Detection of frictional heating on faults using Raman spectra of carbonaceous material

2016 Fiscal Year Final Research Report

• Project/Area Number: 26287124
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Partial Multi-year Fund
• Section: 一般
• Research Field: Geology
• Research Institution: University of Tsukuba
• Principal Investigator: UJIIE Kohtaro 筑波大学, 生命環境系, 准教授 (40359188)
• Co-Investigator(Kenkyū-buntansha): 堤 昭人 京都大学, 理学(系)研究科(研究院), 助教 (90324607)
• Research Collaborator: ITO KEISUKE 筑波大学, 生命環境科学研究科 ; TABATA HIROKI 筑波大学, 生命環境科学研究科 ; FURUICHI HIROYUKI 筑波大学, 生命環境科学研究科
• Project Period (FY): 2014-04-01 – 2017-03-31
• Keywords: 摩擦発熱 / 断層強度 / 炭質物 / ラマンスペクトル / シュードタキライト / 断層ガウジ

Outline of Final Research Achievements

The Raman spectra of carbonaceous material in natural and experimental pseudotachylytes and fault gouges were analyzed to detect increased heating on faults. The results indicate that the Raman spectra can successfully detect increased carbonization associated with frictional heating. This increased carbonization can occur in ~4-16 s and is preserved even after alteration of fault materials. The comparison between experiment and Raman data demonstrated that there is a correlation between the average shear stress and the Raman spectra. Using the correlation, the average coseismic shear stress was estimated. Raman analysis of carbonaceous material-bearing faults will be useful for estimation of coseismic fault strength.

Free Research Field

地質学