京 都 大 学 防 災 研 究 所 年 報 第 50 号 B 平 成 19 年 4 月
Annuals of Disas. Prev. Res. Inst., Kyoto Univ., No. 50 B, 2007⑔੗⋵Ꭸർ࿾ᣇߦ߅ߌࠆ࿾㔡ߩ⊒↢․ᕈ
ጟᧄᜏᄦ*࡮ᐔ㊁ᙗ㓶࡮๺↰ඳᄦ࡮┻ౝᢥᦶ࡮⷏਄᱄਽࡮ᷰㄝ㇌ᒾ
*⑔੗Ꮏᬺ㜞╬ኾ㐷ቇᩞⷐ ᣦ੩ㇺᄢቇ㒐ἴ⎇ⓥᚲ࿾㔡੍⍮⎇ⓥ࠮ࡦ࠲࡯ർ㒽᷹ⷰᚲߪ㧘ᐕࠃࠅർ㒽࿾ၞߩᓸዊ࿾㔡ᵴേࠍᛠីߒߡ߈ߚ ‫৻ߩ࠲࡯࠺ޕ‬రൻߦࠃࠅ᳇⽎ᐡ㧘*KPGVߩᖱႎࠍ౉ࠇߡ⃻࿷⸃ᨆࠍⴕߞߡ޿ࠆ‫ޕ‬ᐕߩᧃ޽ߚࠅࠃࠅ㧘Ꭸർ࿾ၞߩ࿾㔡⊒↢ᢙߦᷫዋ௑ะ߇ુ߃ࠆࠃ߁ߦߥߞߚ‫ߚ߹ޕ‬㧘ᅏ⿧࿾ၞߢߪ㗼⪺ߥᄌൻߪ⹺߼ࠄࠇߥ߆ߞߚ‫ޕ‬หᤨߦ㧘⑔੗⋵ౝߢ⊒↢ߔࠆ᦭ᗵ࿾㔡ߩಽᏓ߇㧘ᅏ⿧࿾ၞߢ㗼⪺ߦߥߞߚ‫ޕ‬ᅏ⿧࿾ၞߪ㧘⃻࿷ᵈ⋡ߐࠇߡ޿ࠆᱡ㓸ਛᏪߦ૏⟎ߒ㧘ᦨㄭߩਥⷐߥ࿾㔡ߩࡔࠞ࠾࠭ࡓ⸃ߩRゲߣ㓸ਛᏪߩਥ࿶ജゲ߇৻⥌ߒߡ޿ࠆ‫ߎޕ‬ߩߎߣߪD୯ߩ⸃ᨆ⚿ᨐߣ߽৻⥌ߒ㧘ᅏ⿧ߢߩ࿾㔡ᵴേߩផ⒖ߦᵈᗧߔࠆᔅⷐᕈࠍ␜ߒߡ޿ࠆߩ߆߽⍮ࠇߥ޿‫ ޕ‬ᴾࠠ࡯ࡢ࡯࠼࿾㔡ᵴേ㧘b୯㧘ᵴᢿጀ㧘㔡ᐲ㧘⊒㔡ᯏ᭴ ߪߓ߼ߦ⑔੗⋵෸߮ߘߩ๟ㄝߪ㧘᦭ผએ᧪ࠃࠅᄢ࿾㔡ߩ⊒↢߇⍮ࠄࠇ㧘․ߦ⑔੗࿾㔡㧔1948㧘M7.1㧕ߪ⸥ᙘߦᣂߒ޿‫ޕ‬ᒰ࿾㔡ߪ㧘ㄭઍㇺᏒߩᦨೋߩ⋥ਅဳ࿾㔡ߣߒߡ㧘ߘߩ⊒↢ᯏ᭴ߣⵍኂ⺞ᩏߩ⸃ᨆߪ⃻࿷ߢ߽㊀ⷐߥ࠹࡯ࡑߦߥߞߡ޿ࠆ‫ޕ‬੩ㇺᄢቇ㒐ἴ⎇ⓥᚲ࿾㔡੍⍮⎇ⓥ࠮ࡦ࠲࡯ർ㒽᷹ⷰᚲߪ㧘1976ᐕࠃࠅ⑔੗⋵෸߮ߘߩ๟ㄝၞߩ࿾㔡ᵴേߩᛠីࠍⴕߞߡ߈ߚ‫ᦨޕ‬ㄭߩ࿾㔡ᵴേߩ․ᓽߣߒߡߪጟᧄઁ㧔2006㧕ߢ߽߰ࠇߡ޿ࠆ߇㧘ᵴᢿጀߦᴪ߁ᵴേߣᦨㄭ㗼⪺ߦߥߞߡ߈ߚ႙⁁ߩᵴേߢ޽ࠆ‫ޕ‬႙⁁ߩಽᏓߪ㧘ᵴᢿጀߩ࠻࡟࡯ࠬࠃࠅ߿߿㔌ࠇߥ߇ࠄಽᏓߒߡ޿ࠆ‫߁ࠃߩߎޕ‬Fig. 1 The square shows the Reihoku region in Fukui

