资源环境科技发展态势分析平台

The detailed features of an earthquake surface rupture may decay quickly in the landscape due to erosion or repair, such that primary displacements are seldom available for repeated study within the weeks following an earthquake. Here we describe a rapidly deployable field workflow using structure-from-motion (SfM) photogrammetry to produce three-dimensional models of offset features and apply the technique to the 24 August 2014 Mw 6.0 South Napa earthquake surface rupture. We use repeated analyses of SfM point clouds using 3-D interactive virtual reality tools to derive precise and reproducible fault-slip measurements along the surface rupture and document the temporal evolution of afterslip at two sites along its trace. The SfM technique, combined with 3-D virtual reality, enables archiving of primary field relationships and assessment of uncertainty in those data to a degree that was previously inaccessible.

Plain Language Summary Earthquakes can cause damage to Earth's surface and to human-built things on it. We can use these broken things to learn important information about the earthquake. However, the broken things often do not last long, due to erosion and repairs, so finding them quickly is important. Here we describe a simple and quick method of capturing surface damage from earthquakes using photos, so we can study the damage even after it is no longer there. We use this method to look at the 24 August 2014 Mw 6.0 South Napa earthquake.