A quake swarm has again occurred (and is possibly ongoing) under Sierraville, CA at approximately the same depth as the previous quake swarm. The previous swarm was determined to be minor magma dike intrusion, which is also likely the case here. There is still no risk of a volcanic eruption, the intrusion is taking place at around 30-40KM beneath the surface, so it is still quite far.
The Sierraville swarm is an interesting one to watch. The area does not have any recent eruptive history, however hot springs and fumeroles can be found near the area.
The current continuation of the quake swarm occurred between December 29th, and January 3rd. Two quakes of mag 1.4 and 1.2 occurred today at a depth of 33KM.
The Sierraville swarm has been felt by residents unaccustomed to frequent quakes. Given the fact that we know these quakes are volcanic intrusions, I'm sure the residents may be a bit nervous. But this swarm will likely never result in an eruption due to its depth. Indeed many magma dike intrusions never result in a surface eruption. It does not mean it's impossible, but I'd try your luck at the lottery first if I were a betting man.
Anyhow, something interesting to watch.