A seminar presented by Jonathan Griffin who has recently submitted his Geology PhD thesis for examination Characterising earthquake hazard in low seismicity regions is challenging due to both the inherent lack of data and an incomplete theoretical understanding of the controls on earthquake occurrence away from plate boundaries.
Several previous studies have suggested that large earthquakes recur less regularly on low activity-rate faults than their more active plate-boundary counterparts, a departure from the quasiperiodic earthquake recurrence predicted by elastic rebound theory. This study first presents a statistical analysis of a global compilation of long-term earthquake records to explore controls on the regularity, or aperiodicity, of earthquake recurrence. Then, focusing on the Otago region, collection of additional paleoearthquake and slip rate data from the Hyde and Dunstan faults is used to test a hypothesis of episodic earthquake activity on faults in Otago. Finally, a novel Bayesian method for forecasting future earthquake probabilities from combined paleoearthquake and slip rate data is presented. This data driven method fully accounts for aperiodicity in the earthquake record by relaxing a priori assumptions of quasiperiodic earthquake recurrence common to other methods. It is argued that this data-driven approach is the most reasonable approach to take given our present understanding (or lack thereof) of the complex processes controlling earthquake recurrence in low seismicity regions.
For the past three years Jonathan has been working on his PhD here at the Department of Geology while on study leave from his position in the Community Safety Branch, Geoscience Australia.
Jonathan works on a range of earthquake and tsunami hazard assessment projects.
|Date||Tuesday, 14 September 2021|
|Time||1:00pm - 2:00pm|
|Audience||Postgraduate students,Staff,Undergraduate students,Alumni,Public|
|Location||Benson Common Room (Gn9), Geology Building, University of Otago, Dunedin |
|Contact Name||Geology Office|