Nott

A Magazine for Alumni and Friends


FallNott Memorial 2015

Drilling deep

Beneath Peru’s largest lake, geologists discover Earth’s climate history … and get a glimpse at our future

J

ust hours into a weeks-long project to core the sediment of Peru’s Lake Junín for clues to climate history, scientists made an exciting discovery: as some had speculated, this lake wasn’t always a lake.


Grace Delgado ’14 was taking samples on the deck of a drilling barge when she noticed a sudden change in the sediment layers. “Look at this. It used to be a peat bog,” she said. “The lake actually dried out.

Indeed, about 55 meters down, the slippery gray clay from a glacial period suddenly gave way to dry, dark brown, decayed plant matter that looked and smelled like the packaged peat you’d find at the garden center.

Sometime around 100,000 years ago, Lake Junín (hoo-NEEN), high in the remote central Andes, recorded a sudden change from a cold to a warm climate. And chances are this could have been a global event.

Last summer, Delgado and Nick Weidhaas ’15 were with an international team of 30 scientists led by Prof. Don Rodbell to extract the first continuous high resolution core of the ancient lake. Funded by the National Science Foundation and the International Continental Drilling Program, the Lake Junín Project is aimed at furthering our understanding of the Earth’s natural climate cycles over the past one million years. It also has important implications for our climate future.

Delgado and Weidhaas are among the dozens of Union students and alumni who have done fieldwork with Rodbell in Peru and other parts of South America. Before this trip, their deepest core of Lake Junín—made with a hand tool—went down only 25 meters, about 50,000 years of deposits.

So, nearly every sample that emerged brought a new insight and a wave of excitement.

Over the past several decades, paleoclimatologists like Rodbell have used ice cores, cave deposits and lake sediment to develop proxy indicators of climate history. Records from the tropics are especially important since this region is the “heat engine” of Earth. Changes in ocean-atmosphere circulation in the western Pacific—such as the El Niño Southern Oscillation—can profoundly impact regional water balance and affect potable water supplies, hydroelectricity generation and agriculture.




Nick Weidhaas ’15, Prof. Don Rodbell and Grace Delgado ’14 with a sediment core from beneath Lake Junín, Peru

Grace Delgado ’14 and Prof. Don Rodbell inspect a core sample

Lake Junín (Chinchaycocha in Quechua—the Incan tongue) is an ideal place to study the Earth’s climate history. Ancient and shallow, Junín has been accumulating sediment undisturbed for perhaps a million years. At 4,000 meters (13,500 feet) above sea level between the western and eastern cordillera in the central Peruvian Andes, Junín covers 300 square kilometers (almost 200 square miles). Dammed on the north and south by alluvial fans—material deposited by rivers—that come from moraines that are at least 250,000 years old, the lake has not been overridden by glaciers in at least one million years, according to research by Jacqueline Smith Garver, former Union research professor.

Today the lake is bordered by a handful of small towns—Junín, Huayre, Carhuamayo and Ondores—and much of the western shore serves as grazing land for sheep, alpaca and cattle. A destination for birders eager to see the endangered Junín Grebe or Junín Rail, the lake was designated a Peruvian National Wildlife Preserve in 1974. Remarkably, there is little interaction between the local population and the lake, perhaps because much of the shore is lined by marshes and there are seasonal fluctuations in the water level.

There is also contamination. The lake and the adjacent grazing areas have been polluted by runoff and dust from the nearby mining of copper, lead and zinc. Making matters worse, Junín was dammed in 1932 to regulate water for hydroelectric production in the Amazon basin. As an unintended consequence, the Rio San Juan, which normally drains the lake, is seasonally redirected, carrying acid mine drainage into the lake. The contamination of Lake Junín was the subject of an earlier study by Rodbell and his colleagues.

Through peripheral NSF grants, the Junín Drilling Project includes a public outreach campaign to local officials, community groups and schools. Scientists distribute stickers and fliers explaining the project and conservation efforts on the lake. Plans are to launch a citizen science project in which teams of locals outfitted with GPS will take soil samples where their livestock graze. The hope is to get hundreds of samples to analyze at Union for lead, zinc, copper and other contaminants to document the full scope of regional mining contamination. The project also plans to renovate an abandoned lakeside lodge for use by the National Park Service and as a way to promote ecotourism.

A 20-by 60-foot barge with a large drilling rig and bright lights looks a bit out of place on Lake Junín. But it is home to geologists and drillers acquiring the first continuous high resolution core record of the lake, and data on the global climate record.

This is hard work. Drillers and scientists get muddy, wet and cold as cores are raised from depth and lowered to the deck. The high altitude, dry air and wind make a 12-hour shift a long grind. It’s worse in the cold and dark of night, a fact not lost on “Team Union,” which has the day shift. Scientists from the University of Pittsburgh get night duty. Drilling goes on 24 hours a day to preserve the integrity of the core. Adding prep time and a round-trip commute from the hotel in Tarma leaves about six hours a day for rest. Breakfast at 3:30 a.m. comes quickly after two or three consecutive shifts.

