01 September, 2013

Plate Tectonics, Geology, Climate ... and Life

Member returns to Antarctica

 

Antartica provides geoscientists with an outstanding outdoor laboratory to research planetary processes.

Geology field schools can be tough – and sometimes they can be hazardous. During a recent geology field school in Antarctica, I became adept at running the gauntlet of lunging fur seals and lumbering elephant seals, their oversized proboscises flared outwards, exposing shiny pink mouths and sizeable teeth.

The old adage, “their bark is worse than their bite,” doesn’t ring true in Antarctica. Our seasoned guides cautioned us that a bite from a fur seal or an elephant seal would require the immediate administration of intravenous antibiotics.

Admittedly bitten by the polar bug, earlier this year I returned to the Bottom of the World, participating in my third science-based expedition in three years, a geological field expedition titled “Antarctica, South Georgia and the Falkland Islands Scotia Arc Tectonics, Climate and Life.”

The world’s last remaining wilderness, Antarctica represents an outstanding outdoor laboratory to research planetary processes, including the interplay between solid earth dynamics, climate change and ocean change. During the past 50 years, the Western Antarctic Peninsula has warmed three degrees Celsius, triggering a cascading series of geological and biological changes in this fragile ecosystem that have global implications.

Thanks in part to funding from the AAPG Foundation (making me its unofficial Antarctic Explorer-in-Residence), I traveled to the Southern Ocean with an intrepid group of 100 explorers from 15 nations – 50 percent of the group was female – aboard the MV Akademik Ioffee, a 117-meter-long, Russian ice-strengthened vessel.

The group included 70 earth scientists (ranging in age from early 20s to late 70s) representing more than 20 specializations – structural geologists, igneous and metamorphic petrographers, mining geologists, petroleum geologists, seismic interpreters, geophysicists, sedimentologists, hydrogeologists, environmental geologists, paleotsunami experts, glaciologists and oceanographers, to name just a few.

In fact, there were enough doctorate geologists on the expedition to staff four or five university earth science departments!

A Mission to Share

The MV Akademik Ioffee departed from the Falkland Islands and sailed to South Georgia and the Western Antarctic Peninsula (these three areas constitute the “Scotia Arc”). Along the way, we experienced numerous Serengeti-like moments, witnessing some of the largest concentrations of wildlife on the planet.

In addition to the AAPG Foundation’s ongoing support during the past three years, I’ve also received continued support from many other partners and sponsors: The Canmore Museum and Geoscience Centre, the Association for Professional Engineers and Geoscientists of Alberta, the Canadian Society of Petroleum Geologists, the Canadian Society of Exploration Geophysicists, the Houston Geological Society, the Association for Women Geoscientists, the Calgary Herald and Ammonite Resources.

“We’re proud to be a sponsor of Susan’s Antarctic expeditions together with the AAPG Foundation and other organizations,” said AAPG Honorary member G. Warfield “Skip” Hobbs, president of Connecticut-based Ammonite Resources.

“I truly believe that the future of the energy and mineral industries requires that we do a better job at explaining our science to the public and its relevance to their quality of life, including how geological and human processes are involved in climate change,” said Hobbs, a former AAPG secretary and a past-president of the American Geosciences Institute (AGI).

“We need to encourage students to consider careers in the earth sciences,” he added, calling Eaton “an outstanding ambassador for the AAPG.”

Diverse Participants, Common Pursuits

Organized around the Geological Society of America’s 125th anniversary, the Scotia Arc Expedition featured a world-renowned group of earth science professors from the Jackson School of Geosciences, Stanford University, Pennsylvania State and the Federal University of Rio de Janeiro.

Led by Ian Dalziel, professor of geological sciences at the Jackson School of Geosciences at the University of Texas at Austin and a Fellow of the Geological Society of America (GSA), the expedition focused on the interplay between geology, geophysics, glaciology, plate tectonics, climate and life.

Before our departure for Antarctica, George H. Davis, regents professor (emeritus) of the University of Arizona and GSA’s then-president, bid us bon voyage, saying: “Given where Earth and human society stand at this moment in time, we know that this trip, at its core, has a certain gravitas. Antarctica is symbolic of rare international cooperation and Earth stewardship.

“But as we speak, issues of climate change and sea level rise rivet attention on Earth’s polar regions,” he continued, “with marked focus on physical changes taking place and the projected impact of these changes on ecological systems.

