Antarctic ice loss speeds up, nearly matches Greenland loss


Ice loss in Antarctica increased by 75 percent in the last 10 years due to a speed-up in the flow of its glaciers and is now nearly as great as that observed in Greenland, according to a new, comprehensive study by UC Irvine and NASA scientists.



In a first-of-its-kind study, an international team led by Eric Rignot, professor of Earth system science at UCI and a scientist with NASA’s Jet Propulsion Laboratory, Pasadena, Calif., estimated changes in Antarctica’s ice mass between 1996 and 2006 and mapped patterns of ice loss on a glacier-by-glacier basis. They detected a sharp jump in Antarctica’s ice loss, from enough ice to raise global sea level by 0.3 millimeters (.01 inches) a year in 1996, to 0.5 millimeters (.02 inches) a year in 2006.



Rignot said the losses, which were primarily concentrated in West Antarctica’s Pine Island Bay sector and the northern tip of the Antarctic Peninsula, are caused by ongoing and past acceleration of glaciers into the sea. This is mostly a result of warmer ocean waters, which bathe the buttressing floating sections of glaciers, causing them to thin or collapse. “Changes in Antarctic glacier flow are having a significant, if not dominant, impact on the mass balance of the Antarctic ice sheet,” he said.



Results of the study are published in February’s issue of Nature Geoscience.



To infer the ice sheet’s mass, the team measured ice flowing out of Antarctica’s drainage basins over 85 percent of its coastline. They used 15 years of satellite radar data from the European Earth Remote Sensing-1 and -2, Canada’s Radarsat-1 and Japan’s Advanced Land Observing satellites to reveal the pattern of ice sheet motion toward the sea. These results were compared with estimates of snowfall accumulation in Antarctica’s interior derived from a regional atmospheric climate model spanning the past quarter century.


The team found that the net loss of ice mass from Antarctica increased from 112 (plus or minus 91) gigatonnes a year in 1996 to 196 (plus or minus 92) gigatonnes a year in 2006. A gigatonne is one billion metric tons, or more than 2.2 trillion pounds. These new results are about 20 percent higher over a comparable time frame than those of a NASA study of Antarctic mass balance last March that used data from the NASA/German Aerospace Center Gravity Recovery and Climate Experiment. This is within the margin of error for both techniques, each of which has its strengths and limitations.



Rignot says the increased contribution of Antarctica to global sea level rise indicated by the study warrants closer monitoring.



“Our new results emphasize the vital importance of continuing to monitor Antarctica using a variety of remote sensing techniques to determine how this trend will continue and, in particular, of conducting more frequent and systematic surveys of changes in glacier flow using satellite radar interferometry,” Rignot said. “Large uncertainties remain in predicting Antarctica’s future contribution to sea level rise. Ice sheets are responding faster to climate warming than anticipated.”



Rignot said scientists are now observing these climate-driven changes over a significant fraction of the West Antarctic Ice Sheet, and the extent of the glacier ice losses is expected to keep rising in the years to come. “Even in East Antarctica, where we find ice mass to be in near balance, ice loss is detected in its potentially unstable marine sectors, warranting closer study,” he said.



Other organizations participating in the NASA-funded study are Centro de Estudios Cientificos, Valdivia, Chile; University of Bristol, United Kingdom; Institute for Marine and Atmospheric Research, Utrecht University, Utrecht, The Netherlands; University of Missouri, Columbia, Mo.; and the Royal Netherlands Meteorological Institute, De Bilt, The Netherlands.

First evidence of under-ice volcanic eruption in Antarctica





BAS Twin Otter in flight during the aerial survey - Carl Robinson-British Antarctic Survey
BAS Twin Otter in flight during the aerial survey – Carl Robinson-British Antarctic Survey

The first evidence of a volcanic eruption from beneath Antarctica’s most rapidly changing ice sheet is reported this week in the journal Nature Geosciences. The volcano on the West Antarctic Ice Sheet erupted 2000 years ago (325BC) and remains active.



