Application of tectonic geomorphology in earthquake hazard assessment

Identification of earthquake sources is essential in earthquake hazard assessments. Ideally, earthquake sources should be identified by using a multidisciplinary approach that includes analysis of detailed seismological, paleoseismological, neotectonic, structural, and geophysical data. However, in many cases the required information is not readily available and the evaluation of seismic sources largely relies on the location of recorded earthquake activity.

Tectonic geomorphology (ground surface evidence of tectonic and earthquake deformation) can be used to help to identify earthquake sources. Tectonic geomorphology is a relatively inexpensive tool to improve the knowledge of earthquake hazard.

This paper illustrates the use of tectonic geomorphology for site specific earthquake hazard assessments in three case studies from different tectonic regions namely, Papua New Guinea, New Zealand and Western Australia. Tectonic geomorphology was used in these regions to:

Recognise potential active faults and estimate associated earthquake magnitudes.
Improve the selection of earthquake time histories used in dynamic analysis.
Assess surface deformation associated with blind faults.
Identify subtle tectonic deformation in areas of low seismicity.