“In this respect, you head out as participant explorers and you return as ambassadors in underscoring to others the preciousness of what you observed, experienced, discussed and concluded while venturing into the Southern Ocean,” he said.


AAPG member Sharon Mosher is the dean of the Jackson School of Geosciences (JSG), current president of AGI and chair of the GSA’s 125th anniversary celebrations.

Mosher started planning the JSG-led geology field trip in 2008. She and her spouse, Mark Helper, also on faculty at the JSG, participated in the Scotia Arc Expedition. It was Mosher’s first visit to the mysterious continent, which is recognized for its environmental, aesthetic and scientific value and protected against future development, including resource extraction.

“I think that scientific advances will come out of the Scotia Arc Expedition,” Mosher said. “I got a much better understanding of how everything fit together – glaciers, ice shelves, oceans currents, the atmosphere and plate tectonics. I think the trip gave us all a better understanding of climate change and Antarctica’s role in climate change, opening the potential for new ideas.

“From a plate tectonic and mineral resource perspective, there were certainly a lot of intense discussions,” she said. “All of a sudden, people started seeing that there were connections across the globe.”


For Abdulaziz Abdullah bin Laboun, professor of petroleum geology at the King Saud University in Riyadh, Saudi Arabia, these global connections materialized on the outcrops. Laboun was struck by the parallels (and timing) between the opening of the Red Sea and the Scotia Sea.

“The ophiolites in Antarctica are similar to those on the Arabian Plate, in terms of the mechanism of opening, subduction and volcanic activity,” Laboun said.

Laboun was delighted to see big ice in action, observing glaciers and icebergs carving into the bedrock – in real time – of South Georgia and the Western Antarctic Peninsula.

“In Saudi Arabia,” he said, “we see the end result of glacial activity – pavement grooves, pluck marks and drop stones in fine sediments.” In the field, Laboun was able to compare modern-day geological processes in Antarctica with the Arabian Peninsula’s geologic past.

And, he was lucky enough to discover (and photograph) a meteorite entombed in an iceberg and presented, for examination, in cross-section.

According to Laboun, there have been four documented episodes of glaciation on the Arabian Peninsula, as evidenced by glacial deposits including paleovalleys containing boulders and tillites, which are oil bearing.

In 2011, Laboun published an article in the Arabian Journal of Geosciences, about a fifth episode of glaciation that he’d documented east of the Gulf of Aqabah. The article was titled “Did Glaciers Exist During the Pleistocene in the Midyan Region, Northwest Corner of the Arabian Peninsula?”

Later this year, Laboun’s textbook detailing all five episodes of glaciation will be published in Saudi Arabia.

Laboun entered academia in 2002, after a career with the Arabian Oil Company (Japan) and Saudi Aramco.

“I’m known in Saudi Arabia as being a field geologist,” he said. “I believe that the ‘field’ is the real geology, as opposed to modern-day ‘computer’ geology.”

Describing the JSG-led trip as a “floating university,” Laboun said that he learned a lot, including climate change and oceanography, two subject areas that are new to him.

Inspired, Laboun is thinking about obtaining funding, in the hope of returning to Antarctica with a group of Saudi geologists.


Expedition leader Ian Dalziel is a self-described “old-fashioned” structural geologist, who has more than 40 years of Antarctic field experience in plate tectonics and volcanism.

His body of Antarctic research involves studying the interaction between plate tectonics and the environment. Increasing levels of atmospheric carbon dioxide, he said, translate to ocean warming. Acting as a global heat sink, the ocean transports this extra energy to the ice shelves and glaciers in the Weddell and Ross seas.

“Climate change is happening,” Dalziel said. “There are uncertainties, and we’re trying to quantify them.

“One thing that earth scientists bring to the table is the dimension of time,” he added.

Describing Antarctica and the Scotia Arc as the “nexus of the world’s great climate engine,” Dalziel said, “You can’t understand the climate unless you understand the solid Earth. Things happening in the interior of the Earth can impact the surface of the Earth in a way that biology cannot.”

At the Drygalski Fjord Ophioltic Complex on South Georgia, Dalziel explained the relationship between the Scotia Arc tectonic plate and climate change in the geological record. The formation of the Scotia Arc tectonic plate and the later opening of the Drake Passage, some 34 million years ago, he said, created “oceanic gateways” on the sea floor that influenced bathymetric movements of the cold waters of the Antarctic Circumpolar Current (ACC).

