Bull Earthq Res Inst Univ Tokyo Vol 2,**3 pp +2-,+, M 1 +3,+ +3,, +321 * +, + + +, Review of Previous Studies on M 1-class Earthquakes that Occurred in the Southern Kanto Region and Data Collection The +3,+ Ibaraki-ken Nanbu Earthquake, the +3,, Uraga-channel Earthquake and the +321 Chiba-ken Toho-Oki Earthquake Takeo Ishibe *, Akihito Nishiyama, Kenji Satake +, + + +, Earthquake Research Institute, University of Tokyo Association for Earthquake Disaster Prevention and Kunihiko Shimazaki Abstract The Earthquake Research Committee of the Headquarters of Earthquake Research and Promotion estimated the probability of an earthquake of magnitude around 1* occurring during the next -* years as 1* This is based on five earthquakes that occurred in the southern Kanto region (ie, the +23 Meiji-Tokyo earthquake, the +23/ and +3,+ Ibaraki-ken Nanbu earthquakes, the +3,, Uraga-channel earthquake and the +321 Chiba-ken Toho-Oki earthquake) However, it has been revealed that the Kanto region is situated on complicated tectonic conditions due to subduction of the Philippine Sea Plate and the Pacific Plate beneath the continental plate, and that various types of earthquake occur Therefore, it is necessary to classify these earthquakes into interplate and slab earthquakes, and to estimate recurrence intervals In this paper, at the outset of such studies, we review previous studies on three earthquakes (the +3,+ Ibaraki-ken Nanbu earthquake, the +3,, Uraga-channel earthquake and the +321 Chiba-ken Toho-Oki earthquake) that occurred after the beginning of the Taisho era ( +3+, +3,0) and describe the collected data Key words: M 1 earthquakes, the +3,+ Ibaraki-ken Nanbu Earthquake, the +3,, Uraga-channel Earthquake, the +321 Chiba-ken Toho-Oki Earthquake, the southern Kanto region +,** + +23 -* km +23/ +3,+ +3,, M 1 -* 1* +321 / * e-mail: ishibe@eriu-tokyoacjp ++- **-, + + + 183
Fig + Five earthquakes (ie, the +23 Meiji-Tokyo earthquake, the +23/ Ibaraki-ken Nanbu earthquake, the +3,+ Ibaraki-ken Nanbu (Ryugasaki) earthquake, the +3,, Uraga-channel earthquake and the +321 Chiba-ken Toho-Oki earthquake) used to estimate the occurrence probability of other M 1 class earthquakes that have occurred in the southern Kanto region The epicenter and magnitude of the +321 Chiba-ken Toho-Oki earthquake are based on the Japan Meteorological Agency (JMA), and others are based on Utsu ( +313) M 1 +3,+ +3,, b +3,, a +31/ a, +31/ b +31-a,,**3 / +31- b, +31/ b+313, +23 +31- b, +31/ d,*** +23/,***, - +3,+ +3,, +3,+ +321 +* + E, -/ 2N, +3,+ M 1 *; +313,+ + +3,+ /*, +3,+ +* +, 2, 184
M 1 185
