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腄腆 膣腴膠膭腴腷膵膒 腅腁 腑膹腱 腳膙膌腓膨膒腫膸腔腽腻 膦腮腐 膣腴膗腬膙膌腹腲膆 膌膁膶膲腵腪 膟膡腑膏膞腋腙腏腈腗 膕膧膑腉腼腇 膙膌膜膀腢腤腪 膙膌膜膀腹腲膏膋膳膬腓膝腰膪腨腒腈腇腏 膥腯膣腚 腊腓腫膸腔 腒膅腍 膦膴膄膣腴膙膌 膛膉腑腌腎 腡膊腐膨膒腍腘腟腛腞腜腠腂腝 膦腈腖腕 膦腓腣膈腺膥膬腓膙膌 膦腥腩 膐膤膫腶腓膙膌腑 膦膖膷腺膣膰腦膙膌腓 膙膌腒 膔膮腭膘 膓膃膇膍 腾膚腸膄 膢膂膱膩 腍腆腏腋 腬腔腢腟腫腯腌腨腣 腬腕腘腤腪腮腝腌腨腣腄腐腎 腬腦腱腟 腩腰腗腨腣 腫腙腩腉腭腥腅腈 腜腨腣腋腧腇腑腚腖腞腛腊腓腂腒腌 腠腡 ῌῌ 183 Bull. Earthq. Res. Inst. Univ. Tokyo Vol. pp. * e-mail : [email protected] M Earthquake Research Institute, University of Tokyo Association for Earthquake Disaster Prevention The Earthquake Research Committee of the Headquarters of Earthquake Research and Promo- tion estimated the probability of an earthquake of magnitude around . occurring during the next years as . This is based on five earthquakes that occurred in the southern Kanto region (i.e., the Meiji-Tokyo earthquake, the and Ibaraki-ken Nanbu earthquakes, the Uraga-channel earthquake and the 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 Ibaraki-ken Nanbu earthquake, the Uraga-channel earthquake and the Chiba-ken Toho-Oki earthquake) that occurred after the beginning of the Taisho era ( ) and describe the collected data. :M earthquakes, the Ibaraki-ken Nanbu Earthquake, the Uraga-channel Earthquake, the Chiba-ken Toho-Oki Earthquake, the southern Kanto region km * Takeo Ishibe *, Akihito Nishiyama , Kenji Satake and Kunihiko Shimazaki Abstract Key words The Ibaraki-ken Nanbu Earthquake, the Uraga-channel Earthquake and the Chiba-ken Toho-Oki Earthquake M Review of Previous Studies on M -class Earthquakes that Occurred in the Southern Kanto Region and Data Collection + , + , + + + , + + + , 2. ,**3 +2- ,+, ++- **-, +++ 1 -* 1* 1* -* 1* +23. +23/ +3,+ +3,, +321 +3,+ +3,, +321 +3+, +3,0 1 +3,+ +3,, +321 ,**. + +23. -* +23/ +3,+ +3,, +321 / + +3,+ +3,, +321 +3,+ +3,, +321 1 1

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183

Bull. Earthq. Res. Inst.

Univ. Tokyo

Vol. pp.

* e-mail : [email protected]

M

Earthquake Research Institute, University of Tokyo

Association for Earthquake Disaster Prevention

The Earthquake Research Committee of the Headquarters of Earthquake Research and Promo-

tion estimated the probability of an earthquake of magnitude around . occurring during the next

years as . This is based on five earthquakes that occurred in the southern Kanto region (i.e.,

the Meiji-Tokyo earthquake, the and Ibaraki-ken Nanbu earthquakes, the

Uraga-channel earthquake and the 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 Ibaraki-ken Nanbu earthquake, the

Uraga-channel earthquake and the Chiba-ken Toho-Oki earthquake) that occurred after the

beginning of the Taisho era ( ) and describe the collected data.

: M earthquakes, the Ibaraki-ken Nanbu Earthquake, the Uraga-channel

Earthquake, the Chiba-ken Toho-Oki Earthquake, the southern Kanto region

km

*

Takeo Ishibe *, Akihito Nishiyama , Kenji Satake and Kunihiko Shimazaki

Abstract

Key words

The Ibaraki-ken Nanbu Earthquake, the Uraga-channel

Earthquake and the Chiba-ken Toho-Oki Earthquake

M

Review of Previous Studies on M -class Earthquakes

that Occurred in the Southern Kanto Region and Data

Collection

+

,

+

,

+ + + ,

+ + + ,

2. ,**3 +2- ,+,

++- **-, + + +

1 -* 1*

1 *

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+321

+3,+ +3,,

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1 +3,+ +3,,

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,**. + +23.

-* +23/ +3,+ +3,,

+321 /

+

+3,+ +3,, +321

+3,+ +3,,

+321

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Fig. . Five earthquakes (i.e., the Meiji-Tokyo earthquake, the Ibaraki-ken Nanbu earthquake, the

Ibaraki-ken Nanbu (Ryugasaki) earthquake, the Uraga-channel earthquake and the Chiba-ken

Toho-Oki earthquake) used to estimate the occurrence probability of ‘other M class earthquakes that have

occurred in the southern Kanto region’. The epicenter and magnitude of the Chiba-ken Toho-Oki

earthquake are based on the Japan Meteorological Agency (JMA), and others are based on Utsu ( ).

M

b a a, b a,

b, b

b, d

. E, . N

M . ;

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1

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, +23. +31- +31/ ,***

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,

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+321 +.* + -/ 2

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Fig. . Hypocenter and focal mechanism of the Ibaraki-ken Nanbu earthquake C : Central

Meteorological Observatory ( ), O : Omori ( a, g), Ushi : Ushiyama ( c), K : Katsumata

( a, b), I : Ishibashi ( a, b, b), Utsu : Utsu ( ), Usa : Usami ( ) . Parenthetic

number (in km) or character (s : shallow ; ? : unknown) indicates hypocentral depth.

a

.

km

mm

B Omori g

a A Ushiyama c . .

. S-P

E N

Ushiyama c km Omori g S-P

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b . a .

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Table . Seismological reports on the Ibaraki-ken

Nanbu earthquake by meteorological observatories

from Ushiyama ( a).

Fig. . Seismograms of the Ibaraki-ken Nanbu

earthquake recorded by the strong motion seismo-

graph at (a) Hongo, and (b) Hitotsubashi (from

Omori, g).

a Yasuda b

. E, . N

. E . N M km

. S E

. E, . N M . km

km b, d

a

S-P a a, b, c

. .

S-P Omori . . S-P

g E, N km

. S-P

km

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Table . Documents on the Ibaraki-ken Nanbu earthquake.

PAC

km

a, b S-P

E, N, km

M . M c

.

M . b . Nm Mw .

. E, . N a, b, c km

M PHS PAC

PAC PHS

PHS

. E, .

N M .

GME

a, b, c

. Nm Mw .

b a, b, ,

c a, b, GME

PHS PAC

km

a

PHS PAC

+2

+2

/ +3,+

+* +33*

+301

+32/

+31/ +31/ ,***

+.* *- - -0 *3 . +* ,

0 1 ,

1 + +313 ,+ +-, 13 /.

1 * +31/ . / +* 0 .

+.* , -0 * +31/ +31/ +31/ /-

+3,- ,

+3,+ +3,, ,**+

.

,**- +313 +.* , -0 *

1 *

,***

,

+32/

+31/ +31/ +31/ / +3,+

/ 0 +* 0 .

+ ,22

13 -.

, +31/ +31/ ,*** ,**-

+31/ ,**- ,**.

0* 1/ +, +0

,, +3,,

+3,+

, ,

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Fig. . Seismic intensity distribution map of the Ibaraki-ken Nanbu earthquake by (a) Omori ( h),

(b) Kanbayashi and Katsumata ( ), (c) Utsu ( ) and (d) Usami ( ).

Central Meteorological Observatory

a

b, c, e Omori h a,

b a, b, c

a Yasuda b

a Ushiyama c Omori h c

:

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c a Nakamura b

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Fig. . Hypocenter [C : Central Meteorological Observatory ( c), N : Nakamura ( a, b), O : Omori

( h), K : Katsumata ( a, b), I : Ishibashi ( c), I : Ishibashi ( a, b) Utsu : Utsu ( ), Usa :

Usami ( )] and focal mechanism [Ishibashi ( d)] of the Uraga-channel earthquake. Parenthetic

number (in km) or character (s : shallow ; ? : unknown) indicates hypocentral depth.

b c mm sec

mm sec

. mm sec

Omori h

km

mm sec

C d .

km

E,

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Fig. . Seismograms of the Uraga-channel earthquake recorded by strong motion

seismographs at (a) Hongo, and (b) Hitotsubashi (from Omori, h).

a, b a, b S-P

M . M .

N, km Omori

h

/ E, . N km

. c

S-P

P

Vp Vs

E, N km

. d

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E, a,

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km M .

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Fig. . Recent seismicity around the Uraga channel from the unified Japan Meteorological

Agency catalog (October, to May ). The blue star indicates hypocenter of the

Uraga-channel earthquake from Ishibashi ( a, b). The open star indicates

epicenter of the Uraga-channel earthquake from Utsu ( ).

1

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Table . Documents on the Uraga-channel earthquake.

Fig. . Seismic intensity distribution map of the Uraga-channel earthquake by (a) Omori

( h), (b) Kanbayashi and Katsumata ( ), (c) Utsu ( ) and (d) Usami ( ).

c Omori h

c Omori h

1

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; km M .

. km km .

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a, b ; ; ;

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Fig. . Focal mechanisms of the Chiba-ken Toho-Oki earthquake from (a) Japan

Meteorological Agency ( a), (b) Kawakatsu ( ), (c) Yamada ( ), (d) Yamada and

Sato ( ), (e) Okada and Kasahara ( ) and (f) Ishibe and Tsuruoka ( ).

