ࡄݪਫ਼ࡄݪ༭࣬ȁల 68 ȁ2005 ා 9 ܿڠشཡब
ࢹ௮ζΛάϋΈڔ૬໐౷̩̿ܖ૧̱̞८၄ਹ༹ࣣͅ ٜ৷Ƚضৣ༹ΟȜΗ͈͒ഐဥ̷͈͂ࠫڙȽୌධུࡪ̤̫ͥͅࢩ
໌നഓɖ
Improved Mapping Method for Deep Crustal Imaging - Application to Wide-angle Refl ection Data in the Southwest Japan Arc and its Interpretation -
Tetsuya TAKEDA
Solid Earth Research Group, National Research Institute for Earth Science and Disaster Prevention, Japan [email protected]
Abstract
Wide-angle refl ection data often show remarkable refl ections from the deep crust. In order to obtain new images of crustal inhomogeneity beneath the southwest Japan arc, I propose an improved mapping method designed for sparse wide-angle refl ection data. The method, an improved form of the Common Scatter-Point (CSP) stacking method, has the advantages of both the Common Mid-Point (CMP) and CSP stacking methods, which means that it can add a migration effect to the CMP method, and has less of the ghost curves that results from the CSP method. When applied to two sets of wide-angle reflection data (the 1988 Kawachinagano-Kiwa profile and the 1989 Fujihashi-Kamigori profile), the method provided clear images of the subducting Philippine Sea plate and the island-arc’s lower crust. The main results are as follows: (1) Intra-plate seismic activity is concentrated within the oceanic mantle, which suggests that the oceanic mantle may be subject to dehydration embrittlement; and (2) The lower crust beneath the southwest Japan arc has strong inhomogeneity, with a wavelength ranging from several to a dozen kilometers, which may result from crustal reconstruction due to igneous activity that has occurred since the Cretaceous.
Key words : Common Scatter-Point (CSP) stacking method, Wide-angle refl ection, The 1988 Kawachinagano-Kiwa profi le, The 1989 Fujihashi-Kamigori profi le, The Philippine Sea plate
͛ͅ ͊ Allmendinger et al., 1986ȫȅ̹͘Ȅߠ୬༹ٜଢ଼̲͉̽̀͢ͅ .1 ́ٮޏࢹ௮ౝऔ͈࡛ે ଔ̯̹ͦ Moho ࿂͉ȄႲഎ́ౙ̈́௸ഽະႲڔఱၘ౷ 1.1 Ȅ1980 ාయͤ͢ COCORPȪ႕̢͊ Brown, ̷̜ͥ͂ͦ́͘ࣉ̢̧̹̦ͣͦ̀Ȅषͅං̹ͣͦৣ͉́ڔȁఱၘ౷ 1991ȫ͞ LithoprobeȪ ႕ ̢ ͊ Cook et al., 1992ȫ͂ ̞̹̽ ౯࿂͉́ Moho ࿂͈Ⴒ͉ߊഎ̱̥ͅంह̱̤̀ͣ ̭̜͂ͥ́ٮޏࢹ௮ౝऔ̦ ̴ȄMoho ࿂͉ 3-5km ͈໙̹ͬ̽͜ໝॠ̈́ڔఱܰ࿅ίυΐͿ·Π͈͂ࣞ͜ྟഽ͈૬໐౷ ঔ̯̠̹ͦͥ̈́̽͢ͅȅౝऔ͉ͅఱၾ͈ܥऺ̦ൎව̯ ̦ྶ̥̹ͣ͂̈́̽Ȫ႕̢͊ Hale and Thompson, 1982ȫḙ̏ ڔȄྟ̈́૦ത͂อૼതͬ౾̱̹۷௶࡛̱ͬ̀ఱၾ ͈̠͢ͅȄৣ༹ٜଢ଼̽̀͢ͅਲြͤං̥̹̈́̽౷ͦ අ͈ڔΟȜΗ̦৾ං̯̠̹ͦͥ̈́̽͢ͅȅࣞྟഽ۷௶ͤ͢ͅ ૬໐͈ळࢹ௮̦ଔ̧̠́ͥ̈́ͤ͢ͅȄఱၘ౷͈ ၑٜ̳ͥષ́ఉఱ࣓̈́ࡃ̱̹ͬȅͬاஃ໐ࢹ௮ౝऔ͞ౝऔ̈́̓ͅঀဥ̱̞̹̀ৣ༹ٜଢ଼ ಭ͞ૺ ࢹ௮ౝऔ͈࡛ેڔෝ̱ͅȄ̷ͦ́͘นட̱̥͂௴̢̥ͣͦ̈́̽ 1.2 ോࡪ౷خ൵ව͈ͬ ࢹ଼ུ̯͉ͦͥ́Ȅบ෫౷ૼ൲̥ͣڔഎȹͅζΛάϋΈ̳̭ͥ͂ͅ ȁ༷֚Ȅോࡪ౷ژ૬໐͈ࢹ௮ͬȸণڔ౷̹ ৣ༹Ȫߠ୬༹ȫౝऔ̦ಎͅڙచચഎͅถ ࡄݪΈσȜί̽̀͢ͅࢩ͉͂ڔȄ൫ྶ̈́ષ໐౷ض̱̹ȅ̷଼͈ࠫ ,อࡉ̦̜̹̽Ȫ႕̢ ̧࣐̹ͩͦ̀Ȫ႕̢͊Ȅบ෫౷ૼ൲ࡄݪΈσȜίȄ1985͈ڔ໐౷ئȪlaminateȫࢹ௮ͬࠁ଼̳ͥ
ࡄݪਫ਼ȁࡥఘ౷ݩࡄݪ໐ܿڠشɖඊၛ࣐ଽ༹૽ȁཡब
Ƚ!175 Ƚ ࡄݪਫ਼ࡄݪ༭࣬ȁల 68 ȁ2005 ා 9 ܿڠشཡब
Ȅ႕̢͊ಎ໐ུͅ ̞͈̈́̓̾̀ͅમळ݈̈́ა̳̭̦ͬͥ͂ඳ̱̥̹̽ȅ̥ͣض1999ȫȅ̷͉͈ͣͦͣౝऔࠫ Ȅਲြ͈ৣ༹͈ٜଢ଼༹͉Ȅ͉̱̀۾࢜ ȁ༹̹༷͘ͅئȄତ km ಼̢ͬͥષͅئঝݿȽؖࢹ௮̫̤ͥ ࣞྟഽ۷௶͈ΟȜΗͬచય̱͈͂̀ئ100m ո ̦ڞۼ๕͈̞֑̞ͬ̾߹০͈ݙ౯ࢹ௮ͬྶ̥ͣͅ ૦തܖ͈ ৣ༹ΟȜΗ͈͒ഐဥ͉ேڙȄ۷௶തྟഽ͈೩̞ࢩ̤ͤ ͅڔ໐౷ئȪIkami et al., 1986, Takeda et al., 2004ȫȄ̷͈̱ ٮະৗ̦̜̭ͥ͂ͬা̱̹Ȫ໌ന , 1997ȫȅ̹͘ ̱̞̞̀̈́ȅ̷͈̹͛Ȅષܱ͈ࡄݪ̤̫ͥͅഐဥࡠ̞ޑ͉ ఊဢίτȜΠ͈ೆ͙ࣺ͙ͤ͢ͅࠁ଼̯̹ͦോࡪ̜́ͥ ͉ౙͅΟȜΗ̺̫͈࿚ఴ͉̩́̈́Ȅ༹ুఘ͜ͅ࿚ఴ̦ ̯ ̜ͥ͂࡞̢ͥȅઐോȪ1999ȫ͉Ȅৣ༹ٜଢ଼༹͈֚̾́ږཤུ͉́Ȅષ໐ζϋΠσͬഥͩͥ෨ȪPnȫ̥ͣ ۾ͅا५έυϋΠ ̜ͥ८၄ਹ༹ࣣͬဥ̞̹ৣ༹౷ૼౝऔ͈ࣞୈഽغȄ̤̱ͤ̀اMoho ࿂͈૬̯͉ఱ̧̩་ ͥͦ ̱ب͜ஜࡪ௰͉́ 32-35km ͂̽͂͜͜૬̞̦Ȅࡪ௰́ ̱̞̀͂͛̀ͥ͘ȅ̷͈ಎ͉́Ȅକৣ࿂ͬͤ͢ ಎ̳͂ͥහփ͈ͬڙ࿂ৣ෨͈ৣޢાࣣͅȄ̷͈̹ اถ̦ڔఱฺ̽̀ͅ౷ڐ27km ͂ஃ̩̤̈́̽̀ͤȄࡪ ͉ սඤ͈ΠτȜΑ͈͙ͬਹࣣ̳̭ͥ͂ͤ͢ͅȄS/Nํڙબݶͬা̱̹ȪIwasaki et al., 2001ȫȅ̱̥̱̦̈́ ८၄̞̱ͥ̀ Ȅ৽̱͂̀ P ෨ȆS ෨̷͈͞ৣ෨൝ ͬ࢜ષ̵଼̯̭̱̞ͥ͂̀ͥͅḙ͈̏ાࣣȄέτΥ͉ضḘ͈̏ͦͣࠫͣ ͦͥ͘ΠτȜΑ͈͙ͬਹ̧ࣣ̳ͥ͂ͅ S/N܄শͬঀဥ̱̹ߠ୬༹ٜଢ଼ͅջ̞̽̀ͥȅߠ୬༹ٜଢ଼ͅ σΖȜϋ͈ͅ ۼ ࢹ௮͈ͺ;Πρͼϋͬೕ͚̭͂ ̦डఱ͂̈́ͥȅొ̱Ḙ༹͈͉̏ࣞྟഽȪ1 ȡ 100mڔഽࢹ௮̥ͣȄ౷௸ͥ͢ ౷ૼౝऔΟȜۼȫͅอૼത̤͍͢૦തͬ౾̱̹࢟֔ڞ ະৗ͞ Moho ࿂͈ࠁે͈ڔȄೄ༷͈࢜౷̧̦͉ͥ́ ࢹ௮̞͈݈̾̀ͅა͉ඳ̱̞ȅ Η͈͒ഐဥͬே̱̞̹̀ͥ͛Ȅႋ୪̳ͥ۷௶ത͈෨ࠁڔৗ̞̹͂̽ळ̈́౷͞ ՛̞மྟ̈́ΟȜΗ͈͒ഐဥ͉ࣉၪ̯̞̞ͦ̀̈́ȅ̦۾߃ා͈ౠႹോ̤̫ͥͅ TASPȪSato et al.,1998ȫ͞ཤུ ͈ ৣ෨ͬঀဥ̳ͥषͅ࿚ఴ͂̈́ͥ෨ࠁ͈ΑΠڙ౯ࣣ൳۷௶ȪIwasaki et al., 1999ȫْ͈͉̈́̓ࠗ́Ȅ̞͘ ̹͘Ȅࢩ؍ ৣ༹ڙ࡞ݞ̯̞̞ͦ̀̈́ȅࢩ̱̀۾ͅضષૼ࡙͈৽ႁ̜́ͤૼ࡙෨ࠁௌैȆ౷ૼ෨ΥσΆȜ τΛΙϋΈ࢘ၘ͞ ৣ༹ΟȜڙෝ̈́ΨͼήτȜΗȜૼ࡙ Vibroseis® ͬ ΟȜῌৣ༹ٜଢ଼ͬ൵ව̳̹͉ͥ͛ͅȄࢩخା͞Ⴒอૼ̦ อ̦ຈါ̜́ͥȅٳ༹͈̹̱اࢹ௮ౝऔ͂൳ഽ͈ Η͈අಭͅඅڔൎව̱̀ȄLithoprobe ͈̈́̓ఱၘ౷ Ȅ႕̢͊Ȅཤ 1.4 ུࡄݪ͈࿒എضෝ̹͂̈́̽ȅ̷͈ࠫخ̦௶ࣞྟഽ۷ ৣ༹ౝऔ͉́ڙୢၴ५౷͉́Ȅၰზ͈ݙ౯̽̀͢ͅ؋̱ષ̬ͣͦ ȁบ෫౷ૼ൲ࡄݪΈσȜίͥ͢ͅࢩུ͈ ̯̹ͦȪന ΥσΆȜ͈ఱ̧̞ఱၾ͈ΘͼζͼΠૼ࡙ͬঀဥ̱̀ږpop-up ࢹ௮̦ࠁ଼̯̞̭̦ͦ̀ͥ͂ ͥ ̦̭̳́͂ͥ௶૬໐̥͈ͣৣ෨ͬ͜۷ڔȄ1999ȫȅొ̱Ȅോࡪ̤̫ͥͅࢹ௮ౝऔ๊͉֚́എͅ ̞̹ͥ͛Ȅ౷̥͕ ૬ڔఞ̯ͦͥȅषͅ෨ࠁܱͬವ͛ͥ͂Ȅ౷ܢ̧͂ͥ ͛ȄΘ̹̞ޑ౷൲ΦͼΒ̦ఱ̧̩Ȅ̹͘౷ૼ෨͈ࡘଚ͜ ̧̳̭̦ͥ͂́ږৣ෨ͬڙͼζͼΠ͓̀ͅΥσΆȜ͈̯̞ Vibroseis® ͉́ ໐̥͈ͣ૦໙͈ఱ̧̞ࢩ ࢹ௮͈ଔ๊͉֚ͅ ͥȪ 1.1ȫȅৣ༹ٜଢ଼͉࡛हٜ̽͂ࣞ͜͜௨ഽ̈́ͼιȜڔMoho ࿂ͅో̳͕ͥ̓૬໐͈́͘౷ ະ͈ڔ໐౷ئ༹̜́ͤȄMoho ࿂͈ࠁે̳ͥ͞ރࣾඳ̜́ͥȅ ΐͬ ̜ࠧ́ͥȅخৣ༹ΟȜΗ͈͒ৣ༹ٜଢ଼͈൵ව ৗࢹ௮݈ͬა̳ͥષ́ৣ༹ٜଢ଼͉ຈါະڙࢩ 1.3 ৣ༹ΟȜΗͬঀ̽̀෨൲ાఘͬৣ༹എͅڙࢩ ζΛάϋΈ̳ͥࡄݪ͉Ḙ̏ͦ́͘ͅ Chang et al.Ȫ1989ȫ͞ Zelt et al.Ȫ 1998ȫ̈́̓ͤ͢ͅ༭̯̞࣬ͦ̀ͥȅChang et al. ৣڙȪ1989ȫ͉Ȅධୌ·ργζ̤̞̀৾ͅං̯̹ͦࢩ ༹ΟȜῌਹࣣஜခࡠओζͼΈτȜΏοϋ༹ͬഐဥ̱ ৽ಫ̱̀ͬٮȄอૼതྟഽ̦̯̞̭͂ͥ͢ͅഐဥࡠ̦̹ ̞ͥȅZelt et al.Ȫ 1998ȫ͉Ȅsynthetic ͈෨ࠁΟȜΗͬै଼ OBHȪ Ocean-Bottom Hydrophoneȫ۷௶͈ΟȜΗٜଢ଼ ̱̀ ৣ༹ΟȜΗ͈͒ਹࣣஜڙ࿅̱̹ΞΑΠͬঔ̱Ȅࢩͬ ෝͬخσΪγΛέ૬ഽζͼΈτȜΏοϋ༹͈ഐဥ΅ ৣ෨ͬဥ̞̀૬໐͈ͼιȜΐڙȄࢩضબ̱̹ȅ̷͈ࠫ 2km ͉ڞۼ ෝ̜̦́ͥȄOBHخζΛάϋΈ̳̭͉ͥ͂ͬ ոඤ́Ȅࠗॳͅဥ̞ͥ௸ഽࢹ௮κΟσ͈௸ഽࢋओ͉ 4% ո 1.1 บ෫౷ૼ൲۷௶ΈσȜίͥ͢ͅߠ୬༹ౝऔ͈۷௶෨ ૬໐̥͈ͣڔષߴ௶ S-1ȫȅ౷ . ޘඤ̫̞́̈́ͦ͊̈́ͣ̈́͂ঐഊ̱̞̀ͥȅུ̤̫̭ͥͅ ࠁ႕Ȫ1989 ා ս̹ͦ͘ႀ֖ȫȅܱ́ڙ̧́ͥȪঅږৣ෨ͬڙࡄݪ͉Ȅ֔Ȫ1991ȫ͞ Matsu’ura et al.Ȫ1991ȫͬ ࢩ̠͈̈́͢ എ̈́ৣ༹ٜଢ଼ ͉ 6km/sec ́ reduce ̱̜̀ͥȅུܖȅ֔Ȫ1991ȫ͉̞͕̞̈́̓ͭ͂̀ੰ ༹̜́ͥ CMP ਹ༹ࣣͬဥ̞̀ζΛάϋΈ̱̤̀ͤḘ̏ͦ Fig. 1.1 Example of the record section of the refraction survey ంह̳ͥཤ߹০͈ৣ࿂ Ȫthe 1989 Fujihashi-Kamigori profi leȫ conducted by theͅڔ໐౷ئ͈ئչോܮͤ͢ͅ ೆ͙ࣺ͚έͻςάϋ٬ίτȜΠ͈ષ࿂ͬ௴̢̭ͥ͂ͅ Research Group for Explosion SeismologyȪRGESȫ. The͞ CMP reduction velocity is 6km/sec. Wide-angle refl ections from ̢̀ح̱̹ȅ̱̥̱Ȅ۷௶തྟഽ̦೩଼̞̭͂ͅ ਹ༹ࣣٜͥ͢ͅଢ଼ͬဥ̞̹̹͛ȄႲ̧̦͉̱̽ͤ͂ the crustal lower part are identifi ed in the area enclosed by .ৣ࿂̥͉ͣȄέͻςάϋ٬ίτȜΠ͈ࠁે͞պ౾ the trapezoid̞̈́
Ƚ!176 Ƚ ࢹ௮ζΛάϋΈȽ໌നڔ૬໐౷̩̿ܖ૧̱̞८၄ਹ༹ࣣͅ
ৣ෨ͬဥ̞̀෨൲ાఘͬζΛ ນ 2.1 Lithoprobe ْࠗͥ͢ͅ Southern Canadian Cordelleraڙࡄݪ͉́Ȅࢩ̷ུ̭́ ࢹ௮ͬȸণ ̤̫ͥͅఱၘ૬໐ࢹ௮ౝऔȪCook et al., 1992ȫ͂ڔάϋΈ̳̭ͥ͂ͤ͢ͅȄോࡪ̤̫ͥͅ૬໐౷ ષߴ௶ͅ . ޘഎȹͅ௴̢̭ͥ͂ͬদ͙ͥȅ̱̥̱Ȅஜ͈̠͢ͅਲ บ෫౷ૼ൲ࡄݪΈσȜίͥ͢ͅژ ৣ༹ౝऔȪบ෫౷ૼ൲ࡄݪΈσȜίȄڙৣ༹ΟȜΗͬঀဥ̱̀૬໐౷ ̤̫ͥࢩڙြ༹͈͉́மྟ̈́ࢩ ڛࢹ௮ͬζΛάϋΈ̳̭͉ͥ͂ඳ̱̞ḙ̷ུ̏́ࡄݪ́ 1995ȫ͈͂ॽအڔ ෝ̈́૧̱̞ζΛάϋΈ Table 2.1 Specification comparison between a continental deepخৣ༹ΟȜῌഐဥڙȄࢩ͉ อ̳ͥȅ̷̱̀Ȅषͅ۷௶̯̹ͦ 2 ΓΛΠ͈ࢩ seismic survey of the Southern Canadian Cordelleraٳ༹ͬ ৣ༹ΟȜῌഐဥ̱Ḙ̷̏́ංͣͦͥͼιȜΐ̥ͣ ȪCook et al., 1992ȫ from the Lithoprobe project, andڙ ೆ͙ࣺ͚έͻςάϋ٬ίτȜΠ͈պ౾͞ࠁેͅ a wide-angle reflection/refraction survey from theͅئോࡪ Fujihashi-Kamigori profileȪ Research Group for 1989 ئޏ۪·ȅ̹͘Ȅ։̈́ͥΞ·ΠΣΛ̳̥ͥͣͅྶ̞̀̾ .*૧ Explosion Seismology, 1995̳ͥ۾ະৗ͞ Moho ࿂͈අಭ͈ͅڔ໐౷ئ̫̤ͥͅ ̱̞ࡉͬං̭ͥ͂ͬ࿒എ̳͂ͥȅ
อٳ૧༹̱̞ .2 อ̜̹̽̀ͅٳ༹ 2.1 ৣ༹ΟȜΗ͈අಭ̞̾̀ͅ୰ྶ̳ͥȅਲြڙडͅࢩ ৣ༹ౝऔ͈ॽအ͉Ȅৣ༹ٜଢ଼͈́͘ੜڙུ͈́ࢩ͈ ḙ͉̏ͦࢃ͈ζͼΈτȜΏοϋੜၑ͈षȄୃ̧̦ͥ́͂ ̳ͥڛၑͬே̱̹ Lithoprobe ْ͈ࠗࢹ௮ౝऔ͈ॽအ͂ ࢹ௮ͬζΛάϋΈ̳̹ͥ͛ͅఱ་ਹါ̜́ͥȅئอૼതȆ૦തྟഽ͉̯̞ȅ֚႕̱͂̀ȄLithoprobe ̱̩౷͂ ْ̤̫ࠗͥͅධಎ؇Οͻͺϋ५ࠏ̤̫ͥͅఱၘ૬໐ ȁ̞̀Ȅ̽͂͜͜ഥൡഎ༹̜̈́́ͥ CMP ਹ༹ࣣ͂ζ ࢹ௮ౝऔȪCook et al., 1992ȫ͂บ෫౷ૼ൲ࡄݪΈσȜίͅ ͼΈτȜΏοϋ༹͈̜֚̾́ͥ८၄ਹ༹ࣣ̞̾̀ͅત ࢹ௮ౝऔȪบ ̳ٚͥḙ͈̏ 2 ͈̾యນഎ̈́ζΛάϋΈ༹ͬ႕͂ͤͅȄڔ౷༷̤̫ͥͅോࡪ౷ܪུ͈ಎ໐Ȇ߃ͥ͢ ෫౷ૼ൲ࡄݪΈσȜίȄ1995ȫ͈ॽအͬນ 2.1 ͅা̳ȅോ ̷༹͈͈ͦͣࡔၑ̷͈͂࿚ఴതͬၑٜ̱̹ષ́Ȅ૧̱ อ৾ͤͅழ͚̭̳͂ͥͅȅٳ༹̞ ۼࢹ௮ౝऔ͉ఱၘ૬໐ࢹ௮ౝऔͅచ̱̀Ȅ૦തڔࡪ౷ ȄංͣͦͥΟȜΗ͈ 2.2 CMP ਹ༹ࣣ̜ͤ́ 500/1 ͉ڞۼ30Ȅอૼത/1 ͉ڞ ࢹ௮ౝऔ͈ΟȜΗͬဥ̞ 2.2.1 CMP ਹ༹ࣣ͈ࡔၑڔओ͉๛̞͛̈́ȅോࡪ౷ڒၾഎ ͅئఱ̧̞̹͛Ȫ ȁࡔၑͬ୰ྶ̳̹ͥ͛ͅȄ 2.1Ȫaȫ́া̳̠̈́͢౷̦ڞۼৣ༹ٜଢ଼࣐̠ͬાࣣ͉Ȅ۷௶ത̀ ̱Ȅ౷ນ͉ͅอૼبକ̈́ৣ࿂̦̜ͥକ 2 ࢹ௮ͬ ͉۾ 1.5kmȫȄ๊֚ͅႋ୪̳ͥΠτȜΑ͈͂ৣ෨͈ ՛̞ȅ̷͈̹͛Ȅৣ෨͈պ̦ఁ̴ͩȄζΛάϋΈ̱ ത͂૦ത̦୭౾̯̞ͦ̀ͥાࣣͬࣉ̢ͥȅಎ͈๔ͬ อૼڎ͜Ⴒ̳ͥৣ࿂͈ठ࡛͉ඳ̱̞ȅ̹͘Ȅૼ࡙͉̀ ૦̜̽̀ͥอૼത͂૦ത͈ழ̵͙ࣣ̤̞ͩ̀ͅȄ̀ ৣ࿂́ৣ̱̀చ͂̈́ͥ૦ത͈ئΘͼζͼΠૼ࡙̜̹́ͥ͛Ȅอૼത͈ૼ࡙෨ࠁ̷͈͞ ത̥̹ͣ෨̦౷ ழ̵̷͙ࣣ̤̞͈ͩ̀ͅৣത͉֚ڎΥσΆȜ͈౷ૼ෨་۟࢘ၚྀ͉ٝ։̈́ͤȄ̷ͦͣͬଷ ͅൢ̧̳ͥ͂Ȅ ࢄ̳̭͉ͥ͂ඳ̱̞ȅ̷͈̹͛։̈́ͥอૼത͈ΟȜΗͬ ౿̳ͥḙ̏ͦͬވৣത͂ࡤ͐ȅCMP ͉͂ȄCommon ௶ৣത͈փ̜́ͥȩ̭͈͈̏͂۷ވਹࣣੜၑ̳ͥष͉ͅಕփ̦ຈါ̜́ͥȅ MidPoint ͈ၞ́ ̺̦Ȅခ၌̈́ത̜ͥ͜ȅ̴͘ૼ࡙̦̀ΘͼζͼΠ ܱ͉ 2.1Ȫbȫ͈̠̈́ͤ͢ͅȄৣ෨শ͉ެͬຝ ৣതೄષ͈౷ນވอ෫̜͈́ͥ́ȄΨͼήυͼΑ͈̠̈́͢ఈ͈ଷࢄૼ࡙ ̩ḙ͈̏ͦͣ۷௶ܱ̜̹̥ͬ͜ ૬໐͈ౝऔ͉ͅޭ͛̀ ͈൳֚ത́อૼ͂૦̱̹̥͈̠ͬ͢ͅ་̳̭۟ͥ͂ͬڔ͜ΥσΆȜ̦ఱ̧̩Ȅ౷ͤ͢ ခ̜࢘́ͥȅ̹͘Ȅ͂͂͜͜ߠ୬༹ͥ͢ͅ௸ഽࢹ௮ଔ NMO ༞ୃ͂ࡤ͐ȅNMO ༞ୃͤ͢ͅৣ෨͉պ̦ఁ̽ Ⴅ͍ͅȨ̭͈͈̏͂༞ୃ̯̹ܱͦͬΔυέ֚؍̀ ࿒എ̱̹͂ౝऔ̜̹́ͥ͛௶ಿ̦ಿ̩୭̱̜̀ͤͬ ૬໐ͬͥߠ୬෨ ΓΛΠশܱ͂ࡤ͐ȅ̷̱̀൳̲ CMP ͬ̾͜ΔυέڔȪ150-200kmȫȄζϋΠσ͉̲ͬ͛౷ ޑ૬໐͈́͘௸ഽࢹ௮ͬୈഽ̩͢ଔ̳̭ͥ͂ ΓΛΠশܱͬ௷̵̱ࣣ̭ͩͥ͂ͤ͢ͅȄৣ෨͉ڔȄ౷̥ͣ ෝ̜́ͥȅৣ༹ٜଢ଼́௸ഽࢹ௮ͬݥ͉͛ͥͅȄ֚ ̯ͦͥḙ͈̏௷̵̱ࣣ͈̭ͩ͂ͬ CMP ਹࣣ͂ࡤ͐ȅ֚خ̦ ഽٜଢ଼࣐̠ͬȅ௸ഽٜଢ଼͉͂Ȅକఉࢹ௮͈ા ༷Ȅެͬຝ̥̞̈́ఈ͈෨Ȫ႕̢͊Ȅೄో P ෨͞ S ෨Ȅ௸๊ͅ Ⴅͅպ֚؍ࣣ͈ৣ෨শ̦߃যഎͅެͬຝ̩ৗͬ၌ဥ̱̀Ȅ multipleȄນ࿂෨̈́̓ȫ͉ȄNMO ༞ୃ̽̀͢ͅ အș̈́௸ഽ͈͂́͜ࢃ͈ΔυέΓΛΠশܱͬै ̦ఁ̞̹ͩ̈́͛ͅ௷̵̱ࣣͩ̀͜ޑ̯̭͉ͦͥ͂̈́ ଼̱௷̵̧̱ࣣ̹ͩ͂ͅȄ̽͂͜͜ৣ෨͈૦໙̦ޑ̩ ̞ȅρϋΘθΦͼΒ͜फ़̯ͦȄ௷̵̱ࣣ̹ͩତȪਹࣣତȫ ̷࡛̹͈͈ͦͬ͜૬̯͈௸ഽ̳͈̜͂ͥ́ͥ͜ȅ̱̥̱Ȅ n ͅ؊̲̀ȄS/N ͉ n1/2 ͂̈́ͥȅ̷̱̀Ḙ͈̏ௌैͬ ͼιȜ͈ئഎ۰༒ͅ౷ڛോࡪ͈ΟȜῌഐဥ̳ͥાࣣȄ ̀ CMP ࣐̠̭́͂ͤ͢ͅȄ̞ޑະৗ༹͈༷͈̭ͬ ͛Ȅ௸ഽ ΐͬං̧̭̦ͥ͂́ͥḙ༹͈͈̏၌ത͉ȄΟȜΗତ̦̹ͥͦٸष͈ৣ෨শ̦ެ̥ͣఱ̧̩ ৣ༹ΟȜ ઁ̞̈́ાࣣ́͜ࢃ̳ͥζͼΈτȜΏοϋੜၑ͈̠̈́͢ڙٜଢ଼̳̭͉ͥ͂ඳ̱̞ȅ̷ͦͅచ̱̀Ȅࢩ ȅକ̧༷̜̭̞̯̭࢜ͥ́͂̈́ܳ֨ͬاΉ͉Ȅߠ୬༹ٜଢ଼̽̀͢ͅषͅশࠗॳ࣐̞ͬȄ௸ ͼιȜΐ͈Ⴆ ఱ̧̩̞̈́ࢹ௮͈ાࣣ͉ͅȄ̥̈́ͤୃ̦اഽࢹ௮̭ͬͥ ͈௸ഽࢹ௮་௸̈́ږഽࢹ௮ͬݥ̞̹͛̀ͥ͛Ȅͤ͢ୃ
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૦തȫȄȪbȫNMO ༞ୃஜ͈͉ڙอૼതȄঅ͉ڙါȅȪaȫକ 2 κΟσȪ२ٽ 2.1 CMP ਹ༹ࣣ͈ ෨ࠁȄȪcȫNMO ༞ୃࢃ͈۷௶෨ࠁȄȪdȫCMP ਹࣣࢃ͈ΔυέΓΛΠশܱ௶۷ Fig. 2.1 Scheme of the Common Mid-PointȪCMPȫ stacking method.Ȫ aȫ Simple model with a single horizontal refl ectorȪ triangles and squares indicate shot points and receivers, respectivelyȫȪbȫBefore NMO correctionȪ cȫAfter NMO correctionȪdȫCMP stacking after NMO correction.
