ཡब‫ݪࡄ੅ܿڠش‬ਫ਼ࡄ‫ݪ‬঩ၳȁల!251!࣢ȁ2004!ා!3!࠮

‫۾‬൐౷֖͈ಎ૬௄౷‫ڰڔ‬൲۷௶֔ͬ၌ဥ̱̹ VSP ༹௸ഽࢹ௮಺औ
५କȁঃ୆ɖ

Seismic Wave Velocity Structures in Kanto Area as Revealed by
the Crustal Activity Observation Well VSP
Fumio YAMAMIZU!Solid Earth Research Group,
National Research Institute for Earth Science and Disaster Prevention, Japan
yamamizu@bosai.go.jp

Abstract
From 1991 to 1996, 12 seismic stations having the deep observation well were constructed in Kanto area in order toimprove the detection capability of Kanto-Tokai observation network. The depth of well is basically 2,000 m. At somestations, the depth is less than 1,300 m since the top of pre-tertiary basement is located in shallower depth. Using these
12 wells, seismic P and S wave velocities were revealed by the VSP )Vertical Seismic Profiling* method. For P wave
source, the VIBROSEIS vibrator was prepared, and the specially designed vibrator was introduced for S source. The
measurement interval was 25 m for depths shallower than 500 m, and was 50 m for deeper than 500 m. Not only P but also
S waves were clearly recorded at every measurement depths of all wells. This shows that the S wave vibrator effectively
excites a pure S wave. Arrival times of P and S waves are determined in terms of time-lag computed by cross-correlation
between two waveforms recorded at close depths. These times are rearranged to travel times at every 25 m interval by the
cubic spline interpolation. Then, detailed velocity structures are estimated by numerical differentiation procedure. Mean
layered structures are also estimated by approximating the travel time curve to several straight lines. All the velocity
structures obtained are in good harmony with the geological and geophysical logging data related to each wells.
A database concerning on the well log data is created in order for easy management, quick search, visual presentation,and down loading those log data. The database has yet only basic functions. On the web browser screen, user can selectstation and data item, extract data in any depth range, see as a graph, get the same graph as a postscript figure, and download data that he wants. Administrator manages the database on the same manner, but an access is protected in terms ofpassword.
Key words : VSP method, Seismic wave velocity Structure, Well logging, Deep observation well, Hi-net, Kanto-Tokaiobservation network

1.ȁ͉̲͛ͅ
ȁ‫۾‬൐౷֖͈ࢩ֖૬໐۷௶ঔ୭Ȫո‫ئ‬ಎ૬௄۷௶ঔ୭ȫ͉ 2,000 m ‫͈ݭ‬۷௶֔ͬ‫ུ̱͂ܖ‬Ȅਉസ࠷̤̫ͥͅ۷௶ෝ
ႁͬ‫ڒ‬౲࢜ͅષ̵̯̭ͥ͂ͬ࿒എ̱͂̀Ȅ1991 ාഽ̥ͣ1996 ාഽ̥̫̀ͅ‫۾‬൐Ȇ൐٬౷‫ڰڔ‬൲۷௶࿌Ȫո‫۾ئ‬൐͕̥Ȅ2003ȫȅུ༭͉࣬́Ȅಎ૬௄۷௶ঔ୭͈۷௶֔ͬ၌
ဥ̱̹ VSP ༹ͥ͢ͅ౷ૼ෨௸ഽࢹ௮಺औ̽̀͢ͅංͣͦ
̹ΟȜΗ̷͈ٜ͂ଢ଼ࠫ‫ͬض‬ಎ૤̭̳͂͛ͥ͂͂ͥ͘ͅȅȁ࢚̯ତ km ͈ஃ໐౷‫͈ڔ‬મळ̈́௸ഽࢹ௮͉۷௶࿌ͅ‫̳۾‬ͥ‫ܖ‬யΟȜΉ̜ͤȄ۷௶ΟȜΗͬୈྟͅੜၑȆٜଢ଼̱Ȅ൐٬۷௶࿌ȫ͈֚໐̱͂̀ା๵̯̹ͦȅ‫۾‬൐൐٬۷௶࿌
͉ 1978 ȡ 1983 ාͅା๵̯ͦ̀ոြȄ൳౷֖͈౷ૼ‫ڰ‬൲ං̹ͣͦ౷ૼ۷௶͈ࠫ‫̩̱ୃͬض‬ၑٜ̳ͥષ́ະ‫͈ࠧخ‬ͅ‫̳ͥ۾‬ΟȜΗͬ೰ુഎͅ೹‫̱ރ‬௽̫̞̀ͥȪ‫ؖ‬ന͕̥Ȅ
2000Ȉ࿐ఆ͕̥Ȅ2001Ȉ‫࢛۾‬Ȅ2001Ȉઐఆ͕̥Ȅ2002Ȉ࿤࢛‫͈ڔ‬Ξ·ΠΣ·Αٜͬྶ̳̹͈ͥ͛‫ܖ‬ய঩ၳ̱͂̀ਹါ
̜́ͥȅ౷ૼࢥ‫ڠ‬എ͉ͅȄVSP ༹̽̀͢ͅං̹ͣͦ S ෨ɖ!

͈̜́ͥ͜ȅ̹͘‫ܡ‬ం͈‫ڎ‬ਅ࠿௄঩ၳ͂͂͜ͅȄஃ໐౷ඊၛ࣐ଽ༹૽ȁཡब‫ݪࡄ੅ܿڠش‬ਫ਼ȁࡥఘ౷‫ݪࡄݩ‬໐࿝
Ƚ!1!Ƚ

ཡब‫ݪࡄ੅ܿڠش‬ਫ਼ࡄ‫ݪ‬঩ၳȁల!251!࣢ȁ2004!ා!3!࠮

௸ഽͬ‫͚܄‬౷ૼ෨௸ഽࢹ௮͉Ȅ৘ष͈౷ૼ൲͈ਔ෨ତఝ
֖͈͈̜́́ͤ͜Ȅਉസ࠷ͅ๭‫̢̀ͦͣࣉ̳͖͂ݞͬٺ‬̞ͥఱ౷ૼ͈ૼ൲අ଻ٜͬྶ̱Ȩ̏͛ळ̥̈́ૼഽထ௶ͬ
࣐̠ષ́ະ‫̢̞͈͈ͥ͂ࠧ͜خ‬ȅȁ‫ͅܡ‬ႝ࿐Ȇ઀ఆȪ1999ȫͤ͢ͅȄಎ૬௄۷௶͈֔ߡॉশ
࣐̹ͩͦͅ‫إ‬෨௸ഽ࠿௄͉̲̳ͬ͛͂ͥ‫ڎ‬ਅ໤ၑ࠿௄
ΟȜΗ̤͍͢౷ৗ঩ၳͅ‫͉̱̀۾‬Ȅೄ୪౷‫ئ‬૬໐͈ૂ༭
̹̳ͬͣܲ͜ਹ̈́ΟȜΗ̱̞͂̀͂͛ͣͦ̀ͥ͘ȅུ༭͉࣬́ȄVSP ༹ͥ͢ͅ௸ഽࢹ௮̭͂ͦͣࢢ֔࠿௄ΟȜΗ͈͂๤‫̳̭̠࣐ͥ͂͂͜ڛ‬ȅ‫̢̀ح‬Ȅ‫ܡ‬ం͈࠿௄঩ၳ̈́
͈̓ΟͻΐΗσΟȜΗ֚ͬͤ͢௄৾ե̞օ̩̳̹ͥ͛ͅȄΟȜΗαȜΑ‫̹࣐̽ͬا‬ȅྚ̺ड઀ࡠ͈‫ܥ‬ෝ̱̥๵̢̀
̞̞̦̈́ȄWeb ήρ;Ύͬঀဥ̱ȄΥΛΠχȜ·ࠐဇ́۷௶֔Ȇ࠿௄ࣜ࿒͈஖఼ȄΟȜΗ͈ಒ੄ȆຝْȄ̤͍͢ΟȜΗ͈೏‫ح‬Ȇ་ࢵȆॉੰ൝̧࣐̠̭̦͈ͬ͂́ͥ́͜
̜ͥȅ
2.ȁVSP ༹‫ٽ‬ါ‫ޓ‬଎ 1 ͅ VSP ༹಺औ͈‫ٽ‬ැ଎ͬা̳ȅVSP ༹͉฽ৣ༹౷
ૼౝऔ͈̜֚̾́ͤȄ౷ນ͈ૼ࡙ȪVibratorȫ̥ͣ‫༷ͅئ‬ഥเ̳ͥೄో෨ȪDirect WavesȫȄ̤͍͢౷௄‫́ٮޏ‬฽ৣ̱ષ༷ͅഥเ̳ͥ฽ৣ෨ȪReflected Wavesȫͬ۷௶֔ඤ͈౷ૼ
ࠗȪWell Seismometerȫ́૬̯ͬྟͅ་̢̦̈́ͣ߫ͤ༐̱ܱ

ȁȁ଎ 1! VSP ༹಺औ‫ٽ‬ැ଎ȁȁFig. 1! Schematic representation of the VSP measurement.

჏̳ͥȅ౷ૼ͈ࠗ૬ഽ̦‫ܡ‬౶̜̭̥́ͥ͂ͣȄೄో෨ͬ၌ဥ̳ͦ͊௸ഽࢹ௮ͬୈഽၻ̩‫̧̦̭́͂ͥ͛ݥ‬Ȅ໤ၑ࠿௄ΟȜΗ͞ࢢ֔౷ৗΟȜΗ͂મळͅచ๤̳̭̦ͥ͂́

࣐̹́̽ȅ۷௶ঔ୭ྴȄ֌ഽȆࠐഽȆࣞഽȄ۷௶֔૬ഽ
ͬນ 1 ͅা̳ȅষ୯ո‫͈ئ‬ٜଢ଼ࠫ‫͈̭͉ض‬ນ͈ਜ਼ͅਲ̽

̧ͥȅ̀া̳̭̳͂͂ͥȅȁ༷֚Ȅ฽ৣ෨ͬ၌ဥུ̳͈̦ͥြ͈ VSP ༹̜́ͤȄΟͻȁૼ࡙̱͂̀ȄP ෨̤͍͢ S ෨୺ဥ̷̸͈͈ͬͦͦ͜ဥփ

ΐΗσੜၑ̽̀͢ͅೄో෨ͬ৾ͤੰ̧฽ৣ෨͈͙ͬ໦ၗ

̱̹ȅP ෨ૼ࡙̱͂̀ఱ߿Ψͼήυ΍ͼΑΨͼήτȜΗȄ
S ෨ဥ̱͂̀઀߿͈ΨͼήτȜΉ̜ͥȅS ෨ΨͼήτȜಒ੄̱Ȅ೒ુ͈฽ৣ༹ܱ჏ͅ௖൚̳͈ͥ͜Ȅ̳̻̈́ͩ฽
ৣ଼ࣣܱ჏ͬै଼̳ͥȪKennett et al., 1980ȫȅೄో෨͂൳
အͅ௶೰૬ഽ̦‫ܡ‬౶̜̭̥́ͥ͂ͣȄ฽ৣ଼ࣣܱ჏ͬ೒
ુ͈฽ৣ༹౷ૼౝऔͤ͢ͅං̹ͣͦ฽ৣ౯࿂଎͂๤‫̳ڛ‬̭ͥ͂ͤ͢ͅȄ฽ৣ༹ͥ͢ͅ฽ৣ౯࿂͈ୈഽ͈࠿બ࣐ͬ

Η͉Ȅ;ͿͼΠͬ೒ુਸ༷࢜ͅ૦൲̵̯͈ͥͬ͜Ȅ‫༷؍‬࢜͜ͅ૦൲‫خ‬ෝ̠̱̹͈̈́́͢͜ͅȄS ෨ͬ࢘ၚၻ̩อ୆
̵̧̯̭̦ͥ͂́ͥȅ଎ 3Ȅ଎ 4 ̷̸ͦͦͅ P ෨ȄS ෨Ψ̧̠̭̦͂́ͥȪ֔୼͕̥Ȅ1986ȫ̞̠͈̜͂́ͥ͜ȅͼήτȜΗ͈‫ٽ‬۷̤͍͢଻ෝͬা̳ȅȁ۷௶֔ඤ౷ૼ͉ࠗ Western Atlas International ২ୋ LRS-ȁུ༭̤̫࣬ͥͅ಺औ༹༷͉Ȅஜ৪͈ೄో෨ͬ၌ဥ̱̹

1300 3 ଼໦౷ૼࠗȪ଎ 5ȫͬঀဥ̱̹ȅ౷ૼ͈ࠗࡥခਔ෨

͈̜́ͤ͜ȄδȜςϋΈࢢͬ၌ဥ̱̹ೄ୪௸ഽ௶೰̱͂

ତ͉ 10 Hz ́Ȅίςͺϋίඤ௫͈͈̜́ͥ͜ȅܱ჏‫͉ܕ‬Ḙ̏̀ͦ́͘͜ͅࢩํ࣐̞ͩͦ̀ͥͅȅඅͅఊന͕̥Ȫ1977Ȅ
1978ȫȄ ५ କ ͕ ̥Ȫ1981ȫȄYamamizu et al.Ȫ1983ȫȄ ५ କ฽ৣ༹౷ૼౝऔ́ঀဥ̯ͦͥౝࣗ‫ܥ‬ȪΟͻΐΗσΞτιΠςΏΑΞθ G-DAPS 3/4ȄȪ‫ڼ‬ȫ౷‫ڠشݩ‬௙ࣣࡄ‫ݪ‬ਫ਼ୋȫͬ

Ȫ1996ȫ͉Ȅཡब‫ݪࡄ੅ܿڠش‬ਫ਼͈ 3,000 m ·ρΑ͈૬௄۷௶֔ͬ၌ဥ̱̹௶೰ͤ͢ͅȄP ෨ S ෨௸ഽࢹ௮̴͈͙̈́ͣ

ঀဥ̱̹ȅ

Q ࢹ௮͈ଔ೰଼̞̰̱̞̾̀͛͘͜ͅ‫̞̬̜ͥ̀ͬض‬ȅ̱௶೰࣐̹ͬ̽ȅ̜ͤ͘߃̨̳ͥ͂ࢢ֔ඤ͈କͬഥͩͥȁP ෨ȆS ෨ΨͼήτȜΗૼ࡙͉͓̩̈́ͥࢢ࢛ັ߃ͅ୭౾
‫إ‬෨Ȫո‫ئ‬ΙνȜή෨ȫ͈႗̦ܳఱ̧̩̹̈́ͥ͛Ȅ͞͞‫׿‬

3.ȁΟȜΗ৾ං̤͍͢ஜੜၑ

̩ͅ୭೰̱̹̭̜͂ͧͥ͜ȅࢢ࢛̥͈ͣ΂έΓΛΠ‫ݻ‬ၗ͉ 20 m ȡ 250 m ̜́ͥȅ௶೰૬ഽ‫͉ڞۼ‬Ȅ૬̯ 500 m ͘

3.1ȁΟȜΗ৾ංȁ‫۾‬൐̤͍͢ਔ༏౷֖̤̫ͥͅ౷‫ڰڔ‬൲۷௶തͬ଎ 2 ͅা̳ȅ‫۾‬൐൐٬۷௶࿌Ȅࣞۜഽ౷ૼ۷௶࿌ȪHi-netȫȄ̤͍͢ఈ‫͈۾ܥ‬۷௶ത̦‫̞ͥ̀ͦ͘܄‬ȅVSP ༹಺औ͉Ȅ࢚

͉́ 25 m ྀȄո૬͉ 50 m ྀͬ‫ུ̹̱͂ܖ‬ȅΑͼȜίਔ
෨ତ͉ P ෨ဥ 10 ȡ 80 HzȄS ෨ဥ 10 ȡ 60 HzȪ֚໐ 50 Hzȫ࿐ȪATGHȫȄ‫؍‬ຩȪYKHHȫȄୌ࿤ࡔȪNSHHȫȄਫ਼ాȪTKRHȫȄ

́ȄΑͼȜίಿ 20 ຟȄΑΗΛ·ٝତ͉௶೰૬ഽͤ͢ͅ
1 ȡ 6 ̱͂Ȅܱ჏ે‫௶̦̱ͣ̈́෇ږͬޙ‬೰ͬૺ̹͛ȅ΍ϋ඾ࣞȪHDKHȫȄ୷ဩȪCBAHȫȄူჇȪYORHȫȄີೋȪFUTHȫȄ

ίςϋΈ‫ ͉ڞۼ‬2-msec ́Ȅ8 ຟ‫ܱۼ‬჏̱̹ȅυȜ΃ΛΠ଼നȪNRTHȫȄࢺ࡫ॄȪEDSHȫȄ૯‫ؖ‬ȪMOKHȫȄ̤͍͢չସॄȪISSHȫ͈ಎ૬௄۷௶ঔ୭ 12 ̥ਫ਼Ȫ଎ 2 ͈୒অ‫֣ڙ‬ȫέͻσΗ͉ঀဥ̵̴ȄΧͼ΃ΛΠέͻσΗȪ৭౯ਔ෨ତ
180 Hzȫ͈͙ഐဥ̱̹ȅ

Ƚ!2!Ƚ

‫۾‬൐౷֖͈ಎ૬௄౷‫ڰڔ‬൲۷௶֔ͬ၌ဥ̱̹ VSP ༹௸ഽࢹ௮಺औȽ५କ

଎2‫۾‬൐̤͍͢ਔ༏౷֖͈౷‫ڰڔ‬൲۷௶തȪ୒‫֣܃‬ȫȄ‫۾‬൐൐٬۷௶࿌ȄࣞۜഽȪHi-netȫ۷௶࿌̤͍͢ఈ‫͈۾ܥ‬۷௶തͬ‫͚܄‬ȅ୒অ‫ ̦֣ڙ‬VSP ಺औͬ৘ঔ̱̹ಎ૬௄۷௶ঔ୭

Fig. 2 Distribution of crustal activity observation stations in and around Kanto area )blue circles*. Kanto-Tokai, Hi-net, and other organization
networks are plotted together. Blue squares with name show the stations for the VSP measurement in this study.