ߥ․ᓽࠍ␜ߒߥ߇ࠄ㧘2003ᐕߩᧃ㗃ࠃࠅᎨർో૕ߢ

Prefecture.࿾㔡⊒↢ᢙߩ ᷫዋ௑ะ߇⹺ ߼ࠄࠇࠆࠃ߁ ߦߥߞߚ ᦨㄭߩ࿾㔡ᵴേ㧔ጟᧄઁ㧘2006㧕‫ޕ‬ᅏ⿧ઃㄭߦ㒢ቯߔࠆߣ㧘㗼⪺ߥᷫዋ௑ะߪ⹺߼ࠄࠇߥ߆ߞߚ‫ޕ‬Fig.1ߦᎨർ࿾ၞࠍ␜
ߔ‫ޕ‬ᅏ⿧ߪ㧘⑔੗⋵ߩ᧲ㇱߦ޽ࠅಽ᳓Ꭸࠍᒻᚑߔࠆ‫ޕ‬

Fig.2ߦ㧘ᦨㄭߩᎨർߩ࿾㔡ᵴേ㧔2001ᐕ1᦬㨪2005ㄭ㓞ߦߪ⊕ጊ߽ሽ࿷ߒ㧘࿾Ზᵴേ߇ᵴ⊒ߥ㗔ၞߢ޽

ᐕ8᦬㧘M҈1㧘h҇30km㧕ࠍ␜ߔ‫ޕ‬࿑ਛߩታ✢ߪ㧘ᵴࠆߎߣ⠨߃ࠄࠇࠆ㧔ጊᧄઁ㧘2004㧕‫ᧄޕ‬ႎ๔ߢߪ㧘bᢿጀߩ࿾਄࠻࡟࡯ࠬߢ޽ࠆ‫ޕ‬㗼⪺ߥᢿጀߪ㧘⑔੗࿾୯ߩ⚿ᨐ㧘㗼⪺ߥ࿾㔡ߩࡔࠞ࠾࠭ࡓ⸃╬ࠍ␜ߒߥ߇㔡ᢿጀ㧘᷷⷗ᢿጀ㧘↲ᭉၔᢿጀ㧔⿧೨ᶏጯߦᴪ߁㧕㧘ࠄ࿾㔡ᵴേߩ․ᓽࠍ᣿ࠄ߆ߦߒ㧘⊒↢․ᕈߦߟ޿ߡቲᘮኹᢿጀߢ޽ࠆ‫ޕ‬࿾㔡ᵴേߪᢿጀઃㄭߦሽ࿷ߔࠆ⸒෸ߔࠆ‫ޕ‬߇㧘✢⁁ߣ޿߁ࠃࠅߪ႙⁁ߦሽ࿷ߒߡ޿ࠆⷰ߇޽ࠆ‫ޕ‬ᴾ－ 327 －㑐ଥߥߊ⊒↢ߒߡ޿ࠆ‫ߪߣߎߩߎޕ‬㧘㓝ࠇߚ㧔⹺⍮㪜㫇㫀㪺㪼㫅㫋㪼㫉㩷㪽㫆㫉㩷㪩㪼㫀㪿㫆㫂㫌㩷㪩㪼㪾㫀㫆㫅㩷㩷㩷㩷㩷㩷㩷㩷㩿㫄㻢㪈䇮㪇㪈㪇㪈㩷㪄㩷㪇㪌㪇㪏䋩㩷㩷㩷㩷㩷㩷㩷ߐࠇߡ޿ߥ޿㧕ᵴᢿጀ߇ሽ࿷ߒߡ޿ࠆߩ߆㧘ᔕജౣ㈩ಽߦࠃࠆᣂߒ޿⎕უ㕙ߩᒻᚑ߇ᆎ߹ߞߡ޿ࠆߎߣ㪈㪊㪍㫦ࠍ␜ໂߒߡ޿ࠆน⢻ᕈ߇޽ࠆ‫ޕ‬ ࡔࠞ࠾࠭ࡓ⸃Fig.3ߦ㧘ᦨㄭࡔࠞ࠾࠭ࡓ⸃ࠍ᳞߼ߚ࿾㔡ߩಽᏓࠍ␜ߔ‫ޕ‬ಽᏓࠍ␜ߒߚᦼ㑆ߪ㧘2004ᐕ5᦬㨪2007ᐕ1᦬㪊㪍㫦ߢ޽ࠆ‫ࠍ⸃ࡓ࠭࠾ࠞࡔޕ‬᳞߼ࠆ੐߇ߢ߈ࠆ࿾㔡ߪ㧘ೋേߩ᛼ߒᒁ߈ᖱႎߦࠃࠆೋേࡔࠞ࠾࠭ࡓ⸃ߩᣇᴺࠍ↪޿ߡ޿ࠆߎߣߦࠃࠅ㧘޽ࠆ⒟ᐲߩⷙᮨ߇ᔅⷐߦ
ߥࠆ‫ᧄޕ‬ႎ๔ߩ႐ว㧘M2.9એ਄ߢ޽ࠆ‫ޕ‬M2.9એ਄ߪ㧘߶߷᦭ᗵ㔡ᐲ߇⸘᷹ߐࠇࠆߣ⠨߃ࠄࠇࠆ‫ߣߎߩߎޕ‬ߪᦨㄭ㧘⑔੗⋵෸߮๟ㄝߢߩ᦭ᗵ࿾㔡ߩ⊒↢߇㧘ᅏ⿧࿾ၞࠍਛᔃߦ⹺߼ࠄࠇࠆࠃ߁ߦߥߞߚߎߣࠍᗧ๧
ߒ㧘⑔੗࿾ᣇ᳇⽎บߩႎ๔㧔2006㧕ߣ৻⥌ߒߡ޿ࠆ‫ޕ‬⑔੗࿾ᣇ᳇⽎บߦࠃࠇ߫㧘㐳⦟Ꮉ਄ᵹᢿጀᏪઃㄭߩ
᦭ᗵ࿾㔡ߩ࿁ᢙ߇Ⴧ߃ߡ߅ࠅ㧘ߎࠇ߇ᅏ⿧ߦ㓸ਛߒߡ޿ࠆࠃ߁ߦ⷗߃ࠆේ࿃ߣߥߞߡ޿ࠆ‫ޕ‬࿾㔡ᵴേߩ

Fig. 2 Seismicity for Reihoku region, M㻢1, h㻡30km.

