Piedras de Fuego

The professor I work for is short on money, so he made this internship program a possibility for aspiring volcanologists so that he can get help for cheap from students like me. In return I am exposed to an active volcano, field measurement equipment and methods, and lab analysis. This past week was really fun and interesting. Several volcaologists from around the world were here this past week doing some collaborated field work and we got to be right in the mix. We spent each day doing field work on different parts of the volcano collecting water, gas, and temperature data and rock samples. The highlight of the week however was our overnight field trip to a place called Playon. But first, a geology lesson...

There are many types of volcanoes and there are many ways volcanoes release their energy and heat. Volcan de Fuego periodically transitions from explosive to effusive.

Explosive eruptions only occur when the magma is silicic and viscous. The magma could contain a lot of gases that expand when they reach atmospheric pressure. If this decompression occurs rapidly, hot ash, rocks and lava could explode and be very destructive.

Effusive activity occurs in almost all volcanic settings and is characterized by passive lava flows and degassing events. The magma degasses periodically and causes a small eruption of gases like water vapor and sulfur dioxide. Effusive activity is also characterized by lava domes.

Currently Volcan de Fuego degasses several times a day and the lava dome continues to grow. Since 2005, the volcano has been building a new lava dome. The lava dome is on the crater rim at the peak of the volcano. As new magma reaches the surface and cools, fresh hot rocks cascade down the slopes of the volcano. These rock falls occur about every 30 minutes and it sounds like an explosion. At night, the hot rocks glow and often cause forest fires.

The Playon is situated just below the reach of the rock falls about 1 km from the summit. We camped there this weekend and remotely measured the gases and temperatures emitted from the dome. The volcano erupted several times while we were there and rocks cascaded towards us every 30 minutes. Each rock sounded like a thunderstorm or an explosion. Around 11 pm we were just hanging out around the campfire and monitoring the equipment when the volcano erupted and the plume rose directly over our heads. It was amazing. The moon light allowed us to watch the whole thing. Red hot rocks (literally) were propelled down the slopes. A small amount of ash collected on my tent and my shoulder. It was the coolest thing I have ever witnessed. This is what I signed up for.

Tomorrow we are going on a plane ride around the volcano.