In this issue
Lake Junín, Peru
In this issue
A sample of sediment shows shells characteristic of a carbonate layer.

“Core on deck,” yells Delgado as three other members of the science team emerge from a small heated shed. Two members of the all-Peruvian drill team extract a two-meter plastic sleeve of sediment from a section of casing and hand it over to the scientists who carefully clean, seal and label each tube. They also send cursory observations of each core to their temporary lab at the hotel.

An outsider might be forgiven for thinking the obvious: it looks like they are collecting mud. But to these geologists, each tube of mud (their word) is like another slice of layer cake, a new insight into the climate history of Lake Junín and Earth itself.

Though complete analysis won’t be done until the cores are back in the states, each tube reveals tantalizing clues. Each layer, ranging from one millimeter to several centimeters thick, represents an annual record. Homogenous, light gray mud suggests glacial runoff during an ice age. Dark specks are plant matter from a highly productive lake during warmer temperatures. Bits of mollusk and crustacean shell come from a carbonate layer deposited during an interval when glaciers had vanished from the landscape.

"Lakes are like garbage cans in that they hold a complete history of everything that happened in a place, region or watershed,” Rodbell said. “It’s up to scientists to decipher the record about what went on.”

Rodbell and his collaborators investigate each layer for “proxy indicators” of climate change that reflect the proximity of glaciers to a lake site, the balance between evaporation and precipitation and even the storminess of a time interval. By dating these events and cycles, they can understand if they were regional or global. A key question is how fast regional or global climate can change when tipping points are crossed. “It turns out that it is very, very rapid, a decade or two,” Rodbell said. “That is, fast enough to make a difference to humans trying to eke out an existence on the Peruvian altiplano or grow wheat in Kansas.”

Human societies have developed in one of the most stable intervals in the Earth’s history, Rodbell said. But the climate record shows that stability is rare and change can come rapidly, particularly at the regional level.

“If change happens slowly and gradually over many centuries, human societies and species can adapt,” he said. “But if we were to cross some climatological tipping point, change could happen so fast that humans and many other species could have a great deal of trouble adjusting.

“We have evidence that tipping points have been crossed in the past, but the problem is we just don’t know how close we are to one, or whether human activity has just triggered one,” he said. “Sometimes I find myself really worried about the future, for the next generation. When you look at the geologic data and consider what we have done to the radiative balance of Earth, you cannot help but get a little panicked.”

The Junín Drilling Project

Every year, the National Science Foundation and the International Continental Drilling Program fund the drilling of one or two large (and old) lakes. These are big, multi-million dollar projects with a long queue.

Rodbell started work on Lake Junín in 1996, when he extracted a core with Jeremy Newman ’97.

In this issue
An earlier core from Lake Junín shows a change from a glacial (light gray) to a warmer climate
In this issue
Crews, including Nick Weidhaas ’14, third from right in foreground, pull the barge through the canal toward Lake Junín.

Last summer, Rodbell was lead investigator of an international team of 30 scientists with a total of $2.66 million in funding from NSF. Nearly $1.3 million is designated for Union (NSF Award ID 1402076), supplemented by funds totaling $550,000 for the drilling project. Other participants are the University of Pittsburgh, the University of Minnesota, Florida Institute of Technology, the University of Oregon and Massachusetts Institute of Technology.

The team was comprised of scientists who offer a special skill—an analytical lab, for example—and who have played roles in other large lake drills. The project contracted with DOSECC, a Salt Lake City-based scientific drilling firm with experience in coring hundreds of meters in the world’s largest lakes. Their equipment was placed in two large containers, trucked to Houston, shipped to Lima and then trucked to the drill site in the high Andes Mountains. Workers dug a canal for a 20- by 60-foot barge to carry the drilling gear to the lake, where they drilled three 200 meter cores from two sites. Teams worked around the clock, no easy task in the cold, thin air at 13,500 feet above sea level, an elevation just shy of Mount Everest base camp.

Rodbell’s annual trips to South America are physically demanding. Heavy gear and camping at high altitudes exact a toll on even the fittest of climbers. But unlike most expeditionists—who shed pack weight as they consume water, food and fuel—Rodbell is constantly adding heavy core samples throughout a trip. His teams have hired local help and rented as many as 25 mules for some expeditions.

What the Lake Junín trip lacked in hauling, it made up for with complicated logistics. The team was based a bit more than an hour from Junín at a hotel in Tarma, where they converted a garage into a temporary lab for preliminary analysis of the cores. At the end of the eight-week project, hundreds of meters of cores were shipped in refrigerated containers to LacCore, the National Lacustrine Core Facility at the University of Minnesota, where they were to be stored and analyzed.

The Junín Drilling Project was the culmination of Rodbell’s career and years in the making. Over the past year, he made four trips to Peru for on-site logistics. His Peruvian colleagues, with whom he has been working for years, were invaluable in the site preparation, permitting and logistics.