Ⓧ▚ᦛ✢ߩߣߎࠈߢ߽߰ࠇࠆ߇㧘ᅏ⿧ߢߩM҈1એ਄ߩ࿾㔡ᢙߦ㗼⪺ߥᄌൻߪ⹺߼ࠄࠇߡ޿ߥ޿ߩߢ㧘߿㪜㪸㫉㫋㪿㫈㫌㫂㪼㫊㪃㩷㪛㪼㪺㫀㪻㪼㪻㩷㫋㪿㪼㩷㪝㪸㫌㫃㫋㪄㫇㫃㪸㫅㪼㩷㪪㫆㫃㫌㫋㫀㫆㫅㫊㩷㪩㪼㪺㪼㫅㫋㫃㫐㩷㩷㩷㩷㩷㩷㩷㩷㩷㩷㩷㩷㩷㩷㩷㩷㩷㩷㩷㩷㩷㩷㩷㩷㩷㩷㩷㩷㩷㩷㩷㩷㩷㩿㪇㪋㪇㪌㩷㪄㩷㪇㪎㪇㪈㪀߿ᄢ߈߼ߩ࿾㔡ߩᲧ₸߇਄߇ߞߚߣ⠨߃ࠆߩ߇ᅷᒰߢ޽ࠆ‫ߪߣߎߩߎޕ‬㧘b୯ߩ⸃ᨆߩ㗄ߢ⹦ߒߊ⼏⺰ߔࠆ‫ޕ‬
Fig.4ߦ㧘2006ᐕ1᦬22ᣣߦ⊒↢ߒߚM4.4ߩ࿾㔡ߩ೨㔡㧘ᧄ㔡㧘૛㔡㧔⊒↢ᓟ2ᣣ㑆㧕ࠍMJHDߢౣ᳿ቯߒߚ߽ߩࠍ␜ߔ‫ߚ߹ޕ‬㧘fig.5ߦᧄ㔡ߩࡔࠞ࠾࠭ࡓ⸃㧔ਅඨ⃿╬Ⓧᛩᓇ㧕ࠍ␜ߔ‫ߩߎޕ‬࿾㔡ߪᩮየ⼱ᢿጀ♽ߩർ⷏┵ߢ⊒↢ߒߚⷰ߇޽ߞߚ߇㧘૛㔡ಽᏓ߿ࡔࠞ࠾࠭ࡓ⸃ࠃࠅᩮየ⼱ᢿጀ♽ߦ㓞ធߔࠆർ᧲㧙ධ⷏ᣇะߦ⿛ะࠍᜬߟ㧘╣ࡩፄᢿጀ㧔࿾㔡⟲ߩ⋥ߋർ⷏㧕ߦ⊒↢ߒߚߣ⠨߃ࠆᣇ߇ᅷᒰ߆߽ߒࠇߥ޿‫᦭ޕ‬ജߥ㪇㪎㩷㪇㪈㪆㪉㪉㩷㪤㪋㪅㪋ᩮየ⼱ᢿጀ♽ߢߪߥߊ㧘⇣ߥߞߚ⿛ะߢ⊒↢ߒߚߎߣ㧘pゲ߇ᱡ㓸ਛᏪߩਥ࿶ജゲߣ৻⥌ߔࠆߎߣࠃࠅ㧘
ᔕജߩౣ㈩ಽߦࠃࠅ⊒↢ߒߚน⢻ᕈ߇⠨߃ࠄࠇࠆ‫ޕ‬⃻࿷㧘ᅏ⿧࿾ၞߦ߿߿ᄢ߈߼ߥ࿾㔡߇⊒↢ߒߡ޿ࠆ‫ޕ‬ᰴ㗄ߩ࿾㔡ߩ⊒↢ᢙߩᄌൻߣ࡝ࡦࠢߐߖߥ߇ࠄ㧘ᵈⷞߒߡ޿ߊᔅⷐᕈ߇޽ࠆߣ⠨߃ࠄࠇࠆ‫ޕ‬

Fig. 3 Distribution of Earthquake of which fault planesolution is estimated.

 ࿾㔡ߩ⊒↢ᢙᧄ┨ߢߪ㧘࿾㔡ߩ⊒↢ᢙߩᄌൻࠍ⼏⺰ߔࠆ‫ᦼޕ‬㑆৻ߟ৻ߟߩ႙ߪ㧘࿾㔡⟲㧔ᧄ㔡࡮૛㔡㧘⟲⊒㧕ߩᒻߪ㧘2001ᐕ1᦬㨪2005ᐕ8᦬ߢ㧘㧹҈1㧘h҇30kmߩ࿾ᘒࠍߥߒ㧘ߘࠇߙࠇᵴേᦼ㑆߇⇣ߥࠆ‫ߩࠇߙࠇߘޕ‬㔡ࠍ࠺࡯࠲ߣߒߚ‫⸃ޕ‬ᨆ㗔ၞߪ㧘Ꭸർో૕ߣᅏ⿧࿾႙ߪ㧘ᵴᢿጀߩ࠻࡟࡯ࠬࠃࠅ޿ߊࠄ߆㔌ࠇߚࠅ߽ߒၞߢ޽ࠆ‫ޕ‬Fig.6ߦᅏ⿧࿾ၞߩ㔡ᄩ࿑㧘fig.7a㧔Ꭸർ㧕㧘ߡ߅ࠅ㧘ࡈ࡟࠶ࠪࡘߥㇱಽࠍ⎕უߒߡ޿ࠆߩ߆߽ߒ7b㧔ᅏ⿧㧕ߦ㧘Ⓧ▚ᦛ✢ࠍ␜ߔ‫࡜ࠢ࠺ߪ✢ᦛߩߎޕ‬ࠇߥ޿‫ߦ․ޕ‬ᅏ⿧࿾ၞߢߪ㧘ᵴᢿጀߩ࠻࡟࡯ࠬߣߪ

