Strengthening African geoscience
Recalls Nyblade, himself a native of Tanzania, "After our initial meeting at the AESEDA symposium, Paul and I brainstormed a lot about this problem. I said 'Let's look at this in a bigger context. Let's not just think about rebuilding geophysics at Wits, let's try to do something on a larger scale for all of Africa.'"
The idea was hatched to put together an initiative that would encompass many universities across the continent—eleven institutions to date—and get scientists from different African nations working on an array of shared geoscience projects. Initially envisioned as a twenty-year project and funded through a private-public partnership of academic, government and industry organizations, AfricaArray was born in January of 2005. Its three founding partners—Wits, Penn State, and the Council for Geoscience (CGS) in Pretoria, South Africa—provided $1.7M in in-kind support at its launch.
Nyblade inspects a seismic station in Cameroon.
AfricaArray's development plan includes three phases over the first decade. "The aim of the first three years is to build on existing programs and expertise within our partner institutions," explains Nyblade. "A primary focus is to rebuild the program at Wits and use that as a model to strengthen other geophysics programs throughout Africa."
As Nyblade points out, to create a viable training program at the master's and doctoral levels, you have to have a research infrastructure. That means you have to have good research projects for students, along with access to new and interesting data sets. "So how do you create all that?" he asks. "Well, I'm a seismologist and one way to do it is to develop a network of seismic stations to record earthquakes in Africa."
These stations—twenty-four now in place, primarily throughout eastern and southern Africa—serve many purposes: they provide data sets for students to use for their research projects; they form networks of shared scientific observatories, which help catalyze scientific community-building through educational and research collaborations; and they capture and interpret seismic data needed to better understand the African superplume.
"AfricaArray is truly an amalgamation of different projects," Nyblade says, "but the common thread is that students can work on African problems, in Africa, with African data sets."
The focus of these research projects is informed, in part, by the practical needs of different industries. For instance, remarks Nyblade, the diamond mining industry is primarily interested in the lithosphere—the rigid outer layer of the earth. "The lithosphere is thickest beneath the oldest parts of the continent and that's where you find diamonds," he explains. Seismic data can help map out those areas.
Another project involves the Bushveld complex in the northern part of South Africa, which holds the largest reserves of platinum in the world. "It's 400 km long and wide and 8-10 km deep. They're mining at the sides of this feature, but what's at the middle, they don't know. We're using seismic data to better understand what it looks like," Nyblade explains.
"I've been doing geophysical research in Africa for twenty years," he adds, "so I knew what many the issues and problems were. I thought these would be fundable scientific projects that would also attract funding from the National Science Foundation (NSF)."
Collaborating in the field
Undergraduate student Candra Gross collecting electrical resistivity data in South Africa.
The NSF has provided significant resources for AfricaArray, notably through a program called Partnerships for International Relationships in Education (PIRE), which funds American-based scientists seeking collaborative international research experience. PIRE has permitted AfricaArray to fund Penn State and African post-doctoral associates, graduate students and research associates to work on the program, and Nyblade is hoping to involve more Penn State scientists as the initiative evolves.
During the summer of 2007, PIRE enabled Penn State geoscience graduate students Angela Larson and Aubreya Adams to travel to Tanzania and Uganda for a month as part of a three year project aimed at better understanding the crustal and upper mantle structure of the Western branch of the Eastern African Rift (EAR) zone. Part of the Great Rift Valley—a fissure in the earth's crust that stretches 6,000 miles from Lebanon to Mozambique—the EAR's Western branch is characterized by a complicated succession of rift segments with an evolutionary history that remains the subject of intense debate.
While there, Larson and Adams will work alongside Fred Tugume and Gabriel Daudi Mulibo to install twenty new broadband seismic stations. Tugume and Daudi Mulibo, from Uganda and Tanzania respectively, are currently getting their doctorates in geoscience from Penn State thanks to funding from AfricaArray.
One concern that the program's founders wanted to address from the outset was how to ensure that Africa and African institutions ultimately reaped the full benefit of the training afforded to Africans who come to the US as students and decide to settle here. In order to maximize the benefit to Africa, Nyblade set in place "a sandwich program," whereby African students could come to the U.S. and work with a supervisor for no more than six months out of twelve. "This past year, I brought in Fred and Gabriel," says Nyblade. "Fred works with the Uganda Geological Survey and Gabriel teaches at the University of Dar es Salaam in Tanzania. "They're absolutely intending to go back," Nyblade says, "and they'll spend a lot of time doing field work in their home countries, operating and maintaining the seismic stations, as part of their degree programs."
Tackling key questions
The majority of NSF's funding to AfricaArray is centered on imaging the African superplume. Remarks Nyblade, "The foundation recognizes that we are addressing a first-order Earth Science question, one that cannot be answered without strong intellectual collaboration and partnerships between scientists in the U.S. and Africa and their respective institutions. And that question is, 'What is the structure and origin of the African superplume?'"
The answer to this question will take time to reveal itself. As Nyblade remarks, geophysicists must measure progress on a different clock: "The mantle is convecting on a geological time scale," he explains, "so although over millions and millions of years the rock actually is moving like a fluid, in our lifetimes nothing is really moving."
Notes Nyblade, "We think our work may hold the key to understanding how the mantle works. "A lot of competing models have been put forward. This superplume-superswell structure—if it goes from the core all the way to the surface—argues for the theory that the whole mantle is circulating in one big rotation."
If this theory can be confirmed, he adds, it would advance the whole field of plate tectonics. "In the 60s," says Nyblade, "there was a revolution in our field when we finally understood that the earth's surface is broken into plates that translate horizontally across the surface. Yet forty years later, we still don't fully understand about the coupling between the plates or the process of convection—what is happening at the surface." And that, says Nyblade, is why AfricaArray has caught the attention of a lot of geoscientists, and why NSF has put a lot of money into it. "This project potentially holds the key to addressing a lot of uncertainty in our field."
Fulfilling their vision
Inside a seismic station in Malawi. The small metal canister with blue wire is the ground motion sensor.
While the ultimate outcome of the scientific mission won't be clear for years to come, the immediate success of AfricaArray is easier to measure.
"We're ahead of schedule," Nyblade comments with pride. "We've already done all we hoped for in our first phase. Within two and a half years we've successfully rebuilt the geophysics department at Wits."
Affirms Dirks, "AfricaArray has given tremendous impetus in revitalizing our program." Since the initiative began, Wits has five times as many undergraduate students enrolled in the geophysics honors program and has almost tripled the number of students receiving master's degrees. AfricaArray's coupling of training and research, says Dirks, "has made high officials in the University and Government realize that geophysics needs to be supported more strongly." Looking ahead, Nyblade hopes to increase the number of permanent observatories and expand them to include sensors from other scientific fields. To this end, he has begun discussions about this with the Penn State Institutes of the Environment and Penn State's meteorology department.
Ultimately, agree Nyblade and Dirks, AfricaArray is the result of a shared vision that grew out of their first conversation four years ago—the hope that geoscience education and training for Africans could help combat disenfranchisement and empower Africa's citizens to take leadership roles in an array of scientific fields vital to the development of the continent's vast and rich natural resources. RPS
Andrew A. Nyblade, Ph.D., is professor of geosciences in the College of Earth and Mineral Sciences; andy@geosc.psu.edu. Paul Dirks, Ph.D., is director of the School of Geosciences at the University of the Witwatersrand, Republic of South Africa; dirksp@geosciences.wits.ac.za.