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km

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direction (hypocentral depth, km), B : reverse fault-

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tion from Iwase and Mizoue ( ) A : strike-slip fault-

M

Fig. . Focal mechanisms of earthquakes occurring

eastern o shore of the Chiba prefecture and classifica-

type with compression axis in northeast-southwest

type with compression axis in east-west direction

(hypocentral depth, km), C : low angle reverse

or northern northwest-southern southeast direction

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Table . Documents on the Chiba-ken Toho-Oki earthquake.

M .

Miko-

cm shiba

cm Okada and Kasahara,

a

a b ; ; ;

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b

M . M

et al.

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Fig. . Seismic intensity distribution map of the Chiba-ken Toho-Oki earthquake by (a) Japan

Meteorological Agency ( a), (b) Usami ( ), (c) Harukawa ( ) and (d) Ara ( ).

; ; ;

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Ansei Edo earthquake, , B , doi :

H., , A high quality digital network for microearth-

quakes and ground tilt observations in the Kanto-

. Tokai area, Japan. , .

Bakun, W.H., , Magnitude and location of historical

earthquakes in Japan and implications for the .

. / JB .

D .

.

Central Meteorological Observatory, a, Some notable

earthquakes occurred near Japan and the distant earth- .

quakes observed in Japan in ,

, .

Central Meteorological Observatory, b, Seismological .

Observation in Tokyo (Jan.-April, ),

, .

.

.

.

. .

pp. a,

.

pp. b, ERTS

. No. .

c, a,

.

.

. b, S-P

Dziewonski, A.M., Chou, T.A.-. and Woodhouse, J. H., , .

Determination of earthquake source parameters from c, S-P

waveform data for studies of global and regional seis- .

micity, , . d,

.

.

S .

M

Green

. .

JUNEC

.

Fukuyama E., , Inversion for the Rupture Details of the P .

East Chiba Earthquake, Japan, Using a Fault

Model Based on the Distribution of Relocated After- .

shocks, , .

.

. a,

: .

B . b,

.

.

. .

Hamada, K., Ohtake, M., Okada, Y., Matsumura, S. and Sato,

J. Geophys. Res.,

Earthquake Predict. Res.,

Seism, Bull. Cent.Met. Obs., Japan,

Seism, Bull.Cent. Met. Obs., Japan,

b

J. Geophys. Res.,

J. Geophys. Res.,

, No.

, No.

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pp. pp.

pp.

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pp.

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.

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. .

.

. Mikoshiba T., M. Miyamoto, S. Kinoshita, , DIGITIZED

DATA ON NRCDP STRONG-MOTION EARTHQUAKE

RECORDS ( ) December , EAST OFF CHIBA

PREFECTURE EARTHQUAKE

. .

. .

a,

. B I .

b,

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. parameters from inversion of body waves, Ph. D. The-

b sis,

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M

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Nakajima, J. and A. Hasegawa, , Cause of M intra-

. slab earthquakes beneath the Tokyo metropolitan area,

Japan : Possible evidence for a vertical tear at the east-

ernmost portion of the Philippine Sea slab,

.

Nakajima, J., F. Hirose, and A. Hasegawa, , Seismotec-

tonics beneath the Tokyo Metropolitan area, Japan :

. E ect of slab-slab contact and overlap on seismicity,

, B , doi : . / JB .

pp.

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J. Geophys.Res., accepted.

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. Takeo, M., , An inversion method to analyze the rupture

Nakamura S., b, On the Destructive Earthquake oc- processes of earthquakes using near-field seismograms,

curred near Tokyo on the , April , , .

, No. , .

a, .

.

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.

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a .

. .

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. .

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. b,

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Okada, Y. and K. Kasahara, , Earthquake of , o .

Chiba, central Japan and possible triggering of eastern pp.

Tokyo earthquake of , , .

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.

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.

e, .

. Uchida, N., J. Nakajima, A. Hasegawa, and T. Matsuzawa,

f, , What controls interplate coupling? : Evidence for

. abrupt change in coupling across a border between two

Omori, F., g, On the Severe Earthquake of Dec. , , overlying plates in the NE Japan subduction zone,

, . , .

Omori, F., h, The semi-destructive earthquake of April

, , , .

.

.

.

.

Sato R. and M. Matsu’ura, , Strains and tilts on the .

surface of a semi-infinite medium,

, . pp.

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.

. b,

.

Shimazaki K., , Unusually low seismic activity in the Ushiyama, T., c, On the Destructive Earthquake near

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, . , .

M

.

.

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.

Seism. Bull. Bull. Seism. Soc. Am.,Cent. Met. Obs., Japan,

Tectonophysics,

Seismological Notes, Earth Planet Sci. Lett.,

Seismological Notes,

Journal of Physics ofthe Earth,

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Wessel, P. and W.H.F. Smith, , Free software helps map .

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a, Earthquake of Dec. , , .

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M

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km

mm

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km S

mm . km,

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B

a

Appendix B. Destructive earthquake in the Tokyo Metropolitan area

on , Dec., from Omori ( a).

C b

Appendix C. Destructive earthquake in the Tokyo Metropolitan area

from Omori ( b).

1

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