－ 328 －㪜㫇㫀㪺㪼㫅㫋㪼㫉㩷㪽㫆㫉㩷㪦㫂㫌㪼㫋㫊㫌㩷㪩㫀㪼㪾㫀㫆㫅㩷㩷㩷㩷㩿㫄㻢㪈䇮㪇㪈㪇㪈㩷㪄㩷㪇㪌㪇㪏㪀㪇㪎㩷㪇㪈㪆㪉㪉㩷㪤㪋㪅㪋㩷㩿㫇㫉㪼㪄㫊㪿㫆㪺㫂䇮㫄㪸㫀㫅㪄㫊㪿㫆㪺㫂䇮㪸㪽㫋㪼㫉㪄㫊㪿㫆㪺㫂㪀㩷㩷㩷㩷㩷㩷㩷㩷㩷㩷㩷㩷㩷㩷㩷㩷㩷㩷㩷㩷㩿㪇㪈㪆㪉㪈㩷㪄㩷㪇㪈㪆㪉㪊䇮㪹㫐㩷㪤㪡㪟㪛㪀

Fig. 6 Seismicity for Okuetsu region, M㻢1, h㻡30km.
Fig. 4 Hypocenters of pre, main, after shocks of M4.4,
ߪ㧘ᅏ⿧࿾ၞߢ࿾㔡߇⊒↢ߒ߿ߔ޿⁁ᴫߦߥߞߡ޿

2007, 01, 22.

ࠆߎߣ␜ໂߒߡ޿ࠆߩ߆߽ߒࠇߥ޿‫ޕ‬ᅏ⿧ઃㄭߩ࿾㔡ᵴേߩ․ᓽߣߒߡߪ㧘ᵴᢿጀߦߪ㑐ଥߥߊ႙⁁ߦ⊒↢ߒߡ޿ࠆࠃ߁ߦ⷗߃ࠆߎߣߢ޽ࠆ‫ޕ‬ᅏ⿧࿾ၞߪᱡ㓸ਛᏪ㧔㣕⼱࡮੗਄㧘2003㧕ߦ૏⟎ߒߡ߅ࠅ㧘ᒰ࿾ၞߢ⊒↢ߒߡ޿ࠆ࿾㔡ߩࡔࠞ࠾࠭ࡓ⸃ࠍ⠨ᘦߔࠆߣ㧘ࡈ࡟࠶ࠪࡘߥ㕙ࠍ⎕უߒߡ޿ࠆࠃ߁ߥ࿾㔡߇⊒↢ߒ߿ߔ޿⁁ᴫߦߥߞߡ޿ࠆߩ߆߽⍮ࠇߥ޿‫ޕ‬ D୯೨┨ߢ߽ขࠅ਄ߍߚ߇㧘ᅏ⿧࿾ᣇߢ߿߿ᄢ߈߼ߩ࿾㔡ᵴേ߇⹺߼ࠄࠇࠆ᭽ߦߥߞߚ‫ࠍ⽎⃻ߩߎޕ‬ቯ㊂ൻߔࠆߚ߼㧘b୯ߩ⸘▚ࠍⴕߞߚ‫ޕ‬Fig.8a㧘8bߦᎨർో૕ߣᅏ⿧ߩ୯ࠍߘࠇߙࠇ␜ߔ‫⸃ޕ‬ᨆࠛ࡝ࠕߪ㧘ⓍFig. 5 Fault plane solution of M4.4, 2007, 01, 22.

