࡌࡓᧉ᭤ࢆᣳࢇ࡛ 6-8m ࡢኚᕪࡀ࠶ࡗࡓࡇ࡛࠶ࡿ㸦Kaneda et al., 2008㸧㸴㸧ࠋ ㈡┴ᩥ㈈ಖㆤ༠࣭㈈ᅋἲே㈡┴ᇙⶶᩥ㈈ಖㆤ༠ 2008㸯㸳㸧ࡢㄪᰝ࡛ࡣࠊᾋᚚᇽ㑇㊧ࡢ῝ࡉ㸰㹫ࡢ ࡇࢁᖹᏳ௦ࡢᆅᒙࡀぢ࠸ࡔࡉࢀࠊᖹᏳ௦ᚋᮇࡽ㙊 ௦ᛴ⃭ỿ㝆ࡋࡓࡇࡀ᫂ࡽࡉࢀࡓࠋࡇࡢ▱ぢ ࡣࠊඖᬺᆅ㟈ࡢࡁሀ⏣᩿ᒙࡀື࠸ࡓࡇㄪⓗ࡛࠶ࡿࠋ ࡢ≧ἣドᣐࡶྜࢃࡏ⪃࠼ࡿࠊඖᬺᆅ㟈ࡢࡁࠊሀ⏣᩿ ᒙࡀື࠸ࡓࡇࡣẚ㍑ⓗ☜ᐇ࡛࠶ࢁ࠺ࠋ ࡋࡋࠊ⍇⍈†すᓊ᩿ᒙᖏ༡㒊ࡣࠊࡽࠊẚⰋ᩿ᒙࠊ ሀ⏣᩿ᒙࠊẚཿ᩿ᒙࠊ⮃ᡤ᩿ᒙࡽᡂࡾ❧ࡘࡀࠊẚཿ᩿ᒙ ࡸ⮃ᡤ᩿ᒙࡢⓎ᥀ㄪᰝࡣ⾜ࢃࢀ࡚࠸࡞࠸ࠋ⮃ᡤ᩿ᒙ㸦➨ 11 ᅗ㸧ࡣᒁⓗࡣ᩿ᒙᆅᙧࡀ᫂░࡛࠶ࡿࡶ㛵ࢃࡽࡎࠊኚ ᆅᙧࡣ㐃⥆࡛ࠊపẁୣࢆኚࡉࡏ࡚࠸࡞࠸ྍ⬟ᛶࡀ 㧗ࡃࠊ᭱㏆ࡢᆅ㟈άືࡣ↓࠸ࠋ1184 ᖺ㸦ᑑỌ୕ᖺࠊඖᬺඖ ➨ 11 ᅗ ⮃ ᡤ ᩿ ᒙ ࡢ ⨨ ᅗ ࠋ ᑠ ᯇ ཎ ࣭ ᖺࡣࠊ※⠊㢗ࡽࡀᩘ㥽ࢆ⋡࠸࡚℩⏣ࡼࡾཧ㸪⢖ὠࡢ 㸦2011㸧㸶㸧ࡼࡿࠋ ྜᡓ࡛ᮌ᭯⩏௰ࢆᩋṚࡉࡏ࡚࠾ࡾࠊ℩⏣ᶫࡀ 1184 ᖺẁ㝵࡛ Ꮡᅾࡋ࡚࠸ࡓࡇࡣ㛫㐪࠸࡞࠸ࠋ୍᪉ࠊඖᬺᆅ㟈ࡢࡢᏱᶫࡢ⿕⅏ࢆࠕᒣᵘグࠖࠕ㓬㓮ᑎ㞧グࠖࡀグ㍕ ࡋ࡚࠸ࡿࡀ㸪℩⏣ᶫࡢ⿕⅏グ㘓ࡣᏑᅾࡋ࡞࠸㸦ᑠᯇཎࠊ2011㸧㸯㸲㸧ࡢ࡛ࠊ℩⏣ᶫࡣⴠࡕ࡞ࡗࡓ⪃࠼ࡿ ࡣ࡞࠸ࠋࡇࡢⅬࡽࡶࠊ⮃ᡤ᩿ᒙࡣື࡞ࡗࡓᛮࢃࢀࡿࠋ 䠒䠊䜎䛸䜑 ➨㸵ᅗி㒔ᕷࡢࢆ♧ࡋࡓࡀࠊி㒔ᗓࡶࠊὠᕷࡶࠊ㈡┴ࡶࠊ⍇⍈†すᓊ᩿ᒙᖏࢆᆅ㟈᩿ᒙࡋࡓሙ ྜࡢᆅ㟈ືࡼࡿ㟈ᗘᐃ⿕ᐖண ࢆ⾜ࡗ࡚࠸ࡿࠋࡋࡋࠊࡼࡃ⪃࠼ࡿࠊࡑࡢࡁࠊ㟈※࡛ࡣ᩿ᒙࡀ ࡁࡃࡎࢀ࡚࠸ࡿࡢ࡛࠶ࡿࠋᙜ↛ࡢࡇ࡞ࡀࡽࠊ⍇⍈†Ỉ࡛ࡶ᩿⤯ࡀ㉳ࡇࡗ࡚࠸ࡿࠋࡶࡕࢁࢇࠊḟࡢᆅ㟈ࡢ Ṕ㜵 ࢩ࣏ࣥ ⍇⍈† Ỉ 2012-06-01.jtd −102− 6 12/06/08 ࠊࡇࡢ㒊ศࡀື࡞࠸ྍ⬟ᛶࡶ࠶ࡿࡀࠊࡇࡢ㒊ศࡀ☜ᐇᗘࡢ㧗࠸ά᩿ᒙ࡛࠶ࡿ௨ୖࠊ࠸ࡘࡣ☜ᐇ⍇⍈ †Ỉࢆ᩿⤯ࡍࡿືࡁࢆࡍࡿࡇࡣ㛫㐪࠸࡞࠸ࠋࡋࡶ῝้࡞ࡢࡣࠊࢺࣥࢿࣝࡢᗏ㠃ࡀ km ཬࡪ㛗࠸㊥㞳 ࡛⍇⍈†ࡢᖹᆒỈ㠃ࡼࡾ㧗ࡃ࡞ࡿࡢ࡛ࠊ▷ᮇ㛫ಟ࡛ࡁࡿᛶ㉁ࡢࡶࡢ࡛ࡣ࡞࠸ࡇ࡛࠶ࡿࠋ᪤Ꮡࡢ⿕ᐖ ᐃ࡛ࡇࡢᵝ࡞ၥ㢟ࡀぢ㏨ࡉࢀ࡚࠸ࡓࡢࡣࠊ┣Ⅼࡔࡗࡓゝ࠼ࡼ࠺ࠋ ᪥ᮏᅜ୰ࡇࡶά᩿ᒙࡀ࠶ࡿࡢ࡛ࠊࡇ࡛ࡶࡇࡢᵝ࡞ࣜࢫࢡࡀ࠶ࡿࡢゝ࠼ࡤពእࡑ࠺࡛ࡣ࡞࠸ࠋ ᆅẆኚືࡀࠊ⍇⍈†Ỉ᩿⤯ࡢࡼ࠺࡞ࡸࡗ࠸࡞⅏ᐖࢆᘬࡁ㉳ࡇࡍࣜࢫࢡࡀᏑᅾࡍࡿࡢࡣࠊࠕ⦪ࡎࢀ᩿ᒙ࡛ ୗὶࡀୖ┙ࠖ࠸࠺እⓗ࡞⨨㛵ಀ࠶ࡿࡇࠊࠕὶ㊰ࡀࢺࣥࢿࣝࠖ࠸࠺㸰Ⅼࡀၥ㢟ࢆ㉳ࡇࡋ࡚࠸ࡿ ࡽ࡛࠶ࡿࠋ ࡶࡕࢁࢇࠊ⌧ᅾࡢᆅ㟈Ꮫࡸά᩿ᒙᏛࡢ▱㆑ࡢ⠊ᅖෆ࡛ࡣࠊࡇࡇ࡛ᐃࡋࡓ㏻ࡾࡢᆅ㟈ࡀ㉳ࡇࡿ࠺ࡣ ศࡽ࡞࠸ࠋ᩿ᒙୖࡢࡾࡢሙᡤኚࡶࡁ࠸ࡋࠊ㟈※᩿ᒙࡀᆅ⾲✺ࡁฟࡿ࠺ࡶண ࡛ࡁ࡞࠸ࠋࡋ ࡋࠊୖ㏙ࡢࡼ࠺࡞ࣜࢫࢡࡀ₯ᅾࡋ࡚࠸ࡿࡇࡔࡅࡣㄆ㆑ࡋ࡚࠾ࡁࡓ࠸ ࡇࡢࣜࢫࢡࡣࠊி㒔ࡢṔྐ㒔ᕷ㜵⅏ࡗ࡚ᴟࡵ࡚῝้࡞ၥ㢟࡛࠶ࡿࡢࡶ㛵ࢃࡽࡎࠊ⌧ᅾࡢⅬ࡛ࡣࠊవ ࡾࡶከࡃࡢࡇࡀ᭕࡛࠶ࡿࠋ⍇⍈†すᓊ᩿ᒙᖏ༡㒊ࡸⰼᢡ᩿ᒙᖏ༡㒊࠾ࡅࡿᆅ㟈Ⓨ⏕ࣜࢫࢡࢆ᫂ࡽ ࡋࠊ⍇⍈†Ỉ᩿⤯ࠊὠἼࠊὥỈࡢࣜࢫࢡࢆホ౯ࡋࠊᑐ⟇ࡀᥦ࡛ࡁࡿࡼ࠺࡞ࡿࡓࡵࠊᚋࡢẚཿ᩿ ᒙࡸ⮃ᡤ᩿ᒙ࡛ࡢ᩿ᒙⓎ᥀ㄪᰝࠊἙᕝᏛࡢඹྠ◊✲࡞ࡀᴟࡵ࡚㔜せ࡛࠶ࡿࠋ ཧ⪃ᩥ⊩ 1 ᆅ㟈ㄪᰝጤဨ㸸୕᪉࣭ⰼᢡ᩿ᒙᖏࡢ㛗ᮇホ౯ࡘ࠸࡚㸬ᆅ㟈ㄪᰝ◊✲᥎㐍ᮏ㒊ᆅ㟈ㄪᰝጤဨ HPࠊ2003㸬 2 Okada, Y.