ෝ̜́ͥȅخζΛάϋΈ̦̈́ږ 2.2.2 CMP ਹ༹ࣣ͈࿚ఴത CMP ਹ༹ࣣ͉́Ȅ1ȫৣ࿂̦କ̜́ͥȄ2ȫକ༷࢜ ஜ̱̞͂̀ͥȅ̷͈̭̞͕͉ͬ͂̈́̓ͭ͂اഽ་௸ͅ ζΛͅږ͛Ȅ߹০͈̯̞ৣ࿂͈ાࣣ͉̥̈́ͤͅୃ̹ άϋΈ̧̦́ͥȄݢ߹০ͬ̾͜ৣ࿂̦̜ͥાࣣ͞କ ༷࢜ͅఱ̧̈́ະৗ̦̜ͥાࣣ͉ͅȄୃ̱̞պ౾ͅζΛ άϋΈ̧̞̞̠́̈́͂ࠧത̦̜ͥȅ̱̹̦̽̀Ȅോࡪ͈ ͛କ༷͈࢜௸ഽ་̹͈ޏ۪·ໝॠ̈́Ξ·ΠΣΛ̠͢ͅ ఱ̧̞౷֖ͅ CMP ਹ̷༹ࣣ͈ͬ͘͘ഐဥ̳̭̦ͥ͂ͅا ͉࿚ఴ̦̜ͥȅ ુ CMP ਹࣣࢃ͉ͅȄ߹০͈̜ͥৣ࿂ͬୃ̱̞պ౾ ͅ࿗̳ζͼΈτȜΏοϋੜၑͬຈါ̳͂ͥȅζͼΈτȜ Ώοϋੜၑͤ͢ͅȄࡉ̥̫ષ͈ৣ࿂͈ਹٜ̈́ͤ̈́̓͜ક ါȅ൝८၄෨শެષ͒۷௶෨ࠁٽఱ̧̈́ા 2.2 ८၄ਹ༹ࣣ͈̦ڙȄྶၸ̈́ࢹ௮ࠁఠͬা̳ȅৣ࿂͈߹০̯ͦ ࣣ͞ະৗ͈ഽ̦ఱ̧̈́ાࣣ͉́ CMP ਹࣣͥ͢ͅ S/N ͈૦໙ͬ૦̫ͤͥȪऒȫȅ૦໙ͬ૦̫̹ͤࢃȄਹ ̯ͦͥȪֲȫȅޑࡉࣺ̞̹͛̈́͛Ȅड߃͉́ CMP ਹ̵ࣣͬ ࣣ̳̭ͥ͂ͤ͢ͅ८၄ത̦̦ض࢜ષ͈࢘ ̴̷͈͘͘ͅζͼΈτȜΏοϋ̳̞̹ͥ͂̽ਹࣣஜζͼ Fig. 2.2 Scheme of the Common Scatter-PointȪ CSPȫstacking ΈτȜΏοϋ̦৽ၠ̧̞͂̈́̽̀̀ͥȅਹࣣஜζͼΈτȜ method. Amplitudes are allocated on the isochrone of the ͈̜̦́ͥ͜Ḛ̏͛͘ scatter traveltimeȪleft*. The scatter point is emphasized̥̥̦ͥۼΏοϋ͈ࠗॳ͉ఱ་শ .*ෝ̹͂̈́̽ȅষ୯́ after the allocated amplitudes are stackedȪ rightخෝ͈࢜ષͤ͢ͅဥܥࠗॳ̞̱ ਹࣣஜζͼΈτȜΏοϋ͈̜֚̾́ͥ८၄ਹ༹ࣣ͈̭͉ ͓ͥȅ ͙̈́ͅȄ௸ഽ͈֚ાࣣḘ͈̏८၄෨൝শެ͉อૼ̞̀̾ͅ ८၄ਹ༹ࣣ ത͂૦തͬઙത̳͂ͥఔȪ3 ষࡓ͈ાࣣ͉ٝഢఔఘȫ 2.3
2.3.1 ८၄ਹ༹ࣣࡔၑ ͂̈́ͥȅ̷͈൝শެષͅশ࣫ t=t0 ܱ̯̹ͦͅ૦໙ ८၄ਹ༹ࣣ͉́Ȅ૦ത̀ͅ۷௶̯ͦͥ෨ࠁ͈૦໙͉ ͬ൝ͅ૦̫ͤḘ͈̏ௌैܱ̯̹͈ͬͦ̀শ࣫́ ̥࢜ͣ൝༷֚ষ८၄̱͂̀८၄̧̱̹̀෨͈ ࣐̠ḙ͈֚̏Ⴒ͈ௌैͬఈ͈͈̀อૼത͂૦ത͈ழ༷̜ͥͣ͠ ̱௷̀ͬض̱Ȅ̷͈८၄ത̱͂̀ࣉ̢ͣͦ ̵͙ࣣͩ́͜൳အ࣐̞ͅȄ̷͈ං̹ͣͦࠫبਹ̵͇ࣣ̜ͩ́ͥ͂ ͥાਫ਼̀ͅ૦໙ͬ૦̫ͤͥȅ႕̢͊Ȅ 2.2 ͈̠͢ͅȄ ̵ࣣ̭ͩͥ͂ͤ͢ͅȄ૯͈८၄ത̺̫̦ޑ̯̩ͦ̀ͥȅ ౷ນ֚ͅழ͈อૼത͂૦ത̦̜ͥાࣣͬࣉ̢ͥȅ̴͘ ༹̭͈͉́௸ഽࢹ௮ͅະৗ͈̜ͥાࣣ́͜Ȅ߹০͈ อૼത̀ͅশ࣫ t=0 ͅอૼ̱̀Ȅ̷ͦͬ૦തܱ̱̹́ ఱ̧̈́ৣ࿂̈́̓ͬୃ̱̞պ౾ͅζΛάϋΈ̳̭̦ͥ͂
ෝ̜́ͥḙ͈̏८၄ਹ༹ࣣͬഐဥ̳ͥष͉ͅȄஜخ ȩ̭͈̏͂Ḙ͈ܱ̏ષ͈শ࣫ t=t0 ͅൢో̱̹ΏΈ̳ͥ͂
σ͉Ḙ͈̏อૼത͂૦ത̦ैͥ t=t0 ͈८၄෨൝শެ ̱͂̀८၄෨শા͈ࠗॳ̦ຈါ̜́ͥḙ͈̏ࠗॳ͈༷ ષ̴͈̞̥͈ͦത̥ͣഥ̧̱̹͈̀͂͜ࣉ̢ͥȅ̻ ༹̞͉̾̀ͅ 2.4.3 ̤̞ࣜ̀ͅ୰ྶ̳ͥȅ
Ƚ!178 Ƚ ࢹ௮ζΛάϋΈȽ໌നڔ૬໐౷̩̿ܖ૧̱̞८၄ਹ༹ࣣͅ
ڛນ 2.2 CMP ਹ༹ࣣ͂८၄ਹ༹ࣣ͈͂ Table 2.2 Comparison between Common Mid-PointȪ CMPȫ and Common Scatter-PointȪ CSPȫstacking methods.
2.3.2 ८၄ਹ༹ࣣ͈࿚ఴത ͼιȜΐ͉͈ئ८၄ਹ༹ࣣ͉́ȄζΛάϋΈ̯ͦͥ౷ ௸ঀဥ̳ͥ௸ഽࢹ௮̥̈́ͤͅຮ̜ۜ́ͥȅ̷͈̹͛૯͈ ഽࢹ௮ͅ߃̞κΟσͬఈ༹͈̜̥̲̽̀ͣ͛͢ͅଔ ̱̤̩̀ຈါ̦̜ͥȅࢵͅਹఱ̈́࿚ఴ̱͂̀Ȅਹࣣତ̦ ઁ̞̈́ાࣣ͉ͅਹࣣ̽̀͢ͅ૯͈८၄ത̦ޑ̯̞ͦ̈́ ါȪIȫȅ८၄෨൝শެͅٽ͛Ȅࡪે࡛ͦͥͅΌȜΑΠͬࠚࡘ̴̧̳̭̦ͥ͂́ 2.3 ૧̱̞८၄ਹ༹ࣣ͈̹ ැٽତͬဥ̞̀૦໙ͬ૦̫ͤͥાࣣ͈۾̲̱̠̀͘ȅུࡄݪ́ঀဥ̳ͥࢩ ਹ͙̦اͼιȜΐ͈Ⴆͅ 2km ͂ல̩Ȅඅ Fig. 2.3 Scheme of the improved mapping method. Amplitudes are-0.5 ͉ڞۼৣ༹ΟȜῌ̤̫ͥ૦തڙ ͅอૼതତ̦գുഎͅະ௷̱̞̀ͥḙ͈̠̏̈́͢ல̞ྟ allocated on the isochrone of the scatter traveltime using a .ഽ͈۷௶͈ાࣣ͉ͅਹࣣତ͉ఱ̧̩ະ௷̱Ḙ͈̏८၄ਹ weighting function ༹ࣣͬഐဥ̳̭͉ͥ͂ະഐ൚̜́ͥȅ 2.4 ૧̱̞८၄ਹ༹ࣣ ͈८၄෨൝শެಿȄdl ̷͉͈൝শެ͈ள̜́ͥȅ อ͈༷࢜ ̹͘Ȅ0 ̥ͣɇ͈́ͬ͂ͥ͘ F ̞̠͂ control factor ͬ൵ٳ૧༹ 2.4.1 ࢃ́મ̱̩୰ྶ̳ͥȅ͉̱̀۾͈݈́͘აͬ൩̢̀͘Ȅ2 ༹͈͈̾අಭͬນ 2.2 ව̳ͥḙ̭̏ͦͦͅ ତ͈൵වͅ۾ତ̞̾̀ͅࣉ̢ͥḙ͈̏ਹ͙۾Ȅ ȁ̴͘ਹ͙̩ޑഎڛ̹͂͛͘ȅ८၄ਹ༹ࣣ͉́Ȅະৗࢹ௮͉ͅͅ ఞ̧̦́ͥȄ۷௶ྟഽ͈ະ௷ ͤ͢Ḙ̏ͦ́͘൝শެ͈ఘ֚ͅအͅ૦̫̞ͤ̀ܢ̦ضζͼΈτȜΏοϋ͈࢘ ତ́ਹ͙ັ̫̱̀૦̫̭ͤͥ͂̈́ͅ۾͈ ࿚ఴ̦̜ͥȅ̹͘ζΛάϋ ̹૦໙ͬȄθ̧̳̭ܳ֨ͬاͼιȜΐႦ̦ ഽࢹ௮͜ຈါ͂̈́ͥȅ༷֚ CMP ਹ༹ࣣ́ ͥȅcontrol factor ͬࡥ̱̹ાࣣ͉́Ȅθ ͈͈̯̩̈́௸̈́ږΈশͅୃ Ȅ८၄ਹ༹ࣣ̤̫ͥͅࡪે͈ΌȜΑΠ͉̲̞̦̈́Ȅ ͥ൝শެ͈ಎ؇ͅ૦໙ͬਬಎ̵̯Ȅಎ̥ͣၗ̹ͦ θ͉ କ༷࢜ͅະৗ̦̜ͥાࣣͅȄୃ̱̞պ౾ͅζΛάϋ ͈͈ఱ̧̩̭͉̈́ͥ͂ͧ́૦໙̯̩̳ͬͥैဥ̳ͬ ତ͉ 0 ͂̈́ͤ૦۾Έ̯̞̞̹ͦ̈́͂̽࿚ఴ̦̜ͥḙ̷̏́Ȅமྟ̈́۷௶ΟȜ ͥȅ̷̱̀Ȅ | θ ȆF | > π/2 ̈́ͥ͂ͅਹ͙ ̠͈̦Ȅͬڬࢹ௮ͬ̾͜౷֖́۷௶ ໙͉૦̫̞ͤͣͦ̈́ḙ̭̏́ਹါ̞̈́ޑΗ͞ോࡪ͈̠̈́͢ະৗ͈ ̯̹ͦΟȜΗͬե̠ાࣣͬே̱Ȅ८၄ਹ༹ࣣ͂ CMP ਹ ୶൵ව̱̹ control factor ̜́ͥḙ͉̏ͦ́͘૦໙ͬ૦ͤ ༹ࣣ͈ၰ༹͈ࠧതͬ༞̞̦̈́ͣȄ̷͈ͦͣ̾၌തͬ ̫ͣͦͥ θ ͈ํս͉ 0 Ʌ | θ | Ʌ π/2 ̜̹̦́̽Ȅcontrol ํ͈ อ̳̭̳ͥ͂ͥͅȅ factor ͬ൵ව̳̭ͥ͂ͤ͢ͅ૦໙̦૦̫ͤͣͦͥ θٳဥ̧༹̠́ͥ̈́ͬ͢ڰडఱࡠ 2.4.2 ૧̱̞८၄ਹ༹ࣣ͈ࡔၑ ս͉ଷࡠ̫̭ͬͥ͂̈́ͥͅȅcontrol factor ͈̦ఱ̧̩ ͤ͘ȄFޛ८၄ਹ༹ࣣ͈ࠧതฺ༹̜̠́ͥͅࡪે͈ΌȜΑΠ ̈́ͥ͂૦໙̦૦̫ͤͣͦͥ | θ | ͈ခ࢘ํս͉ ࡔ֦͉Ȅ८၄෨൝শެષܱͅ෨ࠁ͈૦໙ͬ૦ͤ ͈̦̯̞͂ | θ | ͈ခ࢘ํս͉ࢩ̦ͥȅ͈ ͓̹ͥ͛ F ̦ޭࡠ͈ͬضႀ֖́͘ྔ༑̩̈́૦໙ control factor ͈൵ව͈ͥ࢘͢ͅٸ̫ͥषͅȄ૯͈८၄തո ͬဓ̢̭̜ͥ͂ͥͅȅ̷ͦͅచ̱̀૧̱̞८၄ਹ༹ࣣ́ ͬ͂ͥાࣣͬࣉ̢͙̀ͥȪ 2.4ȫȅF→ ɇ̳ͥ͂ͅȄθ ͉Ȅਲြ͈̠͢ͅ૦໙ͬ൝শެఘͅ૦̫͈ͤͥ ͈ခ࢘ํս̦ޭ͛̀ޛͤ͘ θ =0 ັ߃͈͙ͅ૦໙̦૦ͤ ତ̥ͬ ̫̭ͣͦͥ͂̈́ͥͅȅచͅ F→0 ̳ͥ͂ͅȄ0 Ʌ | θ | Ʌ۾ਹ͙͈ئḘ͈̏૦໙͈૦̫ͤশͅո̩͉̈́́ ̫̭̱̹ͥ͂ͅȪ 2.3ȫȅ π/2 ͂̈́ͤ൝শެఘͅ૦໙ͬ૦̫̭ͤͥ͂̈́ͅ
ȄF→ ɇ̵̭̯ͤ͂ͥ͢ͅا૦ത́۷௶̯̹ͦ౷ૼܱય̤̫̜ͥͥͅশ࣫Ȫt=t0ȫ͈ ͥḙ͉̏ͦ control factor ͬ་ ૦໙ͬ൝শެષͅ૦̫ͤͥાࣣȄ ͈ાࣣ͉ͅ CMP ਹ༹ࣣ͂Ȫొ̱Ȅୃ̱̩͉ CMP ਹ༹ࣣͅ ̞ͦ̀ͥ͘ȫȄF→0 ͈ાࣣ͉ͅਲြ͈܄૬ഽ་͈۟ௌै͜ ੜၑ̭̈́ͥ͂ͬͅা̱̞̀ͥḙ͈̏̈́ثȪ ̧͈͂ȫ! Ȫ1ȫ ८၄ਹ༹ࣣ͂൝ ̠͢ͅȄcontrol factor ͬௌै̳̭̺̫ͥ͂́ CMP ਹ༹ࣣ 0 Ȫ ̧͈͂ȫ ͂८၄ਹ༹ࣣ͈ၰ̧༹̦࡛́ͥȅ༹̯̭͈͈ͣͅ
Ḙ̵̯̏ͤ͂ͥ͢ͅاඵ൝ डఱ͈ιςΛΠ͉Ȅcontrol factor ͬ་͈ڙḙ̭̏́ A ͉ t=t0 ͈́૦໙Ȅθ ͉८၄̳ͥ͂
എ̈́ੜၑ̧̦̭̜́ͥ͂́ͥȅ̾ͤ͘ۼࡘଚ༞ୃࣜȄL ͉ t=t0 ̭͈ၰ༹͈ಎةܜ͉ ഽȄGڙೄ༷̥͈͈࢜ͣ
Ƚ!179 Ƚ ࡄݪਫ਼ࡄݪ༭࣬ȁల 68 ȁ2005 ා 9 ܿڠشཡब
Ȅݙ̹̱ͤͅحͬضCMP ਹ༹ࣣͅζͼΈτȜΏοϋ࢘ ८၄ਹ༹ࣣ͈ࡪે͈ΌȜΑΠͬࠚࡘ̱̹̳̭̦ͤͥ͂ ෝ͂̈́ͥȅخ ͉ ȁ̭̭́ θ ̞̠̾̀͜ͅઁ̱ݪ̳̭̳ͥ͂ͥͅȅθ ഽ̜́ͥȩ̭͈̏͂Ȅڙೄ༷̥͈࢜ͣ൝͈ 2 ڙ८၄ 2.5 ͈̠͢ͅ൝শެ͈८၄ത͈́୪ AB ͬࣉ̢̹ ાࣣȄ८၄෨൝শެ̦ఔ́߃য̧̳́ͥ͂ͥ͂Ȅ
ʚSPA ɁʚRPB Ȫ2ȫ
͂̈́ͥȅ̽̀͢୪͈କ༷̥͈࢜ͣ߹̧ͬ φ ̳͂ͥ͂Ȅ
θ Ɂ φ Ȫ3ȫ
଼̦ၛ̳ͥȅ ȁ̭͉ͦ F ̽̀͢ͅθ ̦ଷࡠ̯ͦͥ͂Ȅ൳শͅ φ ́͘ଷ ࡠ̯̭ͦͥ͂ͬփྙ̳ͥḙ͉̏ͦ́͘Ȅఔఘͅ૦໙ ͬ૦̫̞̹͈ͤ̀́Ȅ࢙͈ఱ̧̈́ৣ࿂ͬୃ̱̞պ ෝ̜̹́̽ȅ̱̥̱φ ̦ଷخ౾ͅζΛάϋΈ̳̭̦ͥ͂ ࡠ̯̞̠̭͉ͦͥ͂͂Ȅφ ͈डఱͤ͢ఱ̧̈́߹০ͬ ̾ৣ࿂ͬୃ̱̞պ౾ͅζΛάϋΈ̧̞̭́̈́͂̈́ͥͅȅ ̾ͤ͘Ȅcontrol factor ͬఱ̧̩̳̭ͥ͂ͤ͢ͅ CMP ਹࣣ ါȪIIȫȅcontrol factor ͈̦ ༹ͅ߃ັ̩̦Ȅ̷ͦ̽̀͢ͅ߹০͈ఱ̧̈́ৣ࿂͕̓ୃٽ 2.4 ૧̱̞८၄ਹ༹ࣣ͈ ̦ضැȅcontrol factor ̦ఱ̧̩̈́ ̱̩ζΛάϋΈ̯̩ͦ̈́̈́ͤȄζͼΈτȜΏοϋ࢘ٽࡠͬ͂ͥાࣣ͈ޭ ͥ̾ͦ̀ͅ CMP ਹ༹ࣣͅ߃ັ̧Ȅ̯̩̈́ͥ̾ͅ ̞̩ͩͦ̀ḙ͈̭͉̏͂ control factor ͬௌै̳ͥषȄુ ͦ̀८၄ਹ༹ࣣͅ߃ັ̩ȅ ͅࣉၪ̱̤̥̫̞̀̈́ͦ͊̈́ͣ̈́ȅ Fig. 2.4 Schematic diagrams of the control factor’s effect. The 2.4.3 ८၄শા͈ࠗॳ ȅ̷͈ੜၑ༹̜༷̥̥͈ͥ́ͥۼimproved mapping method comes close to the CMP ȁ८၄ਹ༹ࣣ͉ࠗॳশ ಎ́ఱ̧͈̈́ۼstacking method as the control factor increases, and it ͈ಎ́͜८၄෨শા͈ࠗॳ͉ࠗॳশ ۼcomes close to the CSP stacking method as the control ;ͿͼΠ̤ͬ͛̀ͤḘ̏ͦͬࠚࡘ̳̭͉ͥ͂ࠗॳশ factor decreases. ͈ఱ໙̈́୯͂̈́ͥȅ Ȅ 2.6 ͬဥ̞̀୰ྶ̱̀۾ȁ८၄෨শζΛί͈ै଼ͅ
̳ͬͥȅ̴͘Ȅ८၄෨͈শ TSPR ͉Ȅ
TSPR Ɂ TSP + TPR Ȫ4ȫ
ါȅऒષ̦อૼത̥ͣٽ 2.6 ८၄෨শζΛί͈ै଼͈ ͈̾ ૦ത̥͈ͣশાȅֲ̦ 2̦ئೄ༷̥͈࢜ͣ ͈শાȅऒ൝͈ 2 ڙ 2.5 ८၄ത P ̤̫ͥͅ८၄ ഽ θ ͂८၄ത P ̤̫ͥͅ൝শެ͈͂୪ AB শાͬ௷̵̱ࣣ̹ͩ८၄෨শાڙ ߸ Fig. 2.6 Scheme of making a scatter traveltime map. Maps of۾͈͂ କ̥͈ͣ߹̧ φ͈ Fig. 2.5 Geometry of the angles θ and φ. θ is an angle between traveltime from a shot pointȪupper leftȫand from a the normal line and the bisector of the scatter angle at the receiver pointȪ lower left*. A scatter traveltime map is scatter point P. φ is an angle between the horizontal line made from a summation of both the traveltime maps and the tangent at P. Ȫright*.
Ƚ!180 Ƚ ࢹ௮ζΛάϋΈȽ໌നڔ૬໐౷̩̿ܖ૧̱̞८၄ਹ༹ࣣͅ
͂ນ̵ͥḙ̭̏́ȄTSP ͉อૼത̥ͣ८၄ത͈́͘শȄ Ȫ8ȫ
TPR ͉८၄ത̥ͣ૦ത͈́͘শ̜́ͥḙ͈̏८၄෨ خȄၗ̀̽͢ͅڞۼဓ̢ͣͦͥȅষͅȪ2ȫ͈૦ത́ শͬݥ༹༷̱͛ͥ͂̀৽ͅ 2 ༹͈༷̦̜̾ͥȅ෨ ෝ̈́ఱ̧̯ s ͉Ȅخෝ̈́ఱ̧̯͉ଷࡠ̫ͬͥȅ̷͈ၗ ༹ͥ͢ͅশࠗॳ༹͂ခࡠओͥ͢ͅশࠗॳ༹̜́ͥ in ̳͂ͥ͂Ȅ ͬڞۼ૦ത Ȅ̷̸ͦͦ෨༹Ȅခࡠओ༹͂ࡤ͐ȫȅ෨ئȪո ༹ͤ͢ͅ८၄෨শͬݥ̹͉͛ͥ͛ͅȄࠗॳ̳ͥκ Ȫ9ȫ ̱Ȅอૼത̥ͣ८၄തبΟσ͈ΈςΛΡͅ८၄തͬ ̯͂ͦͥȅȪ3ȫ͈ control factor ͥ͢ͅ૦໙ͬ૦̫ͤͥႀ ͈́͘෨͂८၄ത̥ͣอૼത͈́͘෨ͬ 1 ུ 1 ུࠗ ࢩ̦͉ͤȄcontrol factor ͈̯̩̳̭͈֖ͬͥ͂̽͢ͅ ఱ་ါ༹̳ͥ́ͬۼॳ̳ͥຈါ̦̜ͥḙ͉̏ͦࠗॳশ ఱ̧̩̈́ͤȄ̷ٜͦ̽̀͢ͅෝ̦՛̩̈́ͥȅcontrol̀ ̱̞̹̀ͥ͛ͅ௸ഽبȄࣞਔ෨߃য̩̫̺̜ͬ̈́́ͥ factor ̽̀͢ͅ૦໙ͬ૦̫ͤͣͦͥ θ ͈डఱͬ θ maxȄ ಠ̱̞௸ഽκΟσ͉̽̀͢ͅ෨ͬࡉ̫̦̾اࢹ௮͈་ చય͂̈́ͥ૬̯ͬ z ̳͂ͥ͂Ȅႀ֖͈ࢩ̦ͤ d ͉Ȅ ̴̧̭̦ͥ͂́শͬࠗॳ̧̞́̈́ΏλΡȜΖȜϋ̦࡛ ાࣣ̦̜ͥȅ༷֚Ȅခࡠओ༹͉֚ഽ͈ࠗॳ́อૼ Ȫ10ȫͥͦ ത̥ͣࠗॳ̳ͥ௸ഽાఘ͈শ֚ͬͅݥ̭̦͛ͥ͂ ̱͂̀Ȅ̷̤̤͢ࡉୟ̧̭̦ͥ͂́ͥ͜ȅ̽̀͢Ḙ̏ͦ ̧́ͥȅ̷ͦͤ͢ͅȄ෨༹͈ાࣣ͈̠͢ͅ෨ͬ ̜ͥ́ٮါள͈ಎ͈́डఱ̦କٜෝ͈ࡠ͈̾ 3 ͣ ࠗॳ̧̞́̈́ΏλΡȜΖȜϋ̦࡛̭̩ͦͥ͂̈́͜Ȅ௸ഽ ͂ࣉ̢ͣͦͥȅ ௸ෝ̜́ͥȅോࡪ̞̠͂خાఘ͈শͬݥ̭̦͛ͥ͂ 2.4.5 ༹͈͂͛͘ ഽࢹ௮̦ໝॠ̈́౷֖ͅഐဥ̳̭ͥ͂ͬࣉၪ̳ͥ͂Ȅུ ତ͂ control factor ͬ൵ව۾ȁ૧̱̞८၄ਹ༹ࣣ͉Ȅਹ͙ ༹͉́ခࡠओ༹ͬनဥ̳ͥȅ̹͘ष͈ࠗॳ͉́ Hole ̳̭ͥ͂ͤ͢ͅḘ̏ͦ́͘༆༹͈̜̹́̽ CMP ਹ༹ࣣ and ZeltȪ1995ȫͥ͢ͅခࡠओ༹͈ͺσΌςΒθͬழ͙ࣺ ͂ਲြ͈८၄ਹ༹ࣣ͈ඵ༹͈͍̾ͬࠫັ̫̹ȅcontrol ̺ͭίυΈρθͬঀဥ̳ͥḙ͈̏ίυΈρθ͉ਲြ͈͜ factor ͬଷࢄ̳̭ͥ͂ͤ͢ͅȄ̷͈ၰޭࡠ̜ͥͅඵ͈̾ ݢ̦اࣞ௸̥̾ࣞୈഽ́ࠗॳ̧̦́Ȅ̹͘௸ഽ་͈ͤ͢ خੜၑ͈ͬ͜ۼ̻ͧͭ͜Ȅ̷͈ၰ༹̦ဏგ̳ͥಎ༹͉ ̈́ાࣣ͞௸ഽϋΠρΑΠ̦ఱ̧̈́ાࣣ́͜հ̱̀ࠗ ੜၑ͉́ၰ༹͈၌തͬ࠳̢͇͈ۼෝ̱̹ͅḙ͈̏ಎ ॳ̧́ͥ၌തͬ̾ȅ ௶Ḙ̏ͦ́͘ζΛάϋΈ̳ͥশͅવ͈̜̹̽۷̤ͤ̀ ஜ͈ခࡠओ༹ͬनဥ̳̜̹ͥͤͅȄ֚ഽͅ௸ഽા തྟഽ̦೩̞ΟȜΗͬե̠ાࣣͅȄ̷͈࢘ႁͬอܞ̧́ Ȅষ͈̭͂ͬࣉ̱̥̀ڰఘ͈শ̦ࠗॳ̧́ͥ၌തͬ ͥ͂ܢఞ̯ͦͥḙ̷̏́ষડ༹͉̭͈͈́ခ࢘̾ͅ ̢ͥȅ ̞̀ତࠗॳͬ͂͜ͅબ̳ͥȅ ૦ത̥ͣ८၄ത͈́͘শͬ TRP ̳͂ͥ͂Ȅ
TRP Ɂ TPR Ȫ5ȫ 3. ΞΑΠ 3.1 ΞΑΠ̜̹̽̀ͅ ̜́ͥȅ̽̀͢ T ͉Ȅ ̳ͥ·ࣜ࿒ͬΙͿΛ͈ئSPR ȁ̭̭͉́Ȅུ༹̞̾̀ͅո
TSPR Ɂ TSP + TRPP Ȫ6ȫ ̹͛ͅၑა෨ࠁͥ͢ͅΞΑΠ࣐̹ͬ̽ȅΙͿΛ·ࣜ࿒͉Ȅ Ȅ2ȫΰΛΡ;ͿȜῄޣגͥ͢ͅض1ȫΑΠτΛΙϋΈ࢘ ͂ນ̧̳̭̦͂́ͥȅ ȪΦͼΒ̦̞̈́ાࣣȫȄ4ȫضȄ3ȫcontrol factor ͈࢘ޣגͥ͢ ̾ͤ͘Ȅ̜ͥอૼത͂૦ത̞̾̀ࠗͅॳ̳ͥાࣣȄอ ȪΦͼΒ̦̜ͥાࣣȫ͈ 4 ࣜ࿒̜́ͥȅضcontrol factor ͈࢘ ૼത̥͈ͣশા͂૦ത̥͈ͣশા̷̸ͬͦͦݥ͛ ̥ږͬޣג͈ض1ȫུ༹͉̤̫́ͥͅΑΠτΛΙϋΈ࢘ ̀Ȅၰ৪͈௷̵̱ࣣͩ̽̀͢ͅȄယօͅ८၄෨শાͬ ȄNMO ༞ୃশͅૼ؇ݻၗ͉͂ض͛ͥȅΑΠτΛΙϋΈ࢘ ࠗॳ̧́ͥȅ ȄέΓΛΠ͂ࡤ͐ȫ̦ఱ̧̩Ȅ̹͘൲ͅ߃̞ܱئȪո ٜෝ 2.4.4 װȄఱ̧̧̩̜֨ͤ́ض̯࢘ͥͦ͊װ͕̓Ȅ෨ࠁ̧̦֨ ٜෝ̞̾̀ͅࣉख़̳ͥȅۼ͉ࣜ́Ḙ༹͈͈̏ߗ͈̭ ̯̹͊ͦ෨ࠁ̷͈ͬ͘͘ঀဥ̱̀ CMP ਹࣣ̳ͬͥ͂ංͣ ٜෝ͉ͅೄٜෝ͂କٜෝ̦̜͂ͥȅೄۼߗ ȅུ༹̤̞̀͜ͅȄΑΠτΛ̵̯ͥاͼιȜΐͬႦͥͦ ٮٜෝͬ 2 ͈̾൳ޭ͈;ͿȜήτΛΠ̦ၗ̧́ͥࡠ ͅࣉၪ̱ΟȜΗ఼̳ͬ৾ͥຈါͬޣגΙϋΈ͈ ̜̳́ͥ͂ͥ̈́ͣ͊Ȅဥ̞ͥ෨͈෨ಿͬ λ ̳͂ͥ͂Ȅ ഽ͈௸̞ͬഥ௸́ٮޏഽ͈௸͈ئȅ2ȫ͉́Ȅ౷̜̦ͥ ೄٜෝ rv ͉Ȅ ͓ͥȅέΓΛΠ̞̀̾ͅޣג̳ͥΰΛΡ;ͿȜή͈ Ȫ7ȫ ͈ఱ̧̞ાࣣͅခࡠओ༹́শાͬࠗॳ̳ͥ͂Ȅຈါ ̳͂ͥ८၄෨শ͉̩́̈́Ȅ̷்̩ͦͤ͢͜ൢో̳ͥΰΛ ͂̈́ͥḙ͉̏ͦ Rayleigh ͈ 1/4 ෨ಿ௱͂ࡤ͊ͦͥȅ Ρ;ͿȜήশͬࠗॳ̳ͥાࣣ̦̜ͥḙ͈̏ΰΛΡ;ͿȜ ̳ͥޣגȄ̷͈ٜෝ͉̱̀ͅ۾Ȅକٜෝ༷֚ͅ ήͬ܄͚শાͬဥ̞̹ાࣣȄ८၄ത͉͂։̈́ͥાਫ਼ͅ ါள̦ݷ̬ͣͦȄȪ1ȫέτΥσΖȜϋȄȪ2ȫ͈̥̩̞̾ ෝ̦̜ͥȅ̷͈̹͛ȄΰΛΡ;ͿȜخζΛάϋΈ̯ͦͥ ȄȪ3ȫ control factor ͥ͢ͅ૦໙ͬ૦̫ͤͥႀ֖ڞۼ૦ത ג̞̈́͘ાࣣ͈শાͬࠗॳ̱Ȅ̷͈܄͚ાࣣ͂܄ήͬ ͈ࢩ̦ͤȄ൝̦̜ͥȅ̴͘Ȫ1ȫ͈έτΥσΖȜϋ͈ࠂ r બ̳ͥȅ3ȫ͉́Ȅࣽٝ൵ව̱̹ control factor̞̀̾ͅޣ ͉Ȅచય͂̈́ͥ૬̯ͬ z ̳͂ͥ͂Ȅ
