Cycle of Interplate Earthquake Along the Sagami Trough, Deduced from Tectonic Geomorphology

Μέγεθος: px

Εμφάνιση ξεκινά από τη σελίδα:

Download "Cycle of Interplate Earthquake Along the Sagami Trough, Deduced from Tectonic Geomorphology"

Μαρία Αθανασίου
5 χρόνια πριν
Προβολές:

1 Bull. Earthq. Res. Inst. Univ. Tokyo Vol. 12,**- pp.,./,/. * Cycle of Interplate Earthquake Along the Sagami Trough, Deduced from Tectonic Geomorphology Masanobu Shishikura* Active Fault Research Center, GSJ/AIST Abstract A tectonic geomorphological study is one of the best methods of evaluating the timing and the crustal deformation of pre-historic earthquake. To reveal the cycle of interplate earthquakes along the Sagami Trough, I investigatedthe emergedshoreline topography andthe fossilizedsessile assemblages in the Miura Peninsula andthe Boso Peninsula. The distribution pattern of coseismic vertical displacement during the +1*- Genroku Kanto Earthquake inferredfrom the height distribution of the paleo-shoreline suggests that the fault source model consists of a dual fault system of the Fault A andb. Fault A is also the source of the +3,- Taisho Kanto Earthquake. The geometry and ages of the emerged shoreline topography divided into several levels indicate that the characteristic earthquake generatedfrom Fault A has occurredabout every.** years. One of several events, it is accompaniedwith a slip of Fault B, which has a recurrence interval of,***,1** years. Key words: tectonic geomorphology, paleo-shoreline, recurrence interval, Sagami Trough, Kanto Earthquake + +** +* / +3,- M +* ;,** *- M 2., Fig. + +3,0; Sugimura and Naruse +3/. +3//,,*,** -** +311 GPS,**.** / 2** +333 /** 0** * m.shishikura@aist.go.jp -*/ 2/

2 Fig. +. Epicenters of the Kanto Earthquakes along the Sagami Trough. Locations of the epicenters are basedon Utsu (+333). Contour interval of bathymetric chart is +** m., +3,- wave-cut bench +3,/ +3,0 Miyabe +3-+, m Fig.,, m Pomatoleios Kraussii *

!G¹TQºB».fw GH v 0 Fig.,. Coseismic vertical displacement during the +3,Taisho Kanto Earthquake, based on a re-leveling of benchmarks. Contours are in meters.

$@ABCDEFGHI JAB7 < 6 7 4K L M EFGH E A N OPQ4 NB=R ST +322> ATA U VW, X +.C YW AT B AMS UZ [\ B ] 03*;1/* yr BP N^ U, Q4B =_`ῌab,**+ a> KB AD +3,- c AB OPQ4 56!"#$%&'( ) C +. Fig. -.$

3 !G¹TQºB».fw GH v 0 Fig.,. Coseismic vertical displacement during the +3,Taisho Kanto Earthquake, based on a re-leveling of benchmarks. Contours are in meters. Compiled from Geophigical Survey Institute (+3,0) and Miyabe (+3-+). -ῌ+!"#$%&'()*+,, -./ , 89 : 6 7,,.*;,.0 m < =Fig. -> 5 +.*;+.0 m 6 7?@ABCDEFGHI JAB7 < 6 7 4K L M EFGH E A N OPQ4 NB=R ST +322> ATA U VW, X +.C YW AT B AMS UZ [\ B ] 03*;1/* yr BP N^ U, Q4B =_`ῌab,**+ a> KB AD +3,- c AB OPQ4 56!"#$%&'( ) C +. Fig. -. Two levels of fossilized sessile assemblages (Pomatoleios Kraussii) in Jogashima, the Miura Peninsula. M.S.L. : mean sea level. Scale bar is graduated in +* cm. U[d 9 e(fgf U Ghi[j -.*/ mm ῌ ua N 34 N =Ozawa et al., +331> M ῌCD GH 7%& kr l[ mab ] krn+/3o,+ B =_`,**-> 4 p AB 6!"#$%&'() qd AD+00-;+21, ri,csn, < B 4,,* *.1 m u, '!"#$%&'( ), *.2 m 1234B=Fig. -> TQ M E AD+00- tu v/'w[ja N xy FGHI ( +./ m 34 CDEFGH < z{iutu CGH S}74 X~ I S}% < B s 34 N OPQ4, [ ^ G 7 [ AB ] N 47 +.*; ^ H [7-GH AD+1*- M EFGHt +./ m CDEFGH %& ) BQ N AB, 6 #$%&'(),,*QT B =_`ῌab,**+ a> ST M EFGHI JAB N J+ªῌ7, «, A p!"#$%&'() NP -, -./0!"#$%&'() TQ56, Jv/'w,S}% < B [j 6 [ia NB M EFGHI 4tu CDEFGH?K,,*!AB t: ±TQ M EFGH CDEF GH S}% G²![ B. Q4 GH! [ Bwf 0![j -ῌ, "# v' f v $! $ /³ µst =+31.>,.* ~ d 8 56 «=CD/' [ X> -N 4,M ¼ 247 ¼

