What are some of the lessons that scientists have learned from the eruption so far?
There have been many lessons learned from the eruption already, and the learning process is still ongoing. Lessons include: 1) We now know that dome growth can resume, even after a long hiatus, without a long period of obvious precursory activity. The earthquake swarm that signaled the start of renewed eruptive activity in 2004 began on September 23, just eight days before the first small explosion on October 1 and eighteen days before lava extrusion began on October 11. For the first 2 days, the swarm resembled several others that had occurred beneath the volcano in preceding years. There is no evidence that the volcano was inflating when the September 2004 earthquake swarm began, as might be expected if magma was accumulating at shallow depth. 2) Once extrusion started, we learned that dome growth can occur continuously for more than 3 years with relatively little seismicity, ground deformation, and volcanic gas emission. The persistence of the eruption was all the more remarkable gi
