Giantess
This morning the webcamera shows an eruption of Giantess, the first eruption in about 22 months. Based on the nature of the play from Giantess, and that I think I saw activity in Vault, it appears that the eruption started in the early morning hours.
Update: 10:45
Well, it appears that the activity was the final stages of a steam-phase eruption that started early last night (say around 22:00). The OFVC seismograph should have the start time, so let's see how wrong I am.