There is a message reporting SEISMON DEAD on the medm screen.
There is also a DIAG_MAIN message reporting: "SEISMON_EQ: Seismon system not updating"
There are instructions for restarting the seismon code on the wiki:
https://cdswiki.ligo-wa.caltech.edu/wiki/seismon
However, I tried restarting everything on both the seismon vm and h1fescript0 (only the epics ioc on screen 1690, checking that I didn't touch anything else, I hope) and the seismon screen is now blank, so I'm not sure what's up. Can't do much more remotely, but I think probably need to completely restart. Good thing tomorrow is maintenance.