Using airborne ice-sounding radar, scientists from British Antarctic Survey (BAS) discovered a layer of ash produced by a ‘subglacial’ volcano. It extends across an area larger than Wales.



Lead author, Hugh Corr of the BAS says, “The discovery of a ‘subglacial’ volcanic eruption from beneath the Antarctic ice sheet is unique in itself. But our techniques also allow us to put a date on the eruption, determine how powerful it was and map out the area where ash fell. We believe this was the biggest eruption in Antarctica during the last 10,000 years. It blew a substantial hole in the ice sheet, and generated a plume of ash and gas that rose around 12 km into air.”



The discovery is another vital piece of evidence that will help determine the future of the West Antarctic Ice Sheet and refine predictions of future sea-level rise. Co-author Professor David Vaughan (BAS) says,



“This eruption occurred close to Pine Island Glacier on the West Antarctic Ice Sheet. The flow of this glacier towards the coast has speeded up in recent decades and it may be possible that heat from the volcano has caused some of that acceleration. However, it cannot explain the more widespread thinning of West Antarctic glaciers that together are contributing nearly 0.2mm per year to sea-level rise. This wider change most probably has its origin in warming ocean waters.”


The subglacial volcano has a ‘volcanic explosion index’ of around 3-4. Heat from the volcano creates melt-water that lubricates the base of the ice sheet and increases the flow towards the sea.



Pine Island Glacier on the West Antarctic Ice Sheet is showing rapid change and BAS scientists are part of an international research effort to understand this change.



Glaciers are like massive rivers of ice that flow towards the coast and discharge icebergs into the sea.



Since the 1970’s scientists have used radar, seismic and satellite technologies to discover a number of features – including lakes – hidden beneath the ice.



The volcano is located beneath the West Antarctic ice sheet in the Hudson Mountains at latitude 74.6°South, longitude 97°West.



Volcanoes are an important component of the Antarctic region. They formed in diverse tectonic settings, mainly as a result of mantle plumes acting on the stationary Antarctic plate. The region also includes amongst the world’s best examples of a long-lived continental margin arc (Antarctic Peninsula), a very young marginal basin (Bransfield Strait) and an oceanic island arc (South Sandwich Islands). Many extinct volcanoes are very well preserved and others are still active (e.g. Deception Island, Mount Erebus, and the South Sandwich Islands). Volcanic eruptions were common during the past 25 million years, and coincided with the great period of climatic deterioration that resulted in the formation of the Antarctic ice sheet. Many of the volcanoes show the effects of interaction with ice. BAS has played a major role in describing these effects and modelling their influences on the resulting volcanic sequences. It is important to describe and understand these interactions in geologically recent times in order to predict future configurations of the ice sheet and its role in the global system.

New Antarctic Ice Core to Provide Clearest Climate Record Yet





Scientist Rebecca Anderson of the Desert Research Institute examines a section of the WAIS Divide ice core recovered from a depth of 500 meters. - Credit: Photo courtesy of Kendrick Taylor
Scientist Rebecca Anderson of the Desert Research Institute examines a section of the WAIS Divide ice core recovered from a depth of 500 meters. – Credit: Photo courtesy of Kendrick Taylor

After enduring months on the coldest, driest and windiest continent on Earth, researchers today closed out the inaugural season on an unprecedented, multi-year effort to retrieve the most detailed record of greenhouse gases in Earth’s atmosphere over the last 100,000 years.



Working as part of the National Science Foundation’s West Antarctic Ice Sheet Divide (WAIS Divide) Ice Core Project, a team of scientists, engineers, technicians and students from multiple U.S. institutions have recovered a 580-meter (1,900-foot) ice core–the first section of what is hoped to be a 3,465-meter (11,360-foot) column of ice detailing 100,000 years of Earth’s climate history, including a precise year-by-year record of the last 40,000 years.



The dust, chemicals and air trapped in the two-mile-long ice core will provide critical information for scientists working to predict the extent to which human activity will alter Earth’s climate, according to the chief scientist for the project, Kendrick Taylor of the Desert Research Institute of the Nevada System of Higher Education. DRI, along with the University of New Hampshire, operate the Science Coordination Office for the WAIS Divide Project.