Ƚ!181 Ƚ ࡄݪਫ਼ࡄݪ༭࣬ȁల 68 ȁ2005 ා 9 ܿڠشཡब
͈ခ࢘ͬબ̳ͥḙ͈̏ control factor ͈ͬ੭șͅ་ ȄͼιȜΐ̦८၄ਹ༹ࣣ̥ͣ CMP ਹ̵ฺ̞̭̯͂ͥͅا ΙͿΛ·̱Ȅ̷͈̥͈̩̞̱ͬ̀ا༹ࣣ͈̠͒̓͢ͅ་ ൚̳ͥੜၑ͉͈̠́̓̈́͢ͅۼഷಎ͈ၰ༹͈ಎا་ ̳ͥȅडࢃͅ 4ȫ͉́Ȅ෨ࠁ૦໙͂ږඅಭ̦̜͈̥ͥͬ ৣ෨শͅΦͼΒ̨͂ͣͬ͠ဓ̢̹ΟȜῌ༹ͬഐ ဥ̳ͥȅषͅോࡪ͉́Ȅ۷௶̯ͦͥΟȜΗ͈ΨΛ·Έ ρ;ϋΡΦͼΒ͉̩ࣞȄ̹͘மྟ̈́۷௶͉́Ȅႋ୪̳ͥ ఱ̧̩։̞̈́̽̀ͥાࣣ̦ఉ̞ȅ̦ޣגത́͜౷ນ͈௶۷ ̷͈̠̈́͢ાུ༹ࣣ͈͈ခ̞࢘̾̀ͅબ̳ͥȅ 2 ͈ڞۼΞΑΠͅঀဥ̱̹κΟσ͉̀ 250m ΈςΛΡ ȅȪaȫޣג͈ض 3.1 NMO ༞ୃ̤̫ͥͅΑΠτΛΙϋΈ࢘ ষࡓκΟσ̜́ͥȅ८၄෨শ͈ࠗॳ͉ͅခࡠओ༹ͬ NMO ༞ୃஜ͈෨ࠁܱȄȪbȫΑΠτΛΙϋΈͅ ဥ̞̹ Hole and ZeltȪ1995ȫ͈ίυΈρθͬঀဥ̳ͥȅ͘ ષࡠͬ୭̫̞̈́ાࣣȄȪcȫΑΠτΛΙϋΈ̦ષࡠ ̹ synthetic ෨ࠁ͈ࠗॳ͉ͅ Zelt and SmithȪ1992ȫ͈෨ 150% ͈ાࣣȄȪdȫΑΠτΛΙϋΈ̦ષࡠ 200% ͈ ༹͈ίυΈρθͬဥ̞̤̀ͤȄ෨༹ͅܖ̞̿̀ ાࣣȅYilmazȪ 2001ȫͤ֨͢ဥ ̱̀ ࠗॳ̯̹ͦͼϋΩσΑ؊൞ͅૼ࡙෨ࠁͬ convolution Fig. 3.1 Stretching effect caused by NMO correctionȪ Yilmaz, ෨ࠁͬै଼̱̞̀ͥȅঀဥ̳ͥ synthetic ෨ࠁ͉ 100Hz 2001*.ȪaȫA synthetic CMP gather before NMO ϋίςϋΈ̱͂Ȅૼ࡙෨ࠁ͉ͅਔ෨ତ 8.3Hz ͈ 1 ͼ·σ correction,Ȫ bȫ after NMO correction without stretch ͈ͼϋ෨ͬঀဥ̱̹ȅ limits,Ȫ cȫ after muting using a stretch upper limit of 150 ޣגΑΠτΛΙϋΈ͈ 3.2 percent, andȪ dȫ after muting using a stretch upper limit ୰ྶ̳ͥȅNMÒ̞̾ͅضडͅΑΠτΛΙϋΈ࢘ of 200 percent. အঊͬ 3.1 ͅা̳ȅ͈ض༞ୃͥ͢ͅΑΠτΛΙϋΈ࢘ ̧̱̹͂ͅ൳̲ CMP ͬ̾͜بȪaȫ͉́କఉࢹ௮ͬ NMO ༞ୃஜ͈ΠτȜΑͬນ̳ḙ̭͉̏́Ȅ4 ཿ͈କ̈́ ̱̹ḙ͈ܱ̏ͬ NMO ༞ୃ̱̹ΠτȜΑ̦بৣ࿂ͬ Ȫbȫ̜́ͥḙ͈̥̥̠̏ͣͩͥ͢ͅȄέΓΛΠ̦ఱ̧ Ȅৣ෨͈ΏΈσ෨ࠁ̧̦̯̩֨͊ͦ̀̀ͦ̾ͥ̈́ͅ ȅ̹͘ஃ̞ৣ࿂̥͈ͣৣ෨̷̧͕͈̯̩̞̓֨͊ͦ ḙ͈̜̏ͥ́ضࣣ̦ఱ̧̞ḙ̦̏ͦΑΠτΛΙϋΈ࢘ڬͥ ါȅऒ͉ٽ͈ض̹͛͘͘ਹࣣ̳ͥ͂Ȅංͣ 3.2 ུ༹̤̫ͥͅΑΠτΛΙϋΈ࢘܄ఱ̧̧̩̯̹ܱ֨͊ͦͬ ઉ̩̭͉͂ྶฒ̜́ͥḙ͈̠̏̈́͢ έΓΛΠ̦ 70km ͈ાࣣ͈८၄෨শાȅֲ͉έͬاͼιȜΐ͈Ⴆͥͦ ཡ̪ևȄུࡄݪ͉́෨ࠁΠτȜΑ̧͈̯֨͊ͦͥ ΓΛΠ̦ 140km ͈ાࣣ͈८၄෨শાȅ൝শެͬاႦ έΓΛΠ̦ 140km ͈ાࣣ͈༷̦ఱ̧̞ȅ͉ڞۼ ࣣͅષࡠͬ୭̫̭̱ͥ͂ͅȄ̷಼̢ͦͬͥાࣣ͉ͅਹڬ ࣣͬȄNMO Fig. 3.2 Schematic diagrams of the stretching effect caused by theڬࣣ̱̞̭̱̹̈́͂͂ȩ̭͈̯̏֨͊ͦͥ Ȅ improved mapping method. Scatter traveltime maps showئ༞ୃஜ͂ NMO ༞ୃࢃ͈෨ࠁΠτȜΆ͈ນ̳Ȫո the cases in which the source-receiver offsets were 70km ۼΑΠτΛΙϋΈ͂ࡤ͐ȫȅ൳̲෨ࠁΠτȜΑષ́͜শ Ȅ൲ັ߃́̽͜ Ȫleftȫand 140kmȪright*. The case of 140km has aṉاͅ؊̲̀ΑΠτΛΙϋΈ͉་ ͂͜ఱ̧̩Ȅ̷ͦͤ͢͜ࢃ͈শ͉࣫́੭ș̯̩̈́ͤͅȄ isochrone contour with a wider interval. 100% ͅ߃ັ̞̞̩̀ȅȪcȫ͂Ȫdȫ͉ NMO ༞ୃশͅਹࣣ̳ ̥ͥ๛̥͈ΑΠτΛΙ͈ષࡠ̷̸ͬͦͦ 150% ͂ 200% ̱̹͂ાࣣ̜́ͥȅષࡠͬ୭̳̭ͥ͂ͤ͢ͅȄȪbȫ͈͢ ̳͂ͥڛఱ̧̈́෨ࠁ͈ე͙͉̩̈́̈́ͥḙ͈̏ඵ̠̾ͬ̈́ 150% ͈༷͉෨ࠁ͈ე͙͉̞̦̓̈́Ȅஃ໐̥͈ͣৣ෨ ෝ̈́ΟȜΗ̦ઁ̩̞̈́̈́̽̀خఱ̧̩ॉੰ̯ͦ̀Ȅঀဥ͉ ȅ༷֚Ȅ200% ͈༷͉Ȅ150% ̧͈͂ͤ͢͜έΓΛΠͥ ͈ఱ̧̞̭͉͂ͧ́෨ࠁ͈͍̦ࡉ̦ͣͦͥȄঀဥ̧́ͥ ௩̢ڬ ΟȜΗၾ͉ఉ̩̈́ͤȄ႕̢͊̽͂͜͜ஃ̞͉́ 4 ̞̀ͥȅ̾ͤ͘ȄΑΠτΛΙϋΈ͈ષࡠ̩ͬࣞ୭̳ͦ ȅ̳ͥحე͙͉ఱ̧̩̦̈́ͥȄঀဥ̧́ͥΟȜΗ͉௩͊ ͬ Ȅ 3.2̞̀̾ͅض༹͈ાࣣ͈ΑΠτΛΙϋΈུ࢘ ဥ̞̀୰ྶ̳ͥȅऒ͈͉έΓΛΠ̦̯̞Ȫ70kmȫ 3.3 ΞΑΠͅঀဥ̱̹କఉ௸ഽκΟσ .ાࣣ͈८၄෨শાͬȄֲ͈͉έΓΛΠ̦ఱ̧̞ Fig. 3.3 Synthetic horizontal multi-layered model
Ƚ!182 Ƚ ࢹ௮ζΛάϋΈȽ໌നڔ૬໐౷̩̿ܖ૧̱̞८၄ਹ༹ࣣͅ
Ȫ140kmȫાࣣ͈८၄෨শાͬນ̳ḙ͈̏শાͅచ؊ ̱̀૦໙ͬ૦̫̞̦ͤ̀ͥȄέΓΛΠ̦ఱ̧̩̈́ ͉ڞۼ֣́া̳̠͢ͅ൳̲ 1sec ́͜൝শެ͈͂ͥ ࢩ̦ͥḙ͉̏ͦ NMO ༞ୃশ͂൳အͅ૦̫ͤͥ૦໙̦ ဥ̫̞̭ͬ̀ͥ͂ͬা̳ȅొ̱ȄNMOै͈̱͊װ̧֨ Ȅུ̦̹̜̱̽́͊װ༞ୃ͈ાࣣ͉́ 1 ষࡓ̧͈́֨ Ȅུ͉́ئষࡓȪ̱̩͉͜ 3 ষࡓȫ͂̈́ͥȅո 2 ༹͉́ ̱Ȅঀဥ̳ͥΟȜږͬޣג͈ضΑΠτΛΙϋΈ༹͈࢘ ȅ̳ͥثῌ̞̾̀ഐୃ̈́ΑΠτΛΙϋΈ͈ષࡠͬບ ঀဥ̳ͥ௸ഽκΟσ͉କఉࢹ௮̱͂Ȅ௶ಿ 180km× ૬̯ 50km ͈ํս́ࠗॳ̳ͬͥȪ 3.3ȫȅৣ࿂͉૬̯ ̱Ȅ̷͈ͦͣષب15kmȄ25kmȄ35kmȄ45km ͈պ౾ͅ ഽϋΠρΑΠ͉Ȅஃ̞༷̥ͣ 6.1→6.4km/secȄ6.4௸͈́ئ →6.9km/secȄ6.9→7.6km/secȄ7.6→8.0km/sec ̱̹͂ȅΏοΛ Πത͉ऒͅ 1 ത͈͙́۷௶ത͉ 1km ྀͅ 179 ത୭̱ 3.4 ΞΑΠͅঀဥ ̱̹synthetic ෨ࠁȅ6km/sec ́ reduce Ȅ1990 ාయஜུ࣐͉́́ͩͦ͘ڞۼḙ͈̏۷௶ത̹ ̱̜̀ͥȅ ̞̹̀ࡑ͈ॽအ͕͖͂൳൝̜́ͥȅષ͈κΟσͅܖ Fig. 3.4 Synthetic seismograms reduced by a velocity of 6km/sec. ଼̞ࣣ̱̹̿̀෨ࠁͬ 3.4 ͅা̳ḙ͈̏τȜΡΓ· ̧́ږΏοϋ͉ͅ 4 ཿ͈ৣ࿂̥͈ͣྶၸ̈́ৣ෨ͬ ͅ 3.5ͬضḙ͈̏෨ࠁΟȜῌȄུ༹ͬഐဥ̱̹ࠫͥ া̳ȅΞΑΠ͉́ΑΠτΛΙϋΈ͈ષࡠ 150%Ȅ170%Ȅ 180%Ȅ190%Ȅ200%Ȅ210%Ȅ250% ͈ાࣣ͂ଷࡠͬ୭̫
,Ȫऒષ̥ͣΑΠτΛΙϋΈ͈ષࡠ̦ 150%, 170%, 180%, 190%ޣג͈ض 3.5 ུ༹ഐဥ̤̫ͥͅΑΠτΛΙϋΈ࢘ 200%, 210%, 250% ̜́ͥાࣣ͂ષࡠ̱͈̈́ાࣣȫ Fig. 3.5 Effects of stretch upper limits in the improved mapping method. The stretch upper limits are 150, 170, 180, 190, 200, 210, and 250% as well as no limit.
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̞̈́ા̵ࣣࣣͬͩ̀ 8 ΩΗȜϋͬࠗॳ̱̹ȅଷࡠͬ୭̫ έΓΛΠ̦̯̞ાࣣ͉ͅȄ்̩̽͂͜͜८၄തͅൢ ࡉͥ͂Ȅऒ̥ͣݻၗ̦ఱ̧̩̈́ ̳ͥ෨͉८၄ത͈ષ༷ͤ͢වৣ̳ͥȅ̱̥̱ȄέΓΛͬضાࣣ͈̞̞ࠫ̈́̀ ८၄തͅවৣ༷ͤ͢ئ੭șͅζΛάϋΈ̯̹ͦৣ࿂̦૬̯༷࢜ͅ Π̦ఱ̧̩̈́ͥ͂Ȅષ༷͉̩́̈́̀ͦ̾ͥͅ ಫ̱̞̀ͥȅඅͅड͜ஃ̞૬̯ 15km ͈ৣ࿂͉́έ ̱̹ΰΛΡ;ͿȜήশ்͈༷̦̩ൢో̱Ȅୃ̱̩८၄ ΓΛΠ 30km ັ߃̥ͣಫ̦ಠ̱̞ȅ̹͘Ȅ֚๔૬̞૬̯ শાͬݥ̧̭̦̩͛ͥ͂́̈́̈́ͥḙ̷̏́Ḙ͈̏ΰΛ ဓ̢̀ͬޣג45km ͈ৣ࿂́͜ 60km ັ߃ͤ͢ఱ̧̩ಫ̱̞̀ͥȅ Ρ;ͿȜήশ̦ζΛάϋΈ͈̠̓̈́͢ͅ બ̳ͥȅ̥̞ͥ ג͈ضȄஃ̞ৣ࿂͈༷̦ΑΠτΛΙϋΈ̠͈̭࢘͢ͅ ͓̹ͥ͛ͅȄ̴͘ΰΛΡͬޣגȄ ȁΰΛΡ;ͿȜῄ͈̞̤̀ض̫̳̞͞ȅષࡠͬ୭̱̹ાࣣ͈ࠫͬޣ ͈ ͿȜήͬࣉၪ̱̞̈́८၄෨শાͬࠗॳ̳ͥȅ 3.6; ͕͉ͭ͂ޣגͥ͢ͅضાࣣ͉ȄΑΠτΛΙϋΈ͈࢘ 150% වৣ̳ͥȅ̷̥༷ͣئ̞̦͛ͣͦ̈́Ȅષࡠ͈୭̦೩̞̭͂ͤ͢ͅঀဥ́ ̠͢ͅΰΛΡ;ͿȜή͉८၄തͤ̓͢ ̠͈͢ئවৣ͈শͬࠗॳ̱̞̠̈́͢ͅȄո༷ئ͈̭̭́ ΟȜΗ͉̥̈́ͤଷࡠ̯̤ͦ̀ͤȄΏοΛΠത̧̥ͣͥ എ߃̞ํսඤ͈͙́ৣ࿂̦ζΛάϋΈ̯̞ͦ̀ͥȪ૬ ̈́ࠗॳ࣐̞ͬȄশાͬݥ͛ͥȅକ 4 ࢹ௮͈ાࣣͬڛ 35km ͈ৣ࿂͈ાࣣȄ 40kmȫȅݙͅ 250% ͈ાࣣ͉Ȅ ႕ͅݷ̬̀ 3.7 ͬဥ̞̀୰ྶ̳ͥḙ͈̏κΟσ͉́૬໐ ̯ ષࡠ͈୭̦̞̭ࣞ͂ͤ͢ͅ 150% ͈ાࣣͤ͢ঀဥ̧́ͥ ̜͕ͥ̓ͅ௸ഽ̦ఱ̧̞ȅࠗॳ༹༷͉Ȅ̴͘ల 2 ո ζΑ·̱Ȅల 1 ͈͙́শࠗॳ̳ͬͥȪIȫḙ̠̳̏ͬئ ΟȜΗ͉௩̢Ȅৣ࿂͉ΏοΛΠത̥ͣͤ͢ၗ̹ͦํս͘ ́ζΛάϋΈ̯̞ͦ̀ͥȪ૬̯ 35km ͈ৣ࿂͈ાࣣȄ ̭ͥ͂ͤ͢ͅల 1 ͤ͢௸̞ల 2 ͈ષ࿂ͬഥ̳ͥΰΛ ͬئȅষͅల 3 ࿒ո̧ͥ́ٸ70kmȫȅ̱̥̱Ȅৣ࿂͈ྎ͉ಫ̱ఱ̧̩ე̞ͭ́ͥȅ Ρ;ͿȜήͬࠗॳ̥ͣੰ ৣ༹͈ΟȜΗ͉Ȅఱၘ૬໐ࢹ௮ౝ ζΑ·̱Ȅల 1 ͂ల 2 ͈͙́শࠗॳ̳ͬͥȪIIȫȅոڙࢃͅഐဥ̳ͥࢩ ൳အ̷ͦͤ͢͜ͅ૬̞ͬζΑ·̱̀Ȅ̷ͦͤ͢͜ஃئ औ͈ΟȜΗ͓͂̀۷௶തྟഽ̦೩̞̹͛ͅΟȜΗၾ͉ ဥ̳̹͉ͥ͛ͅȄ ໐ͅպ౾̳͈͙͈ͥ́শࠗॳ࣐̠ͬȪȪIIIȫ͂ȪIVȫȫȅڰḙ̷̏́Ȅ۷௶ΟȜΗͬडఱࡠ̞̈́ઁ ഐ୨̈́ΑΠτΛΙϋΈ͈ષࡠͬഐ୨̭͐͂ͤ͢ͅͅȄ ̭͂ͧ́ȄȪIIȫ͈ાࣣ͉́ల 1 ͈শા̦ల 2 ̥͈ͣ ෝ̦̜ͥȅ൳အخ̫̞̀ͥͬޣגෝ̈́ႀ֖ͬࢩ̬ͥຈါ̦̜ͥȅષܱ͈ΞΑ ΰΛΡ;ͿȜή͈خζΛάϋΈ Ȅུࡄݪ͉́ಫͥ͢ͅე͙ͬ 190% ͈ાࣣ ͅȪIIIȫ͈ાࣣ͉́Ȅల 2 ̥ͣષ͈শા̷͉̥́ͦͤͣ͢ضΠ͈ࠫ ෝخ̫̞̀ͥͬޣגպ͈̥͈ͣΰΛΡ;ͿȜή͈ئ ͉́͘ݺယ̧́ͥ͂౯̱Ȅષࡠͬ 190% ͅ୭̱̹ȅո ࢃ͉́Ȅ౯͈̞ͤ̈́ાࣣ͉ਹࣣచય̳͂ͥΑΠτΛΙϋ Έ͈ષࡠͬ 190% ̱͂̀ࠗॳ̳ͥȅ ޣגΰΛΡ;ͿȜή͈ 3.3 ഽ͈௸̞ͬഥ̳ͥΰΛΡ௸͉́ٮޏഽ͈௸͈ئ౷ ;ͿȜή̦ంह̳ͥȅ̷ͦඅͅέΓΛΠ͈ఱ̧̞ા ࣣͅခࡠओ༹́শાͬࠗॳ̳ͥ͂Ȅ࿒എ̳͂ͥ८၄෨ শ͉̩́̈́Ȅ̷்̩ͦͤ͢͜ൢో̳ͥΰΛΡ;ͿȜή শͬࠗॳ̳ͥાࣣ̦̜ͥȅ̷͈႕ͬ 3.6 ͬဥ̞̀୰ྶ̳ ب͉ષͤ͢௸ഽ̦௸̞̠̈́͢କ 2 ࢹ௮ͬئȅͥ ೄષͅ८၄ത̦̜̳ͥ͂ͥȩ̭͈̏͂Ȅ͈ٮޏ̱Ȅ̷͈
3.6 ခࡠओ༹ͥ͢ͅশࠗॳ̤̞̀ࠗͅॳ̯ͦͥΰΛ ͈ئΡ;ͿȜήশȅέΓΛΠ͈ఱ̧̞ાࣣ͉ͅ ௸ഽ͈௸̞ͬഥ̱̩̀ͥΰΛΡ;ͿȜήশ͈ ༷̦ೄో෨்̞ͤ͢ȅ Fig. 3.6 Traveltime of head waves calculated using a finite 3.7 ΰΛΡ;ͿȜήͬ܄̞̈́͘শા͈ࠗॳȪକ 4 difference method. In case of a large offset, head waves ௸ഽκΟσͬ႕̱͂̀ȫ propagating in the lower layer at a high velocity are faster Fig. 3.7 Calculation of traveltime map without head waves in a than direct waves. four-horizontal-layered model.
Ƚ!184 Ƚ ࢹ௮ζΛάϋΈȽ໌നڔ૬໐౷̩̿ܖ૧̱̞८၄ਹ༹ࣣͅ
̫̞̞̀̈́ͬޣג̦̜ͥȅ̽̀͢ΰΛΡ;ͿȜή͈ ͈͉ȄζΑ·̱̹͈ೄષ̜͈ͥͅশા̺̫͂̈́ͥȅ ̳̻̈́ͩȄȪIȫȡȪIVȫ͈শા̥ͣȄ႕̢͊ȪIȫ̈́ͣల 1 ȄȪIIȫ̈́ͣల 2 Ȅ͈̠͢ͅਜ਼๔ͅา̧̱Ȅ̷ͦͣͬ ൡࣣ̱̀डਞഎͅশાȪVȫͬංͥḙ͈̠̱̏̀͢ͅං ੰ͉ޣג̥͈ͣΰΛΡ;ͿȜή͈ئশા͉Ȅ̹ͦͣ ఞ̯ͦͥ८၄෨শͬݥ̭͛ͥ͂͂̈́ͥȅ̻͜ 3.8 έΓΛΠ̦ 70km ̧͈͈͂८၄෨শાȅऒ͉ΰΛܢȄ̥ͦ ͚ાࣣȅֲ͉ΰΛΡ;ͿȜήͬ܄͜൳အ̈́ੜၑ࣐̠̭ͬ͂ͅ Ρ;ͿȜήশͬ́ٸȄକఉκΟσոͭͧ ̞̈́͘ાࣣ܄ خ̞̈́͘শાͬݥ̭̦͛ͥ͂܄ΰΛΡ;ͿȜήͬͤ͢ ෝ̜́ͥȅ Fig. 3.8 Scatter traveltime map for a case with a source-receiver ̞̈́͘ાࣣ́ offset of 70km withȪleft*, and withoutȪrightȫ head܄͚ાࣣ͂܄ȄΰΛΡ;ͿȜή͉ͬ́ئո .͙̭̳ͥ͂ͥͅȅࠗॳ͉ͅȄ3.2 ୯͈ waves̱̀ڛশા͈ͬ ΞΑΠͅဥ̞̹କఉ͈௸ഽࢹ௮κΟσͬঀဥ̱Ȅอૼ തȆ૦ത౾͜൳̲̳͂ͥȅ̴͘ȄέΓΛΠ̦ 70 km ͈ાࣣ̜́ͥȪ 3.8ȫȅၰ৪͂͜อૼത͂૦തͅޖͦ͘ শ͉̓ͅओ֑͉̞̈́ȅ̱̥̱ȄΰΛΡ;ͿȜ͈ۼߊ̹ ൝শެ͈ະႲ̦́ٮޏήͬੰ̞̹শા͉́Ȅ ̲̞̀ͥȅอૼത͂૦ത͈ಎ̥ͣକ༷࢜ͅၗͦ̀ ͈ٮޏਲ̷͈̽̀ະႲ͉੭șͅఱ̧̩̈́ͤȄ̩͠ͅ डఱ 1.5sec ͈শΆλΛί̦̲̞̀ͥȅΰΛΡ́ئષ ͅ ͿȜήͬੰݲ̱̹শ͂ੰݲ̱̞̈́শ͈ओͬ 3.9; ̦̹̱̽ͥͦͅٸা̳ȅอૼത͂૦ത͈ಎ̥ͣऒֲͅ ೄષ͉́̽͂͜͜ 3.9 έΓΛΠ̦ 70km ̧͈͈͂ΰΛΡ;ͿȜήশ͈ͬٮޏশ͉ষలͅࢩ̦ͤȄ̷͈̀ ̞̈́͘ાࣣ͈८၄෨শ͈ओ܄͚ાࣣ͂܄ ఱ̧̩Ȅඅֲ͉́ͅडఱ 2sec ͈ओ̦̜ͥȅষͅέ ΓΛΠ̦ 140km ͈ાࣣ͈শાͬা̳Ȫ 3.10ȫȅΰΛΡ Fig. 3.9 Difference between scatter traveltime maps with and .ͿȜήͬੰݲ̱̹শા͉́Ȅ70km ͈ાࣣ͂൳အͅ without head waves for an offset of 70km; ̧́ͥȅশओ͉́ȄඅږশΆλΛί̦͈ئષٮޏ ൝শ͈କ༷͈࢜ະႲ̦࿒ၛ̻Ȅ̺ͭޖͬٮޏͅ डఱ 10km ոષ̞֑̞̦̜ͥȪ 3.11ȫȅΰΛΡ;ͿȜή ͈ࣉၪ͈ခྫͤ͢ͅȄࠗॳ̯̹ͦশાͅओ։̦̲ͥȅ ̷͉ͦอૼത͂૦ത͈ಎ̥ͣၗ̱̹̦ͦͥ̽̀ͅষ ષٮޏలͅఱ̧̩̈́ͤȄέΓΛΠ̦ఱ̧̞ાࣣ͕̓ ൝শެ̦ࡐಠ̜́ͥḙ͈̭̏ͦͣ͂ͤ͢Ȅอ 3.10 έΓΛΠ̦ 140km ̧͈͈͂८၄෨শાȅऒ̦͈́ئ ͚ાࣣȅֲ̦ΰΛΡ;ͿȜ܄ૼത͂૦ത͈ಎ̥ͣၗ̹ͦΟȜΗ͞έΓΛΠ͈ఱ ΰΛΡ;ͿȜήশͬ ̞̈́͘ાࣣ܄ΟȜΗͬե̠षͅΰΛΡ;ͿȜήͬੰݲ̱̫̈́ͦ͊Ȅ ή̧ͬ̈́ ෝ̦̜ͥȅ Fig. 3.10 Scatter traveltime map for a case with a source-receiverخ८၄തͅୃ̱̩ζΛάϋΈ̧̞́̈́ બ̳ͥ offset of 140km withȪleft*, and without head wavesͬޣג͈͒ضΰΛΡ;ͿȜή͈ζΛάϋΈࠫ ̹͛Ȅུ༹ͬဥ̞̀ΑΠτΛΙϋΈ͈ષࡠͬ୭̫̈́ Ȫright*. ̞ૄ͈͂͜ȄΰΛΡ;ͿȜήͬ܄͚ાࣣ͂܄̞̈́͘ા ࣣ͈শાͬࠗॳ̳ͥȩ̭͈̏͂ control factor ͉ F=1 ͂ ͚܄ 3.12 ͅা̳ȅΰΛΡ;ͿȜήͬͬضȅ̷͈̳ࠫͥ ̞̈́͘ાࣣ͉͂́Ȅݻၗ 0 ȡ܄ાࣣ͂ΰΛΡ;ͿȜήͬ 80km ͉́͘ခև̈́ओ͉̞̦̈́ȄΰΛΡ;ͿȜήͬ܄̈́͘ ાࣣ̤̞̀ͅݻၗ 80km ಼̢̭͉ͬͥ͂ͧ́শાͅచ̞ ͼιȜΐ͈̞֑̞̦̲́ئષ͈ٮޏ؊̳̠ͥ͢ͅ ͚শ͉́Ȅ܄ΰΛΡ;ͿȜῄ̥ͬږȅ̱̥̱Ȅ̞ͥ̀ ෝ̦̜͈͈ͥ͜Ȅخࢋ̹̽պ౾ͅζΛάϋΈ̯̞ͦ̀ͥ ष͉༷͈ͅশ̦։̈́ͥႀ֖̞̠͈͉͂Ȅ̷̷͜͜ ૦̫̹ͤͣͦ૦໙̦̯̩ȄৗഎͅζΛάϋΈͅ 3.11 έΓΛΠ̦ 140km ̧͈͈͂ΰΛΡ;ͿȜήশ ̞̈́͘ાࣣ͈८၄෨শ͈ओ܄͚ાࣣ͂܄ͬ ݞ͖̱̞̞̭̦̥̭̦̥̀̈́͂ͩͥ͂ͩͥȅͬޣג̜ͤ͘ ତ Fig. 3.11 Difference between scatter traveltime maps with and۾έΓΛΠ͈ఱ̧̈́ાࣣ͉́ȄȪ2.1ȫ͈ਹ͙͉̭ͦ ͬဥ̞̀૦໙ͬ૦̧̫ͤͥ͂ͅ൝শެಿȪLȫ̦ఱ without head waves for an offset of 140km.