Fig, Hypocenter and focal mechanism of the +3,+ Ibaraki-ken Nanbu earthquake C: Central Meteorological Observatory ( +3,+ ), O : Omori ( +3,, a, +3,, g), Ushi: Ushiyama ( +3,, c), K: Katsumata ( +31/ a, +31/ b), I: Ishibashi ( +31- a, +31- b, +31/ b), Utsu: Utsu ( +313 ), Usa : Usami (,**-) Parenthetic number (in km) or character (s : shallow;? : unknown) indicates hypocentral depth +3,, a +/ 22,3 km /2 mm +23 +23/,* B Omori +3,, g +3,, a A Ushiyama +3,, c - 2 2 2 * 3 - S-P +*,* -2E -/ // 2N Ushiyama +3,, c,3 km Omori +3,, g S-P +-3 2E -/ 2N - +3,+ +3,, b, 0 - +3,, a 0, +3,, a, +3,, b Ushiyama +3,, c 186
M 1 187
Table - Seismological reports on the +3,+ Ibaraki-ken Nanbu earthquake by meteorological observatories from Ushiyama ( +3,, a) Fig - Seismograms of the +3,+ Ibaraki-ken Nanbu +3,+ earthquake recorded by the strong motion seismograph +3,, a Yasuda +3,, b - at (a) Hongo, and (b) Hitotsubashi (from Omori, +3,, g) +3/* +31+ +* +* 0E, -0- + N +* + E -/ 2N M 0- km +* 1 + +31- S-* E +* + E, -/ 2N M 1 + -* km +* km +31- b, +31/ d +31-a S-P +31*, a +31/ a, +31/ b, +31/ c - +31-2 / 2 * S-P Omori 32 0* S-P +3,, g +* +* E, -0 * N /- km, 2/ S-P * 0* km 188
M 1 189
+* km +33* +301 +32/ +31/ a, +31/ b S-P,*** +* *--E, -0 *3 N, +* km, M 01 M, c 1 + +313,+ +-, 13 / M 1 * +31/ b +2 / +* Nm Mw 0 +*, E, -0* N +31/ a, +31/ b, +31/ c /- km M PHS PAC +3,-, PAC PHS +3,+ +3,,,**+ PHS PAC,**- +313 +*, E, -0* N M 1*,***, GME +32/,, +31/ a, +31/ b, +31/ c / +3,+ +2 /0 +* Nm Mw 0 +,22 13 -, b +31/ a, +31/ b,,***,,**- +31/ c a,,**- b,,** GME PHS PAC 0* 1/ km +, +0 PHS PAC,, +3,, a +3,+ Table / Documents on the +3,+ Ibaraki-ken Nanbu earthquake 190
M 1 Fig Seismic intensity distribution map of the +3,+ Ibaraki-ken Nanbu earthquake by (a) Omori ( +3,, h), (b) Kanbayashi and Katsumata ( +31/ ), (c) Utsu ( +323 ) and (d) Usami (,**-) Central Meteorological Observatory +3,, +3,, b, +3,, c, +3,, e Omori +3,, h +31/ a, a +31/ b +31/ a, +31/ b, +31/ c +313,**- +3,, a Yasuda +3,, b +3,+ / +3,, a Ushiyama +3,, c Omori +3,, h +3,, c +3,,,0 +31/ +323,**- +* : ++ +* ++ +-3 3E, -/ N - +3,, M 0 2 ; +313 -+ 0 +3,, M 1 +3,, ++,0 +, +3,, c +3,, a Nakamura +3,, b 191
192
M 1 Fig / Hypocenter [C : Central Meteorological Observatory ( +3,, c), N: Nakamura ( +3,, a, +3,, b), O: Omori ( +3,, h), K: Katsumata ( +31/ a, +31/ b), I + : Ishibashi ( +31/ c), I,: Ishibashi ( +31/ a, +31/ b) Utsu : Utsu ( +313), Usa : Usami (,**-)] and focal mechanism [Ishibashi ( +31/ d)] of the +3,, Uraga-channel earthquake Parenthetic number (in km) or character (s : shallow;? : unknown) indicates hypocentral depth +3,, b +3,, c, --* mmsec, +3,+,0 mmsec +* 0, +23 mmsec 13 Omori +3,, h km,,-- mmsec +3,+ + +23 0 + C +3,, d ++ + 2- km / +-3 1E, -/ ++ N 2 km +3,, a Nakamura +3,, b 30 0- +3,, e 0 km +3,, b +* 0 / +3/* +31+ 2 km +-3 3E, -/ N M 0 3 193