+** m +31. Fig.. +333 +31. +311,***,./1 mm Ozawa et al., +331 Fig.

4 +** m +31. Fig ,***,./1 mm Ozawa et al., +331 Fig. / 0 m + m - - Manshinha and Smylie +31+ Ando +31. Fault A Fig 0 -* 0.1 m Fault B,* +, m Matsuda et al Fig. /. Coseismic vertical displacement during the +1*- Genroku Kanto Earthquake,deduced from height distribution of paleoshoreline. Contours are in meters. Fig... Two levels of emerged wave-cut benches in Kenbutsu,the Boso Peninsula. 248

Fig. 0. Fault source model of the +1*- Genroku Kanto Earthquake. Contours are theoretical vertical displacements in meter. 1*. -* m Imamura +3,2 +3,3.

5 Fig. 0. Fault source model of the +1*- Genroku Kanto Earthquake. Contours are theoretical vertical displacements in meter. 1*. -* m Imamura +3,2 +3, , - 0,*** yr BP.,0** yr BP -,+** yr BP 1,*** cal yr BP /,-** cal yr BP -,0** cal yr BP + +./ m,**+ b., +31.,. Fig. 1; Sugimura and Naruse, +3/.; Yonekura +31/; +312; +32* 249

$,E- C I014 $'& C l-1 ;Fig. 1<4 01 -! qr&'#4 s t JK)*+ u"!( WXv# F GH#$ (JKLMN!" s s w xyz{ * 1r]^}` ~0"$ #$ %& JK)*+,OPQRCA"STG./ %& $' G5 ]^( G -14 01 23&'!"# ;Fig.$ $2<4 UV % ;+32*< -ῐ, G 01 ( )*+ WX01. %&YῌE ;Fig. /< Z[ \ +.C ]^_` ab"! YῌE W *+,O* JKW *+ ;Fig.,< P # JK ST01* ;./]^ 5'c'Y ῌ : 0,+/* yr BP Y : <.$

6 K - fg % ;+333< -!]^QK hia'1jk!"#$ %& $'&( Yῌ : 1,+/* cal yr BP Y :.,3/* cal yr BP Y )*+,-!./01 23&' :,,3/* cal yr BP 8ῌ9: ;+320< ($'& )*+ mnop(,,***e,,1** ] =>?@ A& B%"CD -!,E- C I014 $'& C l-1 ;Fig. 1<4 01 -! qr&'#4 s t JK)*+ u"!( WXv# F GH#$ (JKLMN!" s s w xyz{ * 1r]^}` ~0"$ #$ %& JK)*+,OPQRCA"STG./ %& $' G5 ]^( G &'!"# ;Fig. 2<4 UV % ;+32*< -ῐ, G 01 ( )*+ WX01. %&YῌE ;Fig. /< Z[ \ +.C ]^_` ab"! YῌE W *+,O* JKW *+ ;Fig.,< P # JK ST01* ;./]^ 5'c'Y ῌ : 0,+/* yr BP Y : <.,-** yr BP Y :,,2/* yr BP G 0 JKGST01* ; V< - u * de G l JKGST01* ;x < Fig. 1. Paleo-shorelines on Nishikawana, the southernmost part of the Boso Peninsula. Aerial photo contributed by Chiba Historical Material Research Foundation. Fig. 2. Schematic geomorphic proﬁles of Holocene lowlands in the Boso Peninsula. G : emerged area during the Genroku-type event. T : emerged area during repeated Taisho-type events. Modiﬁed from Shishikura and Miyauchi (,**+). 250

7 +**,** m +* Fig m +*. Fig. 2 Fig. 3 / +* BR-I X BR-X BR-I IX BR-X +* ++,**+ Fig. +* +. C 0,2-* 0,1,* cal yrs BP /,-** /,*0* cal yrs BP - - -,-** -,+** cal yrs BP,,-+*,,,-* cal yrs BP Fig. 3. Seismotectonics model in each area around the Sagami Trough. G: Timing of the Genroku-type Earthquake. d: relative vertical displacement. t: time. 251