Ƚ!185 Ƚ ࡄݪਫ਼ࡄݪ༭࣬ȁల 68 ȁ2005 ා 9 ܿڠشཡब
̧̩̹̈́ͥ͛ͅȄ૦̫ͤͣͦͥ૦໙̦̯̩̈́̽̀ ȅ̷͉ͦ́ȄΑΠτΛΙϋΈ͈ષࡠ̳֦̭̞ͥܳ͂ͥͅ ض୭̫ȄF=10 ̱̹͂ાࣣ́ࠗॳ̳ͥḙ͈̏ࠫͅ 190% ͬ ओ͕͉̓ͭ͂ͅض༷͈̭̩ࠫ͂ͅޥ 3.13 ͅা̳ȅͬ ̴͛ͣͦȄ୶͈ાࣣ̤̞̀ͅၰ৪͈֑̞̦̲֑ͬ ͜ͼιȜΐ̯̞̞ͦ̀̈́ȅ͉́Ḙ͈̏ةႀ֖͉̹̞̀ͅ ̞̈́͘ાࣣ͈܄͚ાࣣ͂܄ၰ৪ͅओ̦̲̞̈́ࡔ֦̞̾̀ͅࣉख़̳ͥȅΑΠτΛΙ 3.12 ΰΛΡ;ͿȜήশͬ ȅొ̱ȄΑΠτΛΙϋضϋΈ͈ષࡠ 190% ͬ୭̫̹ાࣣ͈ζΛάϋΈ̯ͦͥႀ֖ͬ শાུ༹͈͈͒ഐဥࠫ 3.14 ͅা̳ȅέΓΛΠ̦ 70km ͈ાࣣͬࡉͥ͂Ȅอ Έ͈ષࡠ͉̩̈́Ȅcontrol factor ͉ 1 ̜́ͥȅ ષࡠ 190% ಼̢ͬ̀ੰ̥ͦ Fig. 3.12 Seismic sections applied with the improved mapping͉ͅۼ̹ͦ͘ޖૼതȆ૦തͅ ඎ͈ႀ֖̦૬̯ 20km ̜́ͥ͘ȅ̵̷ࣣ͈ͩ̀อૼ method using no stretch upper limit and a control factorͅئ̹ .of 1. WithȪleftȫ and withoutȪ rightȫ head waves ئ͉ٮޏ௰͉́Ȅ190ɓ͈ٸ͈ۼ̹ͦ͘ߊޖത͂૦തͅ ߹০̱̤̀ͤȄ̷಼̢̹ͦͬႀ֖͉ΛΠ̯̞༷ͦ̀ͅ ȅζΛάϋΈশ̷͉͈ͅੰ̥̹ͦႀ֖͉ͅΟȜΗ̦૦ͥ ̫̞ͤͣͦ̈́ȅέΓΛΠ̦ 140km ͈ાࣣ͜൳̲߹࢜ ષࡠ಼̢ͬ̀ੰ̥̹ͦႀ͈ۼȄอૼത͂૦ത͈̜ͤͅ ௰͜ 70km ͈ાࣣٸ͈ۼ૬̯ 40km ́͘ݞ͍Ȅ̷͈ߊ͉֖ ൳အ͈ႀ֖̦ΛΠ̯̞ͦ̀ͥḙ͈̏ͦͣอૼതȆ͂ ௰̜̹ͥͅੰݲ̯̹ͦႀ֖ͅಕٸ͈ۼ૦ത́սͦͥ͘ߊ ࿒̳ͥ͂Ȅ୶͈শओ͈̤̫ͥͅྶ̥ͣͅশओ̦ ̞̈́͘ાࣣ͈܄͚ાࣣ͂܄ఱ̧̞ႀ֖͕͖֚͂౿̱̞̀ͥȅ̾ͤ͘ΑΠτΛΙϋΈ 3.13 ΰΛΡ;ͿȜήশͬ ȅొ̱ȄΑΠτΛΙضݲ̳̭ͥ͂ͤ͢ͅȄৗഎͅΰΛΡ;ͿȜή͈ শાུ༹͈͈͒ഐဥࠫੰͬض࢘ ͜ੰݲ̱̞̭̀ͥ͂̈́ͥͅȅ ϋΈ͈ષࡠͬ 190% ͅ୭̱Ȅcontrol factor ͉ 10ޣג ȅ̜ͥ́ ڙೄ༷̥͈࢜ͣ൝͈ 2 ڙࣽഽ͉ 3.15 ͅ८၄ Fig. 3.13 Seismic sections applied with the improved mapping ڙഎࣞڛഽ θ ͈୲చͬນা̳ͥḙ̏ͦͬࡉͥ͂θ ͈ ഽ̈́ႀ֖͉Ȅশओ͈ఱ̧̭̜̹̈́͂ͧͥͅȅ͉̾ͤ͘Ȅ method using a stretch upper limit of 190% and a control control factor ͥ͢ͅ | θ | ͈ခ࢘ํսଷࡠ̽̀͢ͅȄcontrol factor of 10. WithȪ leftȫ and withoutȪ rightȫ head waves. factor ͈̦ఱ̧̞Ȫ| θ | ͈ခ࢘ํս͉̯̞ȫાࣣ͉ͅ শ̴͈͈ͦఱ̧̞ႀ֖ͅ૦໙̦૦̫̞̭ͤͣͦ̈́͂ͅ ̈́ͥȅࠫޫȄഐ୨̈́ΑΠτΛΙϋΈ͈ષࡠͬ୭̳ͥ Ȅcontrol factor ̱͂̀ఱ̧̞ͬঀဥ̢̳̭ͥ̀ح̭͂ͅ ̫̞̓̈́ȅͬޣגȄΰΛΡ;ͿȜῄ͈ͤ͂͢ ΰΛΡ;ͿȜήͬ܄͚ાࣣ͂܄̞̈́͘ાࣣ́শओ͈ ̲ͥႀ֖͉́Ȅ͂͂͜͜૦໙͈૦̫̦̯̞̭ͤ͂ ȅ̯ͥͦٸȄࢵͅζΛάϋΈ̯ͦͥႀ֖̥ͣ͜ੰ̢̀حͅ ̱̹̦̽̀ȄΰΛΡ;ͿȜήͬ܄͚শા́ࠗॳ̱̀͜ 3.14 ΑΠτΛΙϋΈ͈ષࡠͬ 190% ͅ୭̧̱̹͂ͅ ζΛάϋΈ̯ͦͥႀ֖ȅऒ͉έΓΛΠ̦ 70kmȄ خఱ་̯̩Ȅྫণ̳̭̦͉ͥ͂ޣגΰΛΡ;ͿȜή͈ ෝ̜̭̦̥̹́ͥ͂ͩ̽ȅΰΛΡ;ͿȜήͬੰݲ̱̹ ֲ͉έΓΛΠ̦ 140km ͈ાࣣ ͛ͅȄུ༹̤̞ͅ Fig. 3.14 Mapped area using a stretch upper limit of 190% for̹̥̥̦ͥۼশા͈ࠗॳ͉ͅఱ་শ ͉̀ਲြ͈ΰΛΡ;ͿȜήͬ܄͚শા́ࠗॳ࣐̠ͬȅ offsets of 70kmȪleft*, and 140kmȪ right*. ȪΦͼΒ̱͈̈́ાࣣȫضcontrol factor ͈࢘ 3.4 ݲͅ controlੰ͈ޣגஜ୯͉́ȄΰΛΡ;ͿȜῄͥ͢ factor ̦࣓ࡃ̱̞̭̀ͥ͂ͬ୰ྶ̱̹̦Ȅུ୯͉́ control ८၄ਹ༹ࣣ̥ͣ CMP̵̭̯ͥ͂ͥ͢ͅاfactor ͈ͬ་ အঊͬΙͿΛ·̱Ȩ̭͈̏͂ං͈ͣͦͥاਹ༹ࣣ͈͒་ ੜၑͥ͢ͅζΛάϋΈ͉̹̜̓ͥͅͅۼၰ༹͈ಎ̷͈ ͈̠̈́͢අಭ̦̜͈̥͓ͥͥȅ ̹͛ͥ͛ͅȄऒ̥ږͬض̴͘ȄζͼΈτȜΏοϋ͈࢘ ߹০͈ৣ࿂ͬ 2 ཿ̾κΟσͬ୭̱̹ȅ߹০͈ఱ 3.15 έΓΛΠ̦ 70km ͈ાࣣȪऒȫ͂ 140kmȪ ֲȫ͈ા θ ̳̹ͥ͛ͅȄ̷̸͈ͦͦ ࣣ͈́ ͈ືږζΛάϋΈ͈֑̞ͬͥ͢ͅ Fig. 3.15 Distributions of θ for offsets of 70km left and 140km Ȫ ȫ ڙৣ࿂͈߹̧ͬ 10° ͂ 20° ̳͂ͥȪ 3.16ȫȅष͈ࢩ right . ৣ༹ΟȜΗ͈ॽအ̵ࣣͩ̀ͅȄอૼത͉ 20kmȄ40kmȄ Ȫ *
Ƚ!186 Ƚ ࢹ௮ζΛάϋΈȽ໌നڔ૬໐౷̩̿ܖ૧̱̞८၄ਹ༹ࣣͅ
ത̱͂Ȅ௶ಿ 45 ͅڞۼ 60km ͈ 3 തȄ૦ത͉ 2km 90km× ૬̯ 50km ͈ํս́ࠗॳ̳ͬͥȅঀဥ̱̹ synthetic ෨ࠁ႕ͬ 3.17 ͅা̳ȅ2 ཿ͈ৣ࿂̥͈ͣৣ෨͉ͬ̽ ̧̳̭̦ͥ͂́ͥȅ͉ࣽٝ 9 ͈̾ control factorږ̧͂ͤ ͈̞̾̀ͅΞΑΠ̳̭̳ͥ͂ͥͅȅF ͉̯̞༷ͤ͢Ȅ ͬضȅࠗॳ̜ࠫͥ́̾ 9 ͈ 320 ,160 ,80 ,40 ,20 ,10 ,5 ,2.5 ,1 ͙̹ͥ͛ͅ 2ͬض 3.18 ͅা̳ȅζͼΈτȜΏοϋ͈࢘ ̾ৣ࿂ͬ෨̀ͅা̳ȩ̭͈̏͂ F=1 ͈ાࣣ͉ड͜८ ၄ਹ༹ࣣͅ߃̩ȄF=320 ͈ાࣣ͉ड͜ CMP ਹ༹ࣣͅ߃̞ȅ ࡉͥ͂Ȅ८၄ਹ༹ࣣ͈ͬض̴͘Ȅऒષ͈ F=1 ͈ાࣣ͈ࠫ ږୃͅ අಭ̦̩࡛̤ͦ̀ͤ͢Ȅ2 ཿ͈ৣ࿂͉ 10° ͂ 20° ΟȜΉ͈ڞۼζΛάϋΈ̯̞ͦ̀ͥȅ̱̥̱Ȅல̞ͅ ̜̹ͥ͛ͅȄΌȜΑΠ̦ޑ̩࡛ͦȄͼιȜΐ̦͖̫̀͞ ȅݙͅȄF=320 ͈ાࣣ͉́ȄCMP ਹ༹ࣣ͈අಭ̜̞́ͥ ̠ͥ͢ͅ८၄ਹ༹ࣣ͈ાࣣ̲ͥͅΌȜΑΠ͉̞̓̈́ȅ 3.16 ΞΑΠͅঀဥ̱̹௸ഽκΟσȅऒ߹০͈ 2 ͈̾ৣ ̾͜ȅͬڙȄৣ࿂͈Ⴒ̦ཋ̱̩Ȅ̩͢ಕ࿒̳ͥ͂ৣ࿂͉ ࿂̷̸͉ͦͦ 10° ͂ 20° ߹০̱ొ 1 ཿͅਓ௵̴̱̤̀ͣȄୃ̱̞պ౾͜ͅζΛάϋΈ̯ͦ̀ Fig. 3.16 Synthetic velocity model. The two left dipping refl ectors .ζΛ have dip angles of 10° and 20°, respectivelyͅ °18 ͉ڙȅඅུͅြ 20° ̜́ͥৣ࿂͈߹০̞̞̈́ ̭̞̦͂̈́ضάϋΈ̯̤ͦ̀ͤȄζͼΈτȜΏοϋ͈࢘ ȅ̱̥̱Ȅ10° ͈ৣ࿂͉͕͂ͭ̓ୃٜͅ߃̞պ̥̦ͥͩ ౾ͅζΛάϋΈ̯̞ͦ̀ͥȅষͅȄষలͅ control factor ̦ ̠ȅ੭șͬا་͈ضఱ̧̩̈́ͥ̾ͦ̀ͅȄ̷ฺ̠ͦࠫͅ ͅΌȜΑΠ͉ဲ̢̧̞ͣͦ̀ȄF=20 ͈ા̧ࣣ͉͉́̽ͤ ̧́Ȅ̷̹͈͘Ⴒ̞͜͢ȅ̷ږཿ͈ৣ࿂ͬ 2 ͂ ̦ͦ F=80 ಼̢̨̨̹̭̥͈ͬ͂ͧͣ͂ͦ͂ͦৣ࿂͂̈́ ȅ༷֚́ control factor ̦ఱ̧̩̈́ͥ͂ζͼΈτȜΏοϋͥ ͜৻̧̞̽̀͘Ȅ20° ͈ৣ࿂ͅಕ࿒̳ͥ͂ȄζΛض͈࢘ άϋΈ̧̯͓ͦͥୃ̱̞պ౾̥ͣষల̴̞̩ͦ̀ͅအঊ ̯ͦͥȅF=2.5 ͈ા̧ࣣ͉͉́̽ͤ͂͘ 20° ͈߹০ږ̦ ͬ̽̀͜ζΛάϋΈ̯̞̦ͦ̀ͥȄF=5 ͈ાࣣ͉́ 20° ͢ ͤ߹০̴̦̥̯̩ͩ̈́ͤͅȄF=10 ͈ાࣣ͉́ 18° ̈́̽ͅ ̞̀ͥȅ̷ͦͤ͢͜ఱ̧̈́ control factor ఼̱ͬ̀͜ζΛ 3.17 ΞΑΠͅঀဥ̱̹ synthetic ෨ࠁ႕Ȫอૼത̦ 20km ̜́ͥ͘͘ȅ༷֚Ȅ10° ͈͈ °18 ͉ڙάϋΈ̯̹ͦ߹০ ̧͈͂ȫȅ6km/sec ́ reduce ̱̜̀ͥȅ ͕͖͜ୃ̱̩ 10° ͈߹০ضȄ͈̓ાࣣ͈͉̱ࠫ̀۾࿂ͅৣ Fig. 3.17 Example of synthetic wave forms without noise. The ́ζΛάϋΈ̯̞ͦ̀ͥȅ shot point is located at an offset of 20km. The reduction ̴̞͈ͦͼιȜΐ͜ઁ̩̈́͂͜ৣ࿂͈ంह͉ζΛά velocity is 6km/sec. ϋΈ̧̞̦́̀ͥȄcontrol factor ͬௌै̳̭ͥ͂ͤ͢ͅȄ ΟȜΗ̦̾ૂ༭ၾͅ؊̲̀डഐ̈́ͼιȜΐͬං̭ͥ͂ ȆΌȜΑΠ͈ ΟȜΗ͒ഐဥ̱̹ાུ༹ࣣ͈͈ခ̞࢘̾̀ͅબ̳ضȅ႕̢͊ȄζͼΈτȜΏοϋ̧̦࢘ͥ́ ࠚࡘȆৣ࿂͈Ⴒ͈ 3 ̾ͬ control factor ఼̳ͬͥ ͥȅΞΑΠ͉ͅ 3.4 ୯́ঀဥ̱̹௸ഽࢹ௮κΟσͬဥ̞Ȅ ৣ࿂͈Ⴒ อૼതȆ૦ത౾͜൳̲̜́ͥȅcontrol factor ͜ஜ୯͂͂ضष͈ঐດ̳͂ͥ͂ȄζͼΈτȜΏοϋ࢘ ̺̫ͅਹതͬ౾̩ાࣣ͉ F=1 ఼̱ͬȄΌȜΑΠ͈ ൳အͅ 9 ͈ͤͬ୭̱̹ḙ̏ͦͤ͢ͅஜ୯͈ΦͼΒ ෝ̜́ͥȅঀဥ̳ͥ synthetic ෨خ̦ڛࠚࡘ̺̫ͅਹതͬ౾̩͈̜́ͦ͊ȄF=320 ఼̳̭ͬͥ͂ ͈̞̈́ાࣣ͈͂ ȅ̱̥̱Ȅ3 ͈̾ঐດͅΨρϋΑͬ౾̩ાࣣ͉́Ȅ ࠁͅष͈ോࡪ͈۷௶ܱ͂൳ഽ͈ρϋΘθΦͼΒͬͥ̈́ͅ ȅ̹͘Ȅ෨༹́ࠗॳ̯̹ͦৣ෨শ͉ͅȄ̢̹ح F=80 ັ߃఼͈̳͈̦࡛ͬͥഎ̜̠́ͧḙ͈̠̏͢ ȅঀဥ̱̹෨ࠁ႕̹̱حȄष͈ΟȜΗ͈ાࣣ̤̞̀͜ͅȄအș̈́ F ͈ͬ୭ ດ༊ओ̦ 0.15sec ̨͈ͣͬ͠ͅ Ȅৣ෨̢͉̭̹ͤ͂͢ͅح̱̀ࠗॳ̱̀Ȅ࡛എͅडഐ఼̳̞̈́ͬͦ͊͢ȅ ͬ 3.19 ͅা̳ȅΦͼΒͬ ̧̞́̈́ȅ̹͘Ȅৣ෨শ͜͠ͅږ̥̱͖͂ͤͭ͞ ȪΦͼΒ̜͈ͤાࣣȫضcontrol factor ͈࢘ 3.5 ͦ͘ৣ ̨ͣͬဓ̢̹̹͛Ȅৣ෨͈պ̦ఁ̴ͩႲ̦՛̞ȅ܄ष͈۷௶ΟȜΉ͉Ȅ૦໙͉ͅΦͼΒ̦ 3.20 ͅাͬض෨̦ΦͼΒོ̞̹ͦ̀ͤ͜ͅȄ۷௶തྀͅ։̈́ͥ౷ນ͈ ̭͈ synthetic ෨ࠁུ༹ͬͅഐဥ̱̹ࠫ ৣ̱̀ڛ̫̹ͥ͛ͅৣ෨͈Ⴒ̳̭̦ͬͥ͂ࣾ ̳ȅఘഎͅΦͼΒ͈̞̈́ાࣣ͈ΞΑΠ͂ͬޣג ນ̞ͦ̀ͥȅ̦ޣג̢̹حඳ̜̹̳̭̦́̽ͤͥ͂ఉ̞ḙ̷̏́ȄΦͼΒ͈ఱ̧̈́ ࿂̵̴̧̦͉̽ͤ͂ȄΦͼΒͬ
Ƚ!187 Ƚ ࡄݪਫ਼ࡄݪ༭࣬ȁల 68 ȁ2005 ා 9 ܿڠشཡब
ȅȪऒષ̥ͣ control factor ͈ޣג͈ 3.18 ΦͼΒ͈̞̈́ synthetic ΟȜῌഐဥ̱̹ાུ༹ࣣ͈̤̫ͥͅ control factor ಎ͈ฒ͈෫͉୭̱̹௸ഽࢹ௮κΟσ͈ৣ࿂ͬা̳ȅڎાࣣȫ͈ 320 ,160 ,80 ,40 ,20 ,10 ,5 ,2.5 ,1 ̦ Fig. 3.18 Effect of the control factor of the improved mapping method, which is applied to synthetic data without noise. The control factor range is from 1 to 320. A white dashed line indicates a refl ector of the synthetic velocity model.
ࡉ̞̩̀͂Ȅ८၄ͬضcontrol factor ͈̯̞༷̥ͣਜ਼ࠫͅ ਹ༹ࣣͅ߃̞ F=1 ͉́ৣ࿂͉ΦͼΒོͦ̀̓͜ͅে ༆̧̞́̈́ḙ͈̏߹͉࢜ F=5 ̧́͘ȄF=10 ̥̠ͣ͢͞ ͞ ΦͼΒ͈ಎ̞̹֯ͦ̀ͅৣ࿂ͬে༆̧́ͥȅF=20̩ 40 ͉́ S/N ͜ષ̦ͤȄΩΗȜϋಎ̧͉̽͂̽ͤ͜͜ ̧́ͥȅࢵͅ F ̦ఱ̧̩̈́ͥ̾ͦͅږৣ࿂̹̱ͬ͂ ΦͼΒτασ̦చഎͅ೩̩̞̩̦̈́̽̀Ȅ̷͈༷֚̀ ́ F=160 ̥͉ͣষలͅৣ࿂͈Ⴒ̢̩ͬ̈́̈́ͤȄ ͉ࣾඳ̜́ͥḙ͈̠̏͢ͅȄږF=320 ͈ાࣣ͉́ৣ࿂͈ ༗̯ͦȄږF=40 ഽ͉́ȄΌȜΑΠͬဲ̢̹ષ́ȄႲ͜ ̧̳̭̦̹ͥ͂́ȅ̳̈́ږ߹০̱̹ৣ࿂̧͉ͬ̽ͤ ̻ͩḘ̏ͦ́͘८၄ਹ༹ࣣ͞ CMP ਹ༹ࣣ̞̹͂̽ਲြ͈ ༹ͬഐဥ̱̀͜ȄΦͼΒོ̞̹ͦ̀ͤ͜ͅႲ̦ະ 3.19 ΞΑΠͅঀဥ̱̹ΦͼΒ͈̜ͥ synthetic ෨ࠁ႕Ȫอ ྶၸ̜̹́̽ͤ͂ంह̢̧̯͉̥̥̹̽ͤͩͣ̈́̽ৣ ૼത̦ 20km ̧͈͂ȫȅ5-10Hz ͈ΨϋΡΩΑέͻσ ࿂ͬȄഐ୨̈́ control factor ఼͈̳̭̥ͬͥ͂ͤ̈́͢ͅ ΗȜͬঀဥȅ6km/sec ́ reduce ̱̜̀ͥȅ ͤྶၸͅ௴̢̭̦ͥ͂া̯̹ͦȅ Fig. 3.19 Example of synthetic wave forms with noise. The shot ષ͓̹̠́͢ͅȄ ̭͈Ο ȜΗΓΛΠ͈ાࣣ͉́ point is located at an offset of 20km. The reduction .ৣ࿂̧͉ͬ̽ velocity is 6km/seć͉ضࡠͅ߃̞ࠫئcontrol factor ͈ષࡠ͂ ෝ̈́ control factor ͈͉ৣ࿂ͬخে̴̧́Ȅ఼͂ͤ
Ƚ!188 Ƚ ࢹ௮ζΛάϋΈȽ໌നڔ૬໐౷̩̿ܖ૧̱̞८၄ਹ༹ࣣͅ
ȅȪऒષ̥ͣ control factor ͈ޣג͈ 3.20 ΦͼΒ͈̜ͥ synthetic ΟȜῌഐဥ̱̹ાུ༹ࣣ͈̤̫ͥͅ control factor ಎ͈ฒ͈෫͉୭̱̹௸ഽࢹ௮κΟσ͈ৣ࿂ͬা̳ȅڎાࣣȫ͈ 320 ,160 ,80 ,40 ,20 ,10 ,5 ,2.5 ,1 ̦ Fig. 3.20 Effect of the control factor of the improved mapping method, which is applied to synthetic data with noise. The control factor range is from 1 to 320. A white dashed line indicates a refl ector of the velocity model used.
ଷࡠ̯ͦͥȅ̾ͤ͘Ȅ ͬ control factor ͈ͬഐ୨఼̧̳̭͉ͥ͂̽̀̽͢ͅͅͅۼ͈ ၸͅে༆̧́ͥ F=10 ȡ 80ྶ ΦͼΒ͈ంह̽̀͢ͅ control factor ఼͈͈໙͉ޛͥ͘ȅ ͤ͂ͼιȜΐ̧̳̭̦̹ͥ͂́ȅུ༹͈̾ͤ͘ഐဥͅ 3.6 ΞΑΠ͈͂͛͘ ̽̀͢ȄਲြζΛάϋΈ̦ࣾඳ̧̯̹͂ͦ̀ΟȜΉ͜ ͈ࣽٝΞΑΠͤ͢ͅȄུ༹͈အș̈́၌തͬၑٜ̳̭ͥ ̷͈ͦ̾ஆहഎ̈́ૂ༭̧̱ͬ֨̀Ȅོ̞̹ͦ̀͜ ෝͬা̱̞̀ͥḙ̷̏́Ȅষخণ̧́ ৣ࿂ͬͼιȜΐ̧́ͥྫ͉ޣגȅུ༹́͜ΑΠτΛΙϋΈ̧͈̹̦́͂ ȄࠗॳশͅΑΠτΛΙϋΈ͈ષࡠͬ୭̫̭ͥ͂́ ડུ༹͉́ͬष͈ോࡪ̤̫ͥͅ۷௶ΟȜῌഐဥ̱̦̞̈́ ΟȜΗ̜̥̲ͬͣ ̀Ȅ̷͈ခ࢘ͬબ̳ͥȅ̵̯ͥاζΛάϋΈࢃ͈ͼιȜΐͬႦ ͛ੰݲ̧̳̭̦̹ͥ͂́ȅ८၄শાͬࠗॳ̳ͥषͅવ ȄΰΛΡ 4. ΟȜΗ͈͒ഐဥ͉̱̀۾ΰΛΡ;ͿȜήশ͈࿚ఴͥ̈́͂ͅٺ ࡛ͦͥႀ֖͈૦໙͉̯̩͂͂͜͜Ȅ 4.1 ΟȜΗഐဥ̜̹̦̽̀ͅޣגͿȜή͈; ̹͘ΑΠτΛΙϋΈષࡠͬ୭̳̭ͥ͂͂ control factor ͅ ȁུ༹͈ΟȜΗ͈͒ഐဥ̜̹̽̀ͅȄบ෫౷ૼ൲ࡄݪ გ௶ܮ . ඤಿعఱ̧̈́ͬঀဥ̷̳̭͈ͥ͂̽̀͢ͅႀ֖ͬζΛάϋΈ ΈσȜί̽̀͢ͅ۷௶̯̹ͦ 1988 ා ௶ષߴ . ޘȪบ෫౷ૼ൲ࡄݪΈσȜίȄ1992ȫ͂ 1989 ා ̥̦̭̞͕͉̽ͩ͂̈́̓ͭ͂ޣג͛ͅȄ̹̞̞ͥ̀ੰ̥ͣ ȅུ༹͈අಭ̜́ͥ control factor ͈൵ව͉Ḙ̏ͦ́͘ Ȫบ෫౷ૼ൲ࡄݪΈσȜίȄ1995ȫ͈ 2 ͈̾ΟȜΗ̹ͬ გ௶ܮ . ඤಿع༆ș༹͈̜̹́̽८၄ਹ༹ࣣ͂ CMP ਹ༹ࣣ֚ͬ̾ࠫͅ ఼̱̹ȅ఼͈ၑဇ̱͂̀Ȅ1988 ා Ȅ̷͈෨ࠁΟȜΗ͉֔Ȫ1991ȫ̳͉̱̽̀́̀͢ͅ۾ͅ Ȅၰ̵༹͉̭̯ͤ͂ͥ͢ͅاȄcontrol factor ͬ་̫ັ͍ ੜၑ ͅ CMP ਹ༹ࣣͬঀٜ̽̀ଢ଼̯̤ͦ̀ͤȄུ༹ഐဥࢃ͈͈ۼෝ̱̹ͅḙ͈̏ಎخੜၑ͈͜ۼ̷̻͈ͧͭ͜ಎ ષ́ࢡസࣣ̜̭̦́ͥ͂ݷ̬ͣͦͥȅ̳ͥͬڛ͈͂ضփྙ͉ఱ̧̩Ȅၰ༹͈၌ത͂ࠧതͬ༞എͅΨρϋ ͈ࠫ ̥ͣڔ໐౷ئȄ͉̱̀۾ષߴ௶ͅ - ޘෝ͂̈́ͤȄζͼΈτȜΏοϋ࢘ ̹͘Ȅ1989 ාخΑ̩͢୯̳̭̦ͥ͂ ȆΌȜΑΠ͈ࠚࡘȆৣ࿂͈Ⴒͬࣉၪ̱̀Ȅडഐ ષ໐ζϋΠσ͈́͘૬̯͈௸ഽࢹ௮ͬౝऔ͈చય̱͂̀ض ̈́ͼιȜΐͬං̧̭̦ͥ͂́ͥȅ̹͘ΦͼΒ͈ఱ̧̈́ΟȜ ̞̹ͥ͛Ȅ௶ಿ͉ 200km ಼̢ͬ̀୭̯̞ͦ̀ͥḙ̏ ῌచ̱̀͜ခ࢘́Ȅၰ༹͉́ে༆̧̥̹́̈́̽ৣ࿂ ͈ಿ௶̽̀͢ͅ Pn ̦۷௶̯̤ͦ̀ͤȄMoho ࿂͈૬
Ƚ!189 Ƚ ࡄݪਫ਼ࡄݪ༭࣬ȁల 68 ȁ2005 ා 9 ܿڠشཡब
ζϋΠσडષ໐͈௸ഽ̜̥̲̭͈ͬͣ͛ͥئ̷͈̯͂ ෝ̜́ͥȅ̽̀͢Ḙ͈̏শΟȜΗͬঀဥ̱̀ଔخ̦͂ ૬໐͈ࢹ௮ͬୈഽ͢ڔ̯̹ͦ௸ഽࢹ௮ͬဥ̞ͦ͊Ȅ౷ ̩ζΛάϋΈ̧́ͥ͂ࣉ̢̹ȅ ٜଢ଼ੜၑ͈ၠͦ 4.2 4.1 ٜͅଢ଼ੜၑ͈ fl ow chart ͬা̳ȅུ༹ͬഐဥ̳ ஜੜၑ͉ఱ̧̩ 2 ͈̾ၠ଼̥ͦͣͥȅ͉֚̾۷௶ΟȜͥ Η͈ΦͼΒੰݲ൝͈෨ࠁੜၑ̜́ͤȄ̠͉֚̾͜ζΛά ϋΈͅຈါ̈́௸ഽࢹ௮͈ଔ̜́ͥȅ۷௶ΟȜῌ̤̫ ਔ෨ତȪ8HzקȄૼ࡙̥͈ͣΏΈσస͉̱̀۾ΦͼΒͥͅ ஜࢃȫͬಎ̱͂̀୭̯̹ࠗͦ Bandpass έͻσΗȜ̽͢ͅ ഽ͉ੰݲ̧̳̭̦ͥ͂́ͥȅ̱̥̱ζΛάϋΈ̳̜ͥ̀ ͥષ́අͅ࿚ఴ͈̦͂̈́ͥȄS ෨͂ఉਹৣ̜́ͥȅΘͼ ζͼΠૼ๊࡙͉֚ͅ൝༷എͅΥσΆȜͬ༶ৣ̳ͥത ̯̦ͦͥȄष͉ͅอૼ͕͖͂൳শͅ Sبૼ࡙̜́ͥ͂ ෨̦อ̱̞̀ͥȅ̷͈ࡔ֦͉อૼιΣΒθ֦̱ܳͅ Ȅอૼೄࢃͅ P ෨̦ SV ෨ͅ་̯̞͈̥͈̞۟ͦ̀ͥͥ̀ ৣ༹ΟȜΗ͈ٜଢ଼ fl ow chartڙȅ๊֚ͅ S ෨͉ৣ P ෨͢ 4.1 ࢩ̧̞̞̥͉̥̈́̀̽ͩ͂ͤ̽ ͤ૦໙̦ఱ̧̞̹͛ȄζΛάϋΈশͅΌȜΑΠͬࠁ଼̳ Fig. 4.1 Flow chart to process wide-angle reflection data in this .ȅS ෨͉ P ෨ΏΈσ͂ਔ෨ତఝ֖̦ਹ̈́̽ study̜̦̭ͥ͂ͥ ͛Ȅౙͅ Bandpass έͻσΗȜ̺̫͉́ੰݲ̹̞́ͥ̀ ̧̞̈́ȅF-K έͻσΗȜ͈ঀဥ͙̥̫̽̀͢ͅ௸ഽ͈ಁ̞ ৣ༹ΟȜڙ෨ͬੰݲ༹̳༷̜̦ͥͥ͜Ȅࣽٝဥ̞̹ࢩ Ή͉۷௶ത౾̦ல̩Ȅ̱̥͜ະܰ௱̜̭̥́ͥ͂ͣ aliasing ͈࿚ఴ൝̦อ̳ͥȅ̷͈̹͈ٜ͛ࠨ༹༷̱͂̀Ȅ ȫ̥ͣ S ෨͈ൢশبͅ ̴͘ˬ෨শ͂ Vp/VsȪ 1.73 ࡉୟͤ͜Ȅ̷͈শͬ४ࣉ̱̀ͅ S ෨෨߲ͬੰݲ̳ͥͬ ̭̱̹͂ͅȪ 4.2ȫḙ͈̏ੜၑͤ͢ͅḘ̏ͦ́͘ S ෨͈૦ ໙̯̥̹ͤ̽͢͜ৣ෨̧̳̭̦̠ͬͥ͂́ͥ͢ ȅ̹͘ȄΠτȜΑఘ͈૦໙֚ͬͅ༗̹̽̈́ͅ 4.2 S ෨̦ੰݲ̯̹ͦ۷௶෨ࠁ႕ȅऒ͉ੰݲஜȄֲ͉ੰ ̾ AGCȪAutomatic Gain ControlȫέͻσΗȜͬঀဥ̱̀૦ ݲࢃȅొ̱ȄS ෨ੰݲ͂൳শͅ૦໙͈ఱ̧̞൲ ໙͈̯̞ৣ෨ͬޑ༹̳༷̜̦ͥͥ͜ȄΦͼΒ͜ޑ ͬηνȜΠ̱̞̀ͥȅ ̯̭̦̜̹ͦͥ͂ͥ͛Ȅ̷͈ഐဥ̫̹ͬȅ Fig. 4.2 Example of observed wave forms beforeȪ leftȫ and after ఙୟ͈ئࢵͅ۷௶ܱ͉ͅȄΏοΛΠത̹͉͘۷௶തೄ Ȫrightȫ the S-wave removal. First arrivals with large ̥ͣڔ໐౷ئ͈̈́̓೩௸ഽ͞ৣ࿂̦ఉ̩ంह̳ͥ amplitudes are also removed. ̞ͦ̀ͥ͘ȅఉਹৣ͜ S ෨͈ા܄̦ޣגఉਹৣ͈͈ ࣣ͂൳အ͈ܺͤͅͼιȜΐ̲ͬͥࡔ֦͂̈́ͥḙ̷̏́Ȅ ఉਹৣ͈ੰݲ͈̹͛ͅ Deconvolution ੜၑ࣐̭ͬ̽ͣͦ എͅੰݲ̱̹ضȅDeconvolution ੜၑ͉ͅఉਹৣ̹ͬ࢘ ͤȄܖུ෨ࠁͬͼϋΩσᾼ̷̜̞͉ͥͦ߃̞෨ࠁͅ་ ȅུࡄݪ͉ͅ Deconvolution ༹̜̦ͥض̳̹̱࢘ͥͤ۟ Wiener ͈ထ௶ࢋओέͻσΗȜȪRobinson and ̜͈֚ͥ́̾ Treitel, 1980ȫͬঀဥ̱̹ȅWiener ͈ထ௶ࢋओέͻσΗȜ ࠐًࢃ͈෨ࠁͬထۼȄ̜ͥশ͈࣫́͘෨ࠁ̥̜ͣͥশ͉͂ Ȅထ௶̯̹ͦ෨ࠁͬष͈ܱ̥ͣओ̱̩̭̱֨͂ͅ௶ ݲ̧༹༷̜́ͥ́ͥḙ͈̏ੰͬޣג߫ͤ༐̱࡛ય͈ͤ͢ ͚۷௶෨ࠁ̤̫ͥͅ Deconvolution ഐ܄ 4.3 ఉਹৣ෨ͬ ࡤ͐ȅέͻσΗȜ͈ഐဥ̜̹ͤͅȄ͂ۼထ௶শͬۼࠐًশ ဥ႕ȅऒ͉ഐဥஜȅֲ͉ഐဥࢃȅΩριȜῌ͉Ȅ എ̭͈̈́ΩριȜΗͬদ࣐॒ࢋഎ఼̱ͅض̽͂࢘͜͜ βτȜΗಿ 0.6secȄထ௶ݻၗ 0.07sec ͬঀဥ ̦ضȅέͻσΗȜഐဥࢃ͉Ȅ 4.3 ́া̳̠͢ͅੰݲ̹࢘ Fig. 4.3 Application of deconvolution. BeforeȪ leftȫand after ࡛̞ͦ̀ͥȅొ̱Ȅ٬ဢ۷௶͈ાࣣ̤̫ͥͅ٬࿂͂٬ೲ࿂ Ȫrightȫ deconvolution using an operator length of 0.6sec ఉਹৣ͈ાࣣ͈͂ܢഎܰ௱ୃ̱̞ਔڛ̲ͥ́ۼ͈ and a prediction lag of 0.07 sec. ৣ̈́ڙ։̈́ͤȄࣽٝե̠ఉਹৣ͉ȄවৣȆৣ̦ࢩ
Ƚ!190 Ƚ ࢹ௮ζΛάϋΈȽ໌നڔ૬໐౷̩̿ܖ૧̱̞८၄ਹ༹ࣣͅ
ષߴ௶ਔ༏౷֖͈౷ৗȅ౷ৗऔਫ਼Ȫ1995ȫͤ֨͢ဥ - ޘგ௶ݞ͍ 1989 ාܮ . ඤಿع 4.4 1988 ා Fig. 4.4 Geological map of the Kinki district including the 1988 Kawachinagano-Kiwa and the 1989 Fujihashi-Kamigori profi les, after the Geological Survey of JapanȪ1995*.
