Evaluating Scaling Relationships From Reliable, Insar-derived Earthquake Source Parameters
Description:
Scaling relationships between earthquake source parameters (e.g. fault length, fault width, slip, and seismic moment) have strong implications for earthquake physics and seismic hazard. Questions remain about the existence of a power law (or not), in length-moment scaling, whether small and large earthquakes scale similarly, and whether scaling differs for different tectonic regimes and event types. Source parameters estimated by different groups, and from different data sources, can show significant epistemic uncertainty, which can affect the quality of the scaling relationships obtained.
In this study we aim to use more robust estimates of source parameters by focusing on earthquake models constrained by InSAR. InSAR has been used to study earthquakes over a wide range of magnitudes (4.9 ≤ Mw ≤ 9.0) and can directly constrain estimates of key source parameters (e.g. rupture length) for shallow earthquakes. We compile an InSAR-based source parameter dataset by mining published studies that used InSAR data. For well-studied events, such as the 2015 Gorkha, Nepal and 2019 Ridgecrest, CA earthquakes, we use the range of models to assess source parameter epistemic uncertainties. We supplement this compilation with our own InSAR-constrained models of recent earthquakes absent from the literature. Our final dataset contains parameters from over 200 earthquakes, from 1992 to present.
To evaluate scaling relationships, we use regression analysis to quantify the relationships between key parameters, such as fault length, L and seismic moment, M0. We find that different event types have different length-moment scaling relationships – for thrust faults, we find M0 ∝ L2.2, whereas for strike-slip faults, M0 ∝ L1.9. We do not find a statistically significant improvement to data fit if we include a change of scaling between smaller and larger earthquakes.
Session: Advances in Reliable Earthquake Source Parameter Estimation [Poster]
Type: Poster
Date: 4/16/2025
Presentation Time: 08:00 AM (local time)
Presenting Author: Karlee
Student Presenter: Yes
Invited Presentation:
Poster Number: 34
Authors
Karlee Rivera Presenting Author Corresponding Author krive050@ucr.edu University of California, Riverside |
Gareth Funning gareth@ucr.edu University of California, Riverside |
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Evaluating Scaling Relationships From Reliable, Insar-derived Earthquake Source Parameters
Category
Advances in Reliable Earthquake Source Parameter Estimation