8 Fig. +*. Schematic cross-section of geology and geomorphology in the Iwai Lowland. + : terrestrial deposit,, : aeolian deposit, - : beach ridge deposit,. : backshore deposit, / : foreshore deposit, 0 : shoreface deposit, 1 : marine clay, 2 : bedrock, 3 : location of radiocarbon sample (number means cal yrs BP), +* : location of archaeological site. Modified from Shishikura et al. (,**+). + +,-** cal yrs BP 3** cal yrs BP +, m 0 Fault A Fig. 3 +,,***,,1** Fault B Fault A Fig. 3 Fig. ++ -,*** +,-** cal yr BP, m +33* /,*** -,*** cal yr BP.** +,-** cal yr BP.** +/./ m +.. m 0,2**, - m Endo et al. +32, +,./ +-./ m,./1 mm 0,2** +1./ m 252

9 Fig. ++. Timing and relative coseismic uplift of repeated Kanto Earthquakes. Open rectangle enclosed with dotted line means +. C age samples were not obtained.,*,+ m m +. +/ 0,2** ,2** -2*.** +,-** cal yr BP 212 3** cal yr BP +,/1 +,3- +. C +, Fault A Fault B, Fault A + Fault B.** Fault A + 1 m +1./ mm * mm Fault B,,-** + +, m /., mm Ando, M., +31., Seismo-tectonics of the +3,- Kanto earthquake, Jour. Phys. Earth,,,,,0-,11. Endo, K., K. Sekimoto and T. Takano, +32,, Holocene stratigraphy and paleo-environments in the Kanto Plain, in relation to the Jomon Transgression, Proc. Inst. Natural Sciences, Nihon Univ.,,+, -1 / /2. 253

10 Imamura, A., +3,2, On the seismic activity of Kwanto district, Jour. Astronomy Geophysics, /, +,1 +-/ *-, -* , ,,/+,/ / ,0.1 /1. +32, / /,/ /-+. Mansinha, L. and D. Smylie, +31+, The displacement fields of inclined faults, Bull. Seismol. Soc. Am., 0+, *. +32/ 1.1, *- : +1/ +3, Matsuda, T., Y. Ota, M. Ando and N. Yonekura, +312, Fault mechanism and recurrence time of major earthquakes in southern Kanto district, Japan, as deduced from coastal terrace data, Geol. Soc. Amer. Bull., 23, +0+* ,***, 0-, +./ +2,. Miyabe, N., +3-+, On the verticalearth movements in Kwanto districts, Bull. Earthquake Res. Inst. Tokyo Univ., 3, +,+. +32* /-, , *, Ozawa, S., M. Hashimoto and T. Tada, +331, Verticalcrustal movements in the coastalareas of Japan estimated from tidal observations, Bull. Geogr. Surv. Inst.,.-, +,+. +3,0 + 0/ GPS 1-,1/,3*. +331,1, ,2.,*** +1* ,,.,**- +. C ,**+.*,-/,.,.,**+, /- -/1-1,.,**+ a +1*- +1 -, -2.,**+ b -+,2,3. Sugimura, A. and Y. Naruse, +3/., Changes in sea level, seismic upheavals, and terraces in the southern Kanto region, Japan ( ), Jap. Jour. Geol. Geogr.,,., +*+ ++-.,**- 0*/ , ,/ +** ++ / / Yonekura, N., +31/, Quaternary tectonic movements in the outer area of Southwest Japan with specialreference to seismic crustal deformations, Bull. Dept. of Geogr. Univ. of Tokyo, 1, ,3 / ++3 +,0. Received June,1,,**- Accepted September +1,,**- 254

Σχετικά έγγραφα

Masaaki Hamada *, Takeo Noguchi, Fumihiro Anada, Koji Nohara, Takahiro Miya- uchi, Kazuki Watanabe, Hiroyuki Yamaguchi

Masaaki Hamada *, Takeo Noguchi, Fumihiro Anada, Koji Nohara, Takahiro Miya- uchi, Kazuki Watanabe, Hiroyuki Yamaguchi Bull. Earthq. Res. Inst. Univ. Tokyo Vol. 2,,**1 pp. -./ -/3,**1 + + + +,, - *. +, -. Crustal Deformation Associated with the,**1 Noto Hanto Earthquake and Late Quaternary Marine Terrace Distribution on