෨̜́ͤȄ̹͘ະৗഽ͈ޑ̞ৗಎ̲̞̹́̀ͥ͛Ȅ ࣐̥̾ఝેͅႥ̱̞̀ͥȪ 4.4ȫȅ̷̱̀Ȅܮչോ͈ ౯̳ͥಎ؇ࢹ௮͉Ȅୌධུ؍ະܰ௱̜́ͥȅ̷͈̹͛Ȅ̷͈ੰݲ࢘ ͕͖૯ಎͅպ౾̱ୌ̥͉ͤ̈́ͅܢਔ̷͈ ٮޏఝȪධ௰ȫ̫͂ͥͅ৽ါ̈́౷ৗٸ̯̩Ȅఉਹৣͬۖͅੰ̩̭͉͂ඳ̱̞ȅ ͬඤఝȪཤ௰ȫ๊͉֚͂ͅض ౯̴ͦ؍ऒͅܢࢃܮஜੜၑ͈̠͈֚̾͜ၠ̜ͦ́ͥ௸ഽࢹ௮͈ଔ͉́Ȅ ̜́ͥḙ͈̏ࢹ௮͉ಁ̩͂͜ฒՏ ͈൲শඋ͙৾ͤͬΟȜΗ̱͂̀ȄZelt and ̱͂̀ࠁ଼̯̹̦ͦȄઁ̩̈́͂͜ 5 ͈̾ΑΞȜΐͬࠐܱ௶۷ ,౯̜́ͥȪIchikawaڰ̹̱ק൲͈స̴ͦ؍SmithȪ 1992ȫ͈ͼϋΨȜΐοϋίυΈρθͬঀဥ̱̹ȅκ ࡛̀हֲ͉ ౯̱͈͂̀་պၾ͉ତ km ̜́ͥȅ̥̾̀ڰഎͅஃ໐ࢹ௮Ȫ૬̯ȡ 8kmȫ͂૬໐ࢹ௮ 1980ȫȅུܖΟςϋΈ͉ ࠗॳ࣐̹ͬ̽ȅஃ໐ࢹ ͉Ȅ౯͈ೄ̥͕͖ͣೄͅ୨ͤၛ̹̽౯̜́ͥ́ٴȪ૬̯ 8km ȡȫ̫͂̀ͅ 2 Ȅཤ̥ͣͅضκΟσ̱͂̀କ 3 ࢹ௮ͬဥ ͂ࣉ̢̞̹̦ͣͦ̀Ȅड߃͈ၑౝऔ͈ࠫܢ௮͈κΟςϋΈ͉́Ȅ ഽ́߹০̱̞̀ͥͼιȜΐ̦ං̞ͣͦ̀ͥڙȅొ̱Ȅల 1 ̺̫͉௶͈ດࣞΟȜΗͬঀဥ̷̱̀ 30-40 ഽ͈̹̞ ౷ນ࿂̱͂Ȅอૼത߃ཌྷ͈শΟȜΗ̥ͣݥ̹͛ೄ ȪIto et al., 1996ȫȅಎ؇ࢹ௮͈ධ௰͉ͅঅྔ႑ఝ̦̜ͬͦ ఘࢹ଼̥ح໐ಎ૧ൡ͈ັئ෨͈௸ഽͬอૼത߃ཌྷ͈डஃ໐͈௸ഽ̱͂̀୭̱̹ȅ ͥȅঅྔ႑ఝ͉ฒՏࠏȡో ͼϋΨȜΐοϋশ͉ͅ౷ນ࿂͂อૼത߃ཌྷ͈डஃ໐͈௸ ͣࠁ଼̯̤ͦ̀ͤȄ٬௰̷̞̩͕͈̓ͅාయ͉৹̞ȅ२ ෝ̦خఘࢹ଼̜̹́̽حࡔ͜ັ͈܊ΈςΛΡͬಈষࢵ ෨ఝ͈་଼ٮޏഽͬࡥ̱Ȅఈ͈௸ഽΈςΛΡ͂ ఘࢹ଼̥ͣࠁ଼̯ͦحչോ͉͕͂ͭ̓ັܮ૧̱̦̈́ͣশॼओ͈̦ 0.1sec ոඤ͂̈́ͥ́߫ͤ͘ ఱ̧̩Ȅ ධ٬Πρέ̥͉ͣͅئչോܮ༐̱ࠗॳ࣐̹ͬ̽ȅ૬໐ࢹ௮͈κΟςϋΈ͉́Ȅ୶ͅݥ ̞̀ͥ͂࡞̢ͥȅ̹͘Ȅ ̱͂̀ழ͙ࣺ͙Ȅ̷ͦͤ͢͜૬໐ͬ έͻςάϋ٬ίτȜΠ̦ཤୌ༷࢜ͅ 4cm/year ͈௸ഽ́ೆܡ̹͛ஃ໐ࢹ௮ͬ κΟσͬै଼̱̹ȅͼϋΨȜΐο ͙ࣺ̞ͭ́ͥȪSeno et al., 1993ȫȅέͻςάϋ٬ίτȜΠܢକ 3 ࢹ௮̳͂ͥ ϋশ͉ஃ໐ࢹ௮ͬࡥ̱̹͘͘Ȅ૬໐ࢹ௮͈͙ͬࢵ૧̱Ȅ ̦ೆ͙ࣺ͚ධ٬Πρέ͉́Ȅ1944 ාධ٬౷ૼȪM7.9ȫ͞ ष͜শॼओ͈̦ 0.1sec ոඤ͂̈́ͥ́߫ͤ͘༐ 1946 ාධ٬౷ૼȪM8.0ȫ͈̈́̓ݴఱ౷ૼً̦ݲ߫ͤ༐̱อ͈̭ ා́ 176 ͉ܢ൲ਔڰͼϋΨȜΐοϋࠗॳ̽͢ͅ ̱̤̀ͤȄୌႣ 684 ාո͈͈ࣛٴࠗॳ࣐̹ͬ̽ȅոષȄ2 ̱ Ȅडਞഎͅ௸ഽࢹ௮κΟσͬං̹ȅ ̜ͥȪAndo, 1975ȫȅAndoȪ 1975ȫ̽̀͢ͅ 1944 ාධ٬̀ ༹͈ഐဥ͉́Ȅඅͅ౯͈̞ͤ̈́ࡠͤષܱ͈ ౷ૼ͂ 1946 ාධ٬౷ૼ͈ιΣΒθٜ̦ࡄݪ̯̤ͦ̀ͤȄུ͈ئո ੜၑ̱̹ͬ෨ࠁΟȜΗ͂௸ഽࢹ௮κΟσঀဥ̱̞̀ͥȅ ͂͜ͅୌධུͅచ̱̀έͻςάϋ٬ίτȜΠ௰̦ཤୌ ષ౯̜́ͥ͂༭̯̞࣬ͦ̀ͥȅڙგ௶ ༷࢜ͅೆ͙ࣺ͚೩ܮ . ඤಿعා 1988 4.3 ါ͂۷௶ΟȜΗ ȁུౝऔ͉́Ȅ௶ಿ͉ 65kmȄ۷௶തତ͉ 86 ത̜́ͤȄٽ௶۷ 4.3.1 ཤ௶ͅڞۼ չോ ΘͼζͼΠͥ͢ͅบ෫ത̷͉̤͢ 15kmܮల 5 ষ౷ૼထْ͈ࠗ͂͜Ȅ1988 ා 11 ͅ Ȅ ̥ͣධ̥࢜̽̀ͅਜ਼ͅ S-1 ̥ͣ S-6 ͈́͘ 6 ത̦୭̫ͣئࢹ௮ౝऔ̦࣐̹ͩͦȪոڔ૽ࢥ౷ૼͥ͢ͅ౷̞̤̀ͅ გ۷௶ȫȪบ෫౷ૼ൲ࡄݪΈσȜίȄ ̹ͦȪ 4.5ȫȅͺυΈ༷τȜΘȜܱ̯̹͈́ͦ͜ܮඤಿȽعා 1988 ̀ AD ་̯۟ͦȄܱ́ڞۼ1992ȫḙ͈̏౷֖͉́Ȅအș̈́౷ৗාయ͈౷̦ോࡪͅ ͉ 100Hz ͈ϋίςϋΈ
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გ௶ȅି֣͉ΏοΛΠതȄܮ . ඤಿع 4.5 1988 ා തͬা̳ȅ൳শͅ 1995 ා 5 ȡ 2001 ා௶۷͉܃ฒ อ̱̹౷ૼ͈ૼ࡙ͬίυΛΠ̱ͅۼܢ͈ 4 ȅૼ࡙͉ಎఆ͕̥Ȫ1997ȫͤ֨͢ဥ̞ͥ̀ Fig. 4.5 Location map of the 1988 Kawachinagano-Kiwa profi le. Stars and open circles indicate shot and receiver points, respectively. Hypocenters of micro-earthquakes from May 1995 to April 2001ȪNakamura et al., 1997ȫare superposed.
გ௶͈۷௶෨ࠁȪS-6ȫȅ5-8Hzܮ . ඤಿعგ௶͈۷௶෨ࠁȪS-1ȫȅ5-8Hz 4.7 1988 ාܮ . ඤಿع 4.6 1988 ා ͈ΨϋΡΩΑέͻσΗȜͬঀဥȅ6km/sec ́ reduce ͈ΨϋΡΩΑέͻσΗȜͬঀဥȅ6km/sec ́ reduce ̱̜̀ͥȅ ̱̜̀ͥȅ Fig. 4.6 Record sectionȪ S-1ȫ for the 1988 Kawachinagano-Kiwa Fig. 4.7 Record sectionȪ S-6ȫ for the 1988 Kawachinagano-Kiwa profile using a bandpass filter of 5-8Hz. The reduction profile using a bandpass filter of 5-8Hz. The reduction velocity is 6km/sec. velocity is 6km/sec.
გ௶͈ஃ໐௸ഽࢹ௮κΟσଔܮ . ඤಿع 4.9 1988 ා ͈̹͛ͅͼϋΨȜΐοῢ̤̞ͅঀဥ̱̹κΟσ ഽΈςΛ௸̦܃ΈςΛΡȄٮޏ̦ڙඤಿ . ΩριȜΗȜȅঅع 4.8 ͼϋΨȜΐοϋͤ͢ͅଔ̯̹ͦ 1988 ා ܮგ௶͈ஃ໐௸ഽࢹ௮κΟσȪ૬̯ 8km ́͘ȫ Ρ͈պ౾ͬা̳ȅ Fig. 4.8 Upper crustal velocity model for the 1988 Kawachinagano- Fig. 4.9 Model parameters used for the traveltime inversion of the Kiwa profi le after traveltime inversion. upper crustal velocity model for the 1988 Kawachinagano- Kiwa profile. The boundary and velocity nodes are indicated by squares and circles, respectively.
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გ௶͈ஃ໐௸ഽࢹ௮κΟσܮ . ඤಿع̀ΟΐΗσܱ̱͂̀༗ం̯̹ͦȪบ෫౷ૼ൲ࡄݪΈ ນ 4.1 1988 ා͉ σȜί , 1992ȫȅ۷௶̯̹ͦ෨ࠁܱͬࡉͥ͂ȄS-1 ͈ܱ ଔ͈̹͛ͅͼϋΨȜΐοῢ̤̞ͅঀဥ̱̹κ ΟσΩριȜΗȜ͈ٜ௨ഽ͂ດࢋओ ئ͈̫̥̀ͅ Ȫ 4.6ȫ͉́έΓΛΠ̦ 15km ̥ͣ 30km Table 4.1 Resolutions and standard deviations of the model ږඤͅంह̳ͥ͂এͩͦͥ 2 ਹ͈ৣ෨͈ంहͬڔ໐౷ parameters used to invert the upper crustal velocity ͢ڔ̧́Ȫ 4.6Ȫ aȫȫȄૼ؇ݻၗ̦ 35km ಼̢ͬͥ͂౷ .̧́ͥ model for the 1988 Kawachinagano-Kiwa profi leږ̽͂͜͜૬̞̭̥͂ͧͣൢో̱̹ৣ෨ͤ͜ ඤ̥ͣൢڔȪ 4.6Ȫ bȫȫȅ̹͘ȄS-6 ͈ܱȪ 4.7ȫ́͜౷ ̯ͦͥȪ 4.7Ȫ cȫȫȅ̯ږଔ̯ͦͥৣ෨̦̹̱͂ో କݻၗ̱̀ͅ 50km ͉Ⴒ̳ͥৣ෨ͅۼ͈ 5-7sec ͣͅ ږৣ෨̦ 2 ਹ͉͂̈́̽̀́ۼȄඅͅ -20-0km ͈ߊ̜̦ͤ ΏοΛΠ͈ܱ͂͜ͅಎ؇ࢹ௮ڎ̯ͦͥȪ 4.7Ȫ dȫȫȅ ັ߃̤̞̀ͅ൲শ͈ޫਫ਼എ̈́ಁ̦ͦࡉͣͦͥȅ͘ ̤̞̀ͅȄอૼ͕͖͂൳শͅอ̱̹̥Ȅ̱ܱ͜ڎ̹ ̯ͦͥȅږP ෨̥ͣ་̯̹۟ͦ͂ࣉ̢ͣͦͥ S ෨̦ ͉̩ ͜ಿ̞͈ۼષ͈ S ෨൲͉૦໙̦ఱ̷̧̩͈ࠑশܱ ȄζΛάϋΈஜ͈ੰݲ̦ຈါ̜́ͥȅ́ 4.3.2 ௸ഽࢹ௮ ஃ໐ࢹ௮Ȫ૬̯ȡ 8kmȫ͈ͼϋΨȜΐοϋ͉ͅȄඋ͙৾ ͤୈഽ͈ૂ༭̹ͬ̽ 430 ࡢ͈උ͙৾ͤশͬঀဥ̱̹ȅ ଔ̯̹ͦ௸ഽࢹ௮ͬ 4.8 ͅা̳ȅͼϋΨȜΐοϋ͈ष ̷͈ͣͦͅ ΈςΛΡͬ 4.9ٮޏဥ̞̹௸ഽΈςΛΡ͂ͅ ٜ௨ഽ͂ࢋओͬນ 4.1 ͅা̳ȅٜଢ଼ႀ֖͈͕͖ఘͩͅ ෨̦࿌္̱̞̹̀ͥ͛Ȫ 4.10ȫȄ֚໐͈෨̦̹̀̽ ٮޏඑ̥̞̈́ႀ֖ͬੰ̞̀Ȅ͕͈͂ͭ̓௸ഽΈςΛΡ͂ ΈςΛΡ͈ٜ́௨ഽ͉ 95ɓ಼̢ͬͥȪນ 4.1ȫȅଔࢋओ ΈςΛΡ́ 0.2km ոඤ̜́ͤȄ௸ഽΈςΛΡ́ٮޏȄ͉ ͉ 0.05km/sec ոඤȄඅͅల 3 ͈௸ഽΈςΛΡ͉́෨ ͈එ̥̞̈́௶ၰͬੰ̞̀ 0.02km/sec ոඤ̜́ͥȅ ږಿ̦ 65km ͂ౣ̩ȄPn ́ͬ͘௶͉́௶۷͈̭ ͛Ȅஃ໐ࢹ௮̱̥ݥ̞͛ͣͦ̈́ȅ̽̀͢Ȅ૬̧̹̞̈́́ . ޘ౷༷́ঔ̯̹ͦࢃ͈ܪȄ߃͉̱̀۾໐ࢹ௮ͅ པ௶ȪSasaki et al., 1970ȫ͈૬໐ࢹ௮ـ . ષߴ௶͂ா ̱Ȅ૬̯ 22km ͉́͘ 6.4km/secȄب४ࣉ̱̀ͅ௸ഽͬͬ 35km ͘ ́ ͉ 6.8km/secȄ35km ո૬͉7.6km/sec ͂ ̱ ̹ Ȫ 4.11ȫȅ ݥ̹͛ͣͦஃ໐௸ഽࢹ௮Ȫ 4.8ȫͬࡉͥ͂Ȅ౷ນັ߃͉ ౷ນ͈̮̩͉ا͈͈͜Ȅ̷͈་̜̦ͥا3.1-4.5km/sec ͂་
გ௶͈૬໐௸ഽࢹ௮κΟσȅܮ . ඤಿع 4.11 1988 ා པ௶ـ . ષߴ௶͂ா . ޘგ௶͈ஃ໐௸ഽࢹ௮κΟσ ొ̱Ȅ௸ഽࢹ௮͉ܮ . ඤಿعා 1988 4.10 ̱̞̀ͥȅبଔ͈̹͛ͅͼϋΨȜΐοῢ̤̞ͅঀဥ̱̹෨ ͈૬໐ࢹ௮ͬ४ࣉͅ Fig. 4.11 Lower crustal velocity model for the 1988 Kawachinagano- Fig. 4.10 Ray path diagram used for the inversion of upper the Kiwa profi le. The velocity of the lower crust is assumed crustal velocity model for the 1988 Kawachinagano- to refer to the 1989 Fujihashi-KamigoriȪthis studyȫ and Kiwa profi le. Kurayoshi-HanafusaȪ Yoshii et al., 1974ȫprofi les.
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,გ௶͈۷௶ΟȜῌུ༹ͬഐဥ̱̀ං̹ͣͦৣ౯࿂Ȫऒષ̥ͣcontrol factor ͈̦ 1ܮ. ඤಿع 4.12 1988 ා 2.5, 5, 10, 20, 40, 80, 160, 320 ͈ાࣣȫ Fig. 4.12 Seismic sections of the 1988 Kawachinagano-Kiwa profi le. The range of the control factorȪ Fȫ is from 1Ȫupper leftȫ to 320 Ȫlower right*.
൚̹ͥͅۼஃ̞໐Ȫȡ 500mȫ́͘ͅࡠͣͦȄ̷ͦͤ͢૬̞̭͂ͧ ΐ̦ං̞̞͈ͣͦ̀̈́ͅచ̱̀Ȅ̷͈ͦͣಎ ȅ̷̱ F=20 ȡ 80 ̧͉͉̱̹́̽ͤৣ࿂͈ͼιȜΐ̦ං̞͕͉ͣͦ̀̈́̓ͭ͂اȄକ༷͈࢜௸ഽ་͉̱̀۾ͅ ๕̤͂̈́̽̀ͤȄ ̤ͤḘ༹͈̦̏ष͈ΟȜῌచ̱̀͜ခ̜̭࢘́ͥܖ͈ ഽ̦ 5.6km/sec௸͉ئ̥ͣ ૬̯ 1km̀ എౙ̈́ࢹ௮̜́ͥȅಎ؇ࢹ௮ ͂ͬা̱̞̀ͥȅڛఘഎͅࡉͥ͂௶ Ȩ͉̱̹̏̽ͤ͂ৣ࿂͈ͼιȜΐ̦ං͉ͣͦ́ئັ߃͈൲শ͈ಁ͉̮̩ͦஃ໐͈ࢹ௮̺̫́୰ྶ́ ȁո ̞̀̿ܖͅضఘ ̹ F=40 ͈ાࣣͬ႕͂ͤͅȪ 4.13ȫȄ̷͈ࠫحȄ௶͈͕͖ఘ́ࡉͣͦͥঅྔ႑ఝ͈̈́̓ັ̧ ໐ئඅಭ͓ͬͥȅ̴͘Ȅ૬̯ 30km ոஃ͈͈ئȄ௸ഽࢹ௮എ͉͕͖ͅৗ̜́ͥ͂࡞̢ͥȅ ̭͈௶͉ ̳ͥږཤ߹০͈ৣ࿂̞̩ͬ̾̈́͜ږྶ̞̤̀ͅڔ༹ഐဥ ౷ུ 4.3.3 control factor ͉ȄΞΑΠ͈ાࣣ͂൳အͅ 1, 2.5, 5, 10, 20, ̧̭̦͂́Ḙ͈̏ಎ͉ͅ S-1 ͈ܱષ̹́͛ͣͦ 2 ਹ͈ ̷͉ͦڙ̞ͦ̀ͥ͘ȅ̷͈ͦͣৣ࿂͈߹০܄͘ ৣ࿂ͬ͜ضͬဥփ̱̹ȅഐဥ̱̹͈ࠫ̾ 9 ͈ 320 ,160 ,80 ,40 ͈ Ȅ3.5 ୯͈́ΦͼΒ ̸ͦ 10° ȡ 15° ഽ̜́ͥȅ̹͘௶ධ͈૬̯ 25km͉ض͛̀ 4.12 ͅা̳ȅං̹ͣͦࠫ͂ Ȫ 3.19ȫ͂߹̦࢜ ̭͂ͧͅཤ͒߹০̳ͥৣ࿂ͬে̧́ͥȅS-6 ͈ΏοΛضΟȜῌഐဥ̱̹ΞΑΠ͈̜͈ࠫͥ ̯̹̠ͦ͢ͅȄ̷͈ৣ࿂͉ධ̥ͣږ႒য̱̞̀ͥȅF=1 ͈ાࣣ͉́Ȅ८၄ਹ༹ࣣͥ͢ͅࡪ Πܱ̥ͣ͜ ે͈ΌȜΑΠ̦ఱ̧̩̀ৣ࿂ͬে༆̧̳̭̦ͥ͂́̈́ ૬̯ 33km ̜̹ͤ́͘ 2 ਹ͈ৣ࿂̞̈́̽̀ͥͅȅಕ࿒̳ ̞ȅF ̦ఱ̧̩̈́ͥ̾ͦ̀ͅষలͅৣ࿂̦̥͍ષ̦ͤȄ ̧͓͉Ḙ͈̏ৣ࿂͉૬̯ 35km ಼̢̹ͬັ߃ͤ͢ೆ͙ࣺ ȅ̜̭̞̱ͥ́͂ͥ̀اఱ̧̩་͂͒ °30 ̥ͣ °20 ̦ڙ̳̭ͥ͂ ͙ږͅږF=20 ͞ 40 ̈́ͥ͂ͅཤ߹০͈ৣ࿂ͬྶ ̧̦́ͥȅF=80 ಼̢ͬͥ͂ࣽഽ͉ৣ࿂͈Ⴒ̦͉̽ ̷̷̱͈̀ৣ࿂͉૬̯ 50km ߃̧̩̠̭̦́͂́͘Ȅ ̱۾૬̞̭̜͂ͧͥͅȅ༷֚ Moho ࿂ͤ͢ͅڔࡠͅ߃ັ̩͕̓ͼιȜ ྶ̥ͣͅ౷ئȅF ͈ષࡠݞ̧͍̩̱ͥ̈́̈́ͤ
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ȅऒུ༹͉ഐဥͥ͢ͅৣ౯࿂ȅֲ͉֔Ȫ1991ȫͥ͢ͅৣ౯࿂ȅȪaȫڛ 4.14 ًݲ͈ࡄݪ͈͂ ਹৣ࿂̦ζΛάϋΈ̯̞̞ͦ̀̈́ȄȪbȫႲ̳͈֚ͥ̾ৣ࿂͈̠͢ͅࡉ̢ͥȄȪcȫৣ࿂͈ 2 ȅ̢̞̞̈́̀ͦͣ௴̦ا་͈ڙ߹০ Fig. 4.14 Comparison between this study and the previous study. Cross-sections for this studyȪ leftȫand for Yoshii Ȫ1991ȫȪright*.Ȫ aȫ Undetectable double refl ectors,Ȫ bȫ undetectable multi refl ectors,Ȫ cȫ undetectable change of the dip angle.
തͬা̳ȅ௶۷͉܃ષߴ௶ȅି֣͉ΏοΛΠതȄฒ. ޘგ௶͈ৣ౯࿂ 4.15 1989 ාܮ . ඤಿع 4.13 1988 ා อ̱̹౷ૼ͈ૼͅۼܢȪF=40 ͈ાࣣȫ ൳শͅ 1985 ා 1 ȡ 1994 ා 12 ͈ Fig. 4.13 Seismic section of the 1988 Kawachinagano- ࡙ͬίυΛΠ̱̞̀ͥȅಎఆ͕̥Ȫ1997ȫͤ֨͢ဥ Kiwa profi le and its interpretationȪ F=40*. Fig. 4.15 Location map of the 1989 Fujihashi-Kamigori profile. Stars and open circles indicate shot and receiver points, respectively. Hypocenters of micro-earthquakes from May 1995 to April 2001ȪNakamura et al., 1997ȫ are superposed.
͜ࡉͣͦͥ 2 ਹৣ࿂̦Ȅ֔ͅض̧̳̭̦ͥ͂́ Ȫ 4.7ȫȄུ༹͈ࠫږȄ૬̯ 35km ັ߃̷͉͈ͅంह͉ͬ̀ ཿ͈ৣ࿂̱̱̥͂̀ζΛάϋΈ̯ 1 ͉́ضȄ5 ડͅોͥȅ Ȫ1991ȫ͈͉̱ࠫ̀۾ḙ͈ٜ̏ͦͣ৷̞̈́ͅ ၗ͉́ضȪ 4.14Ȫ aȫȫȅ൳အུ༹͈̞̞ࠫ̈́̀ͦͅ ڛݲ͈ࡄݪً͈͂ 4.3.4 ض͉́֔Ȫ1991ȫ̽̀͢ͅ CMP ਹ༹ࣣͬဥ̞̹ ̯ͦ̀ͼιȜΐ̯̞ͦ̀ͥৣ࿂̦Ȅ֔Ȫ1991ȫ͈ࠫ௶ུ ̯ͦږ ͉́ 40km ͜ͅݞ͐Ⴒ̳ͥ 1 ͈̾ৣ࿂ུ̱͂̀͂ضৣ࿂͈ζΛάϋΈ̦দ͙̤ͣͦ̀ͤȄ̷͈ࠫ Ȫ 4.14ȫȅొ̱Ȅུ༹͢ͅ ͥȪ 4.14Ȫbȫȫḙ͉̏ͦ CMP ਹ༹ࣣͥ͢ͅੜၑ͈̹͛ͅȄ̳ͥڛͬ͂ضഐဥ༹͈ࠫ ൲എͅ૬ഽ་̯̤۟ͦ̀ͤȄਸ͉૬̯ͬা ৣ࿂͈Ⴒ̦ཋ̱̩ 1 ̾ͅࡉ̢̞̀ͥ͂ࣉ̢ͣͦͥȅু͉ضࠫͥ ૬ഽ་͈۟ੜ ̯֑ͣͅത̱͂̀Ȅධ͈૬̯ 25km ͤ͢ೆ͙ࣺ̞͉ͭ́ضȅ༷֚Ȅ֔Ȫ1991ȫ̞̱ͥࠫͥ̀͢ͅ ಼ͬ ૬̯ 35kḿ͉ضၑ̱̞̞͈ͬ̀̈́́ਸ͉؉໘শ̜́ͥȅ̹͘Ȅၰ৪ ͥৣ࿂̦ݷ̬ͣͦͥȅུ༹͈ࠫ ͈͈͛ͣͦͥ͜Ȅ̦֔ا་͈ڙρȜΑΉȜσ̦։̷̞̭̥͈̈́̽̀ͥ͂ͣ͘͘ౙ ̢̹ັ߃́ೆ͙ࣺ͙͉́ ̧̞̱͉͉̈́͂ͤ̽ا་̷̠͈͉̥̈́ͣ͢ضಕփͬါ̳ͥȅ૬̯ 20-30km Ȫ1991ȫ̧͈̭̞͉ࠫ͂̈́́ͅڛͅ ̯ͦ̀ Ȫ 4.14Ȫ cȫȫḙ͈̠̏͢ͅ CMP ਹ༹ࣣ̺̫͉́Ȅఘ͈ږȄS-6 ͈ܱષ̳́͂ͥڛၰ৪̞̤ͬ̀ͅ
Ƚ!195 Ƚ ࡄݪਫ਼ࡄݪ༭࣬ȁల 68 ȁ2005 ා 9 ܿڠشཡब
࢚̯̦ 30-40km ̜̭́ͥ͂Ȅ3ȫPn ௸ഽ̷̦̤͈͢ڔါ͉ೕ͈͈͛ͥ͜ζΛάϋΈ͈ှ̫̞ࠧͥ͂̽ͅ 2ȫ౷ٽ ါள̦ఱ̧̞̹͛ࠨഎ͉̞́̈́ȫږȅུ༹͈ഐဥͤ͢ͅȄ൳̲ΟȜΗ̥ 7.8km/secȪ ొ̱Ȅະ̜̦ͥٮഐဥࡠ̹ ́͘ոષ͈ૂ༭̧̧̳̭̦ͬ֨͂́Ȅৣ࿂͈ ̜̭̦́ͥ͂༭̯̞࣬ͦ̀ͥȅέͻςάϋ٬ίτȜΠ͈̭ͦͣ ෝ̜́ͥȅ ൲̧͉ୌධུͅచ̱̀ཤୌ͈༷࢜ͅ 4cm/year ͈௸ഽ́خࠁે̈́̓ͬ͏̢̹݈͘ა̦ ͜չସს༷ͅئષߴ௶ ֊൲̱̤̀ͤȪSeno et al., 1993ȫȄུ௶ . ޘා 1989 4.4 ါ͂۷௶ΟȜΗ ࢜ͤ͢ೆ͙ࣺ̺ͭέͻςάϋ٬ίτȜΠ̦ంह̳ͥ͂ထٽ௶۷ 4.4.1 ષ ߴ ௶ Ȫ บ෫౷ૼ൲ࡄݪΈσȜίȄ ே̯ͦͥȅWatanabe et al.Ȫ1990ȫ͂ಎఆ͕̥Ȫ1997ȫ̈́̓ . ޘ ා 1989 1995ȫ̦̭͈ͥ౷֖Ȫ 4.15ȫ͉ಎ؇ࢹ௮́ߊ୨ͣͦ ̽̀͢ͅȄુ۷௶ΟȜΗͬဥ̞̀ࠨ̯̹ͦૼ࡙ື ̢̳̠ͥ͂͢௴๕̦̥̈́ͤ ̥ͣέͻςάϋ٬ίτȜΠ͈ೆ͙ࣺ͙ͬܖ͈܊፠ـඤఝ̜̹ͤͅȄఘഎͅࡉ̹ͥ͂ ͬ ૬̯ 50kḿ͉ئఝ͕̓ྶၸ̈́౷͈ఝે ࡄݪ̧̦̯̹̈́ͦ̀ȅ̱̥̱Ȅུ௶ٸࢩ̩Ⴚ̱̞̀ͥȪ 4.4ȫȅ ௰͈৽ͅౢȡΐν ಼̢ͥ૬̞౷ૼ̦̞̹̈́͛ͅέͻςάϋ٬ίτȜΠ͈պ́ͭޖͬ Ⴅ͉̞̦̈́Ȅ௶ષ͈ S-3 ႒̥ͣ̈́ͥ౷֖͂ୌ௰ ౾͈ଔ͉ඳ̱̞ȅ܊ဢఙୟ͂ၘ࡙यߟ͈ܮρ ࢹ௮͈ڔ႒̥ͣ̈́ͥ౷֖͂ͅఱ ȁུౝऔ͉Ȅ̷ͦ́͘৽̱͂̀ஃ໐͈મळ̈́౷܊५غ̱̹߾ಿৗͅܮฒՏ͈ डષ̥ͣڔ໐౷ئ౷༷ȹ༎ਬտ֥ٛȄ ଔͅਹത̦౾̥̞̹ͦ̀ౝऔచયͬܪ̥͘ͅߊ̯ͦͥȪུ͈౷ৗȸ߃ 1987ȫḙ͈̏౷֖͉̭́ͦ́͘บ෫౷ૼ൲ࡄݪΈσȜίͅ ໐ζϋΠσ͈૬̯́͘ͅࢩ̬̹ȅ̷͈̹͛Ȅਲြ 1988 ා გ௶͈̠̈́͢ 60-70km ௶ಿ·ρΑ͈ౝܮ . ඤಿع པ௶̈́̓߫ͤ༐̱ౝऔ̯̤ͦ̀ͤȪ႕̢͊ـ . ாͤ͢ ಿ̯̞ͦ̀ͥȅװͅ ஃ໐͈ࢹ௮̦ౙ̜̭́ͥ͂Ȅ औ̜̹͈̦́̽͜Ȅུ௶͉́ 210kmڔYoshii et al., 1974ȫȄ1ȫ౷
͈ ષߴ௶͈۷௶෨ࠁȪS-1ȫȅ3-8Hz . ޘ 4.16 1989 ා ΨϋΡΩΑέͻσΗȜͬঀဥȅ6km/sec ́ reduce ̱ 4.18 ͼϋΨȜΐοϋͤ͢ͅଔ̯̹ͦ 1989 ාޘ . ષ ̜̀ͥȅ ߴ௶͈ஃ໐௸ഽࢹ௮κΟσȪ૬̯ 8km ́͘ȫ Fig. 4.16 Record sectionȪS-1ȫ of the 1989 Fujihashi-Kamigori Fig. 4.18 Upper crustal velocity model for the 1989 Fujihashi- profile using a bandpass filter of 3-8Hz. The reduction Kamigori profi le after traveltime inversion. velocity is 6km/sec.
