Seismic history of a bedrock fault scarp using quantitative morphology together with multiple dating methods: A case study of the Luoyunshan piedmont fault, southwestern Shanxi Rift, China

Identification of Paleoearthquakes and Coseismic Slips on a Normal Fault Using High-Precision Quantitative Morphology: Application to the Jiaocheng Fault in the Shanxi Rift, China

“…To further determine the weathering bands on the fault surfaces, Student's t-test was applied to identify any morphologic segment along the fault scarp. For more details, please see He et al [32] and Zou et al [33].…”

“…Comparing the fractal results of the fault surfaces (Figures 6 and 7) with the possible exposure models [33] allows the exhumation history of the bedrock fault surfaces on the JCF to be defined as follows. A segment of the fault surface is exhumed by a strong fault activity (rupture earthquake), the height of which is equal to the coseismic slip.…”

“…Over the last two decades, a great number of studies have been conducted to extract paleoearthquake information from bedrock normal faults in the grabens of the U.S.A. [16,22,23], Israel [24,25], Greece [17,[26][27][28], and Italy [29][30][31], using cosmogenic nuclide exposure dating and other physical and chemical indicators. However, only a few studies have applied these techniques to bedrock normal faults in China [32,33].…”

“…In particular, TLS has become a well-established tool for identifying weathering bands and extracting potential paleoearthquake information [20][21][22]48] since it can rapidly obtain three-dimensional morphologic data with high spatial and temporal resolution [49][50][51][52][53][54][55][56]. This method can conveniently determine certain seismic parameters, such as the number of events and coseismic slips, and is suitable for a fault with clear earthquake ages but unclear coseismic slips [32,33,57].…”

“…Second, we scanned two well-preserved bedrock fault surfaces and obtained high-precision 3D morphology data using terrestrial laser scanning (TLS). Third, the fault surface morphologies were quantified as fractal dimensions (D), calculated using the isotropic empirical variogram method and a moving window operation [33], and the morphologic bands were identified using the fractal results. We ascribed the morphologic bands for each fault surface band to individual earthquake events and obtained the coseismic slip and magnitude of each event.…”