㸸Internal deformation due to shear and tensile faults in a half-space, Bulletin of Seismological Society of America, 82, 1018-1040, 1992. 3 㧗ᶫᫀ᫂㸸㣴ࡢ㣚㤡ࠊඖᬺࡢᆅ㟈㬞㛗᫂ࠊᩥᏛࠊ13 ᕳࠊ2 ྕࠊ48-60ࠊ2012㸬 4 ᮾ㒓ṇ⨾࣭బ⸨ẚ࿅ᚿ࣭ᔱᮏᙪ࣭ሐே࣭㤿࣭୰ᮧಇኵ㸸ⰼᢡ᩿ᒙࡢ᭱᪂άືࡘ࠸࡚㸬ά᩿ᒙ◊✲㸪16㸪 44 㸫 52, 1997㸬 5 ྜྷᒸᩄ㺃ⱉ㇂ឡᙪ㺃ᒣ ኴ㺃ᒸ⏣⠜ṇ㺃➉ᮧᜨ1998㸸ࢺࣞࣥࢳⓎ᥀ㄪᰝᇶ࡙ࡃⰼᢡ᩿ᒙࡢ᭱᪂άື 1662 ᖺᐶ ᩥᆅ㟈㸬ᆅ㟈ϩࠊ51ࠊ83-97. 6 Kaneda, H., H. Kinoshita and T. Komatsubara: An 18,000-year record of recurrent folding inferred from sediment slices and cores across a blind segment of Biwako-seigan fault zone, central Japan. Jour. Geophys. Res., 113, B05401, 2008. 