194
M 1 Fig 0 Seismograms of the +3,, Uraga-channel earthquake recorded by strong motion seismographs at (a) Hongo, and (b) Hitotsubashi (from Omori, +3,, h) +31- +-3 -/ E, -/ N * 1* km * + +31/ c S-P +31 +31- P +31 VpVs +-3 // E, -/ *0 N /* km *, +31/ d *- + +/ / 2 P P / +31 a, +31 b +31/ a, +31/ b S-P +31/ +3/* +-3 /3- E, +31+ +31- +31/ a, +31/ -/ +--N -* km b +31/ a, +31/ b M M 03 M 02 +313 +-3 2E, -/, N +31/ a, +31/ b +* M 0 2 +* 2 0 - ++ +,**+ PHS PAC + * +0 * S-P,**- +-3 + E, +-3 1/ E, -/, N, M 0 2 -/ +* N, 1+,+ km Omori +3,, h S-P 1* km 3* km 1 3* km +33,,, M / 1 +31/ a, +31/ b PAC +3,+ 195
Fig 1 Recent seismicity around the Uraga channel from the unified Japan Meteorological Agency catalog (October, +331 to May,**2) The blue star indicates hypocenter of the +3,, Uraga-channel earthquake from Ishibashi ( +31/ a, +31/ b) The open star indicates epicenter of the +3,, Uraga-channel earthquake from Utsu ( +313) 196
M 1 Table 2 Documents on the +3,, Uraga-channel earthquake Fig 2 Seismic intensity distribution map of the +3,, Uraga-channel earthquake by (a) Omori ( +3,, h), (b) Kanbayashi and Katsumata ( +31/ ), (c) Utsu ( +323 ) and (d) Usami (,**-) +33, - -, 2 +3,, +3,, +3,/ +3,, c Omori +3,, h +3,/ 2 +3,, c Omori +3,, h 197
+31/ +323,**- M-T,**- +322 Centroid moment tensor Dzie- +31/ wonski et al, +32+ Nabelek +32 3b +321 M 0 1;,/ 0 + +* dynecm // km +,/ CMT 1 +* dynecm -3 3 km Nabelek 3 +321 M +322 +** km +321 0, +, +1 ++ 2 + +* km /1 3 km Takeo +321, +,- +33* ;,**- +-/ +322 a+-2 +33* + +33* +0+ +333 +* 3-0-, 03, +322 +,/0/ 02 +, 3*+ -2/ +* /* E -/--N +33* ; /* km M 0 1,**- +1 - km,1 km -/+- 03 2 +0 * * 0 m 3c Sato and Matsu ura +31 +321 +322 ; +322 ; / +322 ; +322 ; +322; +322 a, +322 b; ; +322 ; +322 +322 ; +322; +322 ; +322 +322 +322 ; +322 a, +322 b; +322 +323; +322 ; +322; -3 03 +0- +323 ;,* km,* km M 0 1 +33* *0 m +322a 3a - PHS +322 + +0 M /, +322 +/ M, 1 b +322 +321 b +322 +321 +32* 198
M 1 199
Fig 3 Focal mechanisms of the +321 Chiba-ken Toho-Oki earthquake from (a) Japan Meteorological Agency ( +322 a), (b) Kawakatsu ( +322 ), (c) Yamada ( +322), (d) Yamada and Sato ( +322 ), (e) Okada and Kasahara ( +3** ) and (f) Ishibe and Tsuruoka (,**3) PHS /* km +32* PHS +32* +322 +321 +, +322 +, + +322 +322 A: +323 Fukuyama +33+ -* 0* km B: 0* 2* km C:,* * km - +* A PHS B PAC C PHS + C +322 3 d +322 + Qs +322 200