ȁȁȁȁȁȁນ 1ȁȁȁVSP ༹಺औͬ৘ঔ̱̹۷௶֔Ȅਫ਼ह౷Ȅ֌ഽȄࠐഽȄ۷௶֔૬ഽ
ȁȁȁȁȁȁTable 1 Well name, address, latitude, longitude, and depth of well where VSP measurements were held.

Ƚ!3!Ƚ

ཡब‫ݪࡄ੅ܿڠش‬ਫ਼ࡄ‫ݪ‬঩ၳȁల!251!࣢ȁ2004!ා!3!࠮

ȁȁȁȁȁȁȁȁȁȁȁȁ଎ 3

P ෨ૼ࡙ဥΨͼήυ΍ͼΑΨͼήτȜΗȁȁȁȁȁȁȁȁȁȁȁȁFig. 3 General view and specifications of the VIBROSEIS vibrator for P wave source.

ȁȁȁȁȁȁȁȁȁȁȁȁ଎ 4

S ෨ૼ࡙ဥ઀߿ΨͼήτȜΗȁȁȁȁȁȁȁȁȁȁȁȁFig. 4General view and specifications of the buggy-type vibrator for S wave source.

Ƚ!4!Ƚ

‫۾‬൐౷֖͈ಎ૬௄౷‫ڰڔ‬൲۷௶֔ͬ၌ဥ̱̹ VSP ༹௸ഽࢹ௮಺औȽ५କ

ȁȁȁȁȁȁȁȁȁȁȁȁȁ଎ 5

3 ଼໦۷௶֔ඤ౷ૼࠗ

ȁȁȁȁȁȁȁȁȁȁȁȁȁFig. 5 General view and speciﬁcations of the 3-component well seismometer.

3.2ȁΟȜΗஜੜၑ͈૦໙͈‫̓̈́಺ޑ‬Ȅ৽৊༷͈࢜͒जດ་۟ͥ࢘͢ͅ‫ͬض‬ȁS ෨ΨͼήτȜΗૼ࡙͉‫ح‬૦༷࢜ͅస‫ ̹̱ק‬S ෨ͬอ୆̳̦ͥȄࢢ֔ඤ౷ૼ͈ࠗକ໹ 2 ଼໦͈༷͉࢜ະྶ̜́ͤȄྶၸͅࡉ̧̭̦ͥ͂́ͥȅȁ଎ 7. 1)1* ȡ଎ 7. 12)2* ͅȄ௸ഽࢹ௮ٜଢ଼ͅঀဥ̱̹஠

S ෨͈స‫̞̈́ͣࡠ͉̞̞༷̹̱͂ͥ̀࢜࢜ͅק‬ḙ͈̹̏͛Ȅܱ჏ͬা̳ȅ૦໙͉‫ڎ‬ΠτȜΑ͈डఱ౵́ୃܰ‫̜̱̀ا‬ͥȅ‫ڎ‬଎ )1* ̦ P ෨ΨͼήτȜΗૼ࡙ͥ͢ͅષ‫ئ‬൲ܱ჏৾ං̱̹ S ෨ΨͼήτȜῌͥ͢ΟȜΗ͉ٜଢ଼͈ஜͅȄS෨ͬ‫̳ͥ಺ޑ‬ੜၑ࣐̹ͬ̽ȅS ෨ൢోশັ߃͈କ໹ 2 ଼໦ܱ჏ͬঀဥ̱Ȅ‫ވ‬་ΞϋΕσ)1*̜́ͥḙ͈̏ P ෨ဥષ‫ئ‬൲ܱ჏̞͉̾̀ͅȄஜੜၑ࣐ͬ
̞̞̽̀̈́ȅ)2* ̦ S ෨ૼ࡙ͥ͢ͅजດ་۟ࢃ͈స‫༷࢜ק‬͈ܱ჏̜́ͥȅ̴̞͈ͦ۷௶̤̫ܱ֔ͥͅ჏́͜Ȅ͕͖ࢢೲ́͘άνͺ̈́ S ෨̦ܱ჏̯̤ͦ̀ͤȄS ෨ΨͼήτȜΗ͈րႁͬাْ̳‫ܢ‬എܱ̈́჏̢̞͂ͥȅ͈৽৊͈༷࢜ θ ͬ S ෨͈స‫̱༷͂࢜ק‬Ȅ
4.ȁ௸ഽࢹ௮ٜଢ଼
)2*ȁஜ୯͈ܱ჏ͬဥ̞̀௸ഽࢹ௮ٜଢ଼࣐̹ͬ̽ȅ̷͈਀ਜ਼ͤ͢ͅजດ৊͈ٝഢ་࣐̹۟ͬ̽ḙ̭̏́ Ax)i∆t*ȄAy)i∆t*͉ࡓ͈କ໹൲ 2 ଼໦ܱ჏͈ i ๔࿒͈΍ϋίσ౵Ȅ∆t ͉΍Ȫ3ȫΟȜΗ༞ۖȄ
Ȫ4ȫତ౵๷໦ͥ͢ͅમळ௸ഽࢹ௮͈ଔ೰Ȅ͉ȄȪ1ȫ੝൲௢শ͈උ͙৾ͤȄ
Ȫ2ȫૼ࡙͈΂έΓΛΠ༞ୃȄϋίςϋΈ‫̜ͥ́ڞۼ‬ȅAx'ȄAy' ͉जດ་۟ࢃ͈ܱ჏͂̈́
ͥȅ଎ 6 ͅजດ་۟ͥ͢ͅ S ෨‫಺ޑ‬ੜၑࠫ‫͈֚ض‬႕ͬা̳ȅ̤͍͢Ȫ5ȫ௄ߊ໦ͥ͢ͅ߃য௸ഽࢹ௮͈ଔ೰̜́ͥȅȁड੝ͅȄP ෨ȆS ෨੝൲௢শ͉Ȅ΍ϋίςϋΈ‫ڞۼ‬Ȫ2-msecȫ

ऒ 2 ̦̾ੜၑஜ͈କ໹ 2 ଼໦ܱ჏Ȅֲ̦ੜၑࢃ͈ S ෨సྚྖ͈ୈഽͬ֋঵̳̹ͥ͛‫ڎ‬૬ഽ̤̫ͥͅ෨ࠁ͈௖ࡽ௖
‫ͥ͢ͅ۾‬ΗͼθρΈ̥ͣࠨ೰̱̹ȅ̴̞ͦ͜ 0.2-msec ͈‫଼͈༷࢜ק‬໦̜́ͥȅS ෨պ௖͈ାႥͤ͢͞૬̞̭͂ͧ́

ୈഽ͉‫ږ‬༗̯̞ͦ̀ͥę̏̾ͅȄૼ࡙͂ࢢ࢛͈͂΂έΓΛ

Ƚ!5!Ƚ

Ƚ!6!Ƚ

S ෨‫಺ޑ‬ੜၑ͈֚႕Ȅऒ̤͍͢ಎ؇̦ੜၑஜ͈କ໹൲ 2 ଼໦ܱ჏Ȅֲ̦ੜၑࢃ S ෨స‫ܱ͈༷࢜ק‬჏

Fig. 6 An example of effect of S wave emphasizing process. Right and middle are two original horizontal components, left is transformed records to the predominant direction of S wave.

ȁȁȁȁ଎ 6ཡब‫ݪࡄ੅ܿڠش‬ਫ਼ࡄ‫ݪ‬঩ၳȁల!251!࣢ȁ2004!ා!3!࠮

‫۾‬൐౷֖͈ಎ૬௄౷‫ڰڔ‬൲۷௶֔ͬ၌ဥ̱̹ VSP ༹௸ഽࢹ௮಺औȽ५କ

Π‫ݻ‬ၗͬ͂͜ͅȄࢢ࢛̥͈ͣ଒ೄ௢শ̠͂̈́ͥ͢ͅ༞ୃͬ
࣐̹̽ȅ༞ୃࢃ͈଒ೄ௢শͅ cubic spline ‫۾‬ତͥ͢ͅඤொ
ͬഐဥ̱Ȅ௶೰‫ ̦ڞۼ‬25 m ̠͂̈́ͥ͢ͅ༞࣐̞ۖͬडਞ
എ̈́௢শ̱̹͂ḙ͈̏௢শެ஌ͬ଎ 7. 1)1* ȡ଎ 7. 12)2*͈ಎ؇ͅা̳ȅ̴̞͈ͦ௢শެ஌͜ତུ͈ೄ஌́߃য̳

km ັ߃͈௸ഽ࢙෻͈་‫ͅا‬చ؊̳ͥ౷ৗ‫̈́ͦͣࡉ͜ٮޏ‬̞ȅȁS ෨ܱ჏͉́Ȅ1.6 km ո૬́ΙνȜή෨͈‫̦ޣג‬ఱ̧̞Ȫ଎ 7. 1)2*ȫȅ൳଎ͅྶ̥̠ͣ̈́͢ͅȄS ෨੝൲໐͈ S / Ņ̭̦ͥ͂́ͥအͅࡉ̢ͥȅ̳̻̈́ͩȄତ௄ͅߊ໦̳ͥ

๤̦ၻ̩̩̈́௢শ͈උ৾ͤ౵̧͈̦͊ͣ̾ఱ̧̞ḙ͈̹̏͛Ȅ1.2 km ո૬͈ S ෨௸ഽ͉͞͞ୈഽ̦೩̞ȩ̭̦̏͂́Ȅ߃যഎͅତ௄଼ͤͥ͢௄ࢹ௮͂ࡉ̭̦ͥ͂

5. 2ȁ‫؍‬ຩ۷௶ঔ୭Ȫ଎ 8. 2ȫ

̧́ͥḙ̭͉̏́Ȅ̤̤̥͘ͅߊ໦̯̹ͦํսͬड઀ඵȁP ෨ ௸ ഽ ͉ 1.7 km / sec ȡ 2.7 km / secȄS ෨ ௸ ഽ ͉ 0.5
km / sec ȡ 1.2 km / sec ͈̠͢ͅ૬̯͂͂͜ͅౙ಺ͅ௩‫̳ح‬઺༹̽̀͢ͅೄ஌߃য̱Ȅచ؊̳ͥ௸ഽͬ‫߃͛ݥ‬যഎ̈́௸ഽࢹ௮̱̹͂ȅ
ȁP0S ௸ഽࢹ௮͉Ȅ༞ۖࢃ 25 m ‫ͅڞۼ‬ା̢̹ͣͦ௢শͬ
ତ౵๷໦̳̭ͥ͂ͤ͢ͅࠨ೰̱̹ȅ๷໦͉ͅ 5 ത࢖৆ȁȁĩ3*ͬဥ̞̹ḙ̭̏́Ȅvi ̤͍͢ ti ͉૬ഽ i ̤̫ͥͅ௸ഽ̤͢
͍௢শȄh ͉௶೰૬ഽ‫ڞۼ‬Ȫ25 mȫ̜́ͥȅ౤ത̤̞͉̀ͅȄͥ௸ഽࢹ௮ͬা̱Ȅྶၸ̈́௸ഽ‫̞̈́ͦͣ͛෇͉ٮޏ‬ȅࢢ֔౷ৗ͉૬̯࿩ 1.4 km ́͘లঅࠏષ௙௄߲Ȅ1.4 km ȡࢢೲ̦ಎ૧ൡ२‫׆‬௄߲̞͂̈́̽̀ͥȅ୶ల२ࠏ‫ܖ‬๕͉ͅో̱
̞̞̀̈́ȅ࿩ 1.3 km ັ߃ͅࡉͣͦͥ 2.43 km / sec ͂ 2.67
km / sec ͈ P ෨௸ഽ΋ϋΠρΑΠ̦Ȅષ௙௄߲͂२‫׆‬௄߲͈‫ͅٮޏ‬௖൚̳͈ͥ͂͜এͩͦͥȅS ෨௸ഽ̞͉̾̀ͅྶ
ၸ͉̞́̈́ȅ
ȁ଎ 7. 2)1* ͈ P ෨ܱ჏ͬࡉͥ͂Ȅ৻̞̦̈́ͣ͜૬̯࿩
0.8Ȅ̤͍͢ 0.95 km ֲ̥ͣષ༷࢜͒ഥเ̱̞̀ͥ฽ৣ෨̦

ȁȁ෇͛ͣͦͥḙ͉̏ͦͣȄ଎ 8. 2)1* ͈‫إ‬෨࠿௄଎ͅࡉͣͦ
ͥ 0.75 ȡ 0.8 km ̤ ͢ ͍ 0.8 ȡ 1.0 km ͈ ࣞ ௸ ഽ ໐ ໦ ͈ ‫ئ‬)4*࿂̥͈ͣ฽ৣ͂এͩͦͥȅ̹̯ͣ͘ͅ๷৻͉̜̦́ͥ 1.3
km ັ߃̥͈ͣ฽ৣ෨͜෇͛ͣͦͥḙ͈̏฽ৣ෨͉Ȅષܱ͈ષ௙Ƚ२‫׆‬௄߲͈‫̠̜͈͈̥ͧ́ͣ͜ٮޏ‬ȅ
5. 3ȁୌ࿤ࡔ۷௶ঔ୭Ȫ଎ 8. 3ȫ

ͬഐဥ̱̹ȅං̹ͣͦ௸ഽࢹ௮ͬ଎ 7. 1)1* ȡ଎ 7. 12)2*ֲ͈ͅা̳ȅ௄ߊ໦ͥ͢ͅ߃য௄ࢹ௮Ȫ଎ಎೄ஌ȫ͜ਹ͇̀া̱̹ȅນ 2. 1 ȡນ 2. 12 ͅඋ͙̹৾̽ P0S ෨௢শȄȁ ౷ ນ ȡ 0.12 km ȡ 0.46 km ȡ ࢢ ೲ ͈ ͕ ͖ 3 ௄ ࢹ ௮ ͂ ࡉ̧̭̦ͥ͂́ͥȅ‫ڎ‬௄ඤ́ P ෨ S ෨௸ഽ͉๤‫ڛ‬എհ೰΂έΓΛΠ༞ୃࢃ͈଒ೄ௢শȄඤொ༞ۖࢃ௢শȄତ౵๷̱̤̀ͤȄ̷̸ͦͦ 2.2Ȅ3.1Ȅ5.5 km / secȄ̤͍͢ 0.9Ȅ1.5Ȅ
3.4 km / sec ̜́ͥȅࢢ֔౷ৗ͉ 0.5 km ̦́͘లঅࠏȄո໦ͥ͢ͅમळࢹ௮Ȅ̤͍͢߃যࢹ௮ͬা̳ȅ૬̦୶ల२ࠏ‫ܖ‬๕Ȫঅྔ਱႑௄ȫ̜́ͥȅ૬̯ 0.45 km ັ

