Drilling deep to discover life

This winter, John Priscu plans to drill thousands of feet below the frozen ice of Antarctica and expects to find living creatures. If he’s successful, it could help change the way we see our planet.

It is said we know more about Mars than Antarctica’s subglacial environment. Priscu is trying to change that.

He is a Regents Professor in the Montana State University College of Agriculture’s Department of Land Resources and Environmental Sciences. The Ph.D. is also an internationally renowned polar scientist.

His goal is understanding the biogeochemistry and microbiology of icy aquatic environments below ice sheets. These systems exist far below the surface where lakes, hidden from the atmosphere for millions of years, breed microorganisms.

From that, we can learn about climate change, the effects of pollution on our environment and the possibilities of life beyond the earth.

We know so little about the environment below Antarctica’s ice sheet because it is so difficult to reach. Sealed below the world’s largest glaciers, it’s likely the least explored environment on Earth.

“Twenty years ago, everyone thought Antarctica was a big benign block of ice,” Priscu said. “It’s 70 percent of the earths fresh waters. My lab looks at organic matter in the ice on the microbial and cellular levels and we describe the organisms in this ice. We use molecular fingerprints to identify these organisms.”

Priscu’s group conducts National Science Foundation and NASA-funded research in both Antarctica and the Arctic. His current areas of study include long term ecological studies of Antarctic lakes, methane dynamics in Arctic lakes as a comparison for life on other icy worlds, exploration and geomicrobiology of Antarctic subglacial lakes, and microbiology, geochemistry and paleoclimate history of polar and temperate ice cores.

Scientists once thought the interior of Antarctica was lifeless. But the exploration of subglacial lakes through novel drilling technology uncovered a diverse microbial ecosystem. And one surviving without any light.

What Priscu’s team found on a previous expedition was microorganisms that mine minerals in rocks at subzero temperatures to obtain the energy that fuels their growth.

Priscu has conducted research in Antarctica for the past 35 years. It’s a harsh environment. Temperatures can drop below minus 100 degrees Fahrenheit in many locations during the Antarctic winter.

Priscu’s next mission to Antarctica will begin around Dec. 1 and take him and his crew to Antarctica by commercial and military aircraft. His equipment will be trucked from Montana to California by truck, from California to New Zealand by boat, and then to Antarctica by cargo plane.  He’ll be there during the southern hemisphere’s summer, where temperatures could reach as high as 32 degrees Fahrenheit.

But make no mistake. Working conditions are tough. The sun is up 24 hours a day and the crews sleep in tents on the ice, wrapped in big sleeping bags and pile liners overlying insulated ground cloths. Priscu sleeps with ear protection to block out the flapping of the tent and eye guards to block out the sun.

Beginning in the southern hemisphere’s summer of 2018/2019, and continuing for two more years, the Subglacial Antarctic Lakes Scientific Access (SALSA) project will sample from Subglacial Lake Mercer, a hydraulically active subglacial lake in West Antarctica. Researchers hypothesize that sub-ice hydrology and relict deposits of marine organic matter regulate ecosystem processes in these active subglacial lakes.

It’s only the second subglacial lake to be sampled, and Priscu said it will double their knowledge of the deep ecosystems.

A subglacial lake is a body of liquid water sandwiched between an ice sheet and the continental land mass. Scientists believe more than 400 lakes exist beneath the Antarctic ice sheet, many interconnected via streams and wetlands.

After about three to four days of drilling, the research team will have about a week to collect water and sediment samples and conduct experiments in the SALSA field labs.

Robotic tools will capture 4k video and explore the physical characteristics of the lake cavity, while other instruments will collect physical and chemical measurements directly in the drilled water column.

“We are going to drill down through a thousand meters of ice,” he said. The Mercer project will only be the second project to directly sample water and sediments from these lakes. We are looking for life in places where conventional knowledge says it shouldn’t be.”

His team hypothesizes that all these lakes under the ice sheet are filled with life.

“My team will be looking at the density of bacteria cells, the genetic content, how fast they grow and what they eat,” he said.

Priscu’s team is bringing along an HORIBA Scientific Aqualog, a spectrofluorometer to measure dissolved organics in the subglacial system. The Aqualog simultaneously measures both absorbance spectra and fluorescence Excitation-Emission Matrices, giving the researcher a fingerprint of the sample they are studying in fast succession.

“The Aqualog is the perfect instrument to measure organic matter under the ice that hasn’t been seen by the sun for hundreds of thousands of years,” Priscu said. “It will analyze the quality of dissolved organic matter to see if it’s recalcitrant (resistant) and together with other data we collect, determine its age. “

The Aqualog will fingerprint the dissolved organic material and determine what kind of organic matter is actually ancient or being produced contemporarily.

“We are always looking for new and better tools to look at the organic matter, and the by virtue of its rapid sample rate the Aqualog is a good way to go” he said.

To establish and supply the research site at Lake Mercer, in Dec. 2017, three tractors, each capable of pulling 100,000 lbs., drove 650 miles from a remote site to Lake Mercer. The tractors drive at an average speed of seven miles an hour.

The journey took two weeks and carried an estimated one million pounds of material. The convoy delivered drilling equipment, fuel, science labs, and several camp structures to the study site. Three more tractors will haul the remainder of the gear to the site in November 2018.

Subglacial lakes could add to our understanding of the evolution of life in these extreme environments on earth and other celestial bodies, according to Priscu.

The Antarctic field work beginning with background geophysical measurements, field camp fabrication, drilling, sampling and samples began in the austral summer of 2016/2017 and will continue through the 2019/2020 season.

Priscu said the hardest part of his job is dealing with budgets and the logistics of moving all the team’s drills and other equipment, including a vehicle that’s remotely operated under the ice.

He worries, though, about the current trend of global warming and its effects on the earth’s ecosystem.

“It’s not just air temperature,” he said. “We have to understand how warming is going to change the earth’s natural and agricultural ecosystems that will affect humankind. California and many other locations around our planet are going through that now and it will only get worse in the future. We are seeing huge and more frequent fires and floods. Farmers are dealing with climate change. Some crops may not work, and you are going to have to deal with water issues.”

Right now we know the earth is warming and ice is melting fast, Priscu noted.

“If we lose Antarctic ice the sea level will rise and we’d lose Boston and Florida and the San Francisco Bay area. Understanding what happened in the past will help us understand what may happen in the future.”

And understanding how microorganisms survive in the cold darkness of these subglacial lakes will add to our knowledge of how life may exist on cold, distant planets.

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