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Geologist Abroad: Tungurahua, Ecuador

After nearly a week, the unrest of “Mama” Tungurahua has become evident in the city of Quito, in the form a a thin film of volcanic ash. It’s most visible on cars, not unlike the road salt that covers cars back in Ohio. But this accumulation come comes from the thick haze across the valleys of the Inter Andean region of Ecuador.

Dissapating ash cloud near sunset

Dissipating ash cloud near sunset

There are few countries more interesting than Ecuador for a Geology student like myself. I’m spending the second semester of my Junior year studying at a University in Quito, Ecuador’s capital and second largest city. Surrounded by 5000 m mountains and numerous active volcanoes, the city provides the perfect vantage point for observing earth’s tectonic forces and taking in nature’s beauty. Both of these became very evident last week, when Volcàn Tungurahua began another phase of heightened activity.

 Tungurahua is Ecuador’s most active volcano. The last significant eruption occurred in 2011, but she regularly spits lava and ash, and her geothermal activity fuels the hot springs of the popular tourist town on Baños at the foot of the volcano. That’s where I was heading on February 1st. Just a couple days earlier, the Instituto Geofìsico del Ecuador alerted the public of significant seismic events from inside the volcano. They predicted that these may have been a result of new fluid activity, and a new eruptive phase may be imminent. These were accompanied by small emissions of gas and ash, but that is nothing uncommon for the volcano that the locals call “Mama”, as she is the omnipresent force that both formed the landscape, but could also destroy it at any moment. What happened on that Saturday, however, was much more spectacular than I expected. Just after 5:00 pm, a moderate explosion was registered at the summit. Within half an hour, two more large explosions occurred, filling the sky with ash and generating pyroclastic flows on all sides. The column reached upwards of 10 km in height. I witnessed all this from a bus on my way to that very place. She continued to erupt ash and pyroclasts for the next few hours, as I watched mesmerized from the highway. This was unlike anything I had ever seen.

Tungurahua

The ash plume from Tungurahua

By nightfall, the bus stopped about 20 km or so from the volcano. The National Police had closed all highway access to Baños and the surrounding areas. Pyroclastic flows have crossed the highway in the past, and the ash was becoming too thick to drive safely. As it turns out, I never made it to Baños that night, but the trip was still well worth it. Amidst the confusion of the people on the bus as to whether or not we would be able to get to our destination, I stretched my head out the window and was greeted by another spectacular sight. Tungurahua had started to fountain lava in a strombolian-style eruption. Massive incandescent lava blocks followed a ballistic trajectory as explosions continued at the summit. The blasts sounded like fireworks, but an even deeper, more powerful sound. These fireworks, however, blasted lava up to 800 m above the crater and fell nearly 200 m below. This activity continues as of today, though at lower levels.

Check out the video I took from the bus — a little shaky, but still shows the eruption.

The latest activity certainly represents the strongest activity of Tungurahua in recent memory. The ash column produced this week was about twice as tall as that of 2011. Furthermore, pyroclastic flows blanketed nearly all sides of the volcano, though thankfully no injuries have been reported. Ash also covered the city of Cuenca to the South, and fine particles, as mentioned, reached parts of Quito, more than 80 miles to the North. Volcanologists are already descending to the volcano to collect fresh samples, including my Volcanology professor here in Quito. They hope to gather evidence regarding what kind of activity is actually responsible for the recent eruption. Current indications are that activity began as an explosive, Vulcanian eruption, as a result of new material in the conduit. Older, colder magma plugged the volcano’s throat, and when the new, hotter stuff arrived, it built up pressure until the plug couldn’t hold, generating a moderately large explosion accompanied by large amounts of ash. Activity continued as the fresh (probably) andesitic magma bubbled to the surface, creating the spectacular explosive fountain of glowing lava, typical of a strombolian eruption. Hopefully the field work will shed light on what exactly happened.

The rising plume from tungurahua.

The rising plume from Tungurahua.

Once I hear information, I can relay via this outlet. Meanwhile, I can wait for our classes own field trip to Tungurahua in the coming weeks. Then I can see for myself, yet again. I came to Ecuador hoping for an adventure, and that’s certainly what I got. I would have been happy seeing just a small-scale ash plume, but what I was much more that I could have asked. Understanding these forces is what drives me. This is why I came, and this is why I study geology.

For more of my pictures of the eruption, visit my Flickr stream!

Also, for the lastest on volcanism in Ecuador (and webcams!), visit the Instituto Geofísico.

Conner Toth

Conner Toth '15 Geoscience Major Spanish Minor

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