5.ȁ௸ഽࢹ௮‫ٽ‬۷߃͈ྶၸ̈́௸ഽ‫୶̦ٮޏ‬ల२ࠏ‫ܖ‬๕ષ࿂ͅ௖൚̳ͥȅȁ଎ 7. 3)2* ͅȄࢃ௽͈෨ོ͉̞̦ͦ̀ͥ͜ͅȄ࿩ 0.5 km

ȁ̭̭͉́Ȅஜ୯́ං̹ͣͦ‫ڎ‬۷௶ത͈௸ഽࢹ௮ͬ‫ٽ‬۷ັ߃͈‫ܖ‬๕‫ֲ̥ͣٮޏ‬ષ༷ͅഥเ̳ͥ S ෨฽ৣ෨ͬྶၸ

̳ͥȅ̹͘Ȅ౷ৗಔે଎͞‫ܡ‬ం͈‫إ‬෨Ȇྟഽ͈̈́̓໤ၑ

ͅࡉ̧̭̦ͥ͂́ͥḙ͉̏ͦȄ‫ܖ‬๕࿂͈́฽ৣ෨͈΀ΥσΆȜ̦ఱ̧̞̭͂ͬা̱̞̀ͥḙ͈̹̏͛Ȅ૬̯ 0.5 km

࠿௄ࠫ‫ض‬Ȫႝ࿐Ȇ઀ఆȄ1999ȫ͂๤‫̳̭̳ͥ͂͂ͥڛ‬ȅ଎
8. 1 ȡ଎ 8. 12 ͈ )1* ̦௸ഽࢹ௮͂۷௶֔౷ৗ̤͍͢‫إ‬෨ྟഽ࠿௄ࠫ‫ͬض‬๤‫͈̹̱́͜ڛ‬Ȅ)2* ̦໤ၑ࠿௄ࠫ‫ͬ͘ض‬ո૬͈‫ܖ‬๕ඤ͉́૦໙̦઀̯̩̈́ͤȄS / N ๤̦೩‫̱̀ئ‬̞ͥȅS / N ͉೩‫̦̞̱ͥ̀ئ‬Ȅ‫ܖ‬๕ඤ́͜ࢢೲ́͘ S ෨͂͛̀ίυΛΠ̱̹͈̜́ͥ͜ȅ஠ఘഎͅࡉͦ͊Ȅ̴̞ͬ਱໦೏୥̧̳̭̦ͥ͂́Ȅඋ͙৾ͤୈഽ͉‫ږ‬༗̯͈ͦ̀ͦ۷௶֔́ං̹ͣͦࠫ‫͜ض‬౷ৗࢹ௮͞‫ڎ‬ਅ໤ၑ࠿௄ࠫ

̞ͥȅ
5. 4ȁਫ਼ా۷௶ঔ୭Ȫ଎ 8. 4ȫ

‫಺͂ض‬გഎ̜́ͤȄ૞ှ଻̢͈̞͈̜̞ࣞ́ͥ͂ͥ͜ȅ
5. 1ȁ࢚࿐۷௶ঔ୭Ȫ଎ 8. 1ȫ

ȁ૬̯ 0.4 km ոஃ͈໐໦́ȄP ෨௸ഽ̧͈̦͊ͣ̾ఱ̧

ȁ౷ৗࢹ௮͉Ȅडષ໐ 0.04 km ̦‫ؗ‬ୟ௄Ȅ̷͈‫ئ‬࿩ 0.2 km

̩̞͈̦̈́̽̀ͥඅಭഎ̜́ͥḙ͉̏ͦȄ͞͞ఱ̧̩႗

̦́͘లঅࠏ௖࿅௄߲Ȅո‫ࢢئ‬ೲ́͘ಎ૧ൡ௖୼௄߲͂
ଔ೰̯̤ͦ̀ͤȄ୶ల२ࠏ‫ܖ‬๕͉ͅో̱̞̞̀̈́ȅP ෨ S̯̹ܳͦΙνȜή෨͞ΉȜΏϋΈΩͼίਔ༏͈ΓιϋΠ௄ͬഥเ̳ͥͤࣞ͢௸̈́ P ෨̽̀͢ͅȄ૯͈ P ෨੝൲̦ζ෨௸ഽ͂͜૬̯͂͂͜ͅ௩‫ͬ࢜߹̳ͥح‬া̱̤̀ͤȄྶၸ̈́௸ഽ‫̞̈́ͦͣࡉ͉ٮޏ‬ȅडષ໐૬̯ 0.4 〜 0.5 km ͉́͘ P ෨௸ഽ͉ 1.4 km / sec ȡ 3.1 km / secȄS ෨௸ഽ͉ 0.3
km / sec ȡ 1.0 km / sec ͂͞͞‫ࠣͅݢ‬௩‫͈̞̱ͥ̀ͅح‬చ̱

Α·̯̞̹̜̠ͦ̀ͥ͛́ͧȪ଎ 7. 4)1*ȫȅS ෨ܱ჏̤ͅ
̞͉̀Ȅ1.6 km ͤ͢૬̞̭͂ͧ́ΙνȜή෨͈‫͢ͅޣג‬ͤ S / N ๤̦͞͞೩‫̤̱ͤ̀ئ‬Ȅ௸ഽ̧͈̦͊ͣ̾ఱ̧̩
̞̈́̽̀ͥḙ̏ͦͣ໐໦ͬੰ̫͊ȄP ෨ S ෨௸ഽ͂͜૬̯

̀Ȅո૬͉́ࢢೲ́ͤ͘͢۱̥࢙̈́͞෻́௩‫͈̞̱ͥ̀ح‬̦අಭഎ̜́ͥȅࢢೲັ߃͈́ P ෨ S ෨௸ഽ̷̸͉ͦͦ

͂͂͜ͅষలͅ௩‫̤̱ͤ̀ح‬Ȅྶၸ̈́௸ഽ‫ͦͣࡉ͉ٮޏ‬̞̈́ȅࢢೲັ߃͈́௸ഽ͉ȄP ෨࿩ 3.0 km / secȄ̤͍͢ S

3.9 km / secȄ̤͍͢ 2.0 km / sec ̞͂̈́̽̀ͥȅ౷ৗഎ͉ͅ

෨࿩ 1.4 km / sec ̜́ͥȅࢢ֔౷ৗ͉Ȅ౷ນັ߃ͬੰ̞̀Ȅ࿩ 1.0 km ́͘లঅࠏષ௙௄߲Ȅո૬̦ಎ૧ൡȪလ֔௄௖൚ȫ௖࿅௄߲͂௖୼௄߲‫௸ͅۼ‬ഽ΋ϋΠρΑΠ̦‫ܢ‬ఞ̯̦ͦͥȄ௖൚̳ͥ௸ഽ‫̞̈́ͦͣࡉ͉ٮޏ‬ȅ฽చͅȄ0.4 〜 0.5̤͂̈́̽̀ͤȄ୶ల२ࠏ‫ܖ‬๕͉ͅో̱̞̞̀̈́ȅ

Ƚ!7!Ƚ

ཡब‫ݪࡄ੅ܿڠش‬ਫ਼ࡄ‫ݪ‬঩ၳȁల!251!࣢ȁ2004!ා!3!࠮

5. 5ȁ඾ࣞȪ଎ 8. 5ȫ
ȁඅͅ P ෨́ࡐಠ̜̦́ͥȄ1.0 km ັ߃ͅ௸ഽ͈೩‫̦ئ‬̦฽ৣ‫̜̥ͥ́ͣྶ̦̭̞͂ͥ̀̽̈́͂ٮޏ‬ȅ‫ܖ‬๕ඤ͉́ P ෨ S ෨͂͜૦໙̦͞͞઀̯̩̤̈́̽̀ͤȄඋ͙৾ͤࡉͣͦͥḙ͈̹̏͛ࢹ௮̦ໝॠ͈֣͂યͬဓ̢̦ͥḘ͈̏ୈഽ͈Ⴆ‫௸ͥ͢ͅا‬ഽ̧͈̦͊ͣ̾ఱ̧̞ȅ
5. 10ȁࢺ࡫ॄ۷௶ঔ୭Ȫ଎ 8. 10ȫ໐໦ͬੰ̫͊૬̯͂͂͜ͅ௩‫ࢹ̳ͥح‬௮͂ࡉ̭̦ͥ͂́
̧ͥȅྶၸ̈́௸ഽ‫̦̞̈́ͦͣࡉ͉ٮޏ‬Ȅ૬̯ 0.3 〜 0.4 km

ȁஜ଼ܱന۷௶ঔ୭͂౷ၑഎ͜ͅ߃̩Ȅ௸ഽȆࢢ֔౷ৗ̩͂͜͢ͅয̹ࢹ௮ͬা̳ȅࢢ֔౷ৗ͉Ȅ࿩ 0.1 km ͉́́͘͘௸ഽ͈௩‫̦ح‬ఱ̧̩Ȅո૬͉́۱̥͞ͅ௩‫̞̱̀ح‬ͥȅࢢ֔౷ৗ͉Ȅ૬̯࿩ 0.1 km ̦́͘‫ؗ‬ୟ௄Ȅ0.1 ȡ 0.5

లঅࠏ‫ئ‬௙௄߲Ȅ0.1 ȡ 0.7 km ̦ષ௙௄߲Ȅո૬̦୶ల२
ࠏ‫ܖ‬๕̜́ͥȅP ෨ S ෨௸ഽ͉ͅȄ͂͜ͅ૬̯࿩ 0.7 km

km ̦లঅࠏષ௙௄߲Ȅո૬̦૧ల२ࠏ͂చ๤̯̞ͦ̀ͥȅ૬̯ 0.3 〜 0.4 km ͈́͘௸ഽ࢙෻͈་‫ا‬ത̦Ȅ͕͖ષ௙ͅྶၸ̈́‫ͦͣ͛෇̦ٮޏ‬Ȅ୶ల२ࠏ‫ܖ‬๕ષ࿂֚͂౿̱̀
̞ͥȅP ෨௸ഽ͉‫ܖ‬๕ͤ͢ષ́ 1.7 ȡ 1.9 km / secȄ‫ܖ‬๕ඤ௄߲͂૧ల२ࠏ͈͂‫ͅٮޏ‬చ؊̱̞͈̀ͥ͂͜এͩͦͥȅࢢೲັ߃͈ P ෨ S ෨௸ഽ͉Ȅ̷̸ͦͦ 2.8 km / sec ̤͍́͢ 4.4 km / secȄS ෨௸ഽ̷̸͉ͦͦ 0.3 ȡ 0.7 km / secȄ̤͍͢ 2.3 km / sec ̜́ͥȅ

1.4 km / sec ̜́ͥȅ୶ల२ࠏ‫ܖ‬๕͉ͅో̱̞̞̀̈́ȅȁ଼ന۷௶ঔ୭͂൳အͅȄ‫ܖ‬๕࿂̥͈ͣ฽ৣ෨̦ྶၸͅ
ࡉͣͦͥȪ଎ 7. 10)1*Ȅ)2*ȫȅ଼ന̤̞͉͕̀͂ͭ̓ͅ෇

ࡉͣͦͥȅS ෨͜ͅȄP ෨͕̓ࡐಠ͉̞̦́̈́൳̲߹̦࢜

5. 6ȁ୷ဩ۷௶ঔ୭Ȫ଎ 8. 6ȫ
ȁ૬̯࿩ 0.15 km ́͘లঅࠏ‫ئ‬௙௄߲Ȅո‫ࢢئ‬ೲ́͘లে̧̥̹́̈́̽ S ෨฽ৣ෨Ȫ଎ 7. 9)2*ȫ͜Ȅྶၸͅࡉͥ

অࠏષ௙௄߲͂๤‫ڛ‬എ֚အ̈́౷ৗࢹ௮́Ȅ୶ల२ࠏ‫ܖ‬๕̧̭̦͂́ͥȪ଎ 7. 10)2*ȫȅ‫ܖ‬๕ඤ̤̞͉̀ͅȄS / N ͈೩‫ ͤ͢ͅئ‬S ෨͈උ͙৾ͤୈഽ̦৹ۙႦ‫̞̱ͥ̀ا‬ȅ͉ͅో̱̞̞̀̈́ȅޭஃ໐ͬੰ̧ȄP ෨ȆS ෨௸ഽ͂͜ྶ
ၸ̈́௸ഽ‫̞̈́ͦͣࡉ͉ٮޏ‬ȅ‫ئ‬௙௄߲ಎ́ P ෨௸ഽ࿩ 1.4
km / secȄS ෨௸ഽ࿩ 0.4 km / secȄո૬͈ષ௙௄߲́ P ෨࿩
1.8 ȡ 2.3 km / secȄS ෨࿩ 0.5 ȡ 1.1 km / sec ͂ষలͅ௩‫ح‬

5. 11ȁ૯‫ؖ‬۷௶ঔ୭Ȫ଎ 8. 11ȫ
ȁࢢ֔౷ৗ͉Ȅ౷ນ̥ͣ࿩ 0.05 km ́͘‫ؗ‬ୟ௄Ȅ࿩ 0.1 km
́͘లঅࠏ‫ئ‬௙௄߲Ȅ࿩ 0.5 km ́͘లঅࠏષ௙௄߲Ȅո̳ͥࢹ௮̞͂̈́̽̀ͥȅྟഽ͉஠௄ 2. 1 ȡ 2. 2 ͂հ೰̱૬͉ಎ૧ൡȪ࣏୼௄߲ȫ́୶ల२ࠏ‫ܖ‬๕͉ͅో̱̞̞̀̈́ȅ̞̀ͥȅ
5. 7ȁူჇ۷௶ঔ୭Ȫ଎ 8. 7ȫ

͞͞ໝॠ̈́౷ৗ͈֣ય̜̦́ͥȄ௸ഽ͉ P ෨ S ෨͂͜๤‫ڛ‬എౙ੗́Ȅ૬̯͕͖͂͂͜ͅೄ஌എͅ௩‫ࢹ̳ͥح‬௮͂ࡉȁP ෨ S ෨͂͜௸ഽ౵̧͈͊ͣ̾͜ઁ̩̈́Ȅ͕͖ೄ஌എ
ͅ௩‫̠̳̈́ͥ͢ح‬๤‫ڛ‬എհ೰̱̹௸ഽࢹ௮̞͂̈́̽̀ͥȩ̭̦̏ͥ͂́ͥȅྶၸ̈́௸ഽ‫̞̈́ͦͣࡉ͉ٮޏ‬ȅP ෨௸ഽ͉౷ນ̥ͣȄ1.7Ȅ2.1Ȅ2.3Ȅ2.9Ȅ3.3 km / secȄS ෨௸ഽ͉Ȅ0.5Ȅ

ྶၸ̈́௸ഽ‫̞̈́ͦͣ͛෇͉ٮޏ‬ȅP ෨௸ഽ͉Ȅ౷ນ̥ͣ
1.9Ȅ2.1Ȅ2.3Ȅ2.4Ȅ2.6 km / secȄS ෨௸ഽ͉ 0.6Ȅ0.9Ȅ1.0Ȅ1.2Ȅ1.3

0.9Ȅ1.2Ȅ1.6Ȅ1.8 km / sec ̜́ͥȅkm / sec ̜́ͥȅࢢ֔౷ৗ͉Ȅ૬̯࿩ 1.6 km ̦́͘లঅࠏ

ȁࢢ֔౷ৗ͉Ȅ૬̯࿩ 0.5 km ́͘‫ؗ‬ୟ௄Ȅո૬̦ಎ૧ൡ

ષ௙௄߲Ȅո૬̦ಎ૧ൡ२‫׆‬௄߲͂చ๤̯̞ͦ̀ͥȅ୶
ల 3 ࠏ‫ܖ‬๕͉ͅൢో̱̞̞̀̈́ȅ́୶ల२ࠏ‫ܖ‬๕͉ͅో̱̞̞̀̈́ḙ͈̏౷ৗ̥͉ͣȄ0.5
km ͅ௸ഽ‫ܢ̦ٮޏ‬ఞ̯̦ͦͥྶၸ͉́ྫ̞ȅ௸ഽࢹ௮͉

