The M 5.7 Parker Butte Earthquake near Yerington, Nevada: Anatomy of a Dual-Plane Rupture in the Walker Lane from High-Precision Relocated Earthquakes, InSAR, GPS, and Strong-Motion Data

Abstract On 9 December 2024, at 3:08 p.m. local time, the Mw 5.7 Parker Butte earthquake occurred about 24 km north-northeast of Yerington, Nevada. From 1 December 2024 to 10 May 2025, we cataloged 1301 earthquakes, including seven events ML>3.5. We use high-precision earthquake relocation, Interferometric Synthetic Aperture Radar (InSAR) data, Global Positioning System (GPS) data, and strong-motion data to explore the tectonic context and spatiotemporal evolution of this sequence. The high-precision relocations of the sequence reveal a main cluster of earthquakes that form a planar feature which can be fit with a plane striking N62°E and dipping 85° SE. Events that are not in the main cluster are primarily 5–10 km to the southeast and are more scattered, but some smaller linear clusters can be identified. We used InSAR and GPS data to model fault geometry and slip. From this analysis, we found that the ground deformation can be fit with a single fault 12 km long × 8 km wide with a strike of N61.5°E ± 1.0°, dipping 73° ± 1.5° southeast and slip up to ∼50 cm, concentrated between depths of 2.5 and 7 km, consistent with an Mw 5.7 rupture. However, a better fit is found by adding a second fault plane. The second fault strikes N24.5°W and was detected as a displacement discontinuity in descending InSAR scenes, correlating to minor surface fracturing observed in the field, but had low aftershock activity. The GPS observations of interseismic deformation before the event show similar directions of principal strain accumulation and strain release in the mainshock moment tensor. Ground-motion measurements from the mainshock strong-motion data are generally in agreement with existing active crustal ground-motion models for the western United States. The sequence provided a valuable dataset for examining faulting rupture patterns in the Walker Lane Shear Zone.