Shear Wave Splitting Observed in the Southwestern Part of Fukushima Prefecture, Northeastern Japan

Tomomi Okada, Toru Matsuzawa, Satoshi Matsumoto, Koichi Nida, Akihiko Ito, Akira Hasegawa

Research output: Contribution to journalArticle

9 Citations (Scopus)

Abstract

We have investigated shear wave polarization anisotropy in the southwestern part of Fukushima Prefecture, northeastern Japan. Waveform data we analyzed are obtained by a local seismic networks of Tohoku University and Utsunomiya University. We used a cross correlation method to detect the shear wave splitting. For the shallow events beneath the southwestern part of Fukushima Prefecture, observed that fast shear wave oscillation directions (FSODs) are oriented to the NW-SE. The observed delay times are less than 0.1s and tend to have large values in high seismicity regions. For the intermediate-depth events, observed FSODs are oriented parallel to the dip direction of the subducted slab and most of the observed delay times are less than 1 s. We estimated the location and the cause of anisotropy based on these observations. In the upper crust beneath the southwestern part of Fukushima Prefecture anisotropy is estimated to be caused mainly by preferredly oriented cracks controlled by the tectonic stress.

Original languageEnglish
Pages (from-to)303-319
Number of pages17
Journaljournal of physics of the earth
Volume42
Issue number4
DOIs
Publication statusPublished - Jan 1 1994
Externally publishedYes

Fingerprint

wave splitting
S-wave
anisotropy
oscillation
upper crust
seismicity
dip
slab
crack
polarization
tectonics

All Science Journal Classification (ASJC) codes

  • Earth and Planetary Sciences(all)

Cite this

Shear Wave Splitting Observed in the Southwestern Part of Fukushima Prefecture, Northeastern Japan. / Okada, Tomomi; Matsuzawa, Toru; Matsumoto, Satoshi; Nida, Koichi; Ito, Akihiko; Hasegawa, Akira.

In: journal of physics of the earth, Vol. 42, No. 4, 01.01.1994, p. 303-319.

Research output: Contribution to journalArticle

Okada, Tomomi ; Matsuzawa, Toru ; Matsumoto, Satoshi ; Nida, Koichi ; Ito, Akihiko ; Hasegawa, Akira. / Shear Wave Splitting Observed in the Southwestern Part of Fukushima Prefecture, Northeastern Japan. In: journal of physics of the earth. 1994 ; Vol. 42, No. 4. pp. 303-319.
@article{f4b7e3f12b8b4e2f9103c6492298d8dc,
title = "Shear Wave Splitting Observed in the Southwestern Part of Fukushima Prefecture, Northeastern Japan",
abstract = "We have investigated shear wave polarization anisotropy in the southwestern part of Fukushima Prefecture, northeastern Japan. Waveform data we analyzed are obtained by a local seismic networks of Tohoku University and Utsunomiya University. We used a cross correlation method to detect the shear wave splitting. For the shallow events beneath the southwestern part of Fukushima Prefecture, observed that fast shear wave oscillation directions (FSODs) are oriented to the NW-SE. The observed delay times are less than 0.1s and tend to have large values in high seismicity regions. For the intermediate-depth events, observed FSODs are oriented parallel to the dip direction of the subducted slab and most of the observed delay times are less than 1 s. We estimated the location and the cause of anisotropy based on these observations. In the upper crust beneath the southwestern part of Fukushima Prefecture anisotropy is estimated to be caused mainly by preferredly oriented cracks controlled by the tectonic stress.",
author = "Tomomi Okada and Toru Matsuzawa and Satoshi Matsumoto and Koichi Nida and Akihiko Ito and Akira Hasegawa",
year = "1994",
month = "1",
day = "1",
doi = "10.4294/jpe1952.42.303",
language = "English",
volume = "42",
pages = "303--319",
journal = "Journal of Physics of the Earth",
issn = "0022-3743",
publisher = "University of Tokyo Press",
number = "4",

}

TY - JOUR

T1 - Shear Wave Splitting Observed in the Southwestern Part of Fukushima Prefecture, Northeastern Japan

AU - Okada, Tomomi

AU - Matsuzawa, Toru

AU - Matsumoto, Satoshi

AU - Nida, Koichi

AU - Ito, Akihiko

AU - Hasegawa, Akira

PY - 1994/1/1

Y1 - 1994/1/1

N2 - We have investigated shear wave polarization anisotropy in the southwestern part of Fukushima Prefecture, northeastern Japan. Waveform data we analyzed are obtained by a local seismic networks of Tohoku University and Utsunomiya University. We used a cross correlation method to detect the shear wave splitting. For the shallow events beneath the southwestern part of Fukushima Prefecture, observed that fast shear wave oscillation directions (FSODs) are oriented to the NW-SE. The observed delay times are less than 0.1s and tend to have large values in high seismicity regions. For the intermediate-depth events, observed FSODs are oriented parallel to the dip direction of the subducted slab and most of the observed delay times are less than 1 s. We estimated the location and the cause of anisotropy based on these observations. In the upper crust beneath the southwestern part of Fukushima Prefecture anisotropy is estimated to be caused mainly by preferredly oriented cracks controlled by the tectonic stress.

AB - We have investigated shear wave polarization anisotropy in the southwestern part of Fukushima Prefecture, northeastern Japan. Waveform data we analyzed are obtained by a local seismic networks of Tohoku University and Utsunomiya University. We used a cross correlation method to detect the shear wave splitting. For the shallow events beneath the southwestern part of Fukushima Prefecture, observed that fast shear wave oscillation directions (FSODs) are oriented to the NW-SE. The observed delay times are less than 0.1s and tend to have large values in high seismicity regions. For the intermediate-depth events, observed FSODs are oriented parallel to the dip direction of the subducted slab and most of the observed delay times are less than 1 s. We estimated the location and the cause of anisotropy based on these observations. In the upper crust beneath the southwestern part of Fukushima Prefecture anisotropy is estimated to be caused mainly by preferredly oriented cracks controlled by the tectonic stress.

UR - http://www.scopus.com/inward/record.url?scp=0028572585&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0028572585&partnerID=8YFLogxK

U2 - 10.4294/jpe1952.42.303

DO - 10.4294/jpe1952.42.303

M3 - Article

AN - SCOPUS:0028572585

VL - 42

SP - 303

EP - 319

JO - Journal of Physics of the Earth

JF - Journal of Physics of the Earth

SN - 0022-3743

IS - 4

ER -