5. 8ȁີೋ۷௶ঔ୭Ȫ଎ 8. 8ȫȁडષ໐࿩ 0.1 km ͅలঅࠏ‫ئ‬௙௄߲ͅ௖൚̳ͥ͞͞௸ഽ

අͅ S ෨̤̞̀ͅໝॠ́Ȅஃ໐̥ͣఱ̧̩̹̈́̽ͤ઀̯
̩̹̈́̽ͤ͂৮࣐̱̞̠̀ͥ͢ͅࡉ̢ͥȅ1.2 km ո૬͉́Ȅ͈ಁ̞໐໦̦ࡉ̭ͣͦͥ͂ͬੰ̫͊ȄူჇ۷௶ঔ୭͂͢
̩য̹ࢹ௮ͬা̱̞̀ͥȅ૬̯࿩ 1.4 km ո૬́ S ෨௸ΙνȜή෨͈‫̦ޣג‬ఱ̧̩੝൲උ͙̜৾ͤͤ͘ͅୈഽ͉
བ̞̦͛̈́Ȅ଎ 7. 12)2* ͈ܱ჏ͬࡉ̀͜Ȅஃ໐͈́ S ෨ഽ̧͈̦͊ͣ̾ઁ̱ఱ̧̩̞̦̈́̽̀ͥȄ͕͖ೄ஌എͅ

੝൲໐͈৮࣐͉ྶၸ̜́ͥȅP ෨௸ഽ̞̾̀͜ͅ൳အ̈́߹
̦࢜ࡉ̦ͣͦͥȄ̷͕ͦ̓ࡐಠ͉̞́̈́ȅ͚̱ͧ૬̯ 0.2

௩‫̧̦̭́͂ͥࡉ̞̱͂ͥ̀ح‬Ȅྶၸ̈́௸ഽ‫͛෇͉ٮޏ‬̞ͣͦ̈́ȅࢢೲັ߃͈௸ഽ͉ȄP ෨ 2.7 km / secȄS ෨ 1.3
km / sec ̜́ͥȅ‫ئ‬௙௄߲ո‫͈ئ‬౷ৗ͉Ȅ࿩ 0.8 km ́͘లঅࠏષ௙௄߲ո૬̦ಎ૧ൡ२‫׆‬௄߲̤͂̈́̽̀ͤȄ୶ల

5. 12ȁչସॄ۷௶ঔ୭Ȫ଎ 8. 12ȫ

ȡ 0.4 km ࣞ͞͞ͅ௸̈́௄̦ခͤȄ̷ͦͬੰ̫͊૬̯͂͂
͜ͅ௩‫ࢹ̳ͥح‬௮̜́ͥ͂ࡉ̧̭̦ͥ͂́ͥȅ࿩ 0.5 km
͉́͘‫ؗ‬ୟ௄́Ȅ᠒௄̦̈́̓ࢩํսͅ໦ື̱ࣞ௸௄ͬࠁ
଼̱̞̀ͥ‫خ‬ෝ଻̦̜ͥȅࢢೲັ߃͈௸ഽ͉ȄP ෨́ 2.9

२ࠏ‫ܖ‬๕͉ͅో̱̞̞̀̈́ȅ
5. 9ȁ଼ന۷௶ঔ୭Ȫ଎ 8. 9ȫ

km / secȄS ෨́ 1.1 km / sec ̜́ͥȅȁޭஃ̞໐໦ͅࡉ̧͉ͣͦͥ͊ͣ̾Ȅਫ਼ా۷௶ঔ୭͂൳
အͅΙνȜή෨ఈ͈‫̜͈ͥ́ͥ͜͢ͅޣג‬ȅ૬̯࿩ 0.85

ȁ଎ 7. 12)1* ͈ P ෨ܱ჏͙ͬͥ͂Ȅ1.2 km ոஃ́ਅș͈૬̯̥͈ͣ฽ৣ෨̦ఉତ෇͛ͣͦͥȅඅͅȄ࿩ 0.4Ȅ0.6Ȅ̤km ͅྶၸ̈́௸ഽ‫ͦͣ͛෇̦ٮޏ‬Ȅౙ੗̈́ 2 ௄ࢹ௮͂ࡉͥ

͍͢ 1.1 km ັ߃̥͈ͣ฽ৣ෨̦࿒ၛ̞̽̀ͥḙ͉̏ͦͣȨ̭̦̏͂́ͥȅࢢ֔౷ৗ͉࿩ 0.2 km ́͘లঅࠏ‫ئ‬௙௄߲Ȅ
0.2 ȡ 0.9 km ̦లঅࠏષ௙௄߲Ȅո‫୶̦ئ‬ల२ࠏ‫ܖ‬๕Ȫ२൳଎ֲͅা̱̹௸ഽࢹ௮͂๤‫͙̱͂ͥ̀ڛ‬Ȅޫਫ਼എ̈́ࣞ
௸௄͈ೲ࿂ͅ௖൚̱̞̠̀ͥ͢ͅࡉ̢ͥȅ෨୼ఝȫ̞͂̈́̽̀ͥȅ0.85 km ັ߃͈௸ഽ‫͉ٮޏ‬Ḙ͈̏୶ల२ࠏ‫ܖ‬๕ષ࿂ͅ௖൚̳ͥȅP ෨ S ෨௸ഽ͉‫ܖ‬๕ͤ͢ષ

6.ȁ໤ၑ࠿௄ΟȜΗΟȜΗαȜΆȄ̷̸ͦͦ 1.7 ȡ 1.9 km / secȄ0.4 ȡ 0.7 km / secȄ‫ܖ‬๕ඤ͉́Ȅ5.2 ̤͍͢ 2.9 km / sec ̜́ͥȅςϋΈ̦࣐ͩͦࢢ֔౷ৗ͞໤ၑ࠿௄͈̈́̓ΟȜΗ͈ಇୟȁ଎ 7. 9)1* ͅࡉ̠ͣͦͥ͢ͅȄ૬̯ 0.9 km ັ߃ֲ̥ͣષ
༷ͅ฽ৣ̯̹ͦ P ෨͈௖̦ྶၸͅࡉͣͦȄ୶ల२ࠏ‫ܖ‬๕̦࣐̞ͩͦ̀ͥȪႝ࿐ఈȄ1981Ȉႝ࿐Ȉ1996Ȅႝ࿐Ȇ઀ఆȄ
1999ȫḙ̏ͦͣΟͻΐΗσΟȜΗͬൡ֚എͅ֋঵Ȇ‫ۯ‬ၑȄȁ‫۾‬൐౷֖̤̞͉̀ͅȄ2 ȡ 3,000 m ·ρΑ͈ତఉ̩͈δȜ

Ƚ!8!Ƚ

‫۾‬൐౷֖͈ಎ૬௄౷‫ڰڔ‬൲۷௶֔ͬ၌ဥ̱̹ VSP ༹௸ഽࢹ௮಺औȽ५କ

࠿॑ȆນাȆ೹‫̭̳ͬ͂ͥރ‬࿒എ̱͂̀ȄWeb ήρ;ΎΟȜΗαȜΑ͉̭͈̭͂ͬැ൮̤̞̀ͅै଼̱̹͈́͜

ͬέυϋΠ΀ϋΡ̱͂̀ௌै̳ͥΟȜΗαȜΑͬࢹಃ̱̹ȅ໤ၑ࠿௄ΟȜΗ͈͕̥Ȅུ༭࣬́ঀဥ̱̹ VSP ಺̜ͥȅ࡛ે͉ड೩ࡠ͈‫ܥ‬ෝ̱̥঵̴̤̽̀ͣະ਱໦̈́͜

औ̽̀৾͢ͅං̯̹ͦ෨ࠁΟȜΗͬ‫ْ̢̱̭ࠗͬ͂ͥح‬͈‫ه‬ఴ̜́ͥȅ̞̀ͥȅ෨ࠁΟȜῌ‫ܥ̳ͥ۾‬ෝ̞͉࡛̾̀ͅ౲‫͉́ٴ‬ȁུ༭࣬́ࢹಃ̱̹ΟȜΗαȜΑ͉࡛हਫ਼ඤࡠ೰͈ Hi-net
ඤ໐ Web ͈βȜΐͅςϋ·ͬಫ̜̽̀ͤȄల 6 ୯́ა̲ΟȜΗαȜΑ̱͉͂̀ະ਱໦́Ȅέ͹ͼσౙպ͈́ͺΛίυȜΡ̤͍͢Θ;ϋυȜΡ̧̦̺̫̜́ͥ́ͥȅȁ଎ 9. 1 ȡ଎ 9. 5 ͅξȜΎဥβȜΐ͈Α΢ΛίΏοΛΠ͈̜ͬ́ͤȄਅș͈‫ܥ‬ෝͬ‫̢ح‬Ȅਰ৘̵̯̞̩͈͉̀ࣽࢃ

̹ΟȜΗαȜΑ͈‫ܥ‬ෝͬদ̧̳̭̦̠͂́ͥ̈́̽̀͢ͅ
̞ͥȅা̳ȅ଎ 9. 1 ̦ΠΛίβȜΐ́ȄΈρέȆΟȜΗȆSEGY
͈ΗΈ̦Ȅ̷̸ͦͦ࠿௄ΟȜΗ͈࠿̤͍॑͢Έρέນা৫ৃȪ଎ 9. 2Ȅ଎ 9. 5ȫȄΟͻΐΗσΟȜΗ͈Θ;ϋυȜΡȪ଎ 9. 3ȫȄ̤͍͢ VSP ෨ࠁΟȜΗέ͹ͼσ͈Θ;ϋυȜΡȪ଎ 9. 4ȫ

ȁVSP ༹಺औ͈৘ঔͅष̱͉̀Ȅ۷௶ঔ୭ਔ༏ਯྦྷ͈༷ș͈βȜΐ͈͒ςϋ·̞͂̈́̽̀ͥȅςϋ·୶͈βȜΐ̮̈́̓ͬͅယ৥̧̞̹̺࢚̩̤ႛ૭̱ષ̬̳͘ȅ̤̞̀۷௶തྴȆ࠿௄ࣜ࿒ȆΟȜΗํս̈́̓ຈါ̈́ૂ༭ͬ
වႁ̳ͦ͊ਫ਼ါ͈ΟȜΗ͈ΈρέນাȪ଎ 9. 5ȫ͞Θ;ϋȁ̹͘Ȅ಺औ͉̥̈́ͤͅࢩ̞࿂ୟ̦ຈါ̜́ͤȄ۷௶ঔυȜΡ̧࣐̠̭̦ͬ͂́ͥȅྚ̺‫ܥ‬ෝ̦ઁ̞͈̈́́Ȅௌै‫ފ̮ͅ۾ܥ‬ႁ̞̹̺̞̹ȅܱ̱̀ۜ৫̞̹̱̳͘ȅ༹༷͉଎ͬ४ચ̳ͦ͊਱໦̜̠́ͧȅSEGY βȜΐ̤̞͉̀ͅȄVSP ಺औ̽̀͢ͅං̹ͣͦ෨ࠁΟȜΗȪ႕̢͊଎ 6ȫ͈έ͹ͼσͬΘ;ϋυȜΡ̧̳̭̦ͥ͂́ͥȅέ͹ͼσ͉฽ৣ༹౷ૼౝऔ́ດ੔എͅঀဥ̯̞ͦ̀ͥ SEGY ࠁ৆͉̮ͅၑٜȄ̮঑‫͈͂͜׳‬ȄΨͼήτȜΗ͈௧‫إ‬Ȅૼ൲୭̤͍͢ਔ༏͈ാ౷ͬ‫ۯ‬ၑ̳ͥࡇȄঌȄ಴Ȅఆ͈‫߸۾‬੨४ࣉ໲ࡃ
1ȫ Barry, K. M., D. A. Cavers, and C. W. Kneale )1975*:
Recommended standards for digital tape formats.

ȪBarry et al., 1975ȫȄ̹͉͘ SEGY ࠁ৆ͅ੔‫ ̹̱ݶ‬SU ࠁ৆

Geophysics, 40, 344-352.

ȪCohen and Stockwell, 1997ȫͬே೰̱̞̀ͥȅȁ ଎ 9. 6 ̤ ͢ ͍ ଎ 9. 7 ͅ Ο Ȝ Η α Ȝ Α ֋ ঵Ȇ ‫ ۯ‬ၑ ဥ ͈

2ȫ Cohen, J. K., and J. W. Stockwell Jr. )1997*: CWP/SU,ΠΛίβȜΐͬা̳ḙ͈̏ͦͣβȜΐ͉ȄΓ΅νςΞͻͬࣉၪ̱ URL ͬ‫ڎ‬ș༆̱ͅȄ̥̾ξȜΎྴ̤͍͢ΩΑχȜresearch and processing. Center for Wave Phenomena,Ρ͈වႁͬါ‫̳̓̈́ͥݥ‬Ȅ๊֚ξȜΎ͉ͺ·ΓΆ̧̞̠̈́͢ͅ୭೰̱̜̀ͥȅ଎ 9. 6 ͈βȜΐ̤̞͉̀ͅȄ۷௶͈֔૧ܰഴ჏Ȅ࠿௄ΟȜΗࣜ࿒͈೏‫ح‬ഴ჏Ȅഴ჏ΟȜΗ֚။ນাȆॉੰȄ̤͍͢ഴ჏ΟȜΗ͈೏‫ح‬Ȇॉੰ̈́̓‫ۯ‬ၑௌै͈၎Ⴄນা̧࣐̠̭̦ͬ͂́ͥȅ଎ 9. 7 ͈‫ۯ‬ၑ

Seismic Unix Release 30, a free package for seismicColorado School of Mines.
3ȫ ֔୼࿊Ȇఊനု֚Ȇఱୌୃ੗Ȇುֵ໌໲Ȫ1986ȫȇ฽ȁȁৣ༹౷ૼܱ჏ͥ͢ͅ௄պٜଢ଼͈֚਀༹ȅ୞࿳ܿ੅‫ފ‬ٛধȄ51Ȅ24-35ȅ
4ȫ Kennet, P., R. L. Iresson, and P. J. Conn )1980*: Verticalseismic profi ling: their applications in exploration
geophysics. Geophys. Prosp., 28, 676-699.

