When the Earth moves, the victims of earthquakes and tsunamis want to know why.
University of Wyoming geology professor Barbara John is collaborating with an international team of geological experts to find answers—even if it means conducting research on the ocean floor or on mountain tops.
The recipient of several National Science Foundation research grants, John has studied and taught structural geology and tectonics at UW since joining the Department of Geology and Geophysics in 1993. Her research focuses on the slow spreading of the Earth’s crust, which has led to some of the largest faults on the planet, including many under the ocean.
“We’re investigating how this planet works and how the different components interact with each other,” says John, who is partnering with colleagues at UW as well as scientists in Switzerland, Norway, Japan and France. “We use part of that knowledge to try to help address some of the really big challenges facing our planet today, with seven billion people-plus needing energy, water resources, food and the knowledge of how to live with and understand natural disasters.”
The international ramifications of John’s research are evidenced by recent earthquakes that have devastated parts of Japan, New Zealand and Haiti. All these areas lie along major faults in various tectonic settings, the focus of her research for years.
In 2011, John’s research took her, along with UW geophysicist Mike Cheadle, on a virtual investigation of a large submarine fault system in the Caribbean known as the Mid-Cayman Rise. The research project, conducted through the National Oceanic and Atmospheric Administration, used the agency’s premier research ship, the Okeanos Explorer, a resource not usually associated with scientific investigations conducted by UW.
Resulting from the plate spreading between African and Caribbean tectonic plates, the Mid-Cayman Rise is marked by a deep tough and adjacent undersea mountain, Mount Dent, which is taller than Mount Everest would be if resting at the same point. With other shorebased colleagues, John observed exploration of the area and the collection of rock samples by an underwater robot via live video from the seafloor in a computer lab hundreds of miles away.
“Most earthquakes occur at depths from five to 60 kilometers in the Earth and can rupture to the surface, creating the faults we see,” John says. “This study of ancient fault systems will allow us insight into the deep-seated processes associated with their movement, and potentially help predict when faults will move violently in large earthquakes, or when they will behave more gently, quietly creeping.”
As more than 60 percent of the Earth’s surface is underwater, John is interested in what can only be investigated by diving thousands of feet in an armored submersible. On her office walls are mementos of those dives, certificates signed by the submariner pilot noting that she, indeed, is one of the few who have braved the crushing depths of the ocean.
“We use the craft’s mechanical arms to grab rock samples off the ocean floor at the faults and bring them back up to the surface,” says John. “The actual research and analysis is done in our laboratories back home.”
John’s research also has taken her to the top of the Alps and into the Mojave Desert in the search for evidence about how and why the Earth moves. Her international research collaborations and travel have implications in Wyoming, too. A prominent active fault, similar to what John is investigating in the oceans, runs through Grand Teton National Park.
“While there hasn’t been a major earthquake along the Teton fault in nearly a hundred years,” John says, “we’ll better understand what the seismic hazard is to the people living there and elsewhere in Wyoming.”