4.19 1989 ාޘ . ષߴ௶͈ஃ໐௸ഽࢹ௮κΟσଔ ͈̹͛ͅͼϋΨȜΐοῢ̤̞ͅঀဥ̱̹κΟσ ഽΈ௸̦܃ΈςΛΡȄٮޏ̦ڙષߴ௶͈۷௶෨ࠁȪS-4ȫȅ3-8Hz ͈ ΩριȜΗȜȅঅ . ޘ 4.17 1989 ා ΨϋΡΩΑέͻσΗȜͬঀဥȅ6km/sec ́ reduce ̱ ςΛΡ͈պ౾ͬা̳ȅ ̜̀ͥȅ Fig. 4.19 Model parameters used for traveltime inversion of the Fig. 4.17 Record sectionȪS-4ȫ of the 1989 Fujihashi-Kamigori upper crustal velocity model for the 1989 Fujihashi- profile using a bandpass filter of 3-8Hz. The reduction Kamigori profi le. The boundary and velocity nodes are velocity is 6km/sec. indicated by squares and circles, respectively.
Ƚ!196 Ƚ ࢹ௮ζΛάϋΈȽ໌നڔ૬໐౷̩̿ܖ૧̱̞८၄ਹ༹ࣣͅ
ထ̥ͣضཔ௶͈̈́̓ࠫـ . ಿ̵ࣣͩ̀ͅ۷௶തͬఉତ౾̱̹̭͂̽̀͢ͅȄ ֖̥́̾̀औ̯̹ͦாװ͈̭ ಼ͬ ૬̯ 1km͉ا༗̱̞̀ͥȅ۷௶ത͉ 137 ே̯̹̠ͦ͢ͅȄକ༷͈࢜ࢹ௮͈་ږ൳ഽͬ͂ڞۼਲြ͈۷௶ത എౙ̈́ࢹ௮̜̭̦́ͥ͂ͩڛ 1.5km ͬ༗̱̞̀ͥȅΘͼ ̢̩ͥ͂̓̈́̈́ͤȄ͉ڞۼത̜́ͤȄ۷௶ത ۼ͈ ζͼΠͥ͢ͅอૼത̱͂̀௶ͤ͢ S-1 ̥ͣ S-4 ͘ ̥ͥȅొ̱Ȅౢȡΐνρࠏͅచ؊̳ͥ S-1 ̥ͣ S-3 ͈́ 4 ത̦୭̫̤ͣͦ̀ͤȄၾ͉ 500-800kg ̜́ͥȅొ ͈౷ນ̥ͣஃ̞̭͂ͧȪ૬̯ȡ 1kmȫ͉́Ȅକ༷͈࢜ະ 3.4km/sec ͈೩௸ഽ̦̜ ͅۼ͈ ȄS-2 ͂ S-3̩ޑ70km ͂̈́ͤȄอૼതତ͈ະ௷͉ ৗ͉ ̷̤͉͢ڞۼȄอૼത̱ ̥ͤ̈́͂ ෪ཤ໐͉́Ȅ2.9km/sec͈ۼ͈ ๛̞͛̈́ȅ ͤȄS-1 ͂ S-2 S-3 ̥ͥ̈́ͣ܊५غΟȜΉ͉ȄS-1 ͂ S-4 ͈ܱષ́ૼ؇ݻၗ ͈೩௸ഽͬা̱̞̀ͥȅొ̱Ȅ߾ಿৗ̹̯ͦ௶۷ ๕ͅܖ͈ 5.3km/sec ̥ͣئ౷ນ͈̳̪ೄ͉́ۼ180km ಼̢ͬͥ͂Ȅྶ̥ͣͅࡉ̥̫শ̦ 7km/sec ͬ ͂ S-4 ͈ߊ ̦ ̧̳̭̦ͥ͂́ͥȪ 4.16Ȅ 4.17ȫȅ ̤̈́̽̀ͤȄ௸ഽࢹ௮͂౷ৗ͈͂చ؊̦̞͢ȅږષٝͥ Pn ͬ بȄஜ͈̠͢ͅ Moho ࿂ͬକ͉̱̀ͅ۾໐̤͍͢ષ໐ζϋΠ ȁ૬໐ࢹ௮ͅئڔඅͅ S-1 ͈۷௶ܱ෨ࠁ͉ͅȄ౷ σ͈́ৣͥ͂͢ͅএͩͦͥྶၸ̈́ࢃ෨̦ࡉͣͦȄ̷ ̱̤̀ͤȄଔ̷̯̹͈ͦ૬̯͉ 34kmȄडષ໐ζϋ /ಿ̞ reverberation ͬা̱̞̀ͥȪࠑ Πσ௸ഽ͉ 7.6km/sec ̜́ͥȅ̹͘૬̯ 25km ͜ͅ 6.3km͈ۼ෨߲͉ࠑশ͈ Ȅ̷̦̜̦ͥٮޏ̳ͥا૬໐ࢹ௮͈ະ sec ̥ͣ 6.6km/sec ͅ௸ഽ͈་ڔ2sec ഽȫḙ͉̭͈̏ͦ౷֖͈౷ ͉ۼশ ෨ࠁͅ ͈૬̯ݞ͍௸ഽ͈ٜ௨ഽ͉՛̩Ȅમळ݈̈́ა͉ࣾඳ̜ܱ́௶۷ڎাऐ̱̞̀ͥȅ̹̭̞ͬ͂͘ޑৗ̦ ̤̞̀Ȅ૦໙͈ޑ৻͈ओ͉̜͈͈ͥ͜ȄζΛάϋΈ̳ͥ ͥȅ S ෨͈෨̢߲̦͙ͥȅ̯ͣͅบ෫ത߃ཌྷ 4.4.3 ུ༹ഐဥ ͥ̈́͂ٺषͅવ ,ȪέΓΛΠȡ 30kmȫ́۷௶̯̹ͦΠτȜΆ͉Ȅૼ࡙ਔ ȁུ༹͈ഐဥ͉ͅḘ̏ͦ́͂͘൳အͅ F ͈̦ 1, 2.5 Ȅခփ݅̈́ࢃ෨ͬ 5, 10, 20, 40, 80, 160, 320 ͈ 9 ͈ͤાࣣ́ΞΑΠ࣐ͬ̽ͤ͢ͅޣג༏͈́ఉਹৣ͞८၄͈ 4.24 ͂͛̀͘ͅা̳ȅอૼത̷̦̤ͬ͢ض̧̞́̈́ȅ̹͘ȄS-1 ͬੰ̞ܱ̀ఘഎͅ ̹ȅ̷͈ࠫږ͕̓ͭ͂ ത̱̥̞̈́ષȄ۷௶ܱ͈ S/N ̦೩̞̭ 4 ͅڞۼ ૬໐ 70kmڔS/N ̦೩̩Ȅඅͅ S-4 ͉́ΦͼΒτασ̦̩ࣞ౷ ̱̀͜ڛგ௶͈ાࣣ͂ܮ . ඤಿعൢో̱̹͂এͩͦͥࢃ෨͉͕̞͂ͭ̓͛ͣͦ̈́ȅ ̥͂̈́̓ͣȄ̥ͣ ͅضഽࢹ௮ ఘഎͅͼιȜΐ͉̜̩̞ͤ̈́͘͢ȅ̱̥̱Ḙ͈̏ࠫ௸ 4.4.2 ນ̤ͦ̀ͤȄૂ༭ၾ̦ઁ̦̈́ضஃ໐ࢹ௮Ȫ૬̯ȡ 8kmȫ͈ͼϋΨȜΐοϋ͉ͅȄඋ͙ ͜ control factor ͈൵ව͈࢘ ৾ͤୈഽ͈ૂ༭̹ͬ̽ 310 ࡢ͈උ͙৾ͤশͬဥ̞̹ȅ ̞̦̈́ͣ͜ control factor ͬ୯̳̭ͥ͂̽̀͢ͅȄ८၄ਹ ଔ̯̹ͦࢹ௮ͬ 4.18 ͅা̳ȅͼϋΨȜΐοϋ͈षͅ ༹ࣣȪF=1 ̧͈͂ȫ͞ CMP ਹ༹ࣣȪF=320 ̧͈͂ȫ͉́ে ڎ૬໐ࢹ௮͈ͼιȜΐ̦ං̹ͣͦȅڔΈςΛΡͬ 4.19 ͅা̱Ȅ̷ ༆̦ࣾඳ̺̹̽౷ٮޏဥ̞̹௸ഽΈςΛΡ͂ ٜ௨ഽ͂ࢋओͬນ 4.2 ͅা̳ȅอૼത̦ 4 ത͂ઁ̈́ ͼιȜΐͬࡉ̞̩̀͂ F ͈̦̯̞Ȫ1 ͞ 2.5ȫાࣣ͉́Ȅ͈ͣͦ 70km ͂ၗ̞̹ͦ̀ͥ͛Ȅ෨̽̀͢ͅ࿌ ૬̯ 15-35km ఘ̹ͩͤͅ૦໙̦ఱ̧̩Ȅৣ࿂͈ে༆ ̦ڞۼ̷͈̩ ෝͅ߃̞ȅF ͬఱ̧̩̱̞̩̀͂ΦͼΒ͈خս͉ࡠͣͦͥȪ 4.20ȫȅఘഎͅ௸ഽΈςΛ ͉͕͂ͭ̓ະํ္̯ͥͦ ࡛ͦȄ̷̦ͦ́ࣾ͘ඳ̺̹̽ৣ࿂̦̦ض๕ͅ ࠚࡘ࢘ܖΡ͈ٜ௨ഽ͉೩̩Ȅ90% ಼̢̞̦ͬ̈́Ȅ̞ͩͥ͠ ల 3 ͈௸ഽΈςΛΡ͈ٜ௨ഽ͉̀ 99ɓ಼̢ͬ ࡛̳ͥȅ̱̥̱Ȅ̷͈͘͘ F ͬఱ̧̩̳ͥ͂Ⴒ̦̹̜ͥ ΈςΛΡ͈ٜ௨ഽ͉ࡌ͙ ͩͦͥḙ͈̏̽̀͢ાࣣ̭ͦ́͘͜൳အ఼̳ͥͅํսٮޏȪນ 4.2ȫḙ̏ͦͅచ̱̀ͥ ΈςΛΡ́ 0.2km ͉ F=20 ȡ 80 ̦ͅഐ൚̜́ͥḙ͈̠̏͢ͅ S/N ̦̯̩ȄٮޏȄ͉̱̀۾ȅࢋओ಼̢̞ͥ̀ͬͅ 90% ոඤ̜́ͤȄ௸ഽΈςΛΡ͉́എͅ 0.1km/sec ոඤ́ ۷௶ྟഽ͜೩̞ΟȜΗ͈ࡠ̹ͣͦૂ༭ၾ̥͉ͣͅȄਲြ ͼιȜΐͬै଼̳͈ئȅ ͈ CMP ਹ༹ࣣ͞८၄ਹ༹ࣣ͉́౷̜ͥ എ̈́ੜၑۼ̯ͦͥ Pn ̭͉ͥ͂ඳ̱̩Ȅၰ৪͈၌തͬ৾ͤව̹ͦಎږ̞̀Ȅૼ؇ݻၗ͈ఱ̧̞۷௶ത́ ૬໐͞डષ໐ζϋΠσͬഥ̧̹ͩ̽̀ߠ୬෨͈ ̽̀͛̀͢ͅྶၸ̈́ͼιȜΐϋΈ̦࡛̯ͦͥȅڔ౷̓̈́ උ͙৾ͤশͬဥ̞̀Ȅ૬໐ࢹ௮Ȫȡ 40kmȫͬଔ̱̹ȅ F=40 ͈ાࣣͬ৾ͤષ̬̀ං̹ͣͦͼιȜΐ͈අಭͬ ొ̱Ȅ̷͈̠̈́͢ߠ୬෨͈උ͙৾ͤΟȜΗ͉ઁ̞̹̈́͛Ȅ ͓ͥȪ 4.25ȫȅΟȜΗၾ͈ະ௷̥̭̭ͣ͂ͧ̓ͧζΛά ̱̹ȅͼϋΨȜΐο ϋΈ̴̯ͦͅͼιȜΐ͈ࠧ၂̱̞̀ͥႀ֖̜̦ͥ͜Ȅ̷ͦب͉̀କ͈ͬئ૬̯ 8km ո ໐౷ئϋ͉ͅȄඋ͙৾ͤୈഽ͈ૂ༭̹ͬ̽ 148 ࡢ͈උ͙৾ͤ ̭͈́͜౷֖͈̞̩̥͈̾අಭ̦ນ̞ͦ̀ͥȅ̴͘ ಕ࿒̳ͥ͂ȄౙͅႲ̳ͥఱ̧̈́ৣ࿂̦̞̩̥̜̾ͅڔ শͬဥ̞Ȅ̷͈̠̻ Pn ͈උ͙৾ͤশ͉ 23 ࡢ̜́ͥȅ ଔ̯̹ͦ૬໐ࢹ௮ͬ 4.21 ͅা̳ȅͼϋΨȜΐοϋ͈ ̺̫̩ͥ́̈́ତ km ͈෨ಿ͈ౣ̞ৣ࿂Ȫ̱̩͉͜ৣ ۼȄ̷̤͢૬̯ 25km ̥ͣ 35km ͈̤́ͤ́ͭ͘܄ΈςΛΡͬ 4.22 ͅা̱Ȅ ఘȫ͜ٮޏषͅဥ̞̹௸ഽΈςΛΡ͂ ͚ refl ective܄ٜ௨ഽ͂ࢋओͬນ 4.3 ͅা̳ȅ̹͘Ȅࠗॳ̱̹෨ ͉́အș̈́෨ಿȪତȡତ 10kmȫ͈ະৗ̷͈ͬͣͦ ඤ͈ৣڔ໐౷ئȄ௸ഽΈςΛΡȄ zone ͬࠁ଼̱̞̀ͥȅୌ௰͈ႀ֖͉̱́̀͜۾ͬ 4.23 ͅা̳ȅల 5 ͅ ̯̦ͦͥȄS-4 ͈ܱ͈ৗ̦՛̞̹͛ͅȄ൳အږ೩̞Ȫນ 4.3ȫȅ ࿂̦͂ئΈςΛΡٜ͂͜ͅ௨ഽ͉ 30% ոٮޏ ̹͘Ȅडષ໐ζϋΠσͅచ؊̳ͥల 6 ͈௸ഽΈςΛΡ ͅ refl ective zone ͬࠁ଼̧̱̞̥͉̱̞̀ͥ̽ͤ̈́ȅ̹͘Ȅ ΈςΛΡ͉ 60% ͂೩̩Ȅࢋ ߠ୬༹̥ͣଔ̯ͦͥ૬̯͉ͅႲ̳ͥྶၸ̈́ Moho ࿂͉ٮޏȄ಼̢̦̞ͥ̀ͬ 90% ͉ ̯̞ͦ̈́ȅొ̱Ȅ௶ಎ؇໐ͅ૬̯ 33km ͅ౯༌എ́ږ ओ̷̸͉ͦͦ 0.05km/secȄ0.6km ̜́ͥȅ ৣ࿂̦ంह̱̞̀ͥȅ̠͈֚̾͜අಭ̞͂ޑ̦̜͉ͥ ̴͘ஃ໐ࢹ௮Ȫ૬̯ȡ 8kmȫͬࡉͥ͂Ȫ 4.18ȫḘ͈̏౷
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ນ 4.2 1989 ාޘ . ષߴ௶͈ஃ໐௸ഽࢹ௮κΟσଔ ͈̹͛ͅͼϋΨȜΐοῢ̤̞ͅঀဥ̱̹κΟσ ΩριȜΗȜ͈ٜ௨ഽ͂ດࢋओ Table 4.2 Resolutions and standard deviations of the model parameters used to invert the upper crustal velocity model for the 1989 Fujihashi-Kamigori profi le.
4.20 1989 ාޘ . ષߴ௶͈ஃ໐௸ഽࢹ௮κΟσଔ ͈̹͛ͅͼϋΨȜΐοῢ̤̞ͅঀဥ̱̹෨ Fig. 4.20 Ray path diagram used for the inversion of the upper crustal velocity model for the 1989 Fujihashi-Kamigori profi le.
4.21 ͼϋΨȜΐοϋͤ͢ͅଔ̯̹ͦ 1989 ාޘ - ષ ນ 4.3 1989 ාޘ . ષߴ௶͈૬໐௸ഽࢹ௮κΟσଔ ߴ௶͈૬໐௸ഽࢹ௮κΟσ ͈̹͛ͅͼϋΨȜΐοῢ̤̞ͅঀဥ̱̹κΟσ Fig. 4.21 Lower crustal velocity model for the 1989 Fujihashi- .ΩριȜΗȜ͈ٜ௨ഽ͂ດࢋओ Kamigori profi le after traveltime inversion Table 4.3 Resolutions and standard deviations of the model parameters used to invert the lower crustal velocity model for the 1989 Fujihashi-Kamigori profi le.
4.22 1989 ාޘ . ષߴ௶͈૬໐௸ഽࢹ௮κΟσଔ ͈̹͛ͅͼϋΨȜΐοῢ̤̞ͅঀဥ̱̹κΟσ ΩριȜΗȜ Fig. 4.22 Model parameters used for the traveltime inversion of the lower crustal velocity model for the 1989 Fujihashi- Kamigori profi le. The boundary and velocity nodes are indicated by squares and circles, respectively.
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4.23 1989 ාޘ . ષߴ௶͈૬໐௸ഽࢹ௮κΟσ ଔ͈̹͛ͅͼϋΨȜΐοῢ̤̞ͅঀဥ̱ ષߴ௶͈ৣ౯࿂̷͈ٜ͂৷ . ޘ 4.25 1989 ා ̹෨ F=40 Fig. 4.23 Ray path diagram used for the inversion of the Ȫ ͈ાࣣȫ Fig. 4.25 Seismic section of the 1989 Fujihashi-Kamigori profi le lower crustal velocity model for the 1989 Fujihashi- and its interpretation F=40 . Kamigori profi le. Ȫ *
,ષߴ௶͈۷௶ΟȜῌུ༹ͬഐဥ̱̀ං̹ͣͦৣ౯࿂Ȫऒષ̥ͣcontrol factor ͈̦ 1, 2.5 . ޘ 4.24 1989 ා 5, 10, 20, 40, 80, 160, 320 ͈ાࣣȫ Fig. 4.24 Seismic sections of the 1989 Fujihashi-Kamigori profi le. The range of the control factorȪ Fȫ is from 1Ȫupper leftȫ to 320 Ȫlower right*.
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௶ ̯̞ͦ̀ͥḙ͈̏۷௶͉Ȅঅ࣭໐ͅ୭౾̯̹ͦၘષ̞ޑ૬̯ 50km ັ߃͈ͅئȄ̻̠̓͡෪ཤ໐̱̀ ಿ̱̹٬ષװ̯ͦͥȪݻၗ 140-160kmȫḙ͈̏૬̯͉Ȅ̳́ 165km ̷͈͂௶ͬࢵͅධ͈٬ષ́͘ͅږ࿂̦ৣ ඤಿع٬ၘၰ༷́൳শͅঔ̯ͦḘ͉͈̏ͦ ષ໐ζϋΠσͅో̱̞̀ͥḙ͈̏ৣ࿂ ௶ 185km̩͉̈́́ڔ౷ͅ გ௶̷̤ͤ͢͜͢ 150km ୌͅպ౾̳ͥḙ͈̏٬ܮ . ႀ֖ͅࡠ̷͈̥ͣͦͥͦ͂̽͂͜͜ࢩ̦ͤͬ̽ ͈̭̦ Ȅ2002ȫ̥͕ͬئȪ௬ضḘ͈̏ૂ༭ၾ͈ઁ̈́ ၘၰ༷͈ΟȜΗͬൡࣣ̱̹ٜଢ଼͉̥͈̞͍ࠫͥ̀װಎ໐́͘௶̀ refl ective zone ࠁ 5.2 ͅা̳ȅೆ͙ࣺ͚ίτȜΠ͉ 6° ͈߹০ͬ̽̀ ͈ڔ໐౷ئΟȜΉ͉౯̧̞́̈́ȅ̞ ͉́ئȄঅ࣭໐̱اັ߃́་܅ഽ͉٬ڙ̯ ̞̀Ȅ̷͈ږ૬໐́ئȄMoho ࿂͈ంहȄ෪ཤ໐͈౷଼ً ა͉ 5 ડ̀ͅ୰ྶ̳ͥȅ 12° ̞͂̈́̽̀ͥȅ̹͘Ȅ۷௶̯̹ͦ෨ࠁܱ݈̳͛ͣͥͅ۾ৣ࿂͈ٜ৷ͥͦͅ ͂ڔਹৣ෨͉Ȅೆ͙ࣺ͚ίτȜΠ͈ષ࿂͂ോࡪ౷ 2 ͥͦ ߃ͅంह̳ͥ೩௸ഽ֦̱̞ܳ̀ͥ͂ͅմ̱ັٮޏ͈ ٜ৷ .5 ب͂ Ȫ2002ȫ̷͉͈͈௸ഽͬ 4km /sec̥͕ئგ௶ ̞̀ͥȅ௬ܮ . ඤಿعා 1988 5.1 ௶έͻςάϋ٬ίτȜΠ ̱̀Ȅ̷̷͈͈࢚̯̤ͬ͢ 1km ͂ࡉୟ̹̽͜ȅུ 5.1.1 ̯ͦȄ௶ධ͈૬ږȪ 4.13ȫ͉́Ȅ௶ධ͈૬̯ 25km ͢ ͈۷௶ܱ͜ͅ 2 ਹৣ෨̦ضං̹ͣͦࠫ Ȫ2002ȫ̥͕ئ̧́Ȅ૬̯ ̯ 25km ັ߃ͅζΛάϋΈ̯̞ͦ̀ͥȅ௬ږཤͅ߹০̳ͥৣ࿂ͬ૬̯ 50km ́ͤ͘ ̜͂ͥ́ٮޏ͈ئȅ̹͘Ȅ ͂൳အ̭͈ͅ 2 ਹৣ࿂ͬ೩௸ഽ͈ષ̞̱ͥ̀ا་ͅ °30 ̥ͣ °20 ̦ڙ35km ັ߃ͤ͢߹০ ̭͈ৣ࿂͉ͅ௶ධ̥ͣཤ௰ͅઁ̩̈́͂͜૬̯ 33km ࣉ̢Ȅ̷͈͈࢚̯ͬࡉୟ̹̽͜ȅ௸ഽ͉൳̲̩ 4km/sec ̷̳͈࢚̯͉̤ͥ͂͢ 1.5km ͂̈́ͥḙ͉̏ͦȄبͬ ഽ͉́͘ৣ࿂̦໐എͅ 2 ਹ͂̈́ͥႀ֖͛ͣͦ͜ ͚͇֚౿̳ͥȅ̤̤͂ضȪ2002ȫ͈̥͕ࠫئչോ ୶͈௬ܮḙ͈̏૬໐́͘ͅో̳ͥཤ߹০͈ৣ࿂͉Ȅͥ გ௶͈ධܮ . ඤಿعೆ͙ࣺ͚έͻςάϋ٬ίτȜΠ͈ષ࿂ͬ௴̢̞̀ͥ ȁ̭͈౷֖͉́ఈ͜ͅ 1994 ාͅͅئ ࢹ௮֖ٮޏಿ̱̹௶̀ͅ٬ၘװ ͈͂͜ࣉ̢ͣͦȄ̷͈ৣ࿂̞̾̀ͅબ̳ͥȅ ̥ͣ٬ષ́͘ 160km ̴͘ৣ࿂̦έͻςάϋ٬ίτȜΠ͈ષ࿂̜̭́ͥ͂ ౝऔ̦ঔ̯̤ͦ̀ͤȪ႕̢͊ȄୌाȄ1997ȫȪ 5.3ȫȄ ၔັ̫ͥબݶ̱͂̀Ȅ1999 ාͅঔ̯̹ͦঅ࣭໐Ȇ ষ̭͈ͅౝऔ̽̀͢ͅଔ̯̹ͦέͻςάϋ٬ίτȜΠͬ ૬໐ࢹ௮ౝऔͅ ͈૬ུ̯͈͂ࡄݪͥ͢ͅཤ߹০͈ৣ࿂͈͂చ؊ͬ൦ٮޏ౯̳ͥධ٬Πρέ٬ၘ؍ಎ࣭౷༷ͬ ȅୌाȪ1997ȫͥ͂͢ͅȄέͻςάϋ٬ίτȜΠ͉̳ͥ ض৾ͤષ̬ͥȪ 5.1 ͈ఊ̞ȫḙ͈̏ౝऔ̞ࠫ̀̾ ̥̠࢜̾ͦͅȄ3°→5°→10°ͅئȪ2002ȫ̽̀͢ͅ༭࣬ ೆ͙ࣺ͙ই̥͛ͣോࡪ̥͕ئKodaira et al.Ȫ 2001ȫ͞௬ ͉ ഽͬఱ̧̩̱̦̈́ͣஆࣺ̞ͤͭ́ͥڙ੭șͅೆ͙ࣺ͚͂ έͻς͈ضȪ 5.4ȫȅུࡄݪ͈ৣ࿂̦ୌाȪ1997ȫ͈ࠫ ̹͛ͥ͛ͅȄୌा̥ږάϋ٬ίτȜΠ͂Ⴒ̳̭ͥ͂ͬ ொུ̱̀ࡄݪ͈௶ධ͈́ίτȜΠٸͬضȪ1997ȫ͈ࠫ ೆ͙ࣺ͉́ضષ࿂͈૬̯ͬࡉୟ̹̽͜ȅୌाȪ1997ȫ͈ࠫ Ȅུࡄݪ͈ৣ̜ͤ́ °10 ͉ڙ͚ίτȜΠ͈डਞഎ̈́߹০ ொ̳ٸͬۼḙ̷̏́ 2 ͈̾௶͈̜ͥ́ °20 ͉ڙ࿂͈߹০ ̹̜ͅۼಎ̷͈͂ °20 ͂ °10 ͬڙ߹০͈ۼ̷͈͛ͅߊ̹ͥ ೆ͙́ڙȄ10° ͈߹০ضே̱̹ȅ̷͈ࠫͬ̾ 3 ͈ 15° ͥ ࣺ̞ͭ́ͥાࣣ͉́Ȅ௶ධ̤̞̀ͅ૬̯ 20kmȄ15° ͈ ાࣣ͉́૬̯ 24kmȄ20° ͈ાࣣ͉́Ȅ૬̯ 38km ͅో̱̹ȅ
5.1 1999 ාͅঔ̯̹ͦධ٬Πρέ̥ͣঅ࣭໐Ȇಎ࣭ ࢹ௮ౝऔ௶Ȫఊ̞ 5.2 অ࣭໐̤̫ͥͅೆ͙ࣺ͚έͻςάϋ٬ίτȜΠ͈ڔ౯̳ͥ٬ၘൡࣣ౷؍౷༷ͬ Ȫ2002ȫͤ֨͢ဥ ࠁે͂౷ૼ෨௸ഽࢹ௮ȅ౷ૼ͈ૼ࡙͜ίυΛΠ̥͕ئȫȅ௬ Ȫ2002ȫͤ֨͢ဥ̥͕ئFig. 5.1 Location map of the seismic survey line conducted in ̱̜̀ͥȅ௬ 1999Ȫ solid lineȫȪKurashimo et al., 2002ȫ. The line Fig. 5.2 Geometry of the subducting Philippine Sea plate and the intersects with the Nankai trough, in the eastern part of crustal velocity structureȪKurashimo et al., 2002*. The Shikoku Island and the Chugoku District. hypocenters are also superimposed.
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̯̤ͦ̀ ̯͈ 1.8km ͕͖͂౿̱̹ȅ̾ͤ͘Ȅ2 ਹৣ࿂͉Ȅ٬ဢږͅ ष͈௶ධ͉́ৣ࿂͉૬̯ 25km ࿂ͬ௴̢̞̀ͥ͂ࣉ̢ͣͦͥȅئ͚ષ࿂͂ޖల 2 ͬڔ౷ ͖͕͉͂ٮޏ̱̹ાࣣ͈ίτȜΠبͅ °15 ͬڙȄ߹০ͤ ࣣ̳ͥ͂Ȅ૬໐́͘ో̳ͥཤ߹০ͬضഽ̦ষలͅఱ ȁոષ 3 ͈̾ࠫڙ౿̳ͥḙ͈̠̏͢ͅίτȜΠ͈ೆ͙ࣺ͚֚ ࣉၪ̳ͦ͊Ȅུࡄݪ͈ৣ࿂͉ୌाȪ1997ȫ ͈ৣ࿂͉έͻςάϋ٬ίτȜΠ͈ષ࿂ͬນ̧̱̞̭̩̀ͥ͂ͬ͂ͥ̈́ ෝ̦̞ࣞȅ ࣉ̢ͣͦͥḙ̭̏́ୌाȪ1997ȫݞུ͍ࡄݪ̥ͣଔ̯ͦخ૬໐ͅచ؊̳͈ͥٮޏίτȜΠͥ͢ͅ έͻςάϋ٬ίτȜΠષ ͥέͻςάϋ٬ίτȜΠ͈ࠁેͬ͂͛ͥ͂͘Ȅέͻςά͉́ضୌाȪ1997ȫ͈̯ࠫͣͅ എͅ 3°→5°ٴͬڙչോ̥ؗͣ߹০ܮల 2 ̱͂̀ 4.2-4.6km/sec ͂ 5.3-5.9km/ ϋ٬ίτȜΠ͉ڔ࿂ͅ٬ဢ౷ ̈́͂ °20 ́ئչോܮsec ͈͕͖࢚̯͈൝̱̞ 2 ͈̾೩௸ഽ̦ంह̱̤̀ͤȄ →10° ͂ఱ̧̩̱̦̈́ͣஆࣺ͙ͤȄ ̵࢚̯͉ࣣͩ̀ 1.8km ̜́ͥȅུ௶ධ́ࡉͣͦͥ ͤȄ૬̯ 35km ັ߃ͤ͢ 30° ͂ࢵͅఱ̧̩̈́ͥȅίτȜΠ ల 2 ͂ࣉ̢̦ͣͦͥȄೆ͙ࣺڔ࿂ ͈ષ࿂͉ͅ٬ဢ౷ئ͚ષ࿂͂ޖల 2 ͬڔਹৣ࿂͉Ḙ͈̏٬ဢ౷ 2 ෝ̦خ͙ই̥͛ͣઁ̩̈́͂͜૬̯ 33km ̞̞́̀ͥ͘ ̹̜ͥͅۼ̱Ȅ௸ഽ̷͈ͬಎبৣ෨̜͈̥́ͥ͂ͣ ͅضȪ2002ȫ̥͕ͥࠫ͢ͅئȄ௬͉ڙȄ ̜ͥḙ͈̏ೆ͙ࣺ͙ض5km/sec ͬဥ̞̀Ȅ̷͈࢚ͬࡉୟ̹̽͜ȅ̷͈ࠫ Ȫ12°ȫڙέͻςάϋ٬ίτȜΠ͈߹০͈ئ࢚̯͉ 1.9km ͂̈́ͤȄୌाȪ1997ȫ͈ 2 ̾೩௸ഽ͈࢚ ̤̫ͥঅ࣭໐͈ ͓̥ͥ͂̈́ͤఱ̧̞ȅ̳̻̈́ͩέͻςάϋ٬ίτȜ͂ Π͈ࠁે͉ͅఱ̧̈́౷֖̦̜ͥ͂࡞̢ͥȅ ߸ͅ۾ȁষ̭͈ͅέͻςάϋ٬ίτȜΠ͂ૼ࡙ື͈͂ გ௶͈ৣ౯࿂ܮඤಿȽعࣉख़̳ͥȅ1988 ා̞̀̾ Ȫ 4.13ȫͅ౷ૼͬίυΛΠ̱̹ͬা̳Ȫ 5.5ȫȅૼ ་൲۷௶ΓϋΗȜڔ౷ૼࡄݪਫ਼౷ૼ౷ڠఱނ࡙ື͉ ̥ͣރ̯̹ͦΟȜΗͬঀဥ̱Ȅ1995 ා 7 ȡ 2001 ා 6 ౷ૼͬဥ̞̞̀ͥȅૼ࡙ື̹̯ͦ௶۷ͅۼܢ͈́͘ ́ ഽ͉ 20°ڙષࡠ͂ίτȜΠ͈߹̧͉͕͖࣐́Ȅ̷͈͈ ̜ͥȅ̯ͣͅ૬̯ 45km ັ߃͉́ૼ࡙ື͜ίτȜΠ͂ ࣐ͅ߹০̦ 30° ͂ఱ̧̩̞̈́̽̀ͥȅ̱̥̱ȄίτȜΠ
ࢹ௮ౝ֖ٮޏչോؗ́ঔ̯̹ͦ٬ၘܮ 5.3 1994 ාͅ औ௶Ȫಎ͈௰͈ධཤ௶ȫȅୌाȪ1997ȫ͢ ဥ֨ͤ Fig. 5.3 Location map of the seismic line off of the Kii Peninsula in 1994Ȫ the easternmost north-south line in the figureȫ ȪNishisaka, 1997*.
