SUMMARY We present a new surface velocity field for Baja California using GPS data to test the rigidity of this microplate, calculate its motion in a global reference frame, determine its relative motion with respect to the North American and the Pacific plates, and compare those results to our estimate for Pacific–North America motion. Determination of Pacific Plate motion is improved by the inclusion of four sites from the South Pacific Sea Level and Climate Monitoring Project. These analyses reveal that Baja California moves as a quasi‐rigid block but at a slower rate in the same direction, as the Pacific Plate relative to North America. This is consistent with seismic activity along the western edge of Baja California (the Baja California shear zone), and may reflect resistance to motion of the eastern edge of the Pacific Plate caused by the ‘big bend’ of the San Andreas fault and the Transverse Ranges in southern California.

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The Gulf of California, Mexico, accommodates ~90% of North America‐Pacific plate relative motion. While most of this motion occurs on marine transform faults and spreading centers, several fault segments in the central Gulf come close to peninsular Baja California. Here we present Global Positioning System and interferometric synthetic aperture radar data near the Ballenas transform fault, separating the peninsula from Angel de la Guarda Island. We observe interseismic motion between June 2004 and May 2009 and displacements associated with the 3 August 2009 Mw 6.9 earthquake. From the interseismic data we estimate a locking depth of 9–12.5 km and a slip rate of 44.9–48.1 mm/yr, indicating that faults east of Angel de la Guarda deform at negligible rates and that the Ballenas Transform accommodates virtually all of the relative motion between the North American plate and the Baja California microplate. Our preferred model for coseismic slip on a finite rectangular fault plane suggests 1.3 m of strike‐slip displacement along a vertical rupture plane that is 60 km long and extends from the surface to a depth of 13 km in the eastern Ballenas Channel, striking parallel to Baja California‐North America relative plate motion. These estimates agree with the seismic moment tensor and the location of the major foreshock and aftershocks and are compatible with the fault location identified from high‐resolution bathymetric mapping. The geodetic moment is 33% higher than the seismic moment in part because some afterslip and viscous flow in the first month after the earthquake are included in the geodetic estimate. Coulomb stress changes for adjacent faults in the Gulf are consistent with the location of smaller aftershocks following the 2009 main shock and suggest potential triggering of the 12 April 2012 Mw 6.9 Guaymas earthquake.

S U M M A R YThe Crandall Canyon Mine, Utah, collapse in 2007 August resulted in a total of nine fatalities. We processed data from the ALOS satellite acquired before and after the collapse to quantify surface subsidence associated with the collapse to better understand the collapse process. The deformation shows a steep V-shaped pattern of subsidence with slight asymmetry. We compare the fit of four different models that simulate the subsidence pattern. The first two models use elastic half-space rheology. We find that collapse alone cannot explain the observations, and a component of normal faulting is required to fit the data. The second set of models simulates collapse in elasto-plastic media. Only a small component of normal faulting is required in these models. We suggest that considering elasto-plastic material behaviour is particularly important for shallow deformation modelling, where microfractures and other non-elastic rheology are common. Disregarding this material behaviour can lead to biased model parameter estimates.