▚ᦛ✢ࠍ᳞߼ߚ࿾ၞߣߘࠇߙࠇ৻⥌ߒ㧘⸘▚ߦ૶↪
ࠬ࠲࡯╬ߩಣℂߪߐࠇߡ߅ࠄߕ㧘ർ㒽᷹ⷰᚲߩ࠺࡯ߒߚᦼ㑆ߪ㧘2001ᐕ1᦬㨪2005ᐕ6᦬ߢ޽ࠆ‫࠾ࠣࡑޕ‬࠲࠮࠶࠻ߦࠃࠆ߽ߩߢ޽ࠆ‫ޕ‬Ꭸർో૕ࠍ⷗ࠆߣ㧘2003࠴ࡘ࡯࠼ߩਅ㒢ߪ1ߢ޽ࠆ‫ߪߦ▚⸘ޕ‬㧘ᦨዕᴺࠍ↪޿ᐕᧃࠃࠅᷫዋ௑ะߩ․ᓽ߇⹺߼ࠄࠇࠆ‫ޕ‬ㅜਛߢࠬ࠹ߚ‫⚿ޕ‬ᨐࠍ⷗ࠆߣ㧘ᅏ⿧࿾ၞߦ㒢ቯߒߡ᳞߼ߚᣇ߇b࠶ࡊ⁁ߦჇടߒߡ޿ࠆ㧔2002ᐕ10᦬㧕ߩߪ㧘⊕ጊർ୯߇ዊߐߊ㧘ᅏ⿧࿾ၞߢ߿߿ᄢ߈߼ߩ࿾㔡߇⊒↢ߒ⷏ㇱઃㄭߢ⊒↢ߒߚ⟲⊒࿾㔡ࠃࠆ߽ߩߢ޽ࠆ‫ߩߎޕ‬߿ߔ޿⁁ᴫߢ޽ࠆߎߣࠍ዁ߦ⴫ߒߡ޿ࠆߣ⠨߃ߡࠃᷫዋ௑ะߪ㧘ਤᵄ࿾ၞߢ߽ႎ๔ߐࠇߡ޿ࠆ㧔੩ㇺᄢ޿‫ߪߣߎߩߎޕ‬೨┨ߢ߽߰ࠇߚ߇㧘ᅏ⿧࿾ၞߣᎨർቇ㒐ἴ⎇ⓥᚲ࿾㔡੍⍮⎇ⓥ࠮ࡦ࠲࡯㧘2007㧕‫ޕ‬ኻߒߩઁߩ࿾ၞߢ࿾㔡ߩ⊒↢᭽ᑼ߇⇣ߥߞߡ޿ࠆน⢻ᕈߡᅏ⿧࿾ၞߦ㒢ቯߔࠆߣ㧘ߎߩᷫዋߪ߶ߣࠎߤ⏕⹺ࠍ␜ߒߡ޿ࠆน⢻ᕈ߇޽ࠆ‫⑔ߦ․ ޕ‬੗࿾㔡ᢿጀઃㄭߢ߈ߥ޿‫ߪߣߎߩߎޕ‬㧘Ꭸർߩઁߩ࿾ၞߩ࿾㔡⊒↢ߦᵈ⋡ߔࠆߣ㧘ᅏ⿧ઃㄭߣߩႺ⇇ߣߥࠆᳰ↰↸޽ߚᢙ߇㧘߆ߥࠅߩഀวߢᷫዋߒߡ޿ࠆߎߣࠍᗧ๧ߒߡࠅߢ࿾Ზౝ࿾㔡ߩਅ㒢߇ᦨ߽ᵻߊ㧔ጟᧄઁ㧘2006㧕㧘޿ࠆ‫ޕ‬ᅏ⿧࿾ၞߣઁߩ࿾ၞߩ࿾㔡⊒↢ᢙߩࠡࡖ࠶ࡊ

－ 329 －㪚㫌㫄㫌㫃㪸㫋㫀㫍㪼㩷㪺㫌㫉㫍㪼㩷㪽㫆㫉㩷㩷㪩㪼㫀㪿㫆㫂㫌㩷㪩㪼㪾㫀㫆㫅㩷㩷㩷㩷㩷㩷㩷㩷㩷㩷㩷㩷㩿㫄㻢㪈䇮㪇㪈㪇㪈㩷㪄㩷㪇㪌㪇㪏㪀㪹㪄㫍㪸㫃㫌㪼㩷㪽㫆㫉㩷㪩㪼㫀㪿㫆㫂㫌㩷㪩㪼㪾㫀㫆㫅㩷㩷㩷㩿㫄㻢㪈䇮㪇㪈㪇㪈㩷㪄㩷㪇㪌㪇㪍䋩㪹䋽㪇㪅㪐㪌㪍

Fig. 7a Cumulative number for Reihoku region.