WAIS Divide, named for the high-elevation region that is the boundary separating opposing flow directions on the ice sheet, is the best spot on the planet to recover ancient ice containing trapped air bubbles–samples of the Earth’s atmosphere from the present to as far back as 100,000 years ago.



While other ice cores have been used to develop longer records of Earth’s atmosphere, the record from WAIS Divide will allow a more detailed study of the interaction of previous increases in greenhouse gases and climate change. This information will improve computer models that are used to predict how the current, unprecedented high levels of greenhouse gases in the atmosphere caused by human activity will influence future climate.


The WAIS Divide core is also the Southern Hemisphere equivalent of a series of ice cores drilled in Greenland beginning in 1989, and will provide the best opportunity for scientists to determine if global-scale climate changes that occurred before human activity started to influence climate were initiated in the Arctic, the tropics or Antarctica.



The new core will also allow investigations of biological material in deep ice, which will yield information about biogeochemical processes that control and are controlled by climate, as well as lead to fundamental insights about life on Earth.



Says Taylor, “We are very excited to work with ancient ice that fell as snow as long as 100,000 years ago. We read the ice like other people might read a stack of old weather reports.”



The WAIS project took more than 15 years of planning and preparation, including extensive airborne reconnaissance and ground-based geophysical research, to pinpoint the one (less than a square mile) space on the 932,000-square-kilometer (360,000-square-mile) ice sheet that scientists believe will provide the clearest climate record for the last 100,000 years.



With only some 40 days a year when the weather is warm enough for drilling–yesterday’s temperature was a balmy -15 degrees Celsius (5 degrees Fahrenheit)–it is expected to take until January 2010 to complete the fieldwork.



For the project, Ice Coring and Drilling Services of the University of Wisconsin-Madison built and is operating a state-of-the-art, deep ice-coring drill, which is more like a piece of scientific equipment than a conventional rock drill used in petroleum exploration. The U.S. Geological Survey National Ice Core Laboratory in Denver designed the core handling system. Raytheon Polar Services Corporation provides the logistical support. The NSF Office of Polar Programs-U.S. Antarctic Program funds the project. The core will be archived at the National Ice Core Laboratory, which is run by the USGS with funding from NSF.

ANDRILL’s 2nd Antarctic drilling season exceeds all expectations


A second season in Antarctica for the Antarctic Geological Drilling (ANDRILL) Program has exceeded all expectations, according to the co-chief scientists of the program’s Southern McMurdo Sound Project.



One week ago (Nov. 21), the drilling team passed the 1,000-meter mark in rock core pulled from beneath the sea floor in McMurdo Sound, and with a remarkable recovery rate of more than 98 percent. The end of drilling is scheduled for this weekend, and only a few tens of meters of core remain to be recovered for an expected final total of more than 1,100 meters (3,600 feet). It’s the second-deepest rock core drilled in Antarctica, surpassed only by the 1,285 meters (more than 4,215 feet) recovered by last year’s ANDRILL effort, the McMurdo Ice Shelf Project.



As the job nears completion for the Southern McMurdo Sound Project drillers, the co-chief scientists, David Harwood of the University of Nebraska-Lincoln and Fabio Florindo of Italy’s National Institute of Geophysics and Volcanology in Rome, said they couldn’t be more pleased with the results. They said the efforts of the program’s nearly 80 scientists, drillers, engineers, technicians, students and educators in Antarctica, with the operations and logistics support provided by Antarctica New Zealand, have given the world’s scientists more than a kilometer of pristine rock core that records the history of climate and glacial fluctuations in Antarctica over the past 20 million years.



“It’s everything we hoped for,” Harwood said. “Combine the drill hole we recovered last year with this one, from a time period right below it, and it’s more than 2 kilometers (1 1/4 miles) of geological history. It’s phenomenal what we’ve recovered. There’s a lot of diversity in the core, indeed more than we can digest right now. It will take some time to fully resolve the paleoenvironmental and dynamic paleoclimate information in the core.”



