Cycle after cycle, like the ticks of a clock, we get closer and closer to the point where one of these mega-thrust earthquakes are going to occur like happened in Indonesia last year. You can almost look at these slip events as ticks of that clock.

The ash plume can travel, and the hazard to aviation is real, ... To individuals, it's more of an annoyance -- could be an extreme annoyance if a lot of ash comes out.

This is a tragedy.

All of the dome-building that went on after the 1980 big eruption didn't have earthquake activity the way we're seeing it now.

What have we lost? Well, we've lost a scientist who is really concerned about the quality of life for people who live in earthquake country. We have terabytes of information Tony gathered in the '80's and '90's (about earthquakes and land movement). That will be just part of Tony's legacy.

I've lost a dear friend; and, the guy I depended on for so many different things, here in the lab. He's irreplaceable. I don't know where we go from here.

Something's driving this train, and I think there is a growing consensus that at least fresh gases have reached older magma that is shallow in the volcano, activating it.

At no time since the pre-1980 buildup to the eruption on May 18 have we seen earthquakes like this.

He was always cheerful, always helping anyone ... always the first to volunteer to take stuff on.