βȜΐ͉́Ȅ஠ΟȜΗαȜΑ͈ΨΛ·ͺΛί̤͍͢ςΑΠͺ͈‫ܥ‬ෝͬ঵̾ȅΨΛ·ͺΛί͉Ȅஜ̥͈ٝͣओ໦ͬ

5ȫ ࿐ ఆ ં ‫ ܮ‬Ȇ ‫ ۾‬൐ ൐ ٬ ౷ ‫ ڰ ڔ‬൲ ۷ ௶ ࡄ ‫ ݪ‬Έ σ Ȝ ίܱ჏̳ͥȅਲ̽̀Ȅၾഎ͜ͅઁ̩̳͙̈́̀Ȅ̜ͥশത͈

ȁȁȪ2001ȫȇ‫۾‬൐Ȇ൐٬౷֖̤̫ͥͅड߃ 20 ා‫͈ۼ‬౷ૼેఠ̯̥͈͖́̽̀͘ςΑΠͺ̳̭ͥ͂͜ယօͅ‫خ‬ෝ́‫ڰ‬൲Ƚඅ༆ࡄ‫ݪ‬ȶ‫۾‬൐Ȇ൐٬౷֖̤̫ͥͅ౷‫ڰڔ‬൲ͅ‫ݪࡄ̳ͥ۾‬ȷ۷௶଼‫͈͛͂͘ض‬Ȫ̷͈ 2ȫȅཡब‫ش‬̜ͥȅ
7.ȁ̤ͩͤͅ

‫ݪࡄ੅ܿڠ‬ਫ਼ࡄ‫ݪ‬঩ၳȄNo. 209, 130 ppȅ
6ȫ ઐ ఆ ୃ २ Ȇ ‫ ۾‬൐ ൐ ٬ ౷ ‫ ڰ ڔ‬൲ ۷ ௶ ࡄ ‫ ݪ‬Έ σ Ȝ ίȁಎ૬௄۷௶ঔ୭͈۷௶௡౾͉Ȅ੝‫͉͈͈͜ܢ‬࿩ 10 ා

ȁȁȪ2002ȫȇ‫۾‬൐Ȇ൐٬౷֖̤̫ͥͅड߃ 20 ා‫͈ۼ‬౷ૼࠐً̱Ⴧ‫̦اݤ‬࿒ၛ̻ই̧̹͛̀ȅ‫̢̀ح‬Ȅ1995 ාഽ۷௶ࠫ‫ض‬Ȫอૼ‫ࢹܥ‬ٜȫȽඅ༆ࡄ‫ݪ‬ȶ‫۾‬൐Ȇ൐٬౷̥͉ͣ૧̱̞۷௶ΏΑΞθͬनဥ̱̹ࣞۜഽ౷ૼ۷௶࿌
ȪHi-netȫ͈஠࣭ജ‫͙ૺ̦ٳ‬Ȅೊແ‫̦ا‬ಠ̧̱̩̹̈́̽̀ȅ֖̤̫ͥͅ౷‫ڰڔ‬൲ͅ‫ݪࡄ̳ͥ۾‬ȷ۷௶଼‫͈͂͘ض‬͛Ȫ̷͈ 4ȫȅཡब‫ݪࡄ੅ܿڠش‬ਫ਼ࡄ‫ݪ‬঩ၳȄNo. 224,

̭͈̹͛ಎ૬௄۷௶ঔ୭͈۷௶௡౾͈ࢵ૧ȪHi-net ‫ا‬ȫْ̦̯ࠗͦȄ2002 ාഽ৘ঔ̯̹ͦȅ۷௶֔ͬ၌ဥ̱̹ VSP

7ȫ ࿤࢛૝֚Ȇ௩ঊඃൽȆ‫۾‬൐൐٬౷‫ڰڔ‬൲۷௶ࡄ‫ݪ‬Έ༹ͥ͢ͅ P0S ෨௸ഽࢹ௮಺औ͉Ḙ͈̏ࢵ૧ࢥমͬ‫ܥ‬ٛͅȁȁσȜίȪ2003ȫȇ‫۾‬൐Ȇ൐٬౷֖౷ૼ۷௶࿌ͥ͢ͅૼ

84 ppȅ

࣐̹͈̜̽́ͥ͜ȅ࡙͈শߗ‫ۼ‬໦ື͂ܰ࿅໦ື̞̾̀ͅȽඅ༆ࡄ‫ݪ‬ȶ‫۾‬ȁHi-net ͉۷௶֔ͬ‫ུ̳ͥ͂ܖ‬ȅ۷௶֔ߡॉশ͉ͅດ੔എ
ͅ P0S ࠿௄͉̲̱̹ͬ͛͂‫ڎ‬ਅ໤ၑ࠿௄̦৘ঔ̯̭ͦͥ

൐Ȇ൐٬౷֖̤̫ͥͅ౷‫ڰڔ‬൲ͅ‫ݪࡄ̳ͥ۾‬ȷ۷௶଼‫͈͛͂͘ض‬Ȫ̷͈ 5ȫȅཡब‫ݪࡄ੅ܿڠش‬ਫ਼ࡄ‫ݪ‬঩ၳȄ̞͂̈́̽̀ͥͅḙ͈̏ Hi-net ͈஠࣭ജ‫̞̈́͂͜ͅٳ‬Ȅ‫ڎ‬

No. 239, 71 ppȅਅ໤ၑ࠿௄̈́̓ͤ͢ͅ౷‫ࢹئ‬௮ͅ‫̳ͥ۾‬ΟȜΗ̦ਬୟ̯8ȫ ఊനဉȆࢃ൥ങੇȆ‫؂‬࿤ࠗংȆࣞ‫ޘ‬ฎȆ५କঃ୆Ȩ̞̑ͦ̀̀ͥḙ͈̏ͦͣཛྷఱ̈́ΟȜΗͬ֋঵‫ۯ‬ၑ̱ခ࢘ȁȁߪࡔਹ၌Ȫ1977ȫȇ͞͞૬̞ࢹ௮͈ S ෨௸ഽȽ‫܊‬ೖ
3,500 m ౷ૼ۷௶͈֔́௶೰̷͈͂փ݅Ƚȅ౷ૼ 2Ȅͅ၌ဥ̳̹͉ͥ͛ȄΟȜΗέ΁ȜζΛΠͬൡ̱֚ΟȜΗαȜΑͬࢹಃ̳͈̦ͥडၻ༹͈༷̜̠́ͧȅུ༭͈࣬

Ƚ!9!Ƚ

31Ȅ415-433ȅཡब‫ݪࡄ੅ܿڠش‬ਫ਼ࡄ‫ݪ‬঩ၳȁల!251!࣢ȁ2004!ා!3!࠮

9ȫ ఊനဉȆࢃ൥ങੇȆ‫؂‬࿤ࠗংȆࣞ‫ޘ‬ฎȆ५କঃ୆Ȇȁȁߪࡔਹ၌Ȫ1978ȫȇ͞͞૬̞ࢹ௮͈ S ෨௸ഽȪ2ȫȽ‫ئ‬௙ 2,300 m ౷ૼ۷௶̤̫֔ͥͅ௶೰Ƚȅ౷ૼ 2Ȅ31Ȅȁȁਉസ࠷౷֖͈౷ৗࢹ௮ȅཡब‫ݪࡄ੅ܿڠش‬ਫ਼ࡄ‫ݪ‬༭࣬ȄNo. 56Ȅ77-123ȅ
14* ႝ࿐ࢤ༿Ȇ઀ఆ࠲ఊ჊Ȫ1999ȫȇ‫۾‬൐౷֖ࢢ֔ΟȜ

10* ‫ؖ‬ന݅࢕Ȇઐఆୃ२Ȇ࿤࢛૝֚Ȫ2000ȫȇ‫۾‬൐Ȇ൐٬ȁȁΗ঩ၳਬȅཡब‫ݪࡄ੅ܿڠش‬ਫ਼ࡄ‫ݪ‬঩ၳȄNo. 191, 80ppȅȁȁ౷֖౷‫ڰڔ‬൲۷௶࿌͈‫ؾ‬൲ે‫ޙ‬Ƚඅ༆ࡄ‫ݪ‬ȶ‫۾‬൐Ȇ൐

15* ५କঃ୆Ȇࣞ‫ޘ‬ฎȆࢃ൥ങੇȆఊനဉȪ1981ȫȇ͞͞٬౷֖̤̫ͥͅ౷‫ڰڔ‬൲ͅ‫ݪࡄ̳ͥ۾‬ȷ۷௶଼‫͈ض‬͂͛͘Ȫ̷͈ 1ȫȅཡब‫ݪࡄ੅ܿڠش‬ਫ਼ࡄ‫ݪ‬঩ၳȄNo.

ȁȁ૬̞ࢹ௮͈ S ෨௸ഽȪ3ȫȽຸಎ 2,750 m ۷௶̤̫֔ͅ
ͥ௶೰͂͂͛͘Ƚȅ౷ૼ 2Ȅ34Ȅ465-479ȅ

208, 57 ppȅ

16* Yamamizu, F., N. Goto, Y. Ohta, and H. Takahashi

299-308ȅ

11* ‫࢛۾‬ખষȪ2001ȫȇ‫۾‬൐൐٬౷֖͈3ষࡓ௸ഽࢹ௮Ƚ

)1983*: Attenuation of shear waves in deep soil
deposits as revealed by down-hole measurements in theȁȁඅ༆ࡄ‫ݪ‬ȶ‫۾‬൐Ȇ൐٬౷֖̤̫ͥͅ౷‫ڰڔ‬൲ͅ‫̳۾‬ͥࡄ‫ݪ‬ȷ۷௶଼‫͈͛͂͘ض‬Ȫ̷͈ 3ȫȅཡब‫੅ܿڠش‬2,300meter-borehole of the Shimohsa observatory, Japan.

ࡄ‫ݪ‬ਫ਼ࡄ‫ݪ‬঩ၳȄNo. 213, 55 ppȅ
12* ႝ࿐ࢤ༿Ȇ౻നၦংȆࢄঊড়ୃȆ࿐‫้ئ‬ຳȆऎ൥੉ຳȆ

17* ५କঃ୆Ȫ1996ȫȇVSP༹಺औȅਉസ࠷ೄ‫͈ئ‬౷ૼȁȁࣞ‫ޘ‬ฎȪ1981ȫȇ‫۾‬൐Ȇ൐٬౷֖̤̫ͥͅࢢ֔࠿௄঩
ၳਬȅཡब‫ݪࡄ੅ܿڠش‬ਫ਼ࡄ‫ݪ‬঩ၳȄNo. 65Ȅ162 ppȅȁȁ͈ထ౶਀༹͈ࣞഽ‫̳ͥ۾ͅا‬௙ࣣࡄ‫ض଼ݪ‬༭࣬੥Ȅ
79-94ȅ

13* ႝ࿐ࢤ༿Ȫ1996ȫȇࢺ൐૬௄౷‫ڰڔ‬൲۷௶͈֔౷ৗ͂

Ȫࡔࣂ਋ၑȇ2004 ා 1 ࠮ 29 ඾ȫ

J. Phys. Earth, 31, 139-157.

Ƚ!10!Ƚ

‫۾‬൐౷֖͈ಎ૬௄౷‫ڰڔ‬൲۷௶֔ͬ၌ဥ̱̹ VSP ༹௸ഽࢹ௮಺औȽ५କါȁকȁཡब‫ݪࡄ੅ܿڠش‬ਫ਼͈‫۾‬൐Ȇ൐٬౷‫ڰڔ‬൲۷௶࿌͈֚໐̱͂̀‫۾‬൐౷֖ͅା๵̯̹ͦࢩ֖૬໐۷௶ঔ୭ 12 ̥ਫ਼͈۷௶֔ͬ၌ဥ̱̀ VSP ༹಺औ࣐̞ͬȄમळ̈́ P ෨ S ෨௸ഽࢹ௮̦ං̹ͣͦȅ۷௶͈֔૬ഽ͉Ȅ2,000 m ͬ‫୶ུ̱͂ܖ‬ల२ࠏ‫ܖ‬๕͈ஃ̞̭͉͂ͧ́ 1,200 m ̞̱̈́ 1,300 m ͈͈̜ͥ͜͜ȅP ෨ૼ࡙̱͂̀ȄΨͼήυ΍ͼΑΨͼήτȜΗͬȄ
S ෨ૼ࡙̱͂̀අਂ̈́ΨͼήτȜΗͬঀဥ̱̹ȅ௶೰‫ ͉ڞۼ‬0 ȡ 500 m ͉́͘ 25 m ྀȄո૬͉ࢢೲ́͘ 50 m ྀ̜́ͥȅ̴̞͈ͦ۷௶̤̞֔̀͜ͅࢢೲັ߃́͘ P ෨ S ෨͂͜ྶၸܱ̈́჏̦ං̞ͣͦ̀ͥȅඅͅȄS ෨ΨͼήτȜῌܱͥ͢჏͉Ȅ̴̞͈ͦ۷௶̤̞֔̀͜ͅࢢೲັ߃́͘άνͺ̈́ S ෨̦ܱ჏̯̤ͦ̀ͤȄْ‫ܢ‬എ̈́ࠫ‫̜ͥ́ض‬ȅP ෨ S ෨̷̸͈ͦͦ௢শͬȄ‫ڎ‬૬ഽ̤̫ͥͅ෨ࠁ͈௖ࡽ௖‫ͥ͢ͅ۾‬ΗͼθρΈ̥ͣࠨ೰̱ȄCubic spline ‫۾‬ତͥ͢ͅඤொͤ͢ͅ 25m ‫಺ͅڞۼ‬ା̱Ȅତ౵๷໦ͤ͢ͅમळ̈́௸ഽࢹ௮ͬࠨ೰̱̹ȅ̹͘Ȅ‫ڎ‬௢শެ஌͉ତུ͈ೄ஌́߃য̧̭̥́ͥ͂ͣȄ̤̤̥͘ͅତ௄଼ͤͥ͢௄ࢹ௮̱̹͂໹޳എ̈́௸ഽࢹ௮͜া̱̹ȅ̴̞͈ͦ۷௶͈֔́ࠫ‫͜ض‬Ȅ౷ৗࢹ௮͞‫ڎ‬ਅ໤ၑ࠿௄ࠫ‫಺͂ض‬გഎ̜́ͤȄ૞ှ଻̢͈̞͈̜̞ࣞ́ͥ͂ͥ͜ȅȁ‫ܡ‬ం͈໤ၑ࠿௄൝͈ΟͻΐΗσΟȜΗͬൡ֚എͅ֋঵Ȇ‫ۯ‬ၑȆ࠿॑ȆນাȆ೹‫̭̳ͬ͂ͥރ‬࿒എ̱͂̀ȄΟȜΗαȜΑͬࢹಃ̱̹ȅ̺͘ड઀ࡠ͈‫ܥ‬ෝ̱̥๵̢̞̞̦̀̈́ȄWeb ήρ;Ύ̤̱ͬ͂Ȅ࠿௄ΟȜΗ͈࠿॑ȄΈρέນাȄΟȜΗ͈Θ;ϋυȜΡ̧࣐̠̭̦ͬ͂́ͥȅ֋঵‫ۯ‬ၑဥ͈‫ܥ‬ෝ͉ȄΓ΅νςΞͻͬࣉၪ̱ΩΑχȜΡ༗ࢌ̯̹ͦ༆
βȜΐͅͺ·ΓᾺ̱࣐̠̠̞̈́̽̀ͥ͢ͅȅ΅ȜχȜΡȇVSP ༹Ȅ௸ഽࢹ௮Ȅ໤ၑ࠿௄Ȅಎ૬௄۷௶ঔ୭Ȅࣞۜഽ౷ૼ۷௶࿌Ȅ‫۾‬൐൐٬۷௶࿌

Ƚ!11!Ƚ

ȁȁȁȁȁ଎ 7. 1 (1)࢚࿐۷௶̤̫֔ͥͅ P ෨ૼ࡙ͥ͢ͅષ‫ئ‬൲ܱ჏ȪऒȫȄ௢শެ஌Ȫಎ؇ȫȄP ෨௸ഽࢹ௮Ȫֲȫ
Fig. 7. 1 (1) Paste-up of the vertical component records by the P wave source )left*, reduced travel time depth plot )middle*, and P wave velocity structure )right* of the Atsugi well.

ཡब‫ݪࡄ੅ܿڠش‬ਫ਼ࡄ‫ݪ‬঩ၳȁల!251!࣢ȁ2004!ා!3!࠮

Ƚ!12!Ƚ

ȁȁȁȁ଎ 7. 1 (2)࢚࿐۷௶̤̫֔ͥͅ S ෨ૼ࡙ͥ͢ͅକ໹൲ܱ჏ȪऒȫȄ௢শެ஌Ȫಎ؇ȫȄS ෨௸ഽࢹ௮Ȫֲȫ
Fig. 7. 1 (2) Paste-up of the horizontal component records by the S wave source )left*, reduced travel time depth plot )middle*, and S wave velocity structure )right* of the Atsugi well.

‫۾‬൐౷֖͈ಎ૬௄౷‫ڰڔ‬൲۷௶֔ͬ၌ဥ̱̹ VSP ༹௸ഽࢹ௮಺औȽ५କ

Ƚ!13!Ƚ

ȁȁȁȁ଎ 7. 2 (1)‫؍‬ຩ۷௶̤̫֔ͥͅ P ෨ૼ࡙ͥ͢ͅષ‫ئ‬൲ܱ჏ȪऒȫȄ௢শެ஌Ȫಎ؇ȫȄP ෨௸ഽࢹ௮Ȫֲȫ
Fig. 7. 2 (1) Paste-up of the vertical component records by the P wave source )left*, reduced travel time depth plot )middle*, and P wave velocity structure )right* of the Yokohama well.

ཡब‫ݪࡄ੅ܿڠش‬ਫ਼ࡄ‫ݪ‬঩ၳȁల!251!࣢ȁ2004!ා!3!࠮

Ƚ!14!Ƚ

ȁȁȁ଎ 7. 2 (2)‫؍‬ຩ۷௶̤̫֔ͥͅ S ෨ૼ࡙ͥ͢ͅକ໹൲ܱ჏ȪऒȫȄ௢শެ஌Ȫಎ؇ȫȄS ෨௸ഽࢹ௮Ȫֲȫ
Fig. 7. 2 (2) Paste-up of the horizontal component records by the S wave source )left*, reduced travel time depth plot )middle*, and S wave velocity structure )right* of the Yokohama well.