The goal of this drilling project was sediment core retrieval from the middle Miocene Epoch when, for an extended period, Earth was warmer than today. Florindo and Harwood said they are especially pleased to have recovered such high-quality core from this target period.



“We now have a more complete core record from the middle Miocene and a step into a colder period of time, and that was one of our key targets,” Florindo said. “It will tell an important story when we put together our recovery with the record of last season. This is exciting science and it will echo loudly in the scientific community.”



The middle Miocene has long been held as one of the fundamental time intervals in development of the modern Antarctic ice sheets. It encompassed a change from a warm climate optimum approximately 17 million years ago to the onset of major cooling approximately 14 million years ago, and the formation of a quasi-permanent ice sheet on East Antarctica. Florindo and Harwood said fossils and sediments deposited during this year’s ANDRILL target interval suggest the persistence of warmer-than-present conditions over an extended period of the middle and late Miocene when the western Ross Sea and McMurdo Sound resembled the modern climate conditions of southernmost South America, southwestern New Zealand, and southern Alaska, rather than the cold polar climate of today.


“Until now, most climatic interpretations for this time period has been based on measurement of oxygen isotopes in the deep sea, far from Antarctica,” Harwood said. “The cores we’ve recovered will give us a high resolution history of paleoclimate change directly from the Antarctic continent.”



The sediment cores reflect deposition close to or beneath grounded glaciers, alternating with fine-grained sediments, which provide clear evidence for ice advance and substantial retreat during main climate transitions, Florindo and Harwood said. They said programs like ANDRILL are extremely important because of the uncertainties about the future behavior of Antarctic ice sheets. This stratigraphic record will be used to determine the behavior of ancient ice sheets, and to better understand the factors driving past ice sheet, ice shelf and sea-ice growth and decay. This new knowledge will enhance our understanding of Antarctica’s potential responses to future global climate changes.



After a seven-week setup period by Antarctica New Zealand during late winter in the Southern Hemisphere, drilling began Oct. 9 and continued until last week, with the drillers recovering 25 to 70 meters of core each day. There was only one major interruption, occurring in early November when sand and water flowed into the drill hole, but Harwood said the drill team “did an awesome job” of fixing the problem.



Following the planned drilling stoppage at the end of last week, scientists lowered a variety of scientific instruments into the deep drill hole over several days to get a better understanding of the physical properties of the geologic layers under pressure and to obtain an acoustic image of the inside of the borehole. Drilling resumed this week and will continue until probably Sunday to recover about 100 meters of additional core.



The first stop for each core section after recovery is the Crary Science and Engineering Center, operated by the U.S. National Science Foundation at McMurdo Station. After preliminary examination by on-ice scientists, the cores are shipped to Florida State University’s Antarctic Marine Geology Research Facility in Tallahassee for storage and long-term study.



ANDRILL is a multinational collaboration comprised of scientists, students and educators from the four partner nations (Germany, Italy, New Zealand and the United States) to recover stratigraphic records from the Antarctic continental margin. ANDRILL is one of about 220 projects endorsed by the fourth International Polar Year, 2007-2009, one of the largest collaborative science programs ever attempted. Operations and logistics for ANDRILL are managed by Antarctica New Zealand. Scientific research is administered and coordinated through the ANDRILL Science Management Office at the University of Nebraska-Lincoln. For more information, visit http://andrill.org.



Funding support for ANDRILL comes from the U.S National Science Foundation, New Zealand Foundation of Research, Science, and Technology, Royal Society of New Zealand Marsden Fund, Antarctica New Zealand, the Italian National Program for Research in Antarctica, the German Science Foundation and the Alfred Wegener Institute for Polar and Marine Research Science.

New Antarctica research season kicks off





A composed satellite photograph of Antarctica. - Photo: courtesy NASA
A composed satellite photograph of Antarctica. – Photo: courtesy NASA

The approach of winter in the northern hemisphere means that summer is coming to Antarctica – still bitterly cold, but just warm enough to let scientists make progress on ongoing studies.