Fig. 8a The b-value for Reihoku region㪚㫌㫄㫌㫃㪸㫋㫀㫍㪼㩷㪚㫌㫉㫍㪼㩷㪽㫆㫉㩷㪦㫂㫌㪼㫋㫊㫌㩷㪩㪼㪾㫀㫆㫅㩷㩷㩷㩷㩷㩷㩷㩿㫄㻢㪈䇮㪇㪈㪇㪈㩷㪄㩷㪇㪌㪇㪏㪀㪹㪄㫍㪸㫃㫌㪼㩷㪽㫆㫉㩷㪦㫂㫌㪼㫋㫊㫌㩷㪩㪼㪾㫀㫆㫅㩷㩷䋨㫄㻢㪈䇮㪇㪈㪇㪈㩷㪄㩷㪇㪌㪇㪍䋩㪹㩷㪔㩷㪇㪅㪏㪐㪉

Fig. 7b Cumulative number for Okuetsu region.

Fig. 8b The b-value for Okuetsu region.

ߎߩߎߣ߽ᅏ⿧ߢߩ⊒↢᭽ᑼߩᄌൻߦኻᔕߒߡ޿ࠆᧃࠃࠅ⊒↢୘ᢙߩᷫዋ௑ะ߇⹺߼ࠄࠇࠆࠃ߁ߦߥߞ

ߩ߆߽⍮ࠇߥ޿‫ޕ‬ߚ‫ߩߎޕ‬ᷫዋߪ㧘ਤᵄጊ࿾ߢ߽ႎ๔ߐࠇߡ޿ࠆ‫ߘޕ‬ ߅ࠊࠅߦ

ߩࠃ߁ߥ⁁ᴫߩߥ߆ߢ㧘ᅏ⿧࿾ၞߢߪኻᔕߔࠆ⃻⽎ ⑔੗⋵Ꭸർ࿾ၞߩ࿾㔡ᵴേߩ․ᓽߣߒߡ㧘2000ᐕၞߣ⧯⁜࿾ၞߦ㒢ቯߐࠇࠆ௑ะ߇⹺߼ࠄࠇ㧘b୯ߩ⸘߇⹺߼ࠄࠇߕ㧘หߓ㗫ᐲߢ࿾㔡ߪᒁ߈⛯߈⊒↢ߒߡ޿ࠆ‫ᦨޕ‬ㄭߢߪ⑔੗⋵ౝߩ᦭ᗵ࿾㔡ߩ⊒↢߇ᅏ⿧࿾－ 330 －▚⚿ᨐߣ⍦⋫ߒߥ޿‫ߪ⽎⃻ߩࠄࠇߎޕ‬㧘⃻࿷㧘ᅏ⿧⃿‛ℂቇ⎇ⓥળߩቇ↢⻉᳁ߦߪో㕙⊛ߥදജࠍ㗂߈࿾ၞߣᎨർߩઁߩ࿾ၞߢ࿾㔡ߩ⊒↢᭽ᑼ߇⇣ߥߞߡ߹ߒߚ‫ߩࠄࠇߎޕ‬ᣇ‫ߡߒ⸥ߦޘ‬ᗵ⻢⥌ߒ߹ߔ‫ޕ‬޿ࠆน⢻ᕈࠍ␜ߒ㧘ߐࠄߦ⹦⚦ߥ⸃ᨆࠍⴕ߁ᔅⷐᕈෳ⠨ᢥ₂߇⹺⼂ߐࠇࠆ‫ޕ‬ጟᧄᜏᄦ࡮ᐔ㊁ᙗ㓶࡮┻ౝᢥᦶ࡮⷏਄᱄਽࡮ᷰㄝ㇌⻢ㄉᒾ㧔2006㧕㧦⑔੗⋵ᅏ⿧࿾ၞߦ߅ߌࠆᦨㄭߩ࿾㔡ᵴേ , ੩ ㇺ ᄢ ቇ 㒐 ἴ ⎇ ⓥ ᚲ ᐕ ႎ , ╙ 49 ภ B, pp.
ᧄ⎇ⓥࠍㆀⴕߔࠆߦ޽ߚࠅ㧘⑔੗࿾ᣇ᳇⽎บࠃࠅ

