今週のうなぎセミナーについてお知らせいたします。

Here is information of the Unagi-seminar(Dec 24).

************** うなぎセミナーのご案内 (Unagi-seminar) **************

科目：地震学ゼミナールIV B, D / Seminar on Seismology IV B, D（修士・博士）
日時：2020年12月24日（木）14:00～
場所：オンライン(Zoom)

Date and time：Dec 24 (Thursday), 14:00～
Site：Online by Zoom

====

[発表者 (Presenter)]
Professor James Mori

[題目 (title)]
Determining Fault Friction of Large Earthquakes from Temperature Measurements

[要旨 (Abstract)]
We estimated the level of dynamic friction on faults during large earthquakes by measuring the heat generated near the fault. Temperature measurements were made in boreholes that penetrated the faults following the 1999 Chi-Chi Taiwan, 2008 Wenchuan China and 2011 Tohoku-oki Japan earthquakes. The measured temperatures signals can be used to directly calculate the dynamic friction during earthquakes. For all three earthquakes, the locations of the measurements were in regions of large fault slip from 5 to 50 meters. The results for the three earthquakes show relatively low levels for the friction, with values for the coefficient of friction of 0.1 or less. This level of friction is significantly lower than measured values of rock friction in laboratory experiments, which are usually about 0.5 to 0.7. These results are some of the first direct estimates of fault friction during large earthquakes and show that the dynamic friction on the fault during earthquakes can be quite different from the static friction measured for rocks.

====