Among those UW-Madison faculty members who conduct research at the bottom of the word are Jim Bockheim, an expert on Antarctica’s Mars-like soils; Christine Ribic, a wildlife ecologist who studies the super-hardy Adelie penguin; and Charles Bentley, a geologist who is celebrating his 50th anniversary as an Antarctic scientist this year.



This research season also marks the midway point of the International Polar Year (IPY), which extends from March 2007 to March 2009. Organized through the International Council for Science and the World Meteorological Organization, the IPY is a large scientific program dedicated to the Arctic and the Antarctic. The 2007-09 “year” follows previous polar years in 1882-83, 1932-33, and 1957-58.



As visitors soar, scientist maps Antartica’s sensitive soils



Jim Bockheim has trekked to some of the coldest, driest places on earth. As a polar soil scientist, he has spent more than three decades studying glacial cycles and how soils form in these extreme climates. But these days, the ends of the earth are becoming more crowded.



In 2006, almost 30,000 travelers journeyed to Antarctica to see penguins, whales and the South Pole. This kind of adventure doesn’t come cheap. Excursions range from $4,000 to $30,000 per trip. For that price, eco-tourists can play scientist, visit research stations, commune with seals, and even climb unnamed mountains.



Bockheim worries about the impact of this activity on a fragile ecosystem. Polar soils are unique he says. He should know: Bockheim played a key role in naming this soil class-the gelisols-in 1998. Perpetually frozen, Antarctic gelisols have been likened to the soils on Mars. They are also sensitive to human impact.



To that end, Bockheim is collaborating with colleagues from New Zealand and several international organizations to develop comprehensive maps of Antarctica’s permafrost and soils. These maps might soon be used to develop a trail system for visitors.



“If tourism becomes more extensive,” Bockheim says, the maps can show “where the best place would be to lay these trails out with minimum impact.”



But Bockheim isn’t just worried about the impacts of tourists. Research in Antarctica has also increased. McMurdo Station, Antarctica’s largest settlement, now hosts more than 1,000 scientists and support staff year round. And they require amenities such as research labs, dormitories, a bowling alley, satellite television, and a diesel generator for electricity.



Many of these scientists study climate change effects. Bockheim is no exception. Part of his research examines glacial cycles, which he hopes can provide information about future climate events. A better understanding of what caused mass glaciation in the past, he says, can help better predict when it could happen again. The clues are in the soils. And they need protection.



With an increased focus on preserving the ecosystem of the “last continent,” scientists are becoming more careful about how they do business in Antarctica. Each small change is significant.



“Every time I dig a soil pit, I’m conducting some kind of disturbance,” Bockheim says. “So now, we dig the soil layers very carefully and put them on a tarp.” After collecting samples and data, his team gently replaces all the soil and stones. They even pack out their own human waste.



It takes days for Bockheim to get to his remote location in Antarctica’s Dry Valley, but it’s worth it. His benefits include interesting and meaningful research, great scenery, and a mountain with his name on it: Mount Bockheim.



“It’s spectacular,” he says of the experience. “I’m interested in life at the extremes.”

Not so happy feet: Retreating sea ice bad news for penguins



As penguins go, the Adelie is one tough bird. Standing about 2 1/2-feet tall, the diminutive Adelie is one of just a few animals to brave the Antarctic winter, hanging around to feast on krill while other species depart for warmer destinations.



But the Adelie depends on constant sea ice for its successful Antarctic lifestyle, and changes in the marine ice related to global climate change may doom rookeries that have been used by the flightless birds for more than 8,000 years, according to new research.



“The Adelie is integrating all the effects of climate change. They have to deal with it,” explains Christine Ribic, a UW-Madison wildlife ecologist who studies the penguin’s habitat on the western Antarctica Peninsula. “This is a real ice species.”



Ribic and others worry that the Adelie rookeries nearest the U.S. Palmer Antarctic Research Station on Anvers Island will disappear as sea ice retreats south and be replaced by other penguin species – the chinstrap and Gentoo – which are more tolerant of open water. “The fear is that in 5 to 10 years on Anvers Island, the Adelie will go extinct at those sites,” she says.



