CRAFTI: Seismic Research in the Great Rift Valley

One day last spring, my mother asked about my plans for the coming summer, with the suggestion that, after spending last summer on the road as part of a siting team for Earthscope, a nice sedentary internship was just the thing. Imagine her surprise at learning what I had in mind instead: an invitation from my adviser Cindy Ebinger to take a two week trip to Tanzania, where I would be participating in the CRAFTI project (Continental Rifting in Africa: Fluid/Tectonic Interaction), a seismic data acquisition project with collaborators from the US, France, and Tanzania. A couple months later, I was on the first leg of my trip out, flying from Newark to Amsterdam, watching The Hobbit, and feeling increasingly torn between identifying more with Bilbo (I’m going on an adventure!) and Samwise in the first Lord of the Rings movie, taking the first step that puts him the farthest from home he’s ever been. I have done a fair amount of travelling as an undergraduate, but only to Europe and within the US, so it was with a good deal of excitement and not a little trepidation that I looked forward to landing at Kilimanjaro International Airport. The first two days of the trip were spent in the city of Arusha, taking care of the practicalities of heading into the field, not to mention adjusting to the new locale; while jetlag did not linger, nausea from taking antimalarial pills on an empty stomach did. While the drive west towards the survey area was ripe with new, incredible views and animal sitings, it was the first real day of work in the Ngorongoro Conservation Area that really brought home that I was on a whole new continent. Scattering baboons as we entered the park gates in the morning, we caught glimpses of the 100 square mile Ngorongoro Crater below in the mist as we drove around its rim. Our jeep bumped through patches of savannah and skirted the smaller yet still impressive crater Empakai, providing first sightings of the creatures that would become familiar parts of the landscape over the next 2 weeks, like zebra, ostriches, buffalo, and the slowly drifting herds of cows, goats, and sheep followed by their young Maasai herders. Finally, descending the slopes of Empakai, we came into the shadow of Ol Doinyo Lengai, the Mountain of God, and arrived at the seismic station housed there in a Maasai boma (village).

100_2663Ol Doinyo Lengai

Inside the boma, the guard pulled aside the thorn fence protecting the equipment, and we started to work. The project involves a network of 34 seismic stations that was deployed in January 2013, with a profile spanning the East African Rift and other stations spaced around the Ngorongoro Volcanic Highlands and surrounding area. The EAR is an active continental rift zone where the tectonic plates of Africa are pulling apart, to eventually form a new ocean basin; the goal of the CRAFTI project is to investigate how this process of continental rifting works, particularly whether it is driven more by faulting or by intrusion of magmatic dikes. Where we worked in northern Tanzania provides the perfect study region for a first hand view of the rifting process, with different rift segments at different stages of the rifting cycle.

Our specific job this summer was to visit each station, check that the equipment was working as it should, collect the data that had been recorded in the first 6 months, and pay the local guards who had been hired to watch out for the gear. The set up at each site included a buried seismic sensor, a solar panel and GPS unit, and a bucket with the battery, power box, and data acquisition system; ideally, at each site all that had to be done was open the bucket, plug an iPod Touch into the DAS, run through a check list of parameters, and swap out the data disks. Of course, with fieldwork, nothing is ideal, and while I’ve been in the field in other places, this project came with its own unique trials. From the very first station, it was clear there was a significant problem – the GPS units used for accurate timing at the stations had nearly all failed at some point during the six months since installation. The challenge provided by our team’s struggles with the malfunctioning equipment provided a deeper look at the realities of pursuing a science that does just take place in a lab, and I think I came away with a great example of how to adjust to technical difficulties in the field in the future. The team pulled together and did everything we could to work around the broken equipment and to try to figure out a solution, with heroic efforts from Professor Ebinger and our collaborators back in the States to get a fix from the manufacturers.

100_2665

Kids at a Maasai boma

A key component of the project was a good relationship with the local people; the array would not be possible without the Maasai tribesmen and the village schools that agreed to host our stations. Visiting the primary and secondary schools with stations, we brought workbooks and school supplies, and when there were students at the site, we would talk to them about what we were doing and show them the equipment. For the most part, this fell to those of the team who spoke Swahili, which sadly did not include me; in contrast, all Tanzanian students are required to learn Swahili in school and are taught English in secondary school, so with their tribal language many of the younger people we met were bilingual or trilingual, like one teen at our first boma who was pushed forward by her proud father to rather shyly practice her English skills with us. The opportunity to meet and work together with the local people on this project however briefly was part of what made the trip special, not just by helping the project to function but by allowing an exchange of ideas and experiences.

100_2970

This summer’s work in Tanzania was an incredible experience for me. I could wax rhapsodic about the landscapes, the animals – placid giraffes, colobus monkeys with beautiful fur and one cheeky baboon that stole my lunch – or the two vacation days we spent driving through Ngorongoro Crater and Olduvai Gorge, but I’ll let my pictures speak for themselves. As an undergraduate, this was by far the most edifying and gratifying adventure I’ve been on, and I can only hope I’ll be back in years to come.

100_2717

100_2679

100_2740

100_3031

crater

Ngorongoro Crater

cropped-olduvai.jpg

Olduvai Gorge