Using innovative iPad-enabled drone technology, MIT Professor Kristin Bergmann conducted the fieldwork component of her 12.110B (Sedimentary Environments) course as a week-long spring break trip to explore the Carrara Formation in California's Death Valley.
"When my former PhD advisor John Grotzinger was a faculty member at MIT, he worked on a project looking at the variability of a particular unit in the Carrara Formation at a place called Eagle Mountain," says Bergmann, explaining her motivation for visiting the sites she chose. "At Eagle Mountain the unit captured a wide-range of depositional environments across a particularly short distance. I decided to take the class and drones back to the Carrara Formation to test how drones can help with mapping lateral changes in ancient environments. Among the questions we were asking were whether all of the carbonate units in the Carrara Formation are as variable laterally, and whether two other sites show as much lateral variability as Eagle Mountain."
"The Carrara Formation is Cambrian-aged (540 to 490 million years) and is an amazing mixture of early skeletal organisms including trilobites and echinoderms, microbial communities, ooids and siliciclastic rocks. You couldn't ask for a better formation to teach about ancient sedimentary environments and the transition in Earth History from a microbial world to a skeletal one," Bergmann says.
Bergmann was accompanied by senior Geographic Information Systems (GIS) specialist Daniel Sheehan from the GIS Lab, which is part of the MIT Libraries. Sheehan, an expert in GIS software, was responsible for helping to incorporate the iPad-enabled drones into the course. The trip marked the first time the MIT GIS Lab has used drones in this way.
The trip, which ran from March 25 through April 1, brought students to three locations — the Last Chance Range outside of Pahrump, Nevada, and two California sites: Eagle Mountain near Death Valley Junction and Emigrant Pass near Tecopa. Bergmann was assisted by teaching assistant Marjorie Cantine and postdoc Tyler Mackey. Participants included graduate students Rose Palermo, Julia Middleton, Makayla Betts, Elezhan Zhakiya, Anna Rogers, Sam Goldberg, and Kelsey Moore. They were joined by undergraduate non-major seniors Moriel Levy and Daniel Richman. Bergmann's partner Nick Boekelheide and son Owen accompanied the group and were in charge of the campsite and meals.
For Middleton, an MIT-Wood's Hole Oceanographic Institution Joint Program student in the Marine Geology and Geophysics program, the trip to Death Valley marked her first land-based fieldwork experience. "Good coursework changes how you think about topics in a specific setting, while great coursework allows you to bring what you've learned to novel situations and view some aspect of the world in a new way," she says. "Fieldwork is the best example of great coursework, as it lets you develop new understanding as you interact with the world, thereby allowing you to experience your view of the world shifting before your very eyes."
Betts, a first-year graduate student working in Greg Fournier's geobiology group, calls sedimentary rocks "complicated."
"There were so many details and variations within the rocks that I did not know to appreciate before, and spending time picking out these changes across beds and outcrops helped me see the exciting challenge of putting together the ancient puzzle they provide" she says.
Asked about the challenging terrain, Betts says: "At first, we would be checking out a mountainside from a distance and I would wonder: 'How on Earth we were going to be able to measure it while not falling off?' But as we would get closer and start chunking away our work into sections, it became clear that every time, Kristin was careful to choose great sections that were both well exposed and accessible. And of course, the drone was able to go where we could not."
Sheehan, who obtained FAA certification shortly before the trip, served as the pilot-in-charge of drone operations, while Cantine, who plans to get certified as a pilot-in-charge, operated the controller. Sheehan had facilitated flight training at Hanscom Air Force Base and Haystack Observatory prior to the trip, led processing of the data on site, and is helping with processing back on campus. In class, he helped during sessions that focused on using GIS and editing the data the students collected. He also demonstrated software to create 3-D photo reconstructions from the photos taken from the drone.
"The drones we used (were) DJI Phathom 4 Pro drones," he says. "These are commercially available drones with a high resolution camera and with a safe flying time of 20 minutes per battery — 30 minutes total. We used the drones to photograph the surface, initially for orthophotos — the kind you see in Google Maps — and later for 3-D photo reconstructions. We changed during the trip because it became clear that the steep terrain, along with current flight planning software, made it difficult to fly for orthophotos. A second reason is that orthophotos are less useful for mapping steep beds where there may be 10 meters of a unit visible from the side but only 1 to 2 meters from the orthophoto perspective. The resulting 3-D reconstructions show the terrain much as the students experienced it. After image processing, the students were able to add the data they collected on the iPads to the maps, both in GIS and in Lime, a 3D editing software developed for annotating rock outcrops."
Sheehan says the field work went well, "although initially it was a disappointment that we couldn’t also fly for orthophotos."
"We had about two hours of battery life per day — charging the drone batteries is time consuming so we could use only a single charge on each per day. Despite the high wind we experienced — this drone can’t fly in winds higher than 20 mph — we managed to fly for about two hours each day and have a wealth of photos to process. Initial processing has been successful if a bit of a learning experience. A big part of the MIT Libraries interest in this is adding the drone data we collected to the MIT Libraries collections and making then openly accessible around the world. The libraries’ drone project is being funded by the MIT Libraries’ Experimental Collection Fund. We are ready to store the orthophotos and the Digital Elevation Model that was made with the orthophotos, but adding the 3-D reconstructions to our collection will be more of a challenge."
Betts adds that the new iPad technology was useful, even though using it required "a bit of a learning curve."
"With this technology, we were able to easily organize our thoughts and keep consistent note-taking across days and sections," she says. "As someone without previous experience doing this kind of work, it was helpful to be prompted for certain kinds of observations about the rocks. Coming back with drone data was awesome - we are now at the stage of combining the photographs taken by the drone with our observations on the ground, and it is impressive to see how this approach can be used to understand large landscapes."
Reflecting on the use of technology in the field, Betts says: "You're not only identifying sedimentary beds, discovering microbial fossils, and noting anomalous outcrops, you're compiling all you see into an accessible form — so that when you look back at your field notes from the comfort of your desk you can walk back through the terrain. Integrating all the data as it came into your head was the most natural thing in the world. Rather than looking back over disjointed notes scrawled in the margins of a strat[ification] column and trying to combine your thoughts after the fact, the use of sedimentology-specfic iPad apps allowed us to collate on the go."
Bergmann adds that the spring flowers in the desert this year were "amazing."
"In 15 years of going out to the Death Valley area, I've never seen them like that," she says. "The hillsides were covered in vibrant yellow, purple and pink flowers and even grass. The prickly pear cacti — my favorite desert flower — were all blooming."
Bergmann is leading a trip to Newfoundland this August, with priority being given to undergraduate students. An organizational meeting was held on May 2. For more information, contact Kristin Bergmann.