This is part of the Great Basin, so the whole groundmass is being stretched like taffy. The activity may not be magmatic, but with the Bodie-Aurora volcano field in close proximity (especially Mud Springs Volcano-3 miles SSW and believed to be the most recent volcanic feature in Nevada), my money is on magma. What we really need is some field work to determine if there is any heat flow and ground deformation occurring. Alas, this spot is not actively monitored and there is probabaly no baseline to compare to.
Need to evaluate the magma type. The majority of the volcanism in that particular group has been calc-alkaline andesite, dacite and trachyandesite lavas, breccias and ashflow tuffs.
Mud Springs Volcano appears to have been andesitic in nature. These magmas, because of their viscosity, really make a lot of “noise” as they work their way up, meaning the seismic signatures would have been seen for a long time at far deeper depths than this swarm is occuring in.