Fault2SHA Learning Series – Earthquake stress drops by Rachel Abercrombie
July 11 @ 3:00 PM - 4:00 PM
Estimating Earthquake stress drop – resolution and uncertainties
Research Associate Professor
Monday 11th July 2022 15:00 CET (14:00 UK, 15:00 Italy/France – note slight later time)
Stress drop is a fundamental earthquake source parameter that in theory relates the average slip on a fault to rupture area, and in practice controls the high frequency ground shaking. Thus, earthquake stress drop is a key parameter in many ground motion, rupture simulation, and source physics problems in earthquake science. Unfortunately, the measurements, especially those of small and moderate-sized earthquakes (magnitude less than about 5 or 6), are not well resolved, containing significant random and potentially systematic uncertainties. In this talk, I will attempt to provide a context in which to understand the challenges involved in estimating these measurements, and to assess the quality and reliability of reported measurements of earthquake source parameters. I will also discuss some of the ways progress is being made towards more reliable parameter measurements. At present, whether the earthquake source is entirely self-similar, or not, and which factors and processes control the physics of the rupture remains, at least in the author’s opinion, largely unconstrained. Detailed analysis of the best recorded earthquakes, using the increasing quantity and quality of data available, and methods less dependent on simplistic source models is one approach that may help provide better constraints.
Youtube link will become available during the talk