Mount Pinatubo

On April 2nd, 1991, natives living on the north side of Mount Pinatubo started noticing a series of phreatic explosions.

An excerpt from the article 21 facts about Mount Pinatubo
The news reached a volcano observatory in Manila, where seismographic equipment was set to monitor the increasing seismic activity of Mount Pinatubo. Within the next few weeks, several small eruptions scattered the volcanic ash in the surrounding areas. Daily earthquakes were counted in hundreds.