Activity at the Volcano Poas is increasing rapidly, while at the same time drying up the lagoon, say experts, a team of geologists and volcanologists from the seismological network of the Universidad de Costa Rica (UCR).The team visited the colossus on Wednesday where the recorded 18 "phreatic eruptions" in a three hour period, when normal is 1 or 2 per day.
The temperature of the crater is also increasing, which is causing the lagoon to dry up and possibly disappear.
Experts warn that this could bring more acid rain and ash in the area around the volcano.
However, the activity of Poas is not a d
anger to tourists and the national park will continue open.A phreatic eruption, also called a phreatic explosion or ultravulcanian eruption, occurs when rising magma makes contact with ground or surface water.
The extreme temperature of the magma (anywhere from 600 to 1,170 °C (1,112 to 2,138 °F)) causes near-instantaneous evaporation to steam resulting in an explosion of steam, water, ash, rock, and volcanic bombs.
At Mount St. Helens, hundreds of steam explosions preceded a 1980 plinian eruption of the volcano.A less intense geothermal event may result in a mud volcano. In 1949, Thomas Jaggar described this type of activity as a steam-blast eruption. Read More
