Geometric roughness of exposed bedrock scarps


Determining the age of displaced geomorphic or geologic markers is an important step in constraining a fault’s slip rate. Doing so is generally not easy. In times, in can be beneficial to augment dating approaches with additional methods and observations to constrain (relative) age. One of such measures might be the geometric roughness of exposed/outcropping bedrock faults. With the underlying assumptions that a) time of exposure to sub-areal erosion increases with outcrop height, b) that the outcropping fault scarp is generated coseismically (during subsequent surface-rupturing events), and c) that roughness changes due to different time of exposure to sub-areal erosion we can use changes in fault surface roughness as a proxy for age.

Following this assumption, we investigate the roughness of various exposed bedrock fault scarps to identify and establish if the assumed relationship exists. Initial results are promising but more work needs to be done.