Colima Fieldwork

Volcan de Colima, looking north-west, with the active lava dome on the summit and Volcancito on the east flank (taken 3rd June 2014).

Since my last blog post I have been lucky enough to head out to Colima, Mexico, for fieldwork. The state boasts long pacific beaches, beautiful river gorges, friendly locals, delicious food, and one very big, very active volcano. Volcan de Colima has been erupting near-continuously since 1998 and is one of the volcanoes that I am investigating as part of my project (see my introduction to the volcanoes). On a clear day, its hard to not notice the volcano which completely dominates the generally low-lying landscape around it; this is nicely shown by this photo taken from the ISS last year. The latest phase of it's eruption has been going since January 2013, and is producing a new lava dome accompanied by many small pyroclastic flows, rockfalls, and explosions (over 4000 in total as of the start of May 2014).

The lava dome at the summit of Volcan de Colima, looking north-west (taken 3rd June 2014).

So why was I there? To fill myself up on delicious tacos of course! Just kidding. I was there primarily to deploy a new seismometer on a dome called Volcancito which erupted out of the eastern flank of the volcano in 1869-79 (see the first photo). Why there? The existing seismic network has no stations closer than ~1.5km from the summit vent, and if I wanted a clearer record of small volcanic earthquakes I need to place a seismometer closer than that. On Volcancito, the instrument would be less than 1km from the vent, but this comes with a higher risk of damage. The photo below shows the hatch for a small vault built for a seismometer which was deployed in the 90's; note the hole resulting from an explosion in 1999 which destroyed the seismometer inside. The location is also exposed to hurricane force winds, lightning strikes, and tropical rainstorms during the rainy season. I think it's safe to say that this is not the safest bit of fieldwork I've ever been on!

The hatch for the vault built for the original seismometer on Volcancito. Note the damage caused by a large explosion in 1999. 

Unfortunately, before I had even set foot in Mexico, we had our first bit of bad news. The Mexican rainy season, which usually starts mid-June, had already started by mid-May; this included category 4 Hurricane Amanda (perhaps this early start was an effect of El Nino?) Climbing the volcano is risky when it is dry, and even more so when it is wet and windy. The seismometer itself wasn't helping things either. During testing to make sure it was working before deployment, we found it was not quite working properly. Cue frantic e-mails between myself and a helpful engineer from the seismometer manufacturer. Thankfully, we managed to fix it (a miracle!) and after more testing we finally had a chance to deploy it.

The view from Volcancito looking south, with Nick Varley (Universidad de Colima) and Jamie Farquharson (Universite de Strasbourg; @JI_Farquharson) for scale. 

Success? Sadly, no. A number of reasons could be used to explain why, but we simply ran out of time. The early rainy season meant we had only a few days of dry weather at a time, and that was not long enough to get all the equipment we needed to Volcancito. That this is a disappointment is a bit of an understatement, but this was always going to be a risky and ambitious task. The rainy season is now in full swing so there will be little chance to deploy the seismometer before it ends in October.

A full moon shines over Volcan de Colima during an explosion with an incandescent rockfall on the north-west flank (taken 13th June 2014).

But all is not lost! There are a lot of really positive things that came out of this fieldwork. Researchers at the Universidad de Colima were kind enough to grant access to older seismic data from Volcan de Colima, and now my summer will be spent analysing this data thoroughly and carefully. I'm looking forward to what might be revealed from past behaviour of this magnificent volcano. I hope you have enjoyed reading about my experience in Mexico, and thank you for reading. I'll end this post with a short video of a very small pyroclastic flow that I witnessed on the eve of my last day in Colima.