In-situ stress measurement at shallow depth in the vicinity of the epicenter before and after the 2011 Tohoku-Oki Earthquake

Kiyotoshi Sakaguchi, T. Yokoyama

Research output: Chapter in Book/Report/Conference proceedingConference contribution

1 Citation (Scopus)

Abstract

In-situ rock stress measurement was carried out in the Kamaishi mine of Iwate Prefecture to quantify the variation of the shallow crustal stress field associated with the 2011 Tohoku-oki earthquake. Stress measurement was conducted by the Compact Conical ended Borehole Overcoring (CCBO) technique, which is one of the stress relief method. The CCBO technique is the one of the suggested method of ISRM. Measurement period is from 1991 to 2014. Main results obtained in this study can be summarized as follows. The direction of the maximum principal stress did not change much before and after the earthquake. However, the directions of the intermediate principal stress and the minimum principal stress of one year after the earthquake changed from those of before earthquake. Namely, the direction of intermediate principal stress was East-West horizontally, and the direction of minimum principal stress was vertically. This state of stress is reverse fault type and was maintained for three years after the earthquake. The magnitudes of principal stresses and the vertical stress of one year after the earthquake became more than the double before the earthquake. However, the magnitudes of the maximum principal of two year after the earthquake became smaller comparing with those of one year after the earthquake. Furthermore, the magnitudes of the intermediate principal stress and the minimum principal stress of two year after the earthquake became almost same as those before earthquake, and the vertical stress of two year after the earthquake became almost equal with the overburden pressure. And the magnitudes of three principal stresses of three year after the earthquake became the same level before the earthquake.

Original languageEnglish
Title of host publication13th ISRM International Congress of Rock Mechanics
Editors Hassani, Hadjigeorgiou, Archibald
PublisherInternational Society for Rock Mechanics
Pages1-10
Number of pages10
ISBN (Electronic)9781926872254
Publication statusPublished - 2015 Jan 1
Event13th ISRM International Congress of Rock Mechanics 2015 - Montreal, Canada
Duration: 2015 May 102015 May 13

Publication series

Name13th ISRM International Congress of Rock Mechanics
Volume2015- MAY

Other

Other13th ISRM International Congress of Rock Mechanics 2015
CountryCanada
CityMontreal
Period15/5/1015/5/13

Keywords

  • CCBO technique
  • Earthquake
  • In-situ rock stress
  • Rock stress measurement

ASJC Scopus subject areas

  • Geophysics
  • Geochemistry and Petrology

Fingerprint Dive into the research topics of 'In-situ stress measurement at shallow depth in the vicinity of the epicenter before and after the 2011 Tohoku-Oki Earthquake'. Together they form a unique fingerprint.

  • Cite this

    Sakaguchi, K., & Yokoyama, T. (2015). In-situ stress measurement at shallow depth in the vicinity of the epicenter before and after the 2011 Tohoku-Oki Earthquake. In Hassani, Hadjigeorgiou, & Archibald (Eds.), 13th ISRM International Congress of Rock Mechanics (pp. 1-10). (13th ISRM International Congress of Rock Mechanics; Vol. 2015- MAY). International Society for Rock Mechanics.