There are five Adelie rookeries on the peninsula, including those on Anvers Island, and all are within easy reach of an ocean trough where upwelling currents provide nutrients for krill, shrimp-like crustaceans that are the preferred prey for the Adelie.



Recent mapping of the ocean floor, coupled with tracking of satellite-tagged penguins, has revealed the importance of troughs to the rookeries, Ribic says. “Now we know what the ocean floor looks like. For example, the trough at Anvers Island is within 15 to 20 kilometers of where the penguins are. The penguins are limited to regions where prey is available, and that is predictable in terms of centuries.”



The good news, according to Ribic, is that if the Adelie rookeries near Palmer “wink out,” they could return – as long as there is enough sea ice for the penguins to maintain their lifestyle and out-compete their flightless cousins.


Drilling into Antarctica’s past



A team of UW-Madison scientists and engineers is traveling to the West Antarctic Ice Sheet this winter for the inaugural Antarctic run of a powerful new ice-coring drill, called the Deep Ice Sheet Coring (DISC) Drill.



Developed at UW-Madison’s Space Science and Engineering Center by a team led by project manager Alexander Shturmakov, the drill will enable scientists to collect and analyze high-quality cores of the Antarctic ice and bedrock.



Over the course of three work seasons, the team aims to drill through the entire depth of the West Antarctic Ice Sheet, a distance greater than two miles. In subsequent years, they also hope to collect cores from the underlying bedrock – a feat that has never been accomplished in Antarctica.



Ice sheets contain a record of past climates and environments. As layers of snow were compressed into ice, they trapped air bubbles, minute quantities of chemical impurities and biological samples that now offer a look back through Antarctic history.



An interdisciplinary team of scientists from a score of institutions will use the DISC drill cores to study past relationships between geology, biology and climate. They also plan to compare their Antarctic findings to similar data from Greenland ice cores to determine the relationship between environmental changes in the northern and southern hemispheres.



The project team is targeting a region of the West Antarctic Ice Sheet that receives high annual snowfall, which creates thick and more easily analyzed yearly ice layers. Cores from this region should provide a view of past climates with a level of detail unprecedented in Antarctica, with single-year resolution for the past 40,000 to 50,000 years.



Charles Bentley, principal investigator for the DISC drill project and professor emeritus of geology and geophysics, will be traveling to the drilling site from Jan. 12-19, 2008, to see the drill in operation for the first time. This season marks the 50th anniversary of Bentley’s first full field season in Antarctica in 1957-58.

Geologist Discovers Three New Minerals


On a geological expedition along the windswept slopes of the Larsemann Hills in Antarctica, UMaine geologist Edward Grew collected samples of the area’s unique rock formations that would later reveal three minerals previously unknown to science. The minerals, stornesite-(Y), chopinite and tassieite, are extremely rare and represented only by microscopic samples collected by Grew.



The unique mineralogy of the Larsemann Hills, located on the eastern shore of Prydz Bay in Princess Elizabeth Land, inspired Grew and his fellow researcher Chris Carson (now at Geoscience Australia) to make the four-month expedition in 2003 – 2004, which was funded by the National Science Foundation and made possible by the Australian Antarctic Division.


Grew and his colleagues identified and characterized the minerals using cutting edge technologies. Martin Yates used the powerful electron microprobe at UMaine to image the new minerals and measure their chemical compositions. Next, the minerals were sent to Olaf Medenbach at the Ruhr University (Bochum, Germany) and Thomas Armbruster at the University of Bern (Switzerland), who determined the new minerals’ optical properties and crystal structures, respectively. Then Grew submitted a complete dataset for each mineral to a special commission of the International Mineralogical Association, which formally approved them as valid new species. Grew has discovered a total of ten new minerals, and sees each as an opportunity to expand scientific understanding of the Earth and its complex geological processes.



“When new minerals are identified, some have little significance, and some end up being tremendously important,” said Grew. “They all tell us something about how rocks form. Ultimately, discoveries like these contribute to our understanding of the origin of rocks, plate tectonics and other processes, and give us valuable insights into temperature, pressure and other conditions within the Earth at different points of its history.”