‫۾‬൐౷֖͈ಎ૬௄౷‫ڰڔ‬൲۷௶֔ͬ၌ဥ̱̹ VSP ༹௸ഽࢹ௮಺औȽ५କ

Ƚ!15!Ƚ

ȁȁȁȁ଎ 7. 3 (1)ୌ࿤ࡔ۷௶̤̫֔ͥͅ P ෨ૼ࡙ͥ͢ͅષ‫ئ‬൲ܱ჏ȪऒȫȄ௢শެ஌Ȫಎ؇ȫȄP ෨௸ഽࢹ௮Ȫֲȫ
Fig. 7. 3 (1) Paste-up of the vertical component records by the P wave source )left*, reduced travel time depth plot )middle*, and P wave velocity structure )right* of the Nishinohara well.

ཡब‫ݪࡄ੅ܿڠش‬ਫ਼ࡄ‫ݪ‬঩ၳȁల!251!࣢ȁ2004!ා!3!࠮

Ƚ!16!Ƚ

ȁȁȁ଎ 7. 3 (2)ୌ࿤ࡔ۷௶̤̫֔ͥͅ S ෨ૼ࡙ͥ͢ͅକ໹൲ܱ჏ȪऒȫȄ௢শެ஌Ȫಎ؇ȫȄS ෨௸ഽࢹ௮Ȫֲȫ
Fig. 7. 3 (2) Paste-up of the horizontal component records by the S wave source )left*, reduced travel time depth plot )middle*, and S wave velocity structure )right* of the Nishinohara well.

‫۾‬൐౷֖͈ಎ૬௄౷‫ڰڔ‬൲۷௶֔ͬ၌ဥ̱̹ VSP ༹௸ഽࢹ௮಺औȽ५କ

Ƚ!17!Ƚ

ȁȁȁȁ଎ 7. 4 (1)ਫ਼ా۷௶̤̫֔ͥͅ P ෨ૼ࡙ͥ͢ͅષ‫ئ‬൲ܱ჏ȪऒȫȄ௢শެ஌Ȫಎ؇ȫȄP ෨௸ഽࢹ௮Ȫֲȫ
Fig. 7. 4 (1) Paste-up of the vertical component records by the P wave source )left*, reduced travel time depth plot )middle*, and P wave velocity structure )right* of the Tokorozawa well.

ཡब‫ݪࡄ੅ܿڠش‬ਫ਼ࡄ‫ݪ‬঩ၳȁల!251!࣢ȁ2004!ා!3!࠮

Ƚ!18!Ƚ

ȁȁȁ଎ 7. 4 (2)ਫ਼ా۷௶̤̫֔ͥͅ S ෨ૼ࡙ͥ͢ͅକ໹൲ܱ჏ȪऒȫȄ௢শެ஌Ȫಎ؇ȫȄS ෨௸ഽࢹ௮Ȫֲȫ
Fig. 7. 4 (2) Paste-up of the horizontal component records by the S wave source )left*, reduced travel time depth plot )middle*, and S wave velocity structure )right* of the Tokorozawa well.

‫۾‬൐౷֖͈ಎ૬௄౷‫ڰڔ‬൲۷௶֔ͬ၌ဥ̱̹ VSP ༹௸ഽࢹ௮಺औȽ५କ

Ƚ!19!Ƚ

ȁȁȁȁȁ଎ 7. 5 (1) ඾ࣞ۷௶̤̫֔ͥͅ P ෨ૼ࡙ͥ͢ͅષ‫ئ‬൲ܱ჏ȪऒȫȄ௢শެ஌Ȫಎ؇ȫȄP ෨௸ഽࢹ௮Ȫֲȫ
Fig. 7. 5 (1) Paste-up of the vertical component records by the P wave source )left*, reduced travel time depth plot )middle*, and P wave velocity structure )right* of the Hidaka well.

ཡब‫ݪࡄ੅ܿڠش‬ਫ਼ࡄ‫ݪ‬঩ၳȁల!251!࣢ȁ2004!ා!3!࠮

Ƚ!20!Ƚ

ȁȁȁȁ଎ 7. 5 (2) ඾ࣞ۷௶̤̫֔ͥͅ S ෨ૼ࡙ͥ͢ͅକ໹൲ܱ჏ȪऒȫȄ௢শެ஌Ȫಎ؇ȫȄS ෨௸ഽࢹ௮Ȫֲȫ
Fig. 7. 5 (2) Paste-up of the horizontal component records by the S wave source )left*, reduced travel time depth plot )middle*, and S wave velocity structure )right* of the Hidaka well.

‫۾‬൐౷֖͈ಎ૬௄౷‫ڰڔ‬൲۷௶֔ͬ၌ဥ̱̹ VSP ༹௸ഽࢹ௮಺औȽ५କ

Ƚ!21!Ƚ

ȁȁȁȁȁ଎ 7. 6 (1)୷ဩ۷௶̤̫֔ͥͅ P ෨ૼ࡙ͥ͢ͅષ‫ئ‬൲ܱ჏ȪऒȫȄ௢শެ஌Ȫಎ؇ȫȄP ෨௸ഽࢹ௮Ȫֲȫ
Fig. 7. 6 (1) Paste-up of the vertical component records by the P wave source )left*, reduced travel time depth plot )middle*, and P wave velocity structure )right* of the Chiba well.

ཡब‫ݪࡄ੅ܿڠش‬ਫ਼ࡄ‫ݪ‬঩ၳȁల!251!࣢ȁ2004!ා!3!࠮

Ƚ!22!Ƚ

ȁȁȁȁ଎ 7. 6 (2)୷ဩ۷௶̤̫֔ͥͅ S ෨ૼ࡙ͥ͢ͅକ໹൲ܱ჏ȪऒȫȄ௢শެ஌Ȫಎ؇ȫȄS ෨௸ഽࢹ௮Ȫֲȫ
Fig. 7. 6 (2) Paste-up of the horizontal component records by the S wave source )left*, reduced travel time depth plot )middle*, and S wave velocity structure )right* of the Chiba well.

‫۾‬൐౷֖͈ಎ૬௄౷‫ڰڔ‬൲۷௶֔ͬ၌ဥ̱̹ VSP ༹௸ഽࢹ௮಺औȽ५କ

Ƚ!23!Ƚ

ȁȁȁȁȁ଎ 7. 7 (1)ူჇ۷௶̤̫֔ͥͅ P ෨ૼ࡙ͥ͢ͅષ‫ئ‬൲ܱ჏ȪऒȫȄ௢শެ஌Ȫಎ؇ȫȄP ෨௸ഽࢹ௮Ȫֲȫ
Fig. 7. 7 (1) Paste-up of the vertical component records by the P wave source )left*, reduced travel time depth plot )middle*, and P wave velocity structure )right* of the Yohro well.

ཡब‫ݪࡄ੅ܿڠش‬ਫ਼ࡄ‫ݪ‬঩ၳȁల!251!࣢ȁ2004!ා!3!࠮

Ƚ!24!Ƚ

ȁȁȁȁ଎ 7. 7 (2)ူჇ۷௶̤̫֔ͥͅ S ෨ૼ࡙ͥ͢ͅକ໹൲ܱ჏ȪऒȫȄ௢শެ஌Ȫಎ؇ȫȄS ෨௸ഽࢹ௮Ȫֲȫ
Fig. 7. 7 (2) Paste-up of the horizontal component records by the S wave source )left*, reduced travel time depth plot )middle*, and S wave velocity structure )right* of the Yohro well.

‫۾‬൐౷֖͈ಎ૬௄౷‫ڰڔ‬൲۷௶֔ͬ၌ဥ̱̹ VSP ༹௸ഽࢹ௮಺औȽ५କ

Ƚ!25!Ƚ

ȁȁȁȁȁ଎ 7. 8 (1)ີೋ۷௶̤̫֔ͥͅ P ෨ૼ࡙ͥ͢ͅષ‫ئ‬൲ܱ჏ȪऒȫȄ௢শެ஌Ȫಎ؇ȫȄP ෨௸ഽࢹ௮Ȫֲȫ
Fig. 7. 8 (1) Paste-up of the vertical component records by the P wave source )left*, reduced travel time depth plot )middle*, and P wave velocity structure )right* of the Futtsu well.

ཡब‫ݪࡄ੅ܿڠش‬ਫ਼ࡄ‫ݪ‬঩ၳȁల!251!࣢ȁ2004!ා!3!࠮

Ƚ!26!Ƚ

ȁȁȁȁ଎ 7. 8 (2)ີೋ۷௶̤̫֔ͥͅ S ෨ૼ࡙ͥ͢ͅକ໹൲ܱ჏ȪऒȫȄ௢শެ஌Ȫಎ؇ȫȄS ෨௸ഽࢹ௮Ȫֲȫ
Fig. 7. 8 (2) Paste-up of the horizontal component records by the S wave source )left*, reduced travel time depth plot )middle*, and S wave velocity structure )right* of the Futtsu well.

‫۾‬൐౷֖͈ಎ૬௄౷‫ڰڔ‬൲۷௶֔ͬ၌ဥ̱̹ VSP ༹௸ഽࢹ௮಺औȽ५କ

Ƚ!27!Ƚ

ȁȁȁȁȁ଎ 7. 9 (1)଼ന۷௶̤̫֔ͥͅ P ෨ૼ࡙ͥ͢ͅષ‫ئ‬൲ܱ჏ȪऒȫȄ௢শެ஌Ȫಎ؇ȫȄP ෨௸ഽࢹ௮Ȫֲȫ
Fig. 7. 9 (1) Paste-up of the vertical component records by the P wave source )left*, reduced travel time depth plot )middle*, and P wave velocity structure )right* of the Narita well.

ཡब‫ݪࡄ੅ܿڠش‬ਫ਼ࡄ‫ݪ‬঩ၳȁల!251!࣢ȁ2004!ා!3!࠮

Ƚ!28!Ƚ

ȁȁȁȁ଎ 7. 9 (2)଼ന۷௶̤̫֔ͥͅ S ෨ૼ࡙ͥ͢ͅକ໹൲ܱ჏ȪऒȫȄ௢শެ஌Ȫಎ؇ȫȄS ෨௸ഽࢹ௮Ȫֲȫ
Fig. 7. 9 (2) Paste-up of the horizontal component records by the S wave source )left*, reduced travel time depth plot )middle*, and S wave velocity structure )right* of the Narita well.

‫۾‬൐౷֖͈ಎ૬௄౷‫ڰڔ‬൲۷௶֔ͬ၌ဥ̱̹ VSP ༹௸ഽࢹ௮಺औȽ५କ

Ƚ!29!Ƚ

ȁȁȁȁ଎ 7. 10 (1)Fig. 7. 10 (1)Ƚ!30!Ƚ

ࢺ࡫ॄ۷௶̤̫֔ͥͅ P ෨ૼ࡙ͥ͢ͅષ‫ئ‬൲ܱ჏ȪऒȫȄ௢শެ஌Ȫಎ؇ȫȄP ෨௸ഽࢹ௮Ȫֲȫ

Paste-up of the vertical component records by the P wave source )left*, reduced travel time depth plot )middle*, and P wave velocity structure )right* of the Edosaki well.

ཡब‫ݪࡄ੅ܿڠش‬ਫ਼ࡄ‫ݪ‬঩ၳȁల!251!࣢ȁ2004!ා!3!࠮

ȁȁȁȁ଎ 7. 10 (2)ࢺ࡫ॄ۷௶̤̫֔ͥͅ S ෨ૼ࡙ͥ͢ͅକ໹൲ܱ჏ȪऒȫȄ௢শެ஌Ȫಎ؇ȫȄS ෨௸ഽࢹ௮Ȫֲȫ
Fig. 7. 10 (2) Paste-up of the horizontal component records by the S wave source )left*, reduced travel time depth plot )middle*, and S wave velocity structure )right* of the Edosaki well.

‫۾‬൐౷֖͈ಎ૬௄౷‫ڰڔ‬൲۷௶֔ͬ၌ဥ̱̹ VSP ༹௸ഽࢹ௮಺औȽ५କ

Ƚ!31!Ƚ

ȁȁȁȁ଎ 7. 11 (1)૯‫ؖ‬۷௶̤̫֔ͥͅ P ෨ૼ࡙ͥ͢ͅષ‫ئ‬൲ܱ჏ȪऒȫȄ௢শެ஌Ȫಎ؇ȫȄP ෨௸ഽࢹ௮Ȫֲȫ
Fig. 7. 11 (1) Paste-up of the vertical component records by the P wave source )left*, reduced travel time depth plot )middle*, and P wave velocity structure )right* of the Mohka well.

ཡब‫ݪࡄ੅ܿڠش‬ਫ਼ࡄ‫ݪ‬঩ၳȁల!251!࣢ȁ2004!ා!3!࠮

Ƚ!32!Ƚ

ȁȁȁȁ଎ 7. 11 (2)૯‫ؖ‬۷௶̤̫֔ͥͅ S ෨ૼ࡙ͥ͢ͅକ໹൲ܱ჏ȪऒȫȄ௢শެ஌Ȫಎ؇ȫȄS ෨௸ഽࢹ௮Ȫֲȫ
Fig. 7. 11 (2) Paste-up of the horizontal component records by the S wave source )left*, reduced travel time depth plot )middle*, and S wave velocity structure )right* of the Mohka well.

‫۾‬൐౷֖͈ಎ૬௄౷‫ڰڔ‬൲۷௶֔ͬ၌ဥ̱̹ VSP ༹௸ഽࢹ௮಺औȽ५କ

Ƚ!33!Ƚ

ȁȁȁȁ଎ 7. 12 (1)չସॄ۷௶̤̫֔ͥͅ P ෨ૼ࡙ͥ͢ͅષ‫ئ‬൲ܱ჏ȪऒȫȄ௢শެ஌Ȫಎ؇ȫȄP ෨௸ഽࢹ௮Ȫֲȫ
Fig. 7. 12 (1) Paste-up of the vertical component records by the P wave source )left*, reduced travel time depth plot )middle*, and P wave velocity structure )right* of the Isesaki well.

ཡब‫ݪࡄ੅ܿڠش‬ਫ਼ࡄ‫ݪ‬঩ၳȁల!251!࣢ȁ2004!ා!3!࠮

Ƚ!34!Ƚ

ȁȁȁȁ଎ 7. 12 (2)չସॄ۷௶̤̫֔ͥͅ S ෨ૼ࡙ͥ͢ͅକ໹൲ܱ჏ȪऒȫȄ௢শެ஌Ȫಎ؇ȫȄS ෨௸ഽࢹ௮Ȫֲȫ
Fig. 7. 12 (2) Paste-up of the horizontal component records by the S wave source )left*, reduced travel time depth plot )middle*, and S wave velocity structure )right* of the Isesaki well.

‫۾‬൐౷֖͈ಎ૬௄౷‫ڰڔ‬൲۷௶֔ͬ၌ဥ̱̹ VSP ༹௸ഽࢹ௮಺औȽ५କ

Ƚ!35!Ƚ

ȁȁȁȁȁȁȁȁ଎ 8. 1 (1)࢚࿐۷௶̤̫֔ͥͅࢢ֔౷ৗࢹ௮ȄP ෨௸ഽࢹ௮ȄS ෨௸ഽࢹ௮Ȅ‫إ‬෨࠿௄Ȅ̤͍͢ྟഽ࠿௄ࠫ‫͈ض‬๤‫ڛ‬
Fig. 8. 1 (1) Comparison of the well geology, P and S wave velocity structure obtained by the VSP measurement, and sonic velocity and density logs of the Atsugi well.

ཡब‫ݪࡄ੅ܿڠش‬ਫ਼ࡄ‫ݪ‬঩ၳȁల!251!࣢ȁ2004!ා!3!࠮

Ƚ!36!Ƚ

ȁȁȁȁȁ଎ 8. 1 (2)࢚࿐۷௶̤̫֔ͥͅࢢ֔౷ৗࢹ௮Ȅ‫إ‬෨௸ഽȄྟഽȄ‫أ‬ഽȄুடഩպȄ๤೷ࢯȄΠȜΗσ΄ϋζȄ̤͍͢ࢢࠂ࠿௄ࠫ‫͈ض‬๤‫ڛ‬
Fig. 8. 1 (2) Well geology and line up of logging results of Atsugi well. Log items are sonic velocity, density, temperature, spontaneous potential, resistivity, total gamma, and caliper.