გ௶͈ৣ౯࿂ͅ౷ૼܮ . ඤಿع 5.5 1988 ා ౷ૼڠఱނૼ࡙ͬίυΛΠ̱̹ȅૼ࡙ΟȜΗ͉͈ ރ་൲۷௶ΓϋΗȜͤ͢ڔչോ̤̫ؗͥͅೆ͙ࣺ͚έͻςάϋ٬ίτȜΠ ࡄݪਫ਼౷ૼ౷ܮ 5.4 ࠁે͂౷ૼ෨௸ഽࢹ௮ȅୌाȪ1997ȫͤ֨͢ဥ Fig. 5.5 Seismic section for the 1988 Kawachinagano-Kiwa profi le͈ Fig.5.4 Geometry of the subducting Philippine Sea plate and superimposed with hypocenters, which were provided the crustal velocity structure off of the Kii Peninsula by the Earthquake Observation Center of the Earthquake ȪNishisaka, 1997*. Research Institute at the University of Tokyo.
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ષ࿂͂ૼ࡙ື͈ષࡠ͉֚͂౿̴̱̤̀ͣȄુͅ૬̯ͅ ̱̀ 10km ഽ͈ࠏൡओ̦̜ͥḙ͈̏ओ̞݈̾̀ͅა̳ͬ ͥஜͅȄ̴͘ૼ࡙ື͂ίτȜΠષ࿂͈૬̯͈ओུ̦൚ ̳ͥຈါ̦̜ͥḙ͈̏ओ̵̲̯ͬږခփ̜̥́ͥͅ ࡔ֦̱͂̀Ȅૼ࡙͈ࠨୈഽ͈࿚ఴ̦ࣉ̢ͣͦͥȅૼͥ ࡙ࠨୈഽͥ͢ͅૼ̧࡙͈͊ͣ̾ͬࡉୟ̹ͥ͛͜ͅȄૼ ࡙ࠨࢋओͬ 5.6 ͅা̳ḙ̏ͦͤ͢ͅૼ࡙͉͕͂ͭ̓ 1.5km ոඤ͈ୈഽ́ࠨ̯̞̭̦̥ͦ̀ͥ͂ͩͥȅఈ͈ࡔ Ȅૼ࡙ࠨུ༹͂ഐဥ͈षͅဥ̞̹ͣͦ௸ഽ̱֦̀͂ ෝخࢹ௮κΟσ͈֑̞̽̀͢ͅࠏൡഎ̈́ओ̲̞ͬ̀ͥ ෳੰ̳̹ͥ͛ͅȄૼ࡙ࠨ͈षͬͅޣג̦̜ͥȅ̷͈ ဥ̞̹ͣͦ௸ഽࢹ௮Ȫ 5.7ȫͬঀဥ̱̀ठ͍ৣ࿂͈ζΛ άϋΈ࣐̹ͬ̽ȅ൳̲௸ഽࢹ௮κΟσͬဥ̞̭ͥ͂̽͢ͅ ̥ږ߸ͬ۾ȄίτȜΠષ࿂͂ૼ࡙ື͈͂చഎպ౾̀ 5.8 ͅা̳ȅං̹ͣͦࠫͬض̧̭̦͛ͥ͂́ͥȅ̷͈ࠫ 1km ৣ࿂̦૬̩̞̈́̽̀ͥȅ̳͂ͥڛ 5.5 ͂ͬض ࣉၪ̱̀͜ȄίτȜΠષͬޣגષܱ 2 ͈̾ࡔ֦̦ݞ͖̳ ږ2.5km ͈ओ̦ంह̳̭͉ͥ͂±10 ͉ͅۼ࿂͂ૼ࡙ື͈ ൩̢̀͘έͻςάϋ٬ίτȜΠ͂ͬضḙ͈̜̥̏ࠫͥ́ ߸̞̾̀ͅ൦̳ͥȅ۾ૼ࡙ື͈͂ ࢚̯͉ 7km ͂ࡉୟ̞ͣͦ̀ͥ͜ 5.7 ૼ࡙ࠨͅঀဥ̯̹ͦ௸ഽࢹ௮Ȫ֚๔ऒȫȅಎఆ͕̥͈ڔ٬ဢ౷̳́ͅ ඤ͞ Ȫ1997ȫͤ֨͢ဥڔȪୌाȄ1997ȫȄ౷ૼ͉ೆ͙ࣺ͚٬ဢ౷̥̭ͣ͂ ൲ Fig. 5.7 Velocity structure used for hypocentral determinationڰ߃ཌྷ͉͕́͂ͭ̓อ̴̱̤̀ͣȄ̷͈ٮޏίτȜΠ .*ಎ͉٬ဢζϋΠσ͈ඤ໐̜̭̦̥́ͥ͂ͩͥȅ౷ ȪleftmostȫȪNakamura et al., 1997͈ ૼ͈ιΣΒθٜ͈ࡄݪ̥ͣ͜Ȅ৽ါ̈́౷ૼ͈ιΣΒ ၂̻ͥୃ౯߿̜́ͤȄίτȜͤڲཤ௰̦́ڙθٜ͉ࣞ ࡉͣͦͥΑρΑΠ߿౷ૼͬၔັ̫̱̱ͥࠫ͊͊ͅٮޏΠ ං̞̞ͣͦ̀̈́Ȫಎఆ͕̥Ȅ1997ȫȅ̹͘অ࣭໐͈͉ض ௸ഽࢹ௮͂ૼ࡙ືȪ 5.2ȫ̥ͣ͜ȄίτȜΠષ࿂͂ૼ
5.8 ૼ࡙ࠨͅঀဥ̯̹ͦ௸ഽࢹ௮ͬဥ̞̹ાࣣ͈ 1988 გ௶͈ৣ౯࿂ܮ . ඤಿعා გ௶͈ৣ౯࿂ͅ Fig. 5.8 Seismic section for the 1988 Kawachinagano-Kiwaܮ - ඤಿع 5.6 5.5 ́ 1988 ා ဥ̞̹౷ૼ͈ૼ࡙ࠨࢋओ profi le based on the same velocity structure used for the Fig. 5.6 Errors of the hypocenters shown in Fig. 5.5. hypocentral determination.
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൲ͅఱ̧ڰ͈ાࣣ͂൳အͅ 10km ͈ओ̦ంह ςάϋ٬ίτȜΠ͈٬ဢζϋΠσඤ౷ૼ͈௶ུ͉ͅۼ࡙ື͈ ဓ̱̞̀ͥ͂ࣉ̢̧̭̦ͥ͂́ͥȅ۾̩ ൲͈͕̦͂ͭ̓٬ဢζϋΠڰḙ̭̏́͜౷ૼ̞̱ͥ̀ ڔ໐౷ئఝോࡪٸ 5.1.2 ͕͉͂́ٮޏݞ͍ίτȜΠڔσඤͅࡠ̯ͦȄ٬ဢ౷ ͭ̓౷ૼ̦อ̱̞̞̀̈́ḙ͈̠̏̈́͢౷ૼ͈̭༷ܳͤ ȁ 4.13 ͉́૬̯ 20km ̥ͣ 25km ̥̫̀ͅໝତ͈ৣ࿂ ഽ́ཤͅ߹০̱̞̀ڙ͈ ̯ͦȄ̴̞ͦ͜ 10 ȡ 15°ږ̦ ͚ਔ༏֖͈έͻςάϋ٬܄չോͬܮȄঅ࣭໐̥͉ͣ ͈අಭ̺͂ࣉ̢ͣͦͥȅ ͥḙ͈̏ৣ࿂଼͈֦̞̾̀ͅࣉख़̳ͥḙ͈̏ౝऔ͈࣐ވίτȜΠ չോධ໐͉Ȅ͕̦͂ͭ̓অྔ႑ఝ̞̹͂̽ܮ̹ͦͩ ̞͉̀Ȅέͻςάϋ٬ίτȜΠ͈٬ဢζϋΠσඤ́ ఘ̽̀͢ͅࠁ଼̯̞ͦ̀ͥȅح౷ૼ͈ࡔ֦̞̾̀ͅࣉख़̳ͥȅSeno et alȪ. 2001ȫ ίτȜΠೆฺ͙ࣺ͙̠ͅັ̧̞ͥ̀ܳ Ȫunderplatingȫحೲັ̫ັ͂حఘࠁ଼͉ͅĘ͉̏৾ͤັحັ Ḙ͈̏ೆ͙ࣺ͚έͻςάϋ٬ίτȜΠඤ́อ̳ͥ٬͉ ίυΓΑ̦̜ͤȄMatsuda and IsozakiȪ1991ȫ͈̾ͅ 2 ͈͂ اဢζϋΠσඤ౷ૼ͉ζϋΠσ͈କ؊ฺ̠ͅୖ ίυΓᾼ̾حࡔ֦̜́ͥ͂մ̱̞̀ͥȅଳ͕̥Ȫ2000ȫͥ͂͢ͅȄ ̽̀͢ȄίτȜΠೆ͙ࣺ͙ఝ̤̫ͥͅັ̦ শͅୃ౯ ̞̀મ̱̩୰ྶ̯̞ͦ̀ͥȪ 5.10ȫḙ̏ͦͬ֨ဥ̱̀ೲ̹̞ٳࡔࡪͅ൚̹ͥঅ࣭٬ཷ̦ڦչ൨ . ୰ྶ̳ͥȅίτȜΠ͈ೆ͙ࣺ͙শͅ٬̞̀̾ͅحັ̫ັ ࠁ଼̯̹ͦ͂ࣉ̢ͣͦȄ̷̦ͦೆ̦܊৮ͅވอో͈͂ ̷͈͜ͅષ̜ͥͅဢఙୟ̦֚̈́̓͂͂ڔ͙ࣺ̞̹ͭ́ͥ͛ͅίτȜΠ͈٬ဢζϋΠσ̷͉͈ͅ ဢ౷ ૬໐́͘ో̳ͥ͂Ȅئକ ͅೆ͙ࣺ͚ḙ̷̦͈̏ͦ͘͘౷͉܊ෝ̦̜ͤȄ৮خంह̱̞̦̀ͥ܊͘͘৮ ́͘͜ȫ͉୨౯̯ͦȄ̷ڔ͛ͅȄକະհ̭̱̞ͬܳ̀ࣞգ ဢఙୟȪ̧͉͂ͅ٬ဢ౷̹̳ͥاୖ̳͂ͥ ૬ ͈୨̹̭͉ͦ͂ͧષ౯͂̈́ͤȄ୨̹ͦࢃ͈ͧ໐͉͉܊͜౷ૼ̦̭̠ܳͤͥ͂୰ྶ̱̞̀ͥȅ৮́ئႁ ષ̥༷ͣئஆࣺ͚ͤḙ̏ͦͬ߫ͤ༐̱̀ͅئ40-60km ͅ൚̳ͥգႁ͉́ 640-690Ɏ́କ̱ୖ ஜ͈໐͈ ̯ ȪUlmer and Trommsdorff, 1995ȫȅPeacock and Wang ༷ͅষș͂ັ̫௷̱̦̈́ͣΟνȜίτΛ·Αࢹ௮̦อో̳ͥا Ȫunderplatingȫ͂ࡤ͐ḙ͈̏حȪ1999ȫ̽̀͢ͅঅ࣭̥ؗͣೆ͙ࣺ͚έͻςάϋ٬ίτȜ ̱̞̩̀ḙ̏ͦͬೲັ̫ັ ͅبպ͈ષ౯͉Οσζ࿂͂̈́ͥḙ̷̏́ئഽື͉મ̱̩ࡄݪ̯̞ͦ̀ͥȪ 5.9ȫȅͣ͢ͅ ̧͂डأΠ͈ ဥ̦ैح૬̯ 25km ͈̭͂ͧ́͘ͅೲັ̫ັ͈ئչോܮ Ȅ͉ٮޏ̳ͥاୖ͈܊Ȅ૬̯ 40-60km ̤̞̀ͅ৮͂ͥ ·14km ͅպ౾̳ͥḙ͉̏ͦ 5.8 ͅ ൱̞̞̳̀ͥ͂ͥ̈́ͣ͊Ȅ̷͈૬̯́͘ΟνȜίτΛ ̷̤͢ئٮޏίτȜΠ ဥ͈डஜ̦Οσζ࿂͂̈́ͥैح൲͈ಎ͕͖͂ Αࢹ௮̦อో̱Ȅັڰ٬ဢζϋΠσඤ͈́౷ૼ̫̤ͥ ఘ଼̦ಿ̱̀حဥ̦̞̀ັैحέͻ ̜̠́ͧȅ̷͈͘͘ັ̦اକ؊ฺ̠ͅୖ܊౿̳ͥȅ̱̹̦̽̀৮֚ ဥ͈डஜ̦੭șͅ٬௰͒֊൲̧̱̞̀ȄैحȄັ̫̞͊ എͅ֊൲ࢃͅΟσζ࿂̦ॼ̭ͥ͂̈́ͥͅȅ̷͈ॼضࠫ ̯̹̥͈ͦ̾̀Οσζ࿂̦࡛ह͈ཤ߹০͈ৣ࿂̜́ չܮ̥ͣضෝ̦̜ͥȅུࡄݪ͂ୌाȪ1997ȫ͈ࠫخͥ ల 2 ́ڔോ̥ؗͣೆ͙ࣺ͚ίτȜΠષ࿂͉ͅ٬ဢ౷ ̜ͥ͂ࣉ̢̦ͣͦͥ૬̯ 33km ́͘ంह̱̤̀ͤȄ࡛ह ဥ̦ૺ࣐̱̞̀ैحັͅڔ໐౷ئ̀̽͢ͅح͜ೲັ̫ັ ൲͉ڰ଼غఝ͉ͅٸͅࣉ̢ͣͦͥȅ̹͘Ȅ̦̭͂ͥ ۹වͥ͢͞ͅ་଼ैဥ͈̈́܊଼غ̴͙ͣͦȄ͕̓ͭ͂ ٨་͉̺̜̫̞̞ͤ̀̈́͂͘͘ࣉ̢͈ͣڔ౷ͥ̓͢ͅ ܢࢹ௮ࠁ଼͈उ̦ͥ͢ͅحȅ̷͈̹͛ೲັ̫ັͥͦ
5.9 Peacock and WangȪ1999ȫ̽̀ࠗ͢ͅॳ ̯̹ͦঅ࣭ ఘ͈࿅౯࿂ȅMatsuda and IsozakiȪ1991ȫ̥حັ ഽࢹ௮ȅ 5.10أ̥ؗͣೆ͙ࣺ͚έͻςάϋ٬ίτȜΠ͈ Peacock and WangȪ1999ȫ̥ͣ֨ဥ ͣ֨ဥ Fig. 5.9 Thermal structure of the subducting Philippine Sea plate Fig. 5.10 Schematic section of accretionary prismȪ Matsuda and from off of Shikoku IslandȪ Peacock and Wang, 1999*. Isozaki, 1991*.
Ƚ!203 Ƚ ࡄݪਫ਼ࡄݪ༭࣬ȁల 68 ȁ2005 ා 9 ܿڠشཡब
ࣉ̢ͣͦͥḙ̜̏ͦ͂ͥͅٴ͈ܢ࡛ह́͘༗ం̯̞͈̜̠ͦ̀ͥ́ͧȅ ͦই̴̹̥͈̯͛͊ͤͦͅا ͈ΑΞȜΐ͈֑̞ͬນً̱̞̥̀ͥ͜اૺڔȄോࡪ͈ྶၸ̈́ ͉ോࡪ౷͉̥ͣض͈̫̤ࣽٝࠫͥͅئչോܮ ໐̤̫ͥͅໝତ͈ ̱̞ͦ̈́ȅئڔ̯̞ͦ̈́ȅ༷֚Ȅ౷ږMoho ࿂͉ ࣉख़̳ͥ͂Ȅߠ୬༹ٜଢ଼̱̽̀̀͢ͅ۾έͻςάϋ٬ίτȜΠષ࿂ Moho ࿂͈ͅئཤ߹০͈ৣ࿂͞Ȅ̷͈ ̯̹̭̥ͦ͂ͣḘ͈̏౷֖͈ Moho ࿂͉̭ Moho ࿂͈૬̯͉ 34km ͂ࡉୟ̹̦ͣͦ͜Ȅ̷͈૬̯͉ͅږৣ࿂̦͈ ̯͈ͦͥ͜ږ࿂̥ͣඏட௸ഽ̦ఱ̧̩ ࡠ̹ͣͦႀ֖́ 10km ಿ͕͈̓ৣ࿂̦ٮޏৣ࿂͈̠̜͈ͥͣͦ͢ͅ ࣉ̢ͣͦͥḙ͈̠̏͢ͅৣ࿂ ͈Ȅ௶ఘ̹̠ͩͥ̈́͢ͅႲഎ́ྶၸ̈́ৣ࿂͉̞͉͛͂̈́́ٮޏ̳ͥا་ ௸໐౷ ̞ͣͦ̈́ḙ͉̏ͦ Moho ࿂̦ߠ୬༹̽̀͢ͅݥ̹͛ͣͦئ̧̞́̈́ၑဇ̱͂̀Ȅ1ȫږMoho ࿂ͬ ͈̱̀͂ ͉́ٮޏഽࢹ௮̥ͣထே̯̠ͦͥ̈́͢ౙ̈́௸ഽະႲ ا͓̀ Moho ࿂͈́௸ഽ་͂ٮޏৣ࿂͞ίτȜΠ͈ڔ ζϋΠσ̥࢜ͅ ̞̹̜̈́͛́ͥ͂ࣉ̢ͣͦͥȅMooney and MeissnerȪ 1992ȫ̥ͣڔ໐౷ئ̯̞ાࣣȄ2ȫMoho ࿂̦̦ Moho ࿂͉Ⴒഎ͕́͂ͭ̓໙ͬ ͈ڔાࣣȄ ͥ͂͢ͅȄఱၘ౷̜ͥ́ۼ֊ߊ̠̩̞̱̈́̀͢ح੭șͅ௸ഽ̦௩̞ 3ȫMoho ࿂͈ࠁે̦ુܳͅ໖ͅີ̞ͭ́ͥાࣣ൝̦ࣉ̢ ̹̞̈́କ࿂͈̠͈͉̩̈́́̈́͢͜Ȅष͉ͅႲ͉ ͜ 3-5km ͈໙ͬ̽̀͜ٮޏȅ̱̥̱Ȅౝऔ͈௶̦ౣ̞̭̥͂ͣȄߠ୬༹ٜ ߊഎ̱̥ͅంह̵̴Ȅ̷͈ͥͦͣ ֊ષ໐ζϋΠσ́͘௸ഽ̦੭ș̥ͣͅڔ໐౷ئഽ͈ଔ͉̯ͦ̀ ̤ͤȄ௸͈ئଢ଼ͥ͢ͅ Moho ࿂͈૬̷̯͈͂ೄ ̧̞́̈́ၑဇͬඅ̳ ̱̞̀ͥࢹ௮̜͓̞́ͥ͂̀ͥȅBraile and ChangȪ 1986ȫږȄMoho ࿂̴̧̦͉̤̽ͤ͂ͣ ષ໐ζϋΠσ́͘௸ഽ̦̥ͣڔ໐౷ئඳ̱̞ȅ ͉ȄMoho ࿂͉͉̭͂ͥ ֊̜̱́ͥ͂Ȅ̷͈֊͉ถ̩̞̱̀حષߴ௶ ੭șͅ௩ . ޘා 1989 5.2 Ȇࣣၠ̳ͥࡽࢹܚ೩௸ഽ͂ࣞ௸ഽ͈̦࿌࿒ે̞ͅ ڔ໐౷ئඤఝോࡪ 5.2.1 ͼιȜΐ͉́Ȅ ௮̥ͣࢹ଼̯̞ͦ̀ͥκΟσ̱̹ͬȪ 5.11ȫȅ͈ͣڔ໐౷ئං̥ͣͦͥͣض 4.25 ͈ࠫ ఝȪrefl ective ͉ࢵ̭͈ͅκΟσ̥ͣၑა౷ૼܱયͬࠗॳ̱Ȅߠ୬༹ٜ̞ ޑ૬̯25-35km ̥̫̀ͅৣഎৗ͈ ̯ͦͥৣ࿂Ȫ͜ ଢ଼ͬဥ̞̹ાࣣ͉́ Moho ࿂͉Ⴒഎ̥̾ౙ̈́௸ഽະႲږzoneȫͬࠁ଼̱̞̀ͥȅ̷͈ఝ͈ಎͅ ৣఘȫ͉ତ km ȡତ 10km ͈෨ಿ̤ͬ̽̀ͤ͜Ȅ ࿂ͅࡉ̢̦ͥȄৣ༹ٜଢ଼ͬဥ̞̹ાࣣ͉́໙͈̜͉̩̱ͥ အș̈́ఱ̧̯͈ະৗ̦ంह̱̞̀ͥ͂ࣉ ֊ͅࡉ̢̞̠̭͈ͥ͂ͦ́͘ྭٜͬࠨ̱̹ḙ͈͉̏ͅڔ໐౷ئ ࡽࢹ௮͉Ȅ͕͖ೄවৣ̳ͥ෨ͅచ̱͉̀ࡽ̠̈́͢ ͈ئგ௶ܮ . ඤಿعఝ̜̹ͥͅ୶͈ٸȅ̢ͥͦͣ ̹͛ͤ৻̹̳̹͛ͤͥޑખ̽̀͢ͅ෨̫̤ͬۙͥͅۼ ږḘ͕̏ͦ̓ఉအ͈̜ͥະৗࢹ௮͉͉ͅڔ໐౷ئ အ͈֑̞̲̯ͬ ͛ͅߊഎͅື̳ͥৣ࿂͂̈́ͥȅ༷֚Ȅ৽ͅକ༷͈ڔ໐౷ئȪ 4.13ȫḙ͈̞̯̏̈́ͦ ࡔ֦̞̾̀ͅࣉ̢ͥȅ ࢜ͅૺ࣐̳ͥ෨ͬঀဥ̱̹ߠ୬༹ٜଢ଼͉ळ̥̞ೄ̵༷̞࢜ͥ̀ ൲͈ခྫ̜́ͤȄ ͈௸ഽະৗͅచ̱͉̀ຮ̞̹ۜ́̈́͛Ȅౙ̈́௸ഽະڰ଼غఝ͈͂ఱ̧֑̞͉̈́ٸඤఝ͂ ȅ̢ͥͦͣ௴̱̀͂ٮޏ໐ Ⴒئ൲̦ࢩ̩͛ͣͦͥȅڰ଼غ͈̥ͣܮඤఝ͉́ฒՏ ۹ව͈͢ͅ܊଼غrefl ective ͂̈́ͥါ֦̱͉͂̀Ȅ ̦ڔ౷ ఘȪsillȫȄ་଼ैဥ̲̽̀ͥ͢ͅळ̥̞Α܊โે۹වͥ ৗ͈֑̞ͥ͢ͅ܊ΉȜσ͈ࢹ௮ȄζͼυͼΠ͈ంहȄ ࢹ௮̦̜̈́̓ͤȄ๊֚എ଼͉̭͈֦̦ͦͣͅໝࣣ̱̀ ̲̞̭̦̀ͥ͂ఉ̞ȪMooney and Meissner, 1992ȫȅඤఝ ̯̞̭̥ͦ̀ͥ͂ͣḘ͈̏ͦͣࡔ֦ږ൲̦ڰ଼غ͉́ ൲ฺ̠ͅഎ་ڰ଼غ۹ව͈͂܊଼غಎ̫͈́͂ͤͩ͜ ڔ໐౷ئဥ̦ਹါ̈́ࡎͬ՜̞̽̀ͥ͂ࣉ̢ͣͦͥȅै଼ എ̈́ৗ̹ͬ̾͛͜ȄίτȜΠ൲֦̳ܳͥ͢ͅװ͉ ၠȪductile fl owȫ̲ͬͥȅ̷װ͉́ئࢹ௮؊ႁ͈̠̈́ ถȪlaminateȫͅڔ໐౷ئၠฺ̠ͅᆾ౯؊ႁͤ͢ͅװ͈ غࢹ௮ͬࠁ଼̱̀Ȅକͅ߃̞୯ၑ࿂̦อో̱̞̩̀ȅ ۹ව̱̩̀̀̽״Ḙ͈̏୯ၑ࿂̦ͅ܊଼غ൲ͥ͢ͅڰ଼ ഽ௸̞ޑ̞̤̀ͅڔ໐౷ئsill ͬࠁ଼̱Ȅ ̭̀̽͂ͥ͢ͅ ܊଼غϋΠρΑΠͬࠁ଼̱̞̀ͥ͂ࣉ̢ͣͦͥȅࢵͅ ۹ව̷ฺ̞͈ͅਔս͉́എ་଼ैဥ̦൱̧Ȅ̯͈ͣͅ 5.11 Braile and ChangȪ1986ȫ̯̹̽̀ͦ͢ͅ Moho ڔ໐౷ئະৗ̦อో̳̜̠ͥ́ͧḙً͈̏ͤ͢ͅ ෝ̦̜ͥḙ͈̏୰ ֊κΟσȅ֊͉ถ̞೩௸ഽ͂ࣞ௸ഽ͈̦خ̹̞̩̽̀̽̈́ޑৣഎৗ̦͈ Ȇࣣၠ̳ͥࡽࢹ௮̥ͣࢹ଼̯̞ͦ̀ܚৣഎৗ̦ ࿌࿒ે͈ͅڔ໐౷ئఝ͈ٸȄ̳̞̱͊ͣ̈́ͥ͂ୃ̦ ȅͥ ڔ൲ͥ͢ͅ౷ڰ଼غࡔ֦͉Ȅඤఝ͕̞̩̓̈́ޑ̷͕̓ͦ .*٨་ͬࠐࡑ̱̞̞̹̺̀̈́͛͂ࣉ̢ͣͦͥȅ̾ͤ͘ඤ Fig. 5.11 Moho transition zone modelȪBraile and Chang, 1986͈ ,ະৗ̦อో̱̀ The transition zone consists of random, thick-variable͈ڔ໐౷ئ൲̽̀͢ͅڰ଼غఝ͉́ .ࠁ଼̯ high- and low-velocity lamellae̦ڔဥͤ͢ͅ૧̱̞౷ैحఝ͉́ັٸȄ༷̞֚ͥ
Ƚ!204 Ƚ ࢹ௮ζΛάϋΈȽ໌നڔ૬໐౷̩̿ܖ૧̱̞८၄ਹ༹ࣣͅ
̯ͦͥȅ̱̥̱Ȅ૬̯ږ͈ Moho ࿂̞̾̀͜ͅ൳အͅȄߠ୬༹͂ৣ༹ٜ ৣ࢘ၚ͈̞ࣞ S ෨ৣ෨߲̦௶ུ ଢ଼ٜͥ͢ͅ৷͈֑̞̦̜ͤȄMoho ࿂̦ࡽࢹ௮̥ͣ̈́ͥ 50km ̥ͣൢో̱̹ S ෨ৣ෨͈૦໙͉ P ෨͈͈ͤ͜͢ྶ ڔ໐౷ئෝ̦̜ͥȅMoho ࿂̦ ̥ͣͅఱ̧̞ȅষͅȄ૬̯ 50km ̥͈ͣৣ෨͂خ֊̽̀͢ͅࢹ଼̯̞ͦ̀ͥ ৣ෨͈͂૦໙͈ͬ P ෨ৣ෨͂ S ෨ৣ෨͈̥ͣͅ ڰ଼غ֊̽̀͢ͅࢹ଼̯̞̭͉ͦ̀ͥ͂Ȅ̠͈̭̈́͢ ͚෨߲ಎ͈डఱ܄ৣ෨͉ͬͅڛζϋΠσ͈͂ ̤̞̀ࡉୟ̹̽͜ȅ͂ڔ໐౷ئ൲̥ͣ୰ྶ̧̳̭̦ͥ͂́ͥȅ ȄS ෨ৣ෨͈૦໙͈༷̦Ȅض۹ව̽̀͢ͅ sill ̧̦́ ૦໙ͬঀဥ̱̹ȅ̷͈ࠫ܊଼غ൲̦̜ͥ͂Ȅڰ଼غͅٮޏ ໐౷ P ෨ৣ෨͈૦໙ͤ͢ 1.2-3.0 ఱ̧̞̭̦̥̹͂ͩ̽ȅئະৗ̈́ࢹ௮ͬࠁ଼̳ͥȅࢩ֖എ̈́؊ႁાͥ͢ͅ ඤ͉́ Vp/Vs ̦͕̜̳֚͂ͭ̓́ͥ͂ͥ͂Ȅڔ໐౷ئ ၠ̷͈̽̀͢ͅະৗࢹ௮̦କ̧༷࢜֨ͅװ͈ڔ S ෨͈௸ഽ͈೩̞ৗȄ̾ͤ͘࡞̞ ͅئȄକͅ߃̞ถ̞̥ͣ̈́ͥࡽ͈ ̭͉ͦৣ࿂͈̭̯ͤ͂ͥͦ͊͢ͅ ະৗࢹ௮̦ࠁ଼̯ͦͥ͂ࣉ̢ͣͦͥȅषȄඤఝ͉́ ̢۟ͥ͂εͺΕϋ͈̞ࣞৗ͈ంहͬփྙ̳ͥḙ͈̏ ၠఘ͈ంह̳ͬͥȅొ̱ȄΦͼΒͤ͢ͅ௶͉ض̯̞̭̥ͦ̀ͥ͂ͣȄ ࠫږ൲̦ڰ଼غอ̈́ڰ͈̥ͣܮฒՏ Moho ࿂͜ถ̞̥ͣ̈́ͥࡽ ̱̹૦໙̧͈̦͊ͣ̾ఱ̧̥̹̹̽͛ȄεͺΕϋ͈ ͈ئٜ৷ུ̱͂̀௶͈֚̾ ෝ̦ࣉ̢ͣͦͥȅخࢹ௮̱̹ͬ֊̞͂̈́̽̀ͥ ૬̯ 50km ͈ৣ࿂͈ئ෪ཤ໐ 5.2.2 ૬̯̤͉͢ͅئ෪ཤ໐͈౷̥ͣضං̹ͣͦࠫ ̧̳̭̦ͥ͂́ͥږ50km ̧͉̽ͤ͂ͅৣ࿂ͬ ̷ ဓ͓̹ͬȅၠ۾Ȫ 4.25ȫḙ̴͈̏͘ৣ࿂͈́ၠఘ͈ ৣ࿂̱̀ڛఘ̦ంह̳̞̠̭͉ͥ͂͂ȄP ෨͈ાࣣ͂ ̤̫ͥͅ S ෨͈ৣ߸ତ̴͉̞͉̜ࣞ́ͥḙ̷̏́ S-1 ͈ ڛτȜΡΓ·Ώοϋ̤̫ͥͅ P ෨͂ S ෨͈ৣ෨ͬ ̳̹ͥ͛ͅȄ௸ഽ 6km/sec ́ reduce ̱̹͈͜Ȫ 5.12Ȫaȫȫ ͂௸ഽ 3.46km/sec ́ reduce ̱̹͈͜Ȫ 5.12Ȫbȫȫ̵ͬ 5.12Ȫbȫ̧͉̠́ͥ́͢ͅڛা̳ȅ̹͘Ȅယօ̀ͅ ਸͬ 1/1.73 ͅੀ̱̞̀ͥḙ͈̏ 2 ͈̾τȜΡΓ· Ώοϋ̥ͣȄP ෨͈ৣ෨߲͈ΩΗȜῧ̩͢႒য̱̹
ષߴ௶͈۷௶෨ࠁȪS-1ȫȅȪaȫ 3-8Hz . ޘ 5.12 1989 ා ͈ ΨϋΡΩΑέͻσΗȜͬঀဥ̱Ȅ6km/sec ́ ၠΟȜΗ͈ືȪષȫȅڔ౷༷̤̫ͥͅ౷ܪreduce ̱̞̀ͥȅȪbȫ S ෨ৣ෨ͅಕ࿒̳̹ͥ͛ͅȄ 5.13 ߃ ౯̳ͥ؍2-5Hz ͈ΨϋΡΩΑέͻσΗȜͬঀဥ̱Ȅ3.46km/ ಎ͈ಿ༷ࠁ͈ΟȜΗͬঀဥ̱̀Ȅോࡪͬ .ȫȅFurukawa et alئsec ́ reduce ̱̞̀ͥȅ ༷࢜ͅ୨̹̽౯࿂͈́ၠၾȪ Fig. 5.12 Record sectionsȪ S-1ȫ of the 1989 Fujihashi-Kamigori Ȫ1998ȫͤ֨͢ဥ profile usingȪaȫ a bandpass filter of 3-8Hz and a Fig. 5.13 Ȫupperȫ Distribution of heat fl ow data. The contour lines reduction velocity of 6km/sec, andȪ bȫa bandpass fi lter show estimated heat flow.Ȫlowerȫ Heat flow profile of 2-5Hz and a reduction velocity of 3.46km/sec to in the cross-arc direction using heat fl ow data from the clarify the S-wave refl ections. rectangle in the upper fi gureȪFurukawa et al., 1998*.
