re: Moving magma...that doesn't sound good.
Scary and not uncommon for the area. An eagle eye on monitoring the dome, hot springs, wells and gas discharge is ongoing.
I spent a couple days hiking among the Mono Craters in Feb. (burrr) one year and had a great time exploring the snow laced summit of the domes. Lots of black glassey type rock, not sure if it was cassified as obsidian.