“It was exciting to finally be drilling,” he said. “I must say, though, that now that it is all done, I am a bit relieved. I expect I’ll be ready to go back to the small-scale work I’ve been doing with students for many years. The logistics and preparation for a large project like this sort of consume you!”

The climate “debate”

When he began his research in South America, no one was talking about—or debating—global warming. Al Gore and Stephen Schneider had written books and there was some discussion about future climate, but there was little interest (or research money) for work in the tropics. Rodbell’s early work was simply aimed at determining whether the Ice Age in the tropics coincided with those in the more-researched North America and Europe. (It did.) “It was interesting from an academic standpoint,” Rodbell said, “but fairly peripheral to future climate change.”

For Rodbell, the only debate about climate change is what to do about it. “The science is as clear as it ever gets,” he said, “with more than 97 percent of the published literature telling of the clear role that humans are having in affecting global climates.”

In the lab at Union, Prof. Don Rodbell and Dane O’Neil ’14 review an earlier core from Lake Junín.

In cold storage: sediment cores from nearby Ballston Lake

Scientific societies in many fields have developed position statements that greenhouse gases, mostly from human activities, are affecting global temperatures. Among them, the National Academy of Sciences, the American Association for the Advancement of Science, the Geological Society of America and the American Meteorological Society. The U.S. Department of Defense and the Pope have even weighed in. The Pentagon recently cited climate change as a threat to national security due to increased risks of food and water shortages, infectious disease and resultant geopolitical unrest.

Until a few years ago, Rodbell stayed out of the fray, hoping that science would eventually prevail. But it was a campus visit from Christopher Monckton, a climate change denier, which spurred him to act. “I was struck with how little the students knew of the topic, and how effective [Monckton] could be at convincing students that there was something to debate about the role of greenhouse gases in climate change.”

So, he launched a new course on global warming aimed at students with no science background which regularly draws more than 80 students. “I really feel compelled to teach as many students as I can just where the science is on global warming,” he said. “It has become my favorite class to teach, and it is a lot of fun to look at the science, to look at the claims that are made by the deniers and to really try to examine the evidence.”

Rodbell and his faculty colleagues frequently write letters to the editor of the Daily Gazette, the Schenectady newspaper, responding to others who deny global climate change or the human contribution to it.

What most frustrates Rodbell is to hear candidates for political office claim that the jury is still out on climate change and that there is no justification to minimize our carbon footprint. “We don’t challenge a medical treatment for a common malady,” he said. “But somehow it is vogue to dismiss science, malign the motives of scientists and claim that the data just are not good enough. There is plenty of room for debate, but the debate should be focused on how to minimize the negative impact of climate change on human society.”

Starting out in Peru

Rodbell wasn’t planning to study climate change some 30 years ago as a Ph.D. student at the University of Colorado’s Institute of Arctic and Alpine Research. In 1986, fresh off a master’s thesis dating ice age deposits in New Zealand, Rodbell was about to start a fully-funded Ph.D. project on Baffin Island, Canada. Then came an invitation from his Ph.D. advisor to join a natural history study in the remote Peruvian Andes, where explorers had claimed to have found a lost pre-Incan city.

The recent release of Raiders of the Lost Ark had generated a public fascination with archaeology, and media eagerly hyped the project. As it turned out, the “lost” civilization was already known to locals and archaeologists, but the project brought Rodbell to Peru where the remote and rugged terrain—along with a civil war—discouraged other scientists. A dedicated endurance athlete, Rodbell was up to the physical demands of the fieldwork. And he convinced his parents that despite U.S. State Department “no-travel” warnings, he’d be fine.

“You could pick your mountain ranges and do the first work that had ever been done,” he recalls. “It was like the early 20th century in the Rocky Mountains. From a discovery standpoint, it was like low hanging fruit. You’d be guaranteed publishable results mostly because nobody was foolish enough to go there.”

He returned to Colorado, dumped his Baffin Island project and got a one-year Fulbright grant to continue in Peru. Rodbell never had any problems in Peru and got huge amounts of data and samples. He also met his future wife, Cecilia.

Since that first trip, he has returned to South America nearly every summer— usually with Union students—to take dozens of lake sediment cores in Peru, Ecuador and Bolivia. He also has taken dozens of cores in the Northeast, where lakes formed during the Ice Age hold 10,000- to 15,000-year records of environmental change. By comparison, Lake Junín is thought to hold a record of at least 200,000 years.

Prof. Don Rodbell, center, with Nick Weidhaas ’15, left, and Grace Delgado ’14

While the project at Lake Junin awaited a repair on the boat that towed the drilling rig in place, Prof. Don Rodbell led a group to investigate the Huayllay Rock Forest National Sanctuary. The spectacular volcanic rock towers look otherworldly. The thin air at 14,500 feet makes a four-mile hike a strenuous activity for those who normally breathe the air in Schenectady.

 Fall  2015 table of contents