‫۾‬൐౷֖͈ಎ૬௄౷‫ڰڔ‬൲۷௶֔ͬ၌ဥ̱̹ VSP ༹௸ഽࢹ௮಺औȽ५କ

Ƚ!37!Ƚ

ȁȁȁȁȁȁȁ଎ 8. 2 (1)‫؍‬ຩ۷௶̤̫֔ͥͅࢢ֔౷ৗࢹ௮ȄP ෨௸ഽࢹ௮ȄS ෨௸ഽࢹ௮Ȅ‫إ‬෨࠿௄Ȅ̤͍͢ྟഽ࠿௄ࠫ‫͈ض‬๤‫ڛ‬
Fig. 8. 2 (1) Comparison of the well geology, P and S wave velocity structure obtained by the VSP measurement, and sonic velocity and density logs of the Yokohama well.

ཡब‫ݪࡄ੅ܿڠش‬ਫ਼ࡄ‫ݪ‬঩ၳȁల!251!࣢ȁ2004!ා!3!࠮

Ƚ!38!Ƚ

ȁȁȁȁ଎ 8. 2 (2)‫؍‬ຩ۷௶̤̫֔ͥͅࢢ֔౷ৗࢹ௮Ȅ‫إ‬෨௸ഽȄྟഽȄ‫أ‬ഽȄুடഩպȄ๤೷ࢯȄΠȜΗσ΄ϋζȄ̤͍͢ࢢࠂ࠿௄ࠫ‫͈ض‬๤‫ڛ‬
Fig. 8. 2 (2) Well geology and line up of logging results of Yokohama well. Log items are sonic velocity, density, temperature, spontaneous potential, resistivity, total gamma, and caliper.

‫۾‬൐౷֖͈ಎ૬௄౷‫ڰڔ‬൲۷௶֔ͬ၌ဥ̱̹ VSP ༹௸ഽࢹ௮಺औȽ५କ

Ƚ!39!Ƚ

ȁȁȁȁȁȁ଎ 8. 3 (1)ୌ࿤ࡔ۷௶̤̫֔ͥͅࢢ֔౷ৗࢹ௮ȄP ෨௸ഽࢹ௮ȄS ෨௸ഽࢹ௮Ȅ‫إ‬෨࠿௄Ȅ̤͍͢ྟഽ࠿௄ࠫ‫͈ض‬๤‫ڛ‬
Fig. 8. 3 (1) Comparison of the well geology, P and S wave velocity structure obtained by the VSP measurement, and sonic velocity and density logs of the Nishinohara well.

ཡब‫ݪࡄ੅ܿڠش‬ਫ਼ࡄ‫ݪ‬঩ၳȁల!251!࣢ȁ2004!ා!3!࠮

Ƚ!40!Ƚ

ȁȁȁȁȁȁ଎ 8. 3 (2)ୌ࿤ࡔ۷௶̤̫֔ͥͅࢢ֔౷ৗࢹ௮Ȅ‫إ‬෨௸ഽȄྟഽȄ‫أ‬ഽȄুடഩպȄΠȜΗσ΄ϋζȄ̤͍͢ࢢࠂ࠿௄ࠫ‫͈ض‬๤‫ڛ‬
Fig. 8. 3 (2) Well geology and line up of logging results of Nishinohara well. Log items are sonic velocity, density, temperature, spontaneous potential, total gamma, and caliper.

‫۾‬൐౷֖͈ಎ૬௄౷‫ڰڔ‬൲۷௶֔ͬ၌ဥ̱̹ VSP ༹௸ഽࢹ௮಺औȽ५କ

Ƚ!41!Ƚ

ȁȁȁȁȁȁ଎ 8. 4 (1)ਫ਼ా۷௶̤̫֔ͥͅࢢ֔౷ৗࢹ௮ȄP ෨௸ഽࢹ௮ȄS ෨௸ഽࢹ௮Ȅ‫إ‬෨࠿௄Ȅ̤͍͢ྟഽ࠿௄ࠫ‫͈ض‬๤‫ڛ‬
Fig. 8. 4 (1) Comparison of the well geology, P and S wave velocity structure obtained by the VSP measurement, and sonic velocity and density logs of the Tokorozawa well.

ཡब‫ݪࡄ੅ܿڠش‬ਫ਼ࡄ‫ݪ‬঩ၳȁల!251!࣢ȁ2004!ා!3!࠮

Ƚ!42!Ƚ

ȁȁȁȁ଎ 8. 4 (2)ਫ਼ా۷௶̤̫֔ͥͅࢢ֔౷ৗࢹ௮Ȅ‫إ‬෨௸ഽȄྟഽȄ‫أ‬ഽȄুடഩպȄ๤೷ࢯȄΠȜΗσ΄ϋζȄ̤͍͢ࢢࠂ࠿௄ࠫ‫͈ض‬๤‫ڛ‬
Fig. 8. 4 (2) Well geology and line up of logging results of Tokorozawa well. Log items are sonic velocity, density, temperature, spontaneous potential, resistivity, total gamma, and caliper.

‫۾‬൐౷֖͈ಎ૬௄౷‫ڰڔ‬൲۷௶֔ͬ၌ဥ̱̹ VSP ༹௸ഽࢹ௮಺औȽ५କ

Ƚ!43!Ƚ

ȁȁȁȁȁȁȁ଎ 8. 5 (1)඾ࣞ۷௶̤̫֔ͥͅࢢ֔౷ৗࢹ௮ȄP ෨௸ഽࢹ௮ȄS ෨௸ഽࢹ௮Ȅ‫إ‬෨࠿௄Ȅ̤͍͢ྟഽ࠿௄ࠫ‫͈ض‬๤‫ڛ‬
Fig. 8. 5 (1) Comparison of the well geology, P and S wave velocity structure obtained by the VSP measurement, and sonic velocity and density logs of the Hidaka well.

ཡब‫ݪࡄ੅ܿڠش‬ਫ਼ࡄ‫ݪ‬঩ၳȁల!251!࣢ȁ2004!ා!3!࠮

Ƚ!44!Ƚ

ȁȁȁȁȁ଎ 8. 5 (2)඾ࣞ۷௶̤̫֔ͥͅࢢ֔౷ৗࢹ௮Ȅ‫إ‬෨௸ഽȄྟഽȄ‫أ‬ഽȄুடഩպȄ๤೷ࢯȄΠȜΗσ΄ϋζȄ̤͍͢ࢢࠂ࠿௄ࠫ‫͈ض‬๤‫ڛ‬
Fig. 8. 5 (2) Well geology and line up of logging results of Hidaka well. Log items are sonic velocity, density, temperature, spontaneous potential, resistivity, total gamma, and caliper.

‫۾‬൐౷֖͈ಎ૬௄౷‫ڰڔ‬൲۷௶֔ͬ၌ဥ̱̹ VSP ༹௸ഽࢹ௮಺औȽ५କ

Ƚ!45!Ƚ

ȁȁȁȁȁȁȁȁ଎ 8. 6 (1)୷ဩ۷௶̤̫֔ͥͅࢢ֔౷ৗࢹ௮ȄP ෨௸ഽࢹ௮ȄS ෨௸ഽࢹ௮Ȅ‫إ‬෨࠿௄Ȅ̤͍͢ྟഽ࠿௄ࠫ‫͈ض‬๤‫ڛ‬
Fig. 8. 6 (1) Comparison of the well geology, P and S wave velocity structure obtained by the VSP measurement, and sonic velocity and density logs of the Chiba well.

ཡब‫ݪࡄ੅ܿڠش‬ਫ਼ࡄ‫ݪ‬঩ၳȁల!251!࣢ȁ2004!ා!3!࠮

Ƚ!46!Ƚ

ȁȁȁȁȁ଎ 8. 6 (2)୷ဩ۷௶̤̫֔ͥͅࢢ֔౷ৗࢹ௮Ȅ‫إ‬෨௸ഽȄྟഽȄ‫أ‬ഽȄুடഩպȄ๤೷ࢯȄΠȜΗσ΄ϋζȄ̤͍͢ࢢࠂ࠿௄ࠫ‫͈ض‬๤‫ڛ‬
Fig. 8. 6 (2) Well geology and line up of logging results of Chiba well. Log items are sonic velocity, density, temperature, spontaneous potential, resistivity, total gamma, and caliper.

‫۾‬൐౷֖͈ಎ૬௄౷‫ڰڔ‬൲۷௶֔ͬ၌ဥ̱̹ VSP ༹௸ഽࢹ௮಺औȽ५କ

Ƚ!47!Ƚ

ȁȁȁȁȁȁȁȁ଎ 8. 7 (1)ူჇ۷௶̤̫֔ͥͅࢢ֔౷ৗࢹ௮ȄP ෨௸ഽࢹ௮ȄS ෨௸ഽࢹ௮Ȅ‫إ‬෨࠿௄Ȅ̤͍͢ྟഽ࠿௄ࠫ‫͈ض‬๤‫ڛ‬
Fig. 8. 7 (1) Comparison of the well geology, P and S wave velocity structure obtained by the VSP measurement, and sonic velocity and density logs of the Yohro well.

ཡब‫ݪࡄ੅ܿڠش‬ਫ਼ࡄ‫ݪ‬঩ၳȁల!251!࣢ȁ2004!ා!3!࠮

Ƚ!48!Ƚ

ȁȁȁȁȁ଎ 8. 7 (2)ူჇ۷௶̤̫֔ͥͅࢢ֔౷ৗࢹ௮Ȅ‫إ‬෨௸ഽȄྟഽȄ‫أ‬ഽȄুடഩպȄ๤೷ࢯȄΠȜΗσ΄ϋζȄ̤͍͢ࢢࠂ࠿௄ࠫ‫͈ض‬๤‫ڛ‬
Fig. 8. 7 (2) Well geology and line up of logging results of Yohro well. Log items are sonic velocity, density, temperature, spontaneous potential, resistivity, total gamma, and caliper.

‫۾‬൐౷֖͈ಎ૬௄౷‫ڰڔ‬൲۷௶֔ͬ၌ဥ̱̹ VSP ༹௸ഽࢹ௮಺औȽ५କ

Ƚ!49!Ƚ

ȁȁȁȁȁȁȁȁ଎ 8. 8 (1)ີೋ۷௶̤̫֔ͥͅࢢ֔౷ৗࢹ௮ȄP ෨௸ഽࢹ௮ȄS ෨௸ഽࢹ௮Ȅ‫إ‬෨࠿௄Ȅ̤͍͢ྟഽ࠿௄ࠫ‫͈ض‬๤‫ڛ‬
Fig. 8. 8 (1) Comparison of the well geology, P and S wave velocity structure obtained by the VSP measurement, and sonic velocity and density logs of the Futtsu well.

ཡब‫ݪࡄ੅ܿڠش‬ਫ਼ࡄ‫ݪ‬঩ၳȁల!251!࣢ȁ2004!ා!3!࠮

Ƚ!50!Ƚ

ȁȁȁȁȁ଎ 8. 8 (2)ີೋ۷௶̤̫֔ͥͅࢢ֔౷ৗࢹ௮Ȅ‫إ‬෨௸ഽȄྟഽȄ‫أ‬ഽȄুடഩպȄ๤೷ࢯȄΠȜΗσ΄ϋζȄ̤͍͢ࢢࠂ࠿௄ࠫ‫͈ض‬๤‫ڛ‬
Fig. 8. 8 (2) Well geology and line up of logging results of Futtsu well. Log items are sonic velocity, density, temperature, spontaneous potential, resistivity, total gamma, and caliper.

‫۾‬൐౷֖͈ಎ૬௄౷‫ڰڔ‬൲۷௶֔ͬ၌ဥ̱̹ VSP ༹௸ഽࢹ௮಺औȽ५କ

Ƚ!51!Ƚ

ȁȁȁȁȁȁȁȁ଎ 8. 9 (1)଼ന۷௶̤̫֔ͥͅࢢ֔౷ৗࢹ௮ȄP ෨௸ഽࢹ௮ȄS ෨௸ഽࢹ௮Ȅ‫إ‬෨࠿௄Ȅ̤͍͢ྟഽ࠿௄ࠫ‫͈ض‬๤‫ڛ‬
Fig. 8. 9 (1) Comparison of the well geology, P and S wave velocity structure obtained by the VSP measurement, and sonic velocity and density logs of the Narita well.

ཡब‫ݪࡄ੅ܿڠش‬ਫ਼ࡄ‫ݪ‬঩ၳȁల!251!࣢ȁ2004!ා!3!࠮

Ƚ!52!Ƚ

ȁȁȁȁȁ଎ 8. 9 (2)଼ന۷௶̤̫֔ͥͅࢢ֔౷ৗࢹ௮Ȅ‫إ‬෨௸ഽȄྟഽȄ‫أ‬ഽȄুடഩպȄ๤೷ࢯȄΠȜΗσ΄ϋζȄ̤͍͢ࢢࠂ࠿௄ࠫ‫͈ض‬๤‫ڛ‬
Fig. 8. 9 (2) Well geology and line up of logging results of Narita well. Log items are sonic velocity, density, temperature, spontaneous potential, resistivity, total gamma, and caliper.

‫۾‬൐౷֖͈ಎ૬௄౷‫ڰڔ‬൲۷௶֔ͬ၌ဥ̱̹ VSP ༹௸ഽࢹ௮಺औȽ५କ

Ƚ!53!Ƚ

ȁȁȁȁȁȁȁ଎ 8. 10 (1)Fig. 8. 10 (1)Ƚ!54!Ƚ

ࢺ࡫ॄ۷௶̤̫֔ͥͅࢢ֔౷ৗࢹ௮ȄP ෨௸ഽࢹ௮ȄS ෨௸ഽࢹ௮Ȅ‫إ‬෨࠿௄Ȅ̤͍͢ྟഽ࠿௄ࠫ‫͈ض‬๤‫ڛ‬Comparison of the well geology, P and S wave velocity structure obtained by the VSP measurement, and sonic velocity and density logs of the Edosaki well.

ཡब‫ݪࡄ੅ܿڠش‬ਫ਼ࡄ‫ݪ‬঩ၳȁల!251!࣢ȁ2004!ා!3!࠮

ȁȁȁȁ଎ 8. 10 (2)ࢺ࡫ॄ۷௶̤̫֔ͥͅࢢ֔౷ৗࢹ௮Ȅ‫إ‬෨௸ഽȄྟഽȄ‫أ‬ഽȄুடഩպȄ๤೷ࢯȄΠȜΗσ΄ϋζȄ̤͍͢ࢢࠂ࠿௄ࠫ‫͈ض‬๤‫ڛ‬
Fig. 8. 10 (2) Well geology and line up of logging results of Edosaki well. Log items are sonic velocity, density, temperature, spontaneous potential, resistivity, total gamma, and caliper.

‫۾‬൐౷֖͈ಎ૬௄౷‫ڰڔ‬൲۷௶֔ͬ၌ဥ̱̹ VSP ༹௸ഽࢹ௮಺औȽ५କ

Ƚ!55!Ƚ

ȁȁȁȁȁȁȁ଎ 8. 11 (1)૯‫ؖ‬۷௶̤̫֔ͥͅࢢ֔౷ৗࢹ௮ȄP ෨௸ഽࢹ௮ȄS ෨௸ഽࢹ௮Ȅ‫إ‬෨࠿௄Ȅ̤͍͢ྟഽ࠿௄ࠫ‫͈ض‬๤‫ڛ‬
Fig. 8. 11 (1) Comparison of the well geology, P and S wave velocity structure obtained by the VSP measurement, and sonic velocity and density logs of the Mohka well.

ཡब‫ݪࡄ੅ܿڠش‬ਫ਼ࡄ‫ݪ‬঩ၳȁల!251!࣢ȁ2004!ා!3!࠮

Ƚ!56!Ƚ

ȁȁȁȁ଎ 8. 11 (2)૯‫ؖ‬۷௶̤̫֔ͥͅࢢ֔౷ৗࢹ௮Ȅ‫إ‬෨௸ഽȄྟഽȄ‫أ‬ഽȄুடഩպȄ๤೷ࢯȄΠȜΗσ΄ϋζȄ̤͍͢ࢢࠂ࠿௄ࠫ‫͈ض‬๤‫ڛ‬
Fig. 8. 11 (2) Well geology and line up of logging results of Mohka well. Log items are sonic velocity, density, temperature, spontaneous potential, resistivity, total gamma, and caliper.