283-288.ᴾ࿾㔡ᵴേ࿑㧔᦬ႎ㧕߿࠺࡯࠲ࠍㅍߞߡ㗂޿ߡ߅ࠅ߹੩ㇺᄢቇ㒐ἴ⎇ⓥᚲ࿾㔡੍⍮⎇ⓥ࠮ࡦ࠲࡯㧔2007㧕㧦ߔ‫ޕ‬㒐ἴ⑼ቇᛛⴚ⎇ⓥᚲ㧘੗ర᡽ੑᦶඳ჻㧘ᑪ▽⎇╙172࿁࿾㔡੍⍮ㅪ⛊ળ⾗ᢱ.ᴾⓥᚲ࿖㓙࿾㔡 Ꮏቇ࠮ࡦ࠲࡯ 㐳㧘ฎᎹା㓶 ඳ჻ߦߪ㣕⼱ ᆭ࡮੗਄ᱜ᣿㧔2003㧕㧦᷹࿾᷹㊂࠺࡯࠲ߢ⷗MJHDߦߟ޿ߡࡊࡠࠣ࡜ࡓ૶↪⸵นߣߏᢎ᝼ࠍ㗂߈ࠆਛㇱᣣᧄߩ࿾Ზᄌേ㧘᦬ೀ࿾⃿㧘Vol.25㧘No.12㧘߹ߒߚ‫ޕ‬㑐᧲ቇ㒮ᄢቇ㧘೨↰⋥᮸ᢎ᝼㧘੩ㇺᄢቇ㒐

pp.918-928.

ἴ⎇ⓥᚲ㧘የᶈಎᢎ᝼ߦߪࡔࠞ࠾࠭ࡓ⸃ߣ

⑔੗࿾ᣇ᳇⽎บ㧔2007㧕㧦⑔੗⋵࿾㔡ᵴേ࿑㧘1᦬.

HyperDPRIߩ࠰ࡈ࠻࠙ࠛࠕ࡯ߦߟ޿ߡ߅਎⹤ߦߥࠅ

ጊᧄඳᢥ㧔2004㧕㧦⑔੗⋵ᄢ㊁⋆࿾ධ᧲✼ߩᧁ⪭ᢿ߹ߒߚ‫ޕ‬੩ㇺᄢቇ㒐ἴ⎇ⓥᚲ㧘દ⮮ẖᢎ᝼ߦߪᄙߊጀ ߩ ᵴ േ ᐲ ߘ ߩ ᗧ ⟵ 㧘 ࿾ 㔡 㧘 ╙ 2 ポ 㧘 ╙ 57 Ꮞ 㧘ߩࠦࡔࡦ࠻ࠍ㗂߈߹ߒߚ‫⑔ޕ‬੗Ꮏᬺ㜞╬ኾ㐷ቇᩞ࿾

pp.198-208.

Generating Properties of Earthquakes in Reihoku Region

Takuo OKAMOTO*, Norio HIRANO, Hiroo WADA, Fumiaki TAKEUCHI,
Kin’ya NISHIGAMI and Kunihiko WATANABE* Fukui National College of TechnologySynopsis
In Reihoku region, several large active faults, for example Fukui Earthquake Fault, exist. Microearthquakes occurred along the some active faults. In recently, small earthquakes which caused the intensities
in Fukui Prefecture occurred at Okuetsu region and Kanmuridake area. Those earthquakes had about same
p-axis and did not occur along the large active fault. We will study this phenomenon in detail. In this report,
we explain the properties of those phenomena by fault plane solution, b-value and seismicity.
Keywords: sisimicity, b-value, active fault, seismic intensities, fault plane solution－ 331 －