February 19, 2020
For over 100 years, scientists have studied the heat-loving microbial life in pools and springs on the surface of Yellowstone National Park. But what lives below the surface? “Every piece of evidence that we and others have collected over the years points to the presence of a subsurface biosphere in Yellowstone,” Prof. Eric Boyd of Montana State University said. “The intriguing question then becomes how that life is sustained.”
A new prestigious 3-year, $1 million grant from the W.M. Keck Foundation will answer this question about microbial life in the subsurface of Yellowstone, including whether seismic activity helps it to thrive. The project is led by Prof. Boyd and includes T.C. Onstott at Princeton University, Tom Kieft at New Mexico Tech, Barry Freifeld of Class VI Solutions, Inc., and scientists from USGS and the National Park Service.
The Keck grant will support three years of research and fund the design and construction of a specialized instrument triggered by earthquakes to collect samples from deep within one of seven Earthscope Plate Boundary Observatory boreholes. The research will bridge the gap between microbiology and geophysics to determine how Earth’s natural processes influence microbial life.
At the surface, life is generally supported by energy from the sun. In the absence of the sun, microbial life can still flourish with a supply of nutrients such as hydrogen. In rocky environments, such as the Earth’s subsurface, hydrogen can be generated when water reacts with certain minerals. Imagine if you were to drop an iron nail in a glass of water. That nail would rapidly oxidize, forming a thin coat of rust (oxidized iron) and releasing bubbles of hydrogen. However, that coat of rust also protects the metal from further oxidation. Without fresh minerals capable of reacting with water, the potential for how much life can be supported by such nutrients becomes limited. That’s where earthquakes come in.
Earthquakes shear rock and open new fluid flow paths that together expose fresh mineral surfaces to subsurface water that is 100oC. Yellowstone's intense seismic activity is likely at the heart of the interplay of geologic processes that sustain heat-loving microbes known as thermophiles in the subsurface of Yellowstone. Now this team will try to prove it.
To study this process, the researchers will fabricate a Kinetically Activated Subsurface Microbial Sampler, aka. KASMS. This sophisticated unit will be lowered several hundred feet into boreholes that were initially drilled a decade ago as part of the Earthscope Plate Boundary Observatory. The sampler synchronizes the collection of subsurface water with earthquakes of a specified magnitude and location, those powerful enough to shear rocks in the subsurface. It is fully autonomous and can collect and preserve six sets of samples before a researcher must visit the site to retrieve them for geochemical and microbiological analyses. The device replicates similar NSF-supported devices recently installed in a seismically active fault zone at 3 km depth in South Africa and currently being installed at the Chihshang Fault in Taiwan by Onstott, Kieft, Freifeld and Princeton Ph.D. Prof. Lihing Lin of National Taiwan University.
W.M. Keck Foundation grant proposal integrates hypothesis-driven science with engineering innovation. The new equipment and extreme conditions make the project speculative, but potentially transformative for the field.
The award is made in memory of W.M. Keck’s granddaughter Tammis A. Day of Sula, Montana, a poet, playwright, actress, horsewoman and sister to foundation Chair and CEO Robert Day.
The project will be based at MSU and also includes researchers from Salish Kootenai College and Diné College. Much of the funding will support graduate research positions and summer research internships for undergraduate American Indian students from Salish Kootenai and Diné tribal colleges, a demographic that is underrepresented in microbiology research. Summer research internships are aimed at exposing these students to authentic research experiences, with the goal of removing barriers toward their pursuit of an advanced degree in a STEM discipline.