Two or more aerial vehicles, such as drones, can each include one or more cameras for capturing surveying or other image data within a field of view. Some of the image data, as well as other data, can be stored and pre-processed on the vehicles, including via onboard edge computing devices. The image and/or other data can be analyzed by a remote system or service, which has additional computing resources, and used to determine the occurrence or existence of an anomaly, such as a seismic event or structure identified in the field of view. The anomaly determination may be based on a disparity, involving a distance between cameras, the cameras' focal length, and a perpendicular distance from a point between cameras to a surface or subsurface point.