‫۾‬൐౷֖͈ಎ૬௄౷‫ڰڔ‬൲۷௶֔ͬ၌ဥ̱̹ VSP ༹௸ഽࢹ௮಺औȽ५କ

Ƚ!57!Ƚ

ȁȁȁȁȁȁȁ଎ 8. 12 (1)չସॄ۷௶̤̫֔ͥͅࢢ֔౷ৗࢹ௮ȄP ෨௸ഽࢹ௮ȄS ෨௸ഽࢹ௮Ȅ‫إ‬෨࠿௄Ȅ̤͍͢ྟഽ࠿௄ࠫ‫͈ض‬๤‫ڛ‬
Fig. 8. 12 (1) Comparison of the well geology, P and S wave velocity structure obtained by the VSP measurement, and sonic velocity and density logs of the Isesaki well.

ཡब‫ݪࡄ੅ܿڠش‬ਫ਼ࡄ‫ݪ‬঩ၳȁల!251!࣢ȁ2004!ා!3!࠮

Ƚ!58!Ƚ

ȁȁȁȁȁȁȁ଎ 8. 12 (2)չସॄ۷௶̤̫֔ͥͅࢢ֔౷ৗࢹ௮Ȅ‫إ‬෨௸ഽȄྟഽȄ‫أ‬ഽȄুடഩպȄ๤೷ࢯȄ̤͍͢ࢢࠂ࠿௄ࠫ‫͈ض‬๤‫ڛ‬
Fig. 8. 12 (2) Well geology and line up of logging results of Isesaki well. Log items are sonic velocity, density, temperature, spontaneous potential, resistivity, and caliper.

‫۾‬൐౷֖͈ಎ૬௄౷‫ڰڔ‬൲۷௶֔ͬ၌ဥ̱̹ VSP ༹௸ഽࢹ௮಺औȽ५କ

Ƚ!59!Ƚ

ཡब‫ݪࡄ੅ܿڠش‬ਫ਼ࡄ‫ݪ‬঩ၳȁల!251!࣢ȁ2004!ා!3!࠮

଎ 9. 1࠿௄ૂ༭ΟȜΗαȜΑξȜΎဥΠΛίβȜΐ͈Α΢ΛίΏοΛΠ

Fig. 9. 1 Snapshot of the top web page of the well log database system.ȁȁȁȁ

ȁȁȁȁȁȁȁȁȁȁȁ଎ 9. 2

࠿௄ΟȜΗ࠿̤͍॑͢ΈρέນাဥβȜΐ͈Α΢ΛίΏοΛΠ

Fig. 9. 2 Snapshot of web page for selecting and extracting log data, and plotting on graph.

Ƚ!60!Ƚ

‫۾‬൐౷֖͈ಎ૬௄౷‫ڰڔ‬൲۷௶֔ͬ၌ဥ̱̹ VSP ༹௸ഽࢹ௮಺औȽ५କ

଎ 9. 3࠿௄ΟȜΗΘ;ϋυȜΡဥβȜΐ͈Α΢ΛίΏοΛΠ

Fig. 9. 3 Snapshot of web page for downloading log data.ȁȁȁȁȁ

଎ 9. 4

VSP ෨ࠁΟȜΗ൝έ͹ͼσ͈Θ;ϋυȜΡဥβȜΐ͈Α΢ΛίΏοΛΠ

Fig. 9. 4 Snapshot of web page for downloading VSP waveform data file.ȁȁȁȁȁȁȁ

Ƚ!61!Ƚ

ཡब‫ݪࡄ੅ܿڠش‬ਫ਼ࡄ‫ݪ‬঩ၳȁల!251!࣢ȁ2004!ා!3!࠮

ȁȁȁȁȁȁȁȁ଎ 9. 5

࠿௄ΟȜΗΈρέນা͈Α΢ΛίΏοΛΠ

Fig. 9. 5 Snapshot of web page for showing plotted graph, and downloading the graph as a postscript file.

଎ 9. 6࠿௄ΟȜΗഴ჏‫ۯ‬ၑဥΠΛίβȜΐ͈Α΢ΛίΏοΛΠ

Fig. 9. 6 Snapshot of maintenance page for well log data registration.ȁ

Ƚ!62!Ƚ

‫۾‬൐౷֖͈ಎ૬௄౷‫ڰڔ‬൲۷௶֔ͬ၌ဥ̱̹ VSP ༹௸ഽࢹ௮಺औȽ५କ

଎ 9. 7

࠿௄ૂ༭ΟȜΗαȜΑΨΛ·ͺΛίဥβȜΐ͈Α΢ΛίΏοΛΠ

Fig. 9. 7 Snapshot of maintenance page for backing up the whole log database.ȁȽ!63!Ƚ

ཡब‫ݪࡄ੅ܿڠش‬ਫ਼ࡄ‫ݪ‬঩ၳȁల!251!࣢ȁ2004!ා!3!࠮
ນ 2. 1!

࢚࿐۷௶̤̫֔ͥͅ P ෨ S ෨੝൲උ৾౵ȪObs.ȫȄ΂έΓΛΠ༞ୃࢃ͈଒ೄ௢শȪNormalȫȄඤொ༞ۖࢃ͈௢শȪInt.ȫȄ
ତ౵๷໦ͥ͢ͅ௸ഽȪDif.ȫ̤͍͢໹޳௸ഽȪMeanȫ

Table 2. 1! Readings of P and S wave first arrival )Obs.*, normal times after offset correction )Normal*, travel times interpolated at every 25 m
)Int.*, velocities estimated by differentiation )Dif.*, and layered velocity structure approximated )Mean* for Atsugi well.

Ƚ!64!Ƚ

‫۾‬൐౷֖͈ಎ૬௄౷‫ڰڔ‬൲۷௶֔ͬ၌ဥ̱̹ VSP ༹௸ഽࢹ௮಺औȽ५କ
ນ 2. 2!

‫؍‬ຩ۷௶̤̫֔ͥͅ P ෨ S ෨੝൲උ৾౵ȪObs.ȫȄ΂έΓΛΠ༞ୃࢃ͈଒ೄ௢শȪNormalȫȄඤொ༞ۖࢃ͈௢শȪInt.ȫȄ
ତ౵๷໦ͥ͢ͅ௸ഽȪDif.ȫ̤͍͢໹޳௸ഽȪMeanȫ

Table 2. 2! Readings of P and S wave first arrival )Obs.*, normal times after offset correction )Normal*, travel times interpolated at every 25 m
)Int.*, velocities estimated by differentiation )Dif.*, and layered velocity structure approximated )Mean* for Yokohama well.

Ƚ!65!Ƚ

ཡब‫ݪࡄ੅ܿڠش‬ਫ਼ࡄ‫ݪ‬঩ၳȁల!251!࣢ȁ2004!ා!3!࠮
ນ 2. 3!

ୌ࿤ࡔ۷௶̤̫֔ͥͅ P ෨ S ෨੝൲උ৾౵ȪObs.ȫȄ΂έΓΛΠ༞ୃࢃ͈଒ೄ௢শȪNormalȫȄඤொ༞ۖࢃ͈௢শȪInt.ȫȄ
ତ౵๷໦ͥ͢ͅ௸ഽȪDif.ȫ̤͍͢໹޳௸ഽȪMeanȫ

Table 2. 3! Readings of P and S wave first arrival )Obs.*, normal times after offset correction )Normal*, travel times interpolated at every 25 m
)Int.*, velocities estimated by differentiation )Dif.*, and layered velocity structure approximated )Mean* for Nishinohara well.

Ƚ!66!Ƚ

‫۾‬൐౷֖͈ಎ૬௄౷‫ڰڔ‬൲۷௶֔ͬ၌ဥ̱̹ VSP ༹௸ഽࢹ௮಺औȽ५କ
ນ 2. 4!

ਫ਼ా۷௶̤̫֔ͥͅ P ෨ S ෨੝൲උ৾౵ȪObs.ȫȄ΂έΓΛΠ༞ୃࢃ͈଒ೄ௢শȪNormalȫȄඤொ༞ۖࢃ͈௢শȪInt.ȫȄ
ତ౵๷໦ͥ͢ͅ௸ഽȪDif.ȫ̤͍͢໹޳௸ഽȪMeanȫ

Table 2. 4! Readings of P and S wave first arrival )Obs.*, normal times after offset correction )Normal*, travel times interpolated at every 25 m
)Int.*, velocities estimated by differentiation )Dif.*, and layered velocity structure approximated )Mean* for Tokorozawa well.

Ƚ!67!Ƚ

ཡब‫ݪࡄ੅ܿڠش‬ਫ਼ࡄ‫ݪ‬঩ၳȁల!251!࣢ȁ2004!ා!3!࠮
ນ 2. 5!

඾ࣞ۷௶̤̫֔ͥͅ P ෨ S ෨੝൲උ৾౵ȪObs.ȫȄ΂έΓΛΠ༞ୃࢃ͈଒ೄ௢শȪNormalȫȄඤொ༞ۖࢃ͈௢শȪInt.ȫȄ
ତ౵๷໦ͥ͢ͅ௸ഽȪDif.ȫ̤͍͢໹޳௸ഽȪMeanȫ

Table 2. 5! Readings of P and S wave first arrival )Obs.*, normal times after offset correction )Normal*, travel times interpolated at every 25 m
)Int.*, velocities estimated by differentiation )Dif.*, and layered velocity structure approximated )Mean* for Hidaka well.

Ƚ!68!Ƚ

‫۾‬൐౷֖͈ಎ૬௄౷‫ڰڔ‬൲۷௶֔ͬ၌ဥ̱̹ VSP ༹௸ഽࢹ௮಺औȽ५କ
ນ 2. 6!

୷ဩ۷௶̤̫֔ͥͅ P ෨ S ෨੝൲උ৾౵ȪObs.ȫȄ΂έΓΛΠ༞ୃࢃ͈଒ೄ௢শȪNormalȫȄඤொ༞ۖࢃ͈௢শȪInt.ȫȄ
ତ౵๷໦ͥ͢ͅ௸ഽȪDif.ȫ̤͍͢໹޳௸ഽȪMeanȫ

Table 2. 6! Readings of P and S wave first arrival )Obs.*, normal times after offset correction )Normal*, travel times interpolated at every 25 m
)Int.*, velocities estimated by differentiation )Dif.*, and layered velocity structure approximated )Mean* for Chiba well.

Ƚ!69!Ƚ

ཡब‫ݪࡄ੅ܿڠش‬ਫ਼ࡄ‫ݪ‬঩ၳȁల!251!࣢ȁ2004!ා!3!࠮
ນ 2. 7!

ူჇ۷௶̤̫֔ͥͅ P ෨ S ෨੝൲උ৾౵ȪObs.ȫȄ΂έΓΛΠ༞ୃࢃ͈଒ೄ௢শȪNormalȫȄඤொ༞ۖࢃ͈௢শȪInt.ȫȄ
ତ౵๷໦ͥ͢ͅ௸ഽȪDif.ȫ̤͍͢໹޳௸ഽȪMeanȫ

Table 2. 7! Readings of P and S wave first arrival )Obs.*, normal times after offset correction )Normal*, travel times interpolated at every 25 m
)Int.*, velocities estimated by differentiation )Dif.*, and layered velocity structure approximated )Mean* for Yohro well.

Ƚ!70!Ƚ

‫۾‬൐౷֖͈ಎ૬௄౷‫ڰڔ‬൲۷௶֔ͬ၌ဥ̱̹ VSP ༹௸ഽࢹ௮಺औȽ५କ
ນ 2. 8!

ີೋ۷௶̤̫֔ͥͅ P ෨ S ෨੝൲උ৾౵ȪObs.ȫȄ΂έΓΛΠ༞ୃࢃ͈଒ೄ௢শȪNormalȫȄඤொ༞ۖࢃ͈௢শȪInt.ȫȄ
ତ౵๷໦ͥ͢ͅ௸ഽȪDif.ȫ̤͍͢໹޳௸ഽȪMeanȫ

Table 2. 8! Readings of P and S wave first arrival )Obs.*, normal times after offset correction )Normal*, travel times interpolated at every 25 m
)Int.*, velocities estimated by differentiation )Dif.*, and layered velocity structure approximated )Mean* for Futtsu well.

Ƚ!71!Ƚ

ཡब‫ݪࡄ੅ܿڠش‬ਫ਼ࡄ‫ݪ‬঩ၳȁల!251!࣢ȁ2004!ා!3!࠮
ນ 2. 9!

଼ന۷௶̤̫֔ͥͅ P ෨ S ෨੝൲උ৾౵ȪObs.ȫȄ΂έΓΛΠ༞ୃࢃ͈଒ೄ௢শȪNormalȫȄඤொ༞ۖࢃ͈௢শȪInt.ȫȄ
ତ౵๷໦ͥ͢ͅ௸ഽȪDif.ȫ̤͍͢໹޳௸ഽȪMeanȫ

Table 2. 9! Readings of P and S wave first arrival )Obs.*, normal times after offset correction )Normal*, travel times interpolated at every 25 m
)Int.*, velocities estimated by differentiation )Dif.*, and layered velocity structure approximated )Mean* for Narita well.

Ƚ!72!Ƚ

‫۾‬൐౷֖͈ಎ૬௄౷‫ڰڔ‬൲۷௶֔ͬ၌ဥ̱̹ VSP ༹௸ഽࢹ௮಺औȽ५କ
ນ 2. 10!

ࢺ࡫ॄ۷௶̤̫֔ͥͅ P ෨ S ෨੝൲උ৾౵ȪObs.ȫȄ΂έΓΛΠ༞ୃࢃ͈଒ೄ௢শȪNormalȫȄඤொ༞ۖࢃ͈௢শȪInt.ȫȄ
ତ౵๷໦ͥ͢ͅ௸ഽȪDif.ȫ̤͍͢໹޳௸ഽȪMeanȫ

Table 2. 10! Readings of P and S wave first arrival )Obs.*, normal times after offset correction )Normal*, travel times interpolated at every 25 m
)Int.*, velocities estimated by differentiation )Dif.*, and layered velocity structure approximated )Mean* for Edosaki well.

Ƚ!73!Ƚ

ཡब‫ݪࡄ੅ܿڠش‬ਫ਼ࡄ‫ݪ‬঩ၳȁల!251!࣢ȁ2004!ා!3!࠮
ນ 2. 11!

૯‫ؖ‬۷௶̤̫֔ͥͅ P ෨ S ෨੝൲උ৾౵ȪObs.ȫȄ΂έΓΛΠ༞ୃࢃ͈଒ೄ௢শȪNormalȫȄඤொ༞ۖࢃ͈௢শȪInt.ȫȄ
ତ౵๷໦ͥ͢ͅ௸ഽȪDif.ȫ̤͍͢໹޳௸ഽȪMeanȫ

Table 2. 11! Readings of P and S wave first arrival )Obs.*, normal times after offset correction )Normal*, travel times interpolated at every 25 m
)Int.*, velocities estimated by differentiation )Dif.*, and layered velocity structure approximated )Mean* for Mohka well.

Ƚ!74!Ƚ

‫۾‬൐౷֖͈ಎ૬௄౷‫ڰڔ‬൲۷௶֔ͬ၌ဥ̱̹ VSP ༹௸ഽࢹ௮಺औȽ५କ
ນ 2. 12!

չସॄ۷௶̤̫֔ͥͅ P ෨ S ෨੝൲උ৾౵ȪObs.ȫȄ΂έΓΛΠ༞ୃࢃ͈଒ೄ௢শȪNormalȫȄඤொ༞ۖࢃ͈௢শȪInt.ȫȄ
ତ౵๷໦ͥ͢ͅ௸ഽȪDif.ȫ̤͍͢໹޳௸ഽȪMeanȫ

Table 2. 12! Readings of P and S wave first arrival )Obs.*, normal times after offset correction )Normal*, travel times interpolated at every 25 m
)Int.*, velocities estimated by differentiation )Dif.*, and layered velocity structure approximated )Mean* for Isesaki well.

Ƚ!75!Ƚ