Long-term rates of faulting derived from cosmogenic nuclides and short-term variations caused by glacial-interglacial volume changes of glaciers and lakes

authored by

Ralf Hetzel, Andrea Hampel

Abstract

Seismic hazard evaluations on major faults in Earth's crust are based on their slip histories, which reflect the frequency of earthquakes that ruptured a fault in the past. On a 100 000-year timescale, the slip rate of a fault can be determined by dating geomorphic surfaces that are offset by a fault. Application of this method to alluvial fan surfaces and river terraces offset by thrust faults in Tibet yields long-term slip rates of less than 1mm/a. Slip rates on a 10 000-year timescale are derived from paleoseismologic data and document that faults experience considerable slip rate variations on timescales of 100 to 1000 years. In particular, slip rates are often considerable higher in the present interglacial, the Holocene, than during the last glacial period, the Late Pleistocene. The causes of this behavior have remained enigmatic but their assessment is essential for an accurate evaluation of a fault's past and future seismicity. Numerical experiments show that the retreat of lakes and glaciers at the end of the last glacial period can cause an increase in the Holocene slip rate of a fault. Such a correlation between enhanced seismicity and climate-driven mass fluctuations on Earth's surface is best documented for the Wasatch Fault, Utah.

External Organisation(s)

University of Münster
Ruhr-Universität Bochum

Type

Article

Journal

International Journal of Modern Physics B

Volume

20

Pages

261-276

No. of pages

16

ISSN

0217-9792

Publication date

30.01.2006

Publication status

Published

Peer reviewed

Yes

ASJC Scopus subject areas

Statistical and Nonlinear Physics, Condensed Matter Physics

Sustainable Development Goals

SDG 13 - Climate Action

Electronic version(s)

https://doi.org/10.1142/S0217979206033255 (Access: Unknown)