M 1 Okada and Kasahara +33* Hamada et al, +32/ 3e +33* +33*,**+ +, +, + +0 M /, +33/ +33 JUNEC +321,* km, +331 +333 PHS +322a +322 +322 +33*,**- +*,3 2E -/,, - N /2 * km M 0 1 +33* +33* Fig +* Focal mechanisms of earthquakes occurring,**3 Nakajima and Hasegawa,*+* eastern o# shore of the Chiba prefecture and classificatype tion from Iwase and Mizoue ( +322) A : strike-slip fault- +321 with compression axis in northeast-southwest Nakajima direction (hypocentral depth, -* 0* km), B : reverse fault- et al,,**3; Uchida et al,,**3 type with compression axis in east-west direction (hypocentral depth, 0* 2* km), C: low angle reverse fault-type with compression axis in northwest-southeast +3,+ or northern northwest-southern southeast direction (hypocentral depth,,* * km) +31- b, +31/ d +321 201
Table +* Documents on the +321 Chiba-ken Toho-Oki earthquake M 1+ Mikocm -, /2 shiba et al +33* -* 0* cm Okada and Kasahara, +33* 0 - +321 +322 a +322 +321 +322 a +322 b; +322 ; +33* ; +33* PHS PHS +322a,**- ++ 3 +323 +331 +321 +322 b +322 + / M /, M 1 b / +3,+ +3,, +321 -, +* +321 +2// 202
M 1 Fig ++ Seismic intensity distribution map of the +321 Chiba-ken Toho-Oki earthquake by (a) Japan Meteorological Agency ( +322 a), (b) Usami (,**-), (c) Harukawa ( +33* ) and (d) Ara ( +33* ) +31, ; +310 ; +32* ;,**+;,**-; Bakun,**/;,**0;,**1 +3,3 ; +31 ;,** GMT Wessel and Smith, +33+ Shimazaki +31+ ;,**2,+ +1*- +1*- 203
H, +32/, A high quality digital network for microearthquakes +33* +321 and ground tilt observations in the Kanto- +* ---3 Tokai area, Japan Earthquake Predict Res, -, 1 03 Bakun, WH,,**/, Magnitude and location of historical +33* earthquakes in Japan and implications for the +2// -/ 1/ 3* Ansei Edo earthquake, J Geophys Res, ++*, B *,-*, doi :,**0 +* +*,3 /,** JB **--,3,**0 +33, +33,,, D **0 2 ++, +,*,**+ Central Meteorological Observatory, +3,, a, Some notable +2// earthquakes occurred near Japan and the distant earth- /0 0-1* quakes observed in Japan in +3,+, Seism, Bull Cent +322 Met Obs, Japan, +,No +, +--/, Central Meteorological Observatory, +3,, b, Seismological 3/ */ Observation in Tokyo (Jan-April, +3,, ), Seism, Bull +322 +321 Cent Met Obs, Japan, +,No +, ++, +322 0+0 +1, 3, -/ -2 +3,3 +33* + +0 +322 b -/ 10, + 01 +322 +++ pp +31- a, +*,** +, +, +0 ++ +1,0-0, -01,0 pp +31- b, ERTS+ +3,+,0/ -*3-++ No, +-+ +3,, c, +31/ a,,03 +*/ ++ +3/* +22/ - +-, +-0 +3/* +3/* 33 +2 +31/ b, S-P Dziewonski, AM, Chou, TA- and Woodhouse, J H, +32+,,,2-1-0 Determination of earthquake source parameters from +31/ c, S-P waveform data for studies of global and regional seis- + 02 micity, J Geophys Res, 20,,2,/,2/, +31/ d, +322 + 03,**2 + -, +322,**2 S +- **2,**3 +322 +321 M 1 Green +23 +23/, 0 2 +3 +2, +323 +321,**3 JUNEC, +3,-, + -3 2,**3 Fukuyama E, +33+, Inversion for the Rupture Details of the P -00 +321 East Chiba Earthquake, Japan, Using a Fault +322 Model Based on the Distribution of Relocated After- + 0/ shocks, J Geophys Res, 30, 2,*/ 2,+1,*** +33*, - 0 123 +-,3,**-a,,**- +2// + 3 : -+ //,**- B */,,**-b, +323 +321, 3 /0 ++* 30 01,,** +31,,1, +0 1,1-+ +* /210 Hamada, K, Ohtake, M, Okada, Y, Matsumura, S and Sato, +331 204