“The ACC is the world’s biggest current, by volume, and it plays a major role in global climate,” Dalziel said.

Sometime between 34 million to 10 million years ago, Antarctica was thermally isolated by the west to east circulating ACC, and the planet moved into the “Ice House Earth” phase of its geologic history, which was marked by the development of glaciers on most continents.

Once connected to the southern part of South America, today the micro-continent containing South Georgia sits some 2,000 kilometers due east of South America’s Cape Horn. Plate tectonic movements, on the order of 6.5 millimeters per year, continue to transport the micro-continent toward Africa.

“This ophiolitic sequence of rocks at Drygalski Fjord helps us identify where the South Georgia micro-continent originated in continental South America,” Dalziel said. “Here, we see similar rocks of a similar age in a similar tectonic setting, in a place where there is, clearly, a missing piece of the South American continent.”


For Darcy Juday, a retired AAPG member living in Longmont, Colo., participation in the Scotia Arc geology field trip was like coming full circle in her geological career.

Before entering the petroleum industry in 1978, Juday completed a Master’s thesis on hydrothermal manganese deposits in the Mid-Atlantic Ridge, at 26 degrees north latitude. Thirty-five years later, she said, the theories of plate tectonics had changed dramatically from “ridge push” to “slab pull.”

Through lectures delivered by the world’s leading experts in plate tectonics, oceanography and glaciology, Juday discovered the role that plate tectonics plays in global climate change:

“I was fascinated to learn about the strong influence that ocean bottom topography has on climate change,” she said. “The global climate system is very complicated, and there’s an intricate set of feedback loops.

“The lectures were simply fascinating,” she said. “I think that I enjoyed the lectures even more than the outcrops.”

However, she added, “After working in the Gulf Coast for so many years – with 15,000 feet of barely consolidated rocks – it was a pleasure to see outcrops for a change! Certainly the turbidites (on South Georgia) were very interesting to me.”

Juday’s been busy since retiring from the petroleum industry 15 years ago. In 2008, she received a doctorate in soil and crop science from Colorado State, and today she sits on Longmont’s volunteer water board where she deals with many issues including hydraulic fracturing in horizontal wells.

(An epilogue: Inspired by her geology field trip to the Scotia plate – and buoyed by the latest theories in plate tectonics – Juday made the pilgrimage, in June, to Iceland.

“I was able to stand on the mid-Atlantic Ridge, for the first time, and compare and contrast it to what I had observed in Antarctica,” she said, jokingly adding that “I had all the right (winter) clothes for the trip!”)


AAPG student member Hunter Carr hails from Tyler, Texas, and he jumped at the “opportunity of a lifetime” to participate in the JSG field trip led by “a group of geologists and climatologists who have changed our understanding of the world” – even if it meant returning to the University of Georgia with the spring semester already in full swing.

One of five geology students who participated in the expedition, Carr made up for “lost” time in Antarctica, completing the summer semester and picking up a couple of missed courses. He also received one research credit for participating in the GSA geology field trip.

“The GSA field trip taught me how to observe the geology of an area because I was mostly learning from Ph.D. geologists, all specialists in their various disciplines,” Carr said. “Listening to how they approached a problem observed in outcrop was like absorbing 10 geological papers, all at once.

“I was able to see how they dissected an outcrop, discussed it amongst themselves and reached a consensus,” he said. “Within five to ten minutes, they had an outcrop completely figured out.”

In September, Carr enters the final year of his bachelor’s degree in geology. His senior thesis will investigate sulfur isotopes of a volcanogenic massive sulfide deposit, an ancient sea floor smoker in Turkey, that’s subsequently been uplifted.

“Picture yourself on the sea floor, and you have all of these sulfide metals precipitating out,” he said. The GSA geology field trip, with its emphasis on sea floor spreading and plate tectonics, inspired him to undertake this senior thesis in economic geology.

But oil and gas exploration comes as second nature to Carr, a Texan who was raised by a petroleum geologist (his father also is a member of AAPG).

“I’m going through this debate,” he said. “Should I follow the petroleum or the mining route? I guess that it really depends upon the job market when I graduate.

“Antarctica did change me,” he added. “It was such a humbling experience to see nature, life and geology in its purest form. I really discovered a passion that I don’t think most people find at my age.

“The experience lit a fire under me, to continue learning, in all aspects of life, uncovering the secrets of the world.”