Ƚ!205 Ƚ ࡄݪਫ਼ࡄݪ༭࣬ȁల 68 ȁ2005 ා 9 ܿڠشཡब
ͬଔ̧̳̭͉̥̹ͥ͂́̈́̽ȅ et al.Ȫ1993ȫ͈έͻςάϋ٬ίτȜΠ͈൲༷͈࢜ૂ༭ ொ̱ٸఘ͈ ̥ͣȄૼ࡙ື͈൝૬ഽެͬ෪ਔ༏́͘ͅ܊̠̭ـ͈ܢܮȡࡣల२ܮ෪ਔ༏͉́ฒՏ ொ̯̹ͦૼ࡙ື͈૬̯͉ٸȄض൲̦େ̜̹ͭ́̽ ̹Ȫ 5.14ȫȅ̷͈ࠫڰ଼غ̯̤ͦ̀ͤȄ൚শ͉ږ۹ව̦ ೆ͙ࣺ͉́ئչോܮȄ࡛ह͜૬໐ͅఱܰ࿅̈́ισΠ̦ంह̱̞̀ͥ 70km ̹͂̈́̽ȅ5.1.1 ̤̞ࣜ̀ͅȄ̥̭ͣ͂ ൲͈ڰࣉ̢ͣͦͥȅ̱̥̱̦̈́ͣၠၾ͈ࡄݪȪFurukawa ͚ίτȜΠષ࿂͂٬ဢζϋΠσඤ͈́౷ૼ̦̭͂ ૬ഽओ̷͉̤͢ 14km ഽ̜̹́̽ȅ̱͜Ȅ͈ۼet al., 1998ȫ̥ͣȄ෪ਔ༏͈ၠၾ͉ 60-70mW/m2 ́ ಎ͈͂ ίτȜΠ͜ͅ൳အͅίτȜΠ͂ૼ࡙ື͈́ئ५έυϋΠ̺͂এͩͦͥࣞၠ ෪ਔغȄ̷ͦͤ͢ཤ໐͈̜ͤ ͜ຈ̴̱̩͉̞ࣞ̈́͜Ȫ 5.13ȫȅ̽͢ ͈͂ࠏൡओ̦̜̳ͥ͂ͥ̈́ͣ͊Ḙ̷͈̏́έͻςάϋ٬̱̀ڛၾ͈౷֖͂ ισΠͬୟ ίτȜΠષ࿂͈૬̯͉ 55km ͂̈́ͥḙ͈̏έͻςάϋ٬͈ئḘ͈̏ၠၾ͈ΟȜΗ̥͉ͣȄ෪̀ ̯͉ఱږഎͅাऐ̳ͥબݶ͉̩̈́Ȅৣ࿂͈֦̦ܳισΠ̜́ ίτȜΠ͈૬̯͈ࡉୟ͉ͤ͜ఱ̥̜́ͤ͘ະޭ ෝ͉೩̞͂ࣉ̢ͣͦͥȅ ̧̞̦Ḙ͉̏ͦৣ࿂͈૬̯̜́ͥ 50km ̩֚͂͢౿̳ͥȅخͥ ۷ത̥ͣȄ૬̯ 50km ͈ৣ࿂͈ࡔ֦̞̾̀ͅ ȁισΠ͈ఈͅεͺΕϋ͈̞ࣞৗ̱͉͂̀Ȅକ̦ࣉ̹֑̽ ࣉ̢ͥȅέͻςάϋ٬ίτȜΠ͉ୌධུͅచ̱̀ୌධ ̢ͣͦͥȅSeno et al.Ȫ2001ȫ̦৽ಫ̳̠ͥ͢ͅέͻςάϋ ٬ίτȜΠ͈Αρήඤ̭́ܳͥ٬ဢζϋΠσඤ౷ૼ͈ ࢜ͅ௸ഽ 4cm/year ́ૺ̤ͭ́ͤȪSeno et al., 1993ȫḘ༷̏ କະհ͈̺̳ͥ͂ͥ͂͢͜ͅȄ̷͈͈܊౷֖͈૬໐͉ͅչସს༷࿂ͤ͢ೆ͙ࣺ̞ͭ́ͥέͻς ࡔ֦̦৮͈ άϋ٬ίτȜΠ̦ంह̱̞̀ͥ͂ࣉ̢ͣͦͥḙ̏ͦ́͘Ȅ କ؊ฺ̠ͅକ̦ంह̴̱̞͉̜̀ͥ́ͥȅ̱̭͈͜ ુ۷௶̽̀͢ͅݥ̹͛ͣͦૼ࡙ື̥ͣȄೆ͙ࣺͭ́ କ̦չସს༷̥࢜ͣೆ͙ࣺ͚έͻςάϋ٬ίτȜΠ͈ષ έͻςάϋ٬ίτȜΠ͈૬̯ͬଔ̳ͥࡄݪ̦̭ͦ ࿂ͅ֊൲̱̹͂ࣉ̢ͥ͂Ȅ૬̯ 50km ͈ৣ࿂͉ίτȜΠ̞ͥ ෝ̦̜ͥȅخ̢̞ͥ̀௴́͘ତఉ̩̯̞̈́ͦ̀ͥȪ႕̢͊ Watanabe et al., 1990Ȉ, ષ࿂ͅ֊൲̧̱̹̀କͬ ౷ૼ۷͈ڠಎఆ͕̥ 1997ȫȅಎఆ͕̥Ȫ1997ȫ͉Ȅఱ อ̱̹ 13 ྔࡢ͜ 6. ͂͛́͘ۼ࿌̽̀͢ͅ 1985-1994 ා͈ 10 ා௶ ະৗ͞ Moho ࿂͈ڔ໐౷ئ͈ڔૼ࡙ΟȜΗͬାၑ̱Ȅ̷ͦͬ͂͜ͅૼ࡙ື͈൝૬ഽ ȁུࡄݪ͉́Ȅോࡪ౷͈ ৣ༹ڙഽ ͈අಭͬྶ̥̳̹ͣͥ͛ͅͅȄോࡪ̤̫ͥͅࢩڙͬै଼̱̹Ȫ 5.14ȫȅ̷͈൝૬ഽެ͈߹০ެ อ̱̹ȅਲٳೆ͙ࣺ͚έͻςάϋ٬ίτȜΠ͈ࠁે ΟȜῌഐဥ̧́ͥ૧̱̞ζΛάϋΈ༹ͬͅئୌධུͤ͢ ݥ̞̦͛ͣͦ̀ͥȄ෪ਔ༏͉́૬̯ 50km ಼̢ͬͥ ြ͈८၄ਹ༹ࣣ͉́Ȅ८၄෨൝শެષఘͅ૦໙̦ͬ ૬̞౷ૼ̦̞̹̈́͛ͅέͻςάϋ٬ίτȜΠ͈պ ૦̫̞̹̦ͤ̀Ȅུ༹͉́Ȅ૦໙ͬ૦̫ͤͥष̠̈́͢ͅ ତ͂ control factor ͬ൵ව̱Ȅশެષ͈૦໙͈૦۾ίτȜ ਹ͙͈ئ౾͈ଔ͉̯̞̞ͦ̀̈́ḙ̷̏́Ȅ෪ਔ༏ ̱ȄSeno ̫ͤͬ୯̧̠̱̹́ͥ͢ͅȅ̹͘Ȅcontrol factor ͈بಿ̜́ͥ͂װΠ͉չସს̥͈ͣೆ͙ࣺ͙͈ ͬ་̢̭ͥ͂ͤ͢ͅȄ८၄ਹ༹ࣣ͂ CMP ਹ༹ࣣͥ͢ͅੜ ෝ̱̹ͅȅخ൚̹ͥੜၑͬͅۼၑ̺̫̩́̈́Ȅၰ༹͈ಎ ੜၑ͉́Ȅၰ༷͈၌തͬ࠳̢͇̹ζΛ̹̜ͥͅۼಎ͈̭ ෝ̜́ͥȅخάϋΈ̦ ৣ༹ౝऔ͈ॽအ̵ࣣ̹ͩͅ synthetic ෨ࠁΟȜΗڙȁࢩ ͓Ȅͬޣגဥ̞̹ΞΑΠ͉́Ȅ̴͘ΑΠτΛΙϋΈ͈ͬ ΑΠτΛΙϋΈ 190% ͈ષࡠͬ୭̫̭ͥ͂́Ȅఱ̧̩ ̢ͥဲͬا̯͊ͦ̀ე̺ͭ෨ࠁͥ͢ͅͼιȜΐႦ̧֨ ̱̹ȅষͅခࡠओ༹̤̫ͥͅږ̧̭̦̭ͬ͂ͥ́͂ ͬޣג८၄෨শા͈ࠗॳ́อ̳ͥΰΛΡ;ͿȜή͈ ̱Ȅഐ୨̈́ΑΠτΛΙϋΈ͈ષࡠͬ୭̱Ȅఱ̧̞ږ control factor ͈ͬঀဥ̳̭ͥ͂ͤ͢ͅḘ͈̏࿚ఴͬٝ ̧̭̦̥̹́ͥ͂ͩ̽ȅΦͼΒ͈̞̈́ synthetic ෨ࠁΟȜ ͛ͥΞΑΠ͉́Ȅ̥ږͬض౷ૼȪ1984 ȡ 1994 ාȫ͈ Ηͬဥ̞̹ control factor ͈࢘ئڔ 5.14 ୌධུ̤̫ͥͅ౷ Ḙ̵̯̏ͤ͂ͥ͢ͅا൲̦ control factor ͈ͬ 1 ̥ͣ 320 ́͘་ڰ൝૬ഽެȪಎఆ͕̥Ȅ1997ȫȅஜ͉౷ૼ ږအঊ̳ͬͥاা̳ȅఊ̞͉ȄSeno et al.Ȫ 1993ȫ ८၄ਹ༹ࣣੜၑ̥ͣ CMP ਹ༹ࣣੜၑͅ་ͬٮޏક̳ͥ ੜၑ͉́Ȅ८၄ਹ༹ࣣ͙ͣͦͥͅΌȜ͈ۼݥ̹͛ͣͦέͻςάϋ٬ίτȜΠ͈ૺ࣐ ̱̹ȅ̷͈ಎ̀̽͢ͅ ౷ૼ͈૬ഽͬা̳ȅ ΑΠͬࠚࡘ̳ͥੜၑ͞ݙͅ CMP ਹ༹ࣣͅζͼΈτȜΏοئڔொ̯ͦͥ౷ٸ̥༷࢜ͣ ੜၑ࡛̱̤ͬ̀ͤȄၰ༹͈අಭ̦ဏ̳ͥحͬضFig. 5.14 Depth contours of the subcrustal earthquakes ϋ࢘ ͉ ෝ̜̭́ͥ͂া̱̞̀ͥȅcontrol factorخȪ1984~1994ȫin southwestern JapanȪNakamura et al., ࣣ̱̹ੜၑ̦ ८၄ਹ༹ࣣͥ͢ͅࡪે͈ΌȜ͞ضThe solid triangles indicate the leading edge ζͼΈτȜΏοϋ࢘ .*1997 where the seismicity disappears. The solid line indicates ΑΠȄ̤͍͢ৣ࿂͈Ⴒ̈́̓ͬࣉၪ̱̀Ȅ࡛എͅ the depths of the subcrustal earthquakes extrapolated डഐ఼̳̈́ͬͥຈါ̦̜ͥȅΦͼΒ̦̜ͥ synthetic along the plate motion as shown by Seno et al.Ȫ 1993*. ෨ࠁΟȜΗͬဥ̞̹ΞΑΠ͉́Ȅcontrol factor ͈୯͢ͅ
Ƚ!206 Ƚ ࢹ௮ζΛάϋΈȽ໌നڔ૬໐౷̩̿ܖ૧̱̞८၄ਹ༹ࣣͅ
ͤȄྶၸ̈́ৣ࿂͈ͼιȜΐͬ௴̢̧̭̦̹ͥ͂́ḙ̏ ৫ৃ ͉ͅȄུࡄݪ̞̾ͅޗढܲॄ܊౷ૼࡄݪਫ਼͈ڠఱނȁ ̳ͥܞΦͼΒ͈ఱ̧̞ા༹ࣣ̭͈̦́࢘͜ႁͬอ͉ͦ չܮ͉ͅޗ֔ຮጵ͈ڠা̱̞̀ͥȅ ̮̀ঐ൵ೀ̧̱̹͘ȅུఱ̭ͬ͂ ౷ૼࡄڠఱނιϋΠͬȄ̳ͥ۾ࢹ௮ͅڔ౷͈ئৣ༹ΟȜ ോڙ༹ͬषͅോࡪ́۷௶̯̹ͦ 2 ႕͈ࢩུ ੩࡞ͬȄ̳ͥ۾എٜ৷ͅڠ͉ͅ౷ৗޗῌഐဥ̱̹ȅ̷͈ष͉ͅ൲උ͙৾ͤশ̥ͣͼϋΨȜ ݪਫ਼͈ऎႴ ౷༷̤̫ͥͅܪ͉ͅ߃ޗཡबࡄݪਫ਼͈չࠩڠസఱނ ΐοϋ̽̀͢ͅݥ̹͛ှ͈̞ࣞ௸ഽࢹ௮ͬဥ̞̀ ੩࡞ͬೀ̧̱̹͘ȅ̤̈́Ȅ1988 ා̳ͥ۾ζΛάϋΈ࣐̹ͬ̽ȅུ༹ഐဥͤ͢ͅȄ८၄ਹ༹ࣣ͞ Moho ࿂͈ࡄݪͅ ષߴ௶̤̫ͥͅ . ޘგ௶ݞ͍ 1989 ාܮ . ඤಿع ৣ࿂͈ئCMP ਹ༹ࣣ͉́௴̢̧̭͈̥̹ͥ͂́̈́̽౷ ৣ༹ΟȜΗ͉บ෫౷ૼ൲ࡄݪΈσȜί̥ͣȄ̹͘ڙৣഎৗͬೕ̧͚̭̦͂́Ȅष ࢩ͈ڔ໐౷ئࠁે͈͞ ౷ૼࡄڠఱނ൲͈ૼ࡙ື͉ڰչോ̤̫ͥͅ౷ૼܮ ΟȜΉུ༹͈͜ခ͉࢘બ̯̹ͦȅ௶۷͈ ೀ̧̱̹͘ȅ̱̀ރ་൲۷௶ΓϋΗȜ̥ͣڔչ ݪਫ਼౷ૼ౷ܮȄ͉́ئგ௶ܮ . ඤಿعȄ̥ͣضං̹ͣͦࠫ ཤୌ༷࢜ͅೆ͙ࣺ͚έͻςάϋ٬ίτȜΠͬ௴̢Ȅ ̭̭ܱ̱̀ۜͅ৫͈փͬນ̱̳͘ȅͅئോ ఱ̧̩̈́̽͂͒ °30 ̥ͣ °20 ̦ڙ૬̯ 30km ́߹০̷̤͢ ̞̭̦̥̹̀ͥ͂ͩ̽ȅ̹͘ίτȜΠષ࿂͂ૼ࡙ື͈͂ ४ࣉࡃ ,൲͈͕͂ͭ 1ȫAllmendinger, R., Farmer, H., Hauser, E., Sharp, J., Tishڰୈྟ̈́చպ౾ͬࡉୟ̭ͥ͂ͤ͜͢ͅȄ౷ૼ ٬ဢζϋΠσඤ̧̞̭̦́ܳ̀ͥ͂ྶ̥ͣ͂̈́̽ D. V., Oliver, J., and Kaufman, S.Ȫ 1986ȫ: Phanerozoic͉̓ ߸ tectonics of the Basin and Range-Colorado Plateau۾ഽ͈͂أ൲͈ಎ͂ίτȜΠ͈ڰȅ̷͈ࡔ֦͉౷ૼ̹ .Ȅ٬ဢζϋΠσ͈କ؊ฺ̠ͅକະհ̽͢ͅ transition from COCORP data and geologic data: a review̥ͣ ໝତ͈ཤ߹০ in Reflection Seismology: The Continental Crust, edited͉ͅڔ໐౷ئෝ̦̞ࣞȅخ̧̞ͥ̀ܳ̀ ,̯̹ͦḙ଼͈֦͉̏Ȅέͻςάϋ٬ίτȜ by Barazangi, M. and Brown, L. D., Am. Geophys. Unionږৣ࿂̦͈ .ဥ̽̀͢ͅࠁ଼̯̹ͦ Geodyn. Ser. 14, 257-267ैحΠ͈ೆฺ͙ࣺ͙̠ͅೲັ̫ັ ݲ͈Οσζ࿂ͬ௴̢̞͈̥̱̞̀ͥͦ̈́͜ȅ 2ȫAndo, M.Ȫ 1975ȫ: Source Mechanisms and Tectonicً Ḙ͈̏ Significance of Historical Earthquakes along the Nankai̥ͣضߴ௶͈ΟȜΗ̥ͣං̹ͣͦࠫئ . ޘ .გ௶͈ Trough, Japan. Tectonophysics, 27, 119-140ܮ . ඤಿعఝ̤̫ͥͅٸ͉ڔ໐౷ئ͈ئ௶ Ȅ૬̯ 25-35km ͅ෨ಿ̱ͅ 3ȫบ෫౷ૼ൲ࡄݪΈσȜίȪ1985ȫȇಿࡇ̤͍͢ਔ༏̩ޑະৗ̦ͤ͢ڔ໐౷ئ ͚ refl ective zone ͬࠁ଼̱ ౷֖̤̫ͥͅบ෫౷ૼ൲͈۷௶ȅ౷ૼࡄݪਫ਼Ꮓ༭Ȅ܄ତ km- ତ 10km ͈ৣ࿂ͬ̀ ̞̭̦̥̹̀ͥ͂ͩ̽ḙ͉̏ͦඤఝ̤̫ͥͅฒՏܮ̥ͣ 60, 615-637. չോ̤̫ͥͅܮ٨་̫̹̹̺ͬ͛͂ࣉ̢ 4ȫบ෫౷ૼ൲ࡄݪΈσȜίȪ1992ȫȇ͈ڔ൲̽̀͢ͅȄ౷ڰ଼غ͈ გ௶ȫȅ౷ૼࡄݪܮඤಿȽع͈ บ෫౷ૼ൲͈۷௶Ȫًاૺڔḙ͈̠̏̈́͢ະৗ͈ओ͉ോࡪ౷ͥͦͣ .ΑΞȜΐ͈֑̞ͬນ̱̞͈̥̱̞̀ͥͦ̈́͜ȅ ਫ਼Ꮓ༭Ȅ67, 303-323 ౷༷ͅܪMoho ࿂͉Ȅߠ୬༹ٜଢ଼̽̀͢ͅଔ̯ͦͥ૬̯͉ͅྶ 5ȫบ෫౷ૼ൲ࡄݪΈσȜίȪ1995ȫȇಎ໐Ȇ߃ ௶Ƚષߴޘࢹ௮औȪڔ̴̯ͦȄ֚໐ႀ֖ͅ 10km ಿ͈ৣ࿂̦ ̤̫ͥ૽ࢥ౷ૼͥ͢ͅ౷ږၸ̈́ৣ࿂͉ .ంह̳̺̫̜ͥ́ͥȅ̾ͤ͘ Moho ࿂͉Ⴒ̳ͥౙ̈́௸ ȫȅ౷ૼࡄݪਫ਼Ꮓ༭Ȅ70, 9-31 ౯૽؍ȄBraile and ChangȪ 1986ȫ͈̳ 6ȫบ෫౷ૼ൲ࡄݪΈσȜίȪ1999ȫȇཤུࡪ̩͉̈́́ٮޏഽະႲ ,ઽ௶ȫȅ౷ૼࡄݪਫ਼Ꮓ༭Ȅ74܊ȽۀȆࣣၠ̳ͥࡽ ࢥ౷ૼౝऔȪܚถ̞೩௸ഽ͂ࣞ௸ഽ͈̦࿌࿒ેͥͅ .ෝ̦̜ͥḙ͈̏ 63-122خ̜ͥ́ٮޏ̞̱ͥ̀֊ࢹ௮́ ၠ̽̀͢ͅࠁ଼ 7ȫBraile, L. and Chang, C. S.Ȫ 1986ȫ: The continentalװ൲͂ڰ଼غ̱͈͂̀ Moho ࿂͉Ȅ֊ ৣ Mohorovicic discontinuity; Results from near-vertical̞ޑͅ 50km ئ୰ྶ̧́ͥȅ෪ཤ໐͈౷̹̯͂ͦ ̯ͦȄS ෨͂ P ෨͈ৣ෨૦໙̥ͣȄ̷͈ৣ and wide-angle seismic refraction studies. in Reflectionږ࿂̦ ࿂͉ͅεͺΕϋ͈̞ࣞৗ̦̜ͥ͂ଔ̯ͦͥȅၠ Seismology: A gloval perspective, edited by Barazangi, M. ,ෝ͉೩̩Ȅ and Brown, L. D., Am. Geophys. Union, Geodyn. Ser. 13خၾ͈ΟȜΗ̥ͣȄ̷͈ৗ͉ισΠ̜́ͥ .ζϋΠσକ؊̽̀͢ͅอ̱̹କ̦չସს༷̥࢜ͣ 257-272 ೆ͙ࣺ͚έͻςάϋ٬ίτȜΠ͈ષ࿂ͅ֊൲̧̱̹̀͜ 8ȫBrown, L. D.Ȫ1991ȫ : A new map of crustal ‘terranes' in ෝ̦̜ͥȅ the United States from COCORP deep seismic reflectionخ̢̞ͥ̀௴͈ͬ .എȹͅ௴̢Ȅ૬໐ profi ling. Geophys. J. Int., 105, 3-13ژȸণͬڔ༹ഐဥͤ͢ͅോࡪ౷ུ ਹါ̈́ࡉͬං̧̭̦̹ͥ͂́ȅ̯ͣͅఈ 9ȫChang, W. F., McMechan, G. A., and Keller, G. R.Ȫ 1989ȫ̳ͥ۾ࢹ௮ͅ ৣ༹ΟȜΗ͈͒ഐဥ̽̀͢ͅȄࢩํսͅ : Wave Field Processing of Data From a Large-Apertureڙ౷֖͈ࢩ͈ .Seismic Experiment in Southwestern Oklahoma. J ͈ڔෝ̱ͅȄോࡪ౷خͼιȜΐϋΈ͈ͬڔോࡪ౷̹ͥͩ .Geophys. Res., 94, 1803-1816 ރࠁ̷଼̥͈ͣอో́ͬ͘ၑٜ̳ͥષ́ਹါ̈́ૂ༭ͬ ̧́ͥ͂ࣉ̢ͥȅ 10ȫ౷ৗऔਫ਼Ȫ1995ȫȇ100 ྔ͈ 1 ུ౷ৗల 3 ๅ CD-ROM ๅ ତ౷ G-1:ȅ౷ৗऔਫ਼Ȫ༎ȫȅ 11ȫCook, F. A., Varsek, J. L., Clowes, R. M., Kanasewich, E.
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R., Spencer, C. S., Parrish, R. R., Brown, R. L., Carr, S. ߄ന࣐݅ȆչࠩȆୌനၻȆ࿐ఆઍ२Ȇ֔࿊Ȫ2002ȫ ݞ͍डષ໐ζϋΠσ͈౷ڔD., Johnson, B. J., and Price, R. A.Ȫ 1992ȫ : Lithoprobe ȇঅ࣭໐౷֖̤̫ͥͅ౷ crustal reflection cross section of the southern Canadian ૼ෨௸ഽࢹ௮͂ೆ͙ࣺ͚έͻςάϋ٬ίτȜΠ͈ࠁ Cordellera, 1, Foreland thrust and fold belt to Fraser river ેȅ౷ૼȄ54-4Ȅ489-505ȅ fault. Tectonics, 11, 12-35. 23ȫMatsuda, T. and Isozaki, Y.Ȫ 1991ȫ: Well-Documented 12ȫFurukawa, Y., Shinjoe, H., and Nishimura, S.Ȫ 1998ȫ : Travel History of Mesozoic Pelagic Chert in Japan: From Heat flow in the southwest Japan arc and its implication Remote Ocean to Subduction Zone. Tectonics, 10, 475-499. for thermal processes under arcs. J. Geophys. Res., 25, 24ȫઐോȪ1999ȫȇ८၄ਹ༹ࣣͥ͢ͅৣ༹౷ૼౝऔ༹ ஃৣ༹͍̤͢ۼࡄݪȽ̳࢟֔ͥ۾ͅاࣞୈഽ͈ .1087-1090 ࠏࡄڠࢥ֭ڠఱڠఱނ13ȫHale, L. D. and Thompson, G.A.Ȫ1982ȫ : The Seismic ΟȜΗ͈͒ഐဥȽȅ288pp., ࢲฎআაȅڠ౷ݩΏΑΞθࢥشReflection Character of the Continental Mohorovicic ݪ Discontinuity. J. Geophys. Res., 87, 4625-4635. 25ȫMatsu’ura, R., Yoshii, T., Moriya, T., Miyamachi, H., ংȪ1999ȫȇ Sasaki, Y., Ikami, A., and Ishida, M.Ȫ 1991ȫ : CrustalםئढȆ௬ܲॄ܊14ȫനೄȆऎႴȆ ࢹ௮ȅ Structure of a Seismic-Refraction Profi le across the Medianڔৣ༹౷ૼౝऔ̥͙̹ͣ؈ֵୢၴ५౷͈౷ .and Akaishi Tectonic Lines, Central Japan. Bull. Earthq .43-39 ,27 ٸ౷ݩȄۏ 15ȫHole, J. A. and Zelt, B. C.Ȫ 1995ȫ: 3-D fi nite-difference Res. Inst. Univ. Tokyo, 66, 497-516. refl ection traveltimes. Geophys. J. Int., 121, 427-434. 26ȫMooney, W. D. and Meissner, R.Ȫ 1992ȫ : Multi-genetic 16ȫIchikawa, K.Ȫ 1980ȫ : Geohistory of the Median Tectonic origin of crustal refl ectivity: a review of seismic refl ection Line of Southwest Japan. Mim. Geol. Soc. Japan, 18, profiling of the continental lower crust and Moho. in 187-212. Continental Lower Crust, edited by Fountain, D. M., 17ȫIkami, A., Yoshii, T., Kubota, S., Sasaki, Y., Hasemi, A., Arculus, R., and Kay, R, 45-79, ELSEVIER, Amsterdam. Moriya, T., Miyamachi, H., Matsu'ura, R. S., and Wada, K. 27ȫಎఆୃຳȆള༏ ࢴȆݺ ೄȆ࿐ఆઍ२Ȇ२׆ੳ ൲අڰ౷ૼ͈ئڔఝ̤̫ͥͅ౷ٸȪ1986ȫ: A seismic-refraction profi le in and around Nagano Ȫ1997ȫȇୌධུ .ཡबࡄݪਫ਼ා༭ȄNo.40, 1-20ڠസఱނprefecture, central Japan. J. Phys. Earth, 34, 457-474. ȅ ౷༷ȹ༎ਬտ֥ٛȪ1987ȫȇུ͈ܪ18ȫIto, T., Ikawa, T., Adachi, I., Isezaki, N., Hirata, N., 28ȫུ͈౷ৗȸ߃ Asanuma, T., Miyauchi, T., Matsumoto, M., Takahashi, ౷ৗ 6 ߃ܪ౷༷ȅ297pp., ވၛๅ . չോؗධ٬Πρέ̤̫ͥͅܮM., Matsuzawa, S., Suzuki, M., Ishida, K., Okuike, S., 29ȫୌाࢬୃȪ1997ȫȇ Kimura, G., Kunitomo, T., Goto, T., Sawada, S., Takeshita, έͻςάϋ٬ίτȜΠ͈ೆ͙ࣺ͙֖ݞ͍ോࡪஜ໐ ࢲਘআڠ౷شࡄݪڠၑڠࢹ௮ȅ38pp., ୷ဩఱڔT., Nakaya, H., Hasegawa, S., Maeda, T., Murata, A., ͈౷ Yamakita, S., Yamaguchi, K., and YamaguchiȪ 1996ȫ: S., აȅ Geophysical exploration of the subsurface structure of the 30ȫPeacock, S. M. and Wang, K. )1999*: Seismic Median Tectonic Line, East Shikoku, Japan. Jour. Geol. Consequences of Warm Versus Cool Subduction Soc. Japan, 102, 346-360. Metamorphism: Examples from Southwest and Northeast 19ȫIwasaki, T., Kato, A., Abe, S., Ichinose, Y., Umino, N., Japan. Science, 286, 937-939. Okada, T., Koshiya, S., Kosuga, M., Saka, M., Sato, H., 31ȫRobinson, E. A. and Treitel, S.Ȫ1980ȫ: Geophysical signal Shimizu, N., Takeda, T., Tsumura, N., Noda, K., Hasegawa, analysis: Prentice-Hall Book Co. A., Hirata, N., Watanabe, K., Ikawa, T., and Ohguchi, T. 32ȫSasaki, Y., Asano, S., Muramatu, I., Hashizume, M., Ȫ1999ȫ : Seismic Refraction Observation at the Sen'ya and Asada, T.Ȫ 1970ȫ: Crustal Structure in the Western Fault Zone, Northern Honshu, Japan, Bull. Earthq. Res. Part of Japan Derived from the Observation of the First Inst., 74, 49-62. and Second Kurayosi and the Hanabusa Explosions 20ȫIwasaki, T., Kato, W., Moriya, T., Hasemi, A., Umino, N., ȪContinued*. Part 2. Crustal structure in the western part Okada, T., Miyashita, K., Mizokami, T., Takeda, T., Sekine, for JapanȪ Continued*. Bull. Earthq. Res. Inst. Univ. S., Matsushima, T., Tashiro, K., and Miyamachi, H.Ȫ2001ȫ Tokyo, 48, 1129-1136. : Extensional structure in northern Honshu Arc as inferred 33ȫSato, H., Hirata, N., Ito, T., Tsumura, N., and Ikawa, T. from seismic refraction/wide-angle reflection profiling. Ȫ1998ȫ : Seismic refl ection profi ling across the seismogenic Geophys. Res. Lett., 28, 2329-2332. fault of the 1995 Kobe earthquake, southwestern Japan. 21ȫKodaira, S., Kurashimo, E., Takahashi, N., Nakanishi, Tectonophysics, 286, 19-30. A., Miura, S., Park, J. O., Iwasaki, T., Hirata, N., Ito, K., 34ȫSeno, T., Stein, S., and Gripp, A. E.Ȫ 1993ȫ: A Model and Kaneda, Y.Ȫ 2001ȫ: Structural factors controlling the for Motion of the Philippine Sea Plate Consistent With rupture process of a megathrust earthquake at the Nankai NUVEL-1 and Geological Data. J. Geophys. Res., 98, trough seismogenic zone. Geophys. J. Int., 149, 815-835. 17941-17948. .ढȆਜ֚Ȇ 35ȫSeno, T., Zhao, D., Kobayashi, Y., and Nakamura, Mܲॄ܊ঊȆനೄȆٗזংȆඃםئ22ȫ௬
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Ȫ2001ȫ: Dehydration in serpentinized slab mantle: Seismic edited by Doherty, S. M., pp.1000, Society of Exploration evidence from southwest Japan, Earth Planets Space, 53, Geophysicists, Tulsa. 861-871. 40ȫYoshii, T., Sasaki, Y., Tada, T., Okada, H., Asano, S., 36ȫ໌നഓȪ1997ȫȇ૽ࢥ౷ૼ۷௶ΟȜΗ͈ठٜଢ଼͢ͅ Muramatu, I., Hashizume, M., and Moriya, T.Ȫ 1974ȫ : The third Kurayosi explosion and the crustal structure in the ڠၑڠఱނࢹ௮͈ٜྶȅ26pp.Ȅڔಎ໐ུ͈౷ͥ .ࢲਘআა . western part of Japan. J. Phys. Earth, 22, 109-121ڠ౷ݩთିၑشࠏࡄݪ ೆ͙ࣺ͚έͻςάϋͅئ37ȫUlmer, P. and Trommsdorff, V.Ȫ 1995ȫ: Serpentine stability 41ȫ֔ຮጵȪ1991ȫȇུႥോ .Ȅ61, 570ڠش٬ίτȜΠȅ .to mantle depths and subduction-related magmatism Science, 268, 858-861. 42ȫZelt, C. A. and Smith, R. B.Ȫ 1992ȫ : Seismic travel 38ȫWatanabe, H. and Maeda, N.Ȫ1990ȫ: Seismic Activity of inversion for 2-D crustal velocity structure. Geophys. J. Subcrustal Earthquakes and Associated Tectonic Properties Int., 108, 16-34. in the Southeastern Part of the Kinki District, Southwestern 43ȫZelt, B. C., Talwani, M., and Zelt, C. A.Ȫ 1998ȫ : Prestack Japan. J. Phys. Earth, 38, 325-345. depth migration of dense wide-angle seismic data. 39ȫYilmaz, Ö.Ȫ2001ȫ : Seismic Data Analysis; Processing, Tectonophysics, 286, 193-208. Inversion, and Interpretation of Seismic Data, vol.1, ȪAccepted : April 20, 2005ȫ
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