M 1-3+ pp +/0pp +333 +323-3/ pp -,** 30 02* -+ pp +322 +322 +321 +,,1 3/ * /* /- +322 +321 +, +1 +323 +321-1 +-1 +,0 + +0 +322 +321,/,,- +322 +321 3/330,,3 +322,2/,3-0 +, +3, +3,/ +33* +321 33, - /3 03 -, Mikoshiba T, M Miyamoto, S Kinoshita, +33*, DIGITIZED +31/ DATA ON NRCDP STRONG-MOTION EARTHQUAKE RECORDS () December +1, +321 EAST OFF CHIBA - PREFECTURE EARTHQUAKE /- +*- + + ++- +32* +33* -/ +, 00 +* +32/ +322 a, +321 -/ -- +-1 B I +322 -+3-,* +322 +321 +, +322 b, +321 +, +1 M 01 -/ /-+ + 0 +322 +321,*** +3,+ +, 2 * 2123, /- 2-22 +321 +321 +, +1,**+,- 3-30 - 0+ 03 +322 +321 +, +1 +31/ a, +3,- - III /2 /3 - Nabelek J L, +32, Determination of earthquake source ++1 +,, parameters from inversion of body waves, Ph D Theb, - +31/ sis, Mass Inst of Technology /* 00 +3,- -1 1 +, +- +322 +3,,,,0-0 -0 +++ +331 +321,**3 M1 +*,02,**3 B +, *0 1 +3,/ Nakajima, J and A Hasegawa,,*+*, Cause of M1 intra- 33,, -+ slab earthquakes beneath the Tokyo metropolitan area, +322 Japan: Possible evidence for a vertical tear at the easternmost portion of the Philippine Sea slab, J Geophys +,03 Res, accepted +33* Nakajima, J, F Hirose, and A Hasegawa,,**3, Seismotectonics -/ +3 beneath the Tokyo Metropolitan area, Japan:,3 E# ect of slab-slab contact and overlap on seismicity, J +31+ +22/ +31* Geophys Res, ++,B*2-*3,doi: +* +*,3 /,**2 JB **0+*+ +0- pp +322 +321 +322 a, +321-0 +, 0+ 0- +, * 1, 2* +322 b,,**1 *,3+ -*+ +2//,***,, +*+ +*1 * +3,, a, 205
+ +-3 +/0 Takeo, M, +321, An inversion method to analyze the rupture Nakamura S, +3,, b, On the Destructive Earthquake oc- processes of earthquakes using near-field seismograms, th curred near Tokyo on the,0, April +3,,, Seism Bull Bull Seism Soc Am, 11, 3* /+- Cent Met Obs, Japan, +,No +,-3 +322 +321 +322 a, + +2, ---/ +3,, +322 b, -0 -, +2-0 +, +- +2 +322 +31,0, - +31 a,3,3 1 +322 +321 3-2/ -20 +0 / +*+ +*1 +31 b, +322 +321 / 3-21-22 3/ *- +33 +321 M 0 1 +322 a, +321 /2, 1-0/ -1 +322 b, +321 +322 +321 +, +1 * 2+ 20 B I +322 32333* +322 +321 +, +3,, + 0- -3 23 Okada, Y and K Kasahara, +33*, Earthquake of +321, o # +/- +/ Chiba, central Japan and possible triggering of eastern +301,++ pp Tokyo earthquake of +322, Tectonophysics, +1,, -/+ -0 +31* +3,, a, 2 ++-1 ++- -3 2 /30* +31- /* +3,, b, - *+,2/ 0121 +3,, c, +31-3 23,/ +3,, d,,,1,3-3 23 +/, +322 +321 +, +1 +3,, e,, +31-3 3+, 0 Uchida, N, J Nakajima, A