7 すᒣோ: ඖᬺᖺ1185ி㒔ᆅ㟈࠾ࡅࡿி㒔࿘㎶ᆅᇦࡢ⿕ᐖᐇែ㸪Ṕྐᆅ㟈, No.16, pp163-184, 2000. 8 ᑠᯇཎ㷹㸸㏆Ụ┅ᆅ༡㒊ࡢάᵓ㐀ඖᬺᖺᆅ㟈ࡢ㉳㟈᩿ᒙ㛵ࡍࡿ⪃ᐹࠊ➨ 28 ᅇṔྐᆅ㟈◊✲Ⓨ⾲ㅮ₇せ᪨㞟ࠊ 16ࠊ2011㸬 9 㧗ᶫᫀ᫂㸸᪥ᮏྐᏛ⪅ࡢぢࡓඖᬺᖺ᭶ி㒔ᆅ㟈ࡘ࠸࡚ࠊ᭶หᆅ⌫ࠊ27ࠊ11ࠊ2005㸬 10 ி㒔ᕷ㸸ி㒔ᕷ➨㸱ḟ⿕ᐖᐃࠊhttp://www.city.kyoto.lg.jp/shobo/page/0000015600.htmlࠊ2003. 11 ᒸ⏣⠜ṇ㺃ᮾ㒓ṇ⨾㺃୰⏣ 㧗㺃᳜ᮧၿ༤㺃Ώ㎶‶ஂ1996㸸1:25,000 㒔ᕷᅪά᩿ᒙᅗ㺀ி㒔ᮾ㒊㺁㸬ᅜᅵᆅ⌮㝔ᢏ⾡ ㈨ᩱࠊD.1-333. 12 Ᏹబ⨾㱟ኵ㸸ࠕ᭱᪂∧ ᪥ᮏ⿕ᐖᆅ㟈⥲ぴ >416@-2001ࠖࠊᮾிᏛฟ∧ࠊ2003㸬 13 ∦ᑿᾈ㸸Ἴᒣᆅ࠾ࡅࡿ᭱㏆ࡢᚤᑠᆅ㟈άືࡢ㟼✜ࠊி㒔Ꮫ㜵⅏◊✲ᡤᖺሗ 48ࠊBࠊ167-174ࠊ2005㸬 14 బ⸨ẚ࿅ᚿ࣭ᖹ⏣┤࣭ᒾᓮ㈗ဢ࣭⧴⧭୍㉳࣭ఀ⸨₩࣭ᱵ⏣ᗣᘯ࣭ఀ⸨㇂⏕࣭➟ཎᩗྖ࣭ຍ⸨┤Ꮚ㸸㏆␥ᆅẆᵓ㐀᥈ ᰝࠊ㒔ᕷ⅏ᐖ㍍ῶ≉ูࣉࣟࢪ࢙ࢡࢺᡂᯝሗ࿌᭩ࠊ538-553ࠊ2006㸬 15 ㈡┴ᩥ㈈ಖㆤ༠࣭㈈ᅋἲே㈡┴ᇙⶶᩥ㈈ಖㆤ༠2008㸸⍇⍈†す༡㒊ࡢ†ᗏ࣭†ᓊ㑇㊧ ┿㔝⯚⁀࣭ ᾋᚚᇽ㑇㊧࣭✰ኴ㑇㊧࣭၈ᓮ㑇㊧࣭Ụ†ᗏ㑇㊧ࠊ⍇⍈†㛤Ⓨᴗ㛵㐃ᇙⶶᩥ㈈Ⓨ᥀ㄪᰝሗ࿌᭩㸶ࠊ2008㸬 −103− Ṕ㜵 ࢩ࣏ࣥ ⍇⍈† Ỉ 2012-06-01.jtd 7 12/06/08