EAPSI: Earthquake Probability Assessment Using Slow Slip Events

Yohler Ryan M, Columbia MO

Investigators

Abstract

The research will focus on an important aspect of earthquake science called slow slips events (SSEs). SSEs are similar to earthquakes, but occur more slowly and do not cause damage. Recently, SSEs have been discovered in areas where large earthquakes happen (the Western United States, Japan, and New Zealand are all examples). The goal of this research is to improve our knowledge of how these events change the probability of future large earthquakes in New Zealand. The results may be applicable to a similar region on the west coast of the U.S. New Zealand is an excellent study site because it has known SSEs, a dense network of GPS stations used to study SSEs, and world experts in the field. Another goal is to further engage the public with earthquake science to eliminate barriers between scientific research and the public. Public understanding of earthquake hazards is the first step in saving lives and reducing response time of local rescue authorities. The project will be conducted at GNS Science under the mentorship of Dr. Laura Wallace, an expert on Hikurangi plate locking models. The main question of this project is "how do SSEs change time-dependent large earthquake probabilities?" First we will place bounds on the size of earthquake events in New Zealand. Then we will use delayed failure models to study how the stress from SSEs changes large earthquake probabilities in a time-dependent sense. By utilizing these two separate techniques of moment-bounding and estimation of time-dependent large earthquake probabilities, we hope to develop a systematic way to relate SSEs to large earthquakes, especially in areas where extraordinarily large earthquakes are plausible. This project funds a new research collaboration between a U.S. Graduate student, Ryan Yohler, and a prominent earthquake scientist, Dr. Laura Wallace, and her colleagues at GNS Science in New Zealand, jointly funded by NSF and the Royal Society of New Zealand.