Mexico No.3: A Sense of Scale

March 1st to March 3rd, 2015

All around the Pacific, the Earth has been sewn up. Like the stitching on a softball, a horseshoe-shaped scar curls around the outer rim of our largest ocean, a forty-thousand kilometre line of crumpled mountains and spewing volcanoes, of active faults and oceanic arcs and marine trenches which all together mark the boundary where the innards of the Earth have been sewn shut and where, periodically, the stitches fail and the inside comes spewing out. This line is called the Pacific Ring of Fire, and along its length we find over three-quarters of the world's active or dormant volcanoes.

Now, every geologist knows the importance of a sense of scale. It must be large enough to understand 'the bigger picture', and small enough to show us the finer details. Forty thousand kilometres is longer than most of us can conceive of, or than that the Proclaimers would be willing to walk. So let's look closer: the American Cordillera. Still too big? We'll divide and conquer: the American Cordillera can be split into three sections, which are the Andes, Central America, and the North American Cordillera. Although I can go further into detail, let's pause for a moment at this scale on the map.

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The North American Cordillera forms the northern section of the American Cordillera. It is not the largest section - the Andes are over 7,000 km in length - and yet the NAC punches above its weight class for both its proportion of the volcanic and seismic activity along the Pacific Ring of Fire, and for the amount of exposure in the academic community it receives - understandable, given the vast economic resources of these three countries. (Case in point: enter 'Mount St. Helens volcano' in Google Scholar and watch the landslide of papers and citations that your search generates.) 

The North American Cordillera extends from the far-north Aleutian Islands, to the southernmost tip of Chiapas, across three countries as diverse as Canada and USA and Mexico, with people with their own customs and their own thoughts, with different explanations of how the volcanoes came to be and what we should do with them now that they are here. 

Does geography influence how we create cultures and form customs? When I first studied the different cordilleras within the Pacific Ring of Fire, I thought it fortunate that these geographical divisions usually reflected differences in the local population's relationship to that volcano; a pretty naive view, because of course distance and division in geography would contribute to independent evolution - just look at Madagascar's indigenous species. However, it is interesting to note that some challenges of volcanology seem to remain there regardless of scale, problems that are encountered both in the local village and across oceans and time zones. 


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Now, earlier in this post I said I'd go into further detail. Within the Pacific Ring of Fire there is the American Cordillera, of which the North American Cordillera is the northern section; part of this Cordillera is the Basin-and-Range Province, within which you'll find the Trans-Mexican Volcanic Belt, and at the western end of this belt sits Volcan de Colima, which we are monitoring at the CIIV.

Here we are, finally, at the volcano: take a seat, catch your breath. Have a minute to enjoy the view: beautiful, no? However, even in paradise there is trouble. A good explanation of the challenges we face every day in monitoring could be our recent trip to La Mesa.

La Mesa is a large and prosperous avocado farm on the western side of Volcan de Colima. The farm is at 1700 metres altitude, and has a generally clear view of the volcano. We plan to monitor it for two days, with the following equipment (flyspec for SO2 flux, visual camera, video camera, thermal camera, infrasound).

Over the course of the three days (1st - 3rd March 2016), we encounter the following problems:

1. Locked gates. The land around the volcano is mostly farms and haciendas, as the fertile earth is perfect for cattle-grazing and crop-growing. Attempting to approach the volcano requires navigation of mazes of wood-and-wire fences, and searching for the one person on a farm who has an access key. As luck would have it, that person has usually gone to market that morning.
2. Equipment failure. Our flyspec has its good days and bad days, and the first day is a bad day. The laptop continually bombards us with messages that it cannot locate the motors, the GPS, the spectrometer. Scans will stop after two minutes, or with no warning. Fixing the flyspec is something of a trial-and-error effort: on the second day, it works almost perfectly.
3. Volcan de Colima's behaviour. I know, funny that this should be a big deal! Changes in activity levels and weather conditions can seriously affect our plans for the day. We planned to spend three days monitoring at La Mesa. However, on the 2nd the wind changed early in the morning; any eruption plumes were driven east, away from our monitoring site. So we drove to another hacienda on the other side of the volcano, which involved taking three hours of time out of our monitoring day. 

These are a sample of the main challenges that we encounter on our everyday monitoring of the volcano. What are the solutions? Surprisingly, we find that 'local solutions to local problems' is not applicable here - solutions apply internationally, and basically comprise of two things: money, and communication. If we had more money, we could replace the old equipment. Poof! Our problems with poor data and equipment failure in-field would not be a problem. Also, having more money would not render us so dependent on good weather for field trips; we could go more often, or set up some sort of semi-permanent network for monitoring. Better communication would work well on a number of levels: between the students monitoring in-field, and those working in the lab in Colima; between different departments in the university; and between the volcanologists and the people whose land we borrow to study the volcano. Better communication could be a key to a locked gate, a collaboration on a project, or more effective evacuation plans (coming up in a future blog post). Whatever it is specifically, better communication is something that works, regardless of scale.

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This was a hard post to write, and I'd like to do more justice to the subject (or subjects) that I've brought up. I really think that the problem lies in the fact that this is simply too big a topic for a Blogger post. Personally I think it would make a fantastic book to explore this area, south to north or north to south, and see how the volcanoes change and the people too. Don't you?