Hasegawa, and T Matsuzawa, +3,, f,,**3, What controls interplate coupling?: Evidence for +* +/- abrupt change in coupling across a border between two Omori, F, +3,, g, On the Severe Earthquake of Dec 2, +3,+, overlying plates in the NE Japan subduction zone, Seismological Notes,,, +,+ Earth Planet Sci Lett,,2-, +++ +,+ Omori, F, +3,, h, The semi-destructive earthquake of April +322,0, +3,,, Seismological Notes, -, + -* +32* + -/ * +1 +31- +322 /* + +, -0 +, / ++ +310 Sato R and M Matsu ura, +31, Strains and tilts on the /+,*3,-* surface of a semi-infinite medium, Journal of Physics of,**- +0,**+ the Earth,,,,,+-,,+ 0*/ pp +322 +3,, a, +, 2 +321 + +- +,1* +3,, b, +31 + ++ ++3 Shimazaki K, +31+, Unusually low seismic activity in the Ushiyama, T, +3,, c, On the Destructive Earthquake near focal region of the great Kanto earthquake of +3,- th Tokyo on the night of 2, December +3,+, Seism Bull Tectonophysics, ++, -*/ -+, Cent Met Obs, Japan, +,No +, -0-2 +33* +313 +22/ +3,/ M 0 -/ ++ +2 /,/- +32/ -*2 +323 M 0 * -0,/,/1 +3*+ +3,0,12 206
M 1 pp +3,, a, Wessel, P and WHF Smith, +33+, Free software helps map -3 2 0* and display data, EOS Trans AGU, 1,, + Yasuda Ch, +3,, b, List of the After-shocks of the Strong +322a, Earthquake of Dec 2, Seismological Note,,,,,,- +3-2 / 3 +,1+ +, +, +*1pp +322 b,,**+ - -2 /* B I +322 -,+ -,, +33/, +322 +321 +, +1 20,1-3 + 00 (Received November +2,,**3) +322 (Accepted January,,*+*) /,,/ -2 207
A +, 2 +3,, a Appendix A Destructive earthquake around Inba-numa of the Chiba prefecture on 2, December from Ushiyama ( +3,, a) +* +, 2 ++ -+ -2 3 1 ++ ++ 2 +* + - - // m, -0 m, - + *- cm / 3+ m - *3 cm 2 + +, 0 + / / + 208
M 1 +,* + -* 3 +0 m / +/ + cm +, + cm, 0+ cm +/,1- m - + 3+ cm + -3-3+ cm km + -cm / +/ m, + */ mm + /, +/ mm +/ ++ / 2*, +, +1 +, +, +1 + // + km + + km +* + 1 km ++ + km - 1 km, / - 0 + 0 2 / cm - 2 ++/ + cm, 0 12 2 cm,/ 209
+* -3, 2 3 -+ -0 2 3 -, 3-0 3 * - +* 0 +* -2 1* km +, ++ + +* 3 -- 3 * 3 0 *,+ + -2 - /* ++ / 2 3 -+ 0 +* +, - + / +, + +/, cm +, 2 3 /, /- 3 2 3 -+ 0, - 0 m / 0 +/, +2, cm - +* 3 -, 1 -,,,/ + *+ -2, mm -0 m,0,/ +*, mm + + 2 m,,*, - -1, 1 +,* -* mm + / mm +* -* ++ - +, - 2 3 - /* /* +* -0-3 - +* /+, 3 + -1 ++ / /* - 1 /0,3-1 3 /02 210
M 1,+ / 2 B +3,, a Appendix B Destructive earthquake in the Tokyo Metropolitan area on 2, Dec, +3,+ from Omori ( +3,, a) +* +, 2 3 +2// ++ ++,10,* +/* 3 -+ +, 1, cm,2 + +2 +/,*,2 22 0/ km 0/ +0 0, 2 km,3 km 1, - /2 mm + 3 C +3,, b Appendix C Destructive earthquake in the Tokyo Metropolitan area from Omori ( +3,, b) ++,0 +*, +,-- mm +* ++ + +, 2 +3,+ +* 0 13 km S 0/ * mm + -,* 12 / km, + 01 mm, - 3,1 km 211
-,/, +, 2 + +/,* +22/,1 212