Scientist Studies Minnesota’s Rock In Antarctica





An intrusion (the forcible entry of molten rock or magma into or between other rock formations) in Antarctica. Unlike Minnesota, geologists get a perfectly clear view of intrusions in Antarctica.
An intrusion (the forcible entry of molten rock or magma into or between other rock formations) in Antarctica. Unlike Minnesota, geologists get a perfectly clear view of intrusions in Antarctica.

Geologists learn by looking at rocks. Of course, it’s not that simple. Here in Minnesota, the tapestry of mineral-laden geology lies buried under forests, soils and parking lots. This makes Dean Peterson’s job difficult. As one of the economic geologists at the University of Minnesota, Duluth’s Natural Resources Research Institute (NRRI), his job is to understand the state’s geology–where and what types of ore minerals were deposited some 1.1 to 2.7 billion years ago. In Minnesota, geologists figure it out by reading scattered outcroppings and drilling holes. It’s doable, but it’s difficult.



So when Peterson was offered an opportunity to spend a month in Antarctica’s Dry Valleys, he jumped at the chance. Yes, that’s a long way from Minnesota, but surprisingly, the geology is the same. Both areas were focal points of dynamic magmatic systems associated with continental rifting-molten rock flowed up from the earth’s mantle, forming intrusions in the upper crust. The geologic setting was the same.



But the beauty of Antarctica for geologists is the 100 percent exposure of rock. They can look at layer upon ancient layer of deposits, up to 10,000 feet high. In Minnesota, the Duluth Complex, a large, composite of mafic rocks (rich in dark-colored minerals like magnesium and ireon) in northeastern Minnesota, was the hot spot for dynamic magmatic molten movement. It’s where NRRI’s economic geologists go to identify valuable mineral deposits.


Understanding local deposits



“In the Duluth Complex, I study the ‘plumbing’ of the intrusions. That’s the key to finding the higher grade ore deposits,” says Peterson. “So in the Dry Valleys I can actually see how the magma moves up from the earth’s crust, how it crosses certain rock bodies, and where it picks up sulfur to form sulfide minerals. In Antarctica I could see the ‘plumbing’ that I can’t see in Minnesota.”



If that wasn’t exciting enough for Peterson (and it was) he also spent a month with one of the most renowned geologists in the country, Bruce Marsh of Johns Hopkins University.



Did you know?



Antarctica is the coldest, windiest, and harshest continent. The continent is covered in continuous darkness during the austral winter and continuous sunlight in the summer. (The average annual temperature is -56°F at the Amundsen-Scott South Pole Station, the southernmost continually inhabited place on the planet).


Source U.S. Antarctic Program



“Spending time seeing this fabulous geology and learning from Dr. Marsh is really something special,” says Peterson.



Paul Morin, a visualization expert in the geology and geophysics department on the U’s Twin Cities campus, and researchers from Poland and Slippery Rock University in Pennsylvania joined Peterson on the expedition. The trip was funded by a grant from the National Science Foundation.



From Peterson’s travel notebook:



  • Antarctica is not as cold as people might think. Temperatures were, on average, in the 20s to 30s Fahrenheit and sometimes down to 10 at night, but we got used to it right away. After a day we were in shirtsleeves and a windbreaker. The sun is always out and intense.

  • When the wind stops blowing there is utter silence. There is nothing to make a noise. It’s eerie at first, but then I got used to it. The silence really gives you time to think. When we went back to McMurdo (U.S. Field Station) the noise created by 1,100 people living in close quarters was unbelievable.

  • Humans have evolved in humid environments where water vapor in the atmosphere selectively absorbs light–as you look into the distance things get bluer and bluer. We unconsciously perceive distance using the air’s absorption of light. Antarctica is the driest place on earth. The humidity in the Dry Valleys averages about 1 or 2 percent. The air’s dryness adds an additional dimension to an Antarctic experience–light doesn’t change color with distance. Mount Erebus, 120 miles away, will look exactly like it would if you were right next to it. It’s hard to visually calculate any distance.