Using a sUAV and photogrammetry software to measure scarp heights on the Cucamonga Fault

SMSU Event Center BC

The Cucamonga thrust fault marks the southern boundary of the San Gabriel Mountains. Over the course of four days a DJI Phantom 4 Pro sUAV was used to collect aerial photographs along the southernmost strand of the Cucamonga fault on the Day Canyon alluvial fan. Agisoft photogrammetry software was used to create a digital elevation model (DEM) from the images that were collected. With the DEM, a total of 10 profiles were constructed across the scarp along with two profiles parallel to the scarp. From those profiles, it was determined that the scarp height was an average of 6-7 m everywhere along the fan even though some parts of the fan appear to have different ages. This suggests all the different parts of the fan may have experienced the same number of earthquakes, and that it is possible that no earthquakes with significant slip at the surface occurred during the time between deposition of the oldest and youngest parts of the fan for which scarp profiles were made.