Personnel Arctic Logistics Arctic Flora & Fauna Resolute Bay Camp I: Dragon Creek,    Axel Heiberg       ï Expedition Fiord Region       ï Agate Fiord Region Camp II: Blackwelder Mtns,    Ellesmere Island Camp III: Audhild Bay,    Ellesmere Island       ï Hansen Point Region Sponsors & Links

Why an expedition to the High Canadian Arctic?

During the summer of 2000, Professor John Tarduno, Post-Doctoral Researcher Rory Cottrell and five students conducted geological studies on Axel Heiberg and Ellesmere Islands.   This expedition, the forth of its kind from the University of Rochester, involved collecting rock and fossil samples for analysis in the Paleomagnetic Laboratory of the University of Rochester (New York, USA).    We hope to use these samples to understand the processes that caused climate change in the Arctic region between 200 and 65 million years ago.   Our field work lasted approximately one month (July 2000). 

Our main focus was the collection of samples for "paleomagnetic" analysis.   The direction of the ancient Earth's magnetic field is recorded in a rock when it forms.   We can measure this ancient direction using highly sensitive magnetometers, such as those at the University of Rochester.   In the past, the poles of the Earth's magnetic field have flipped, or reversed, at infrequent intervals. Therefore, if a rock formed when the magnetic field was reversed, the ancient direction we measure in it today will point toward the South pole.   We can use this characteristic (whether the ancient magnetic direction points to the North or South pole) to determine the age of a rock. 

To obtain samples for "paleomagnetic" analysis, we drill small one inch cores into the bedrock using portable drills.   Next, the present-day orientation of a sample is recorded using a "Sun compass" (which tells us the direction of the sun at a given time relative to the sample).   These measurements allow us to relate any further magnetic analyses done on the rock to the rock's original orientation in the Arctic.    We must use a sun compass instead of a conventional magnetic compass because our field area is very close to the present magnetic north pole, and, as a result, there are drastic fluctuations in the daily magnetic field in this area.

Rock samples were collected in the Blackwelder Mountains (Camp II) and near the south shore of Audhild Bay (Camp III), both on Ellesmere Island.   At each locality, we hope the sequence of magnetic directions will allow us to determine precisely the age of the rocks.    Preliminary laboratory results confirm that these rocks to carry a characteristic remanent magnetization needed for dating purposes.   The rocks from which these samples were taken are important because they indicate that in the past (about 135 million years ago) the climate in the Arctic changed from being very warm to relatively cold.   Climate changes can be preserved in rocks in several ways that can be read by geologists.   One way is in the type of fossils rocks contain.   For example, we have previously discovered fossil reptiles in Arctic rocks that suggest extremely warm past climates (Camp I: Expedition Fiord).   Another way is in the type of "sedimentary" structures that make up the rock.    Some of structures in the rocks we collected in 2000 indicate cool conditions, where freezing would have been common. We would ultimately like to know why and how the Earth changed between these "warm" and "cool" states. 

The first step in this work, however, is to determine the precise age of the rocks.   With this age information, we can compare the Arctic rocks with rocks formed at the same time at different places on the Earth.   This comparison allows us to learn what the climate was like elsewhere on the Earth when the climate was changing in the Arctic region and can help us determine whether or not the Arctic climate change is a global or regional event.   These comparisons can help us identify the processes that caused the climate to change (for example, changes in carbon dioxide levels in the atmosphere or changes in oceanic currents that distribute heat throughout the planet.) 

At the same time that we are analyzing the magnetic directions preserved in the rocks, we are also investigating the magnetic mineral grains they contain.   Magnetic directions are recorded by tiny iron-rich minerals (known as magnetite grains) that are either present when or form while a rock forms.   Unfortunately, sometimes other iron-bearing minerals can form much later than the original formation of the rock.    These minerals (hematite, for example), can record a "false" magnetization, which differs greatly from the "primary" magnetic signal that is useful for determining a rock's true age.   Therefore, we also spend a considerable amount of time determining the type of magnetic minerals that are in a given rock sample.   This is done through visual analysis using high-powered microscopes, and with magnetic tests, since different magnetic minerals have different magnetic properties. 

At present, our paleomagnetic laboratory analysis is in its beginning stages. We know that some of the rocks we collected in 2000 do preserve a magnetic signal which will be useful for determining the rock age.   We have been able measure the weak signals using our laboratory magnetometers, and to further analyze the magnetic directions using computer workstations.   These data will be used to guide the future sampling that will be needed to complete our study. 
 
 

Professor, students trek to Arctic to study climate. 

Emily Brandon, Campus Times Staff   February 8, 2001

While many college students were getting a tan last summer, Professor of Earth and Environmental Sciences John Tarduno and his students were trekking through the snow of the Arctic region in the name of science.   This was the fourth in a series of expeditions to the high Canadian Arctic to collect geological samples and chart the unexplored wilderness in order to better understand the geological history of North America.

The trip, from July 4 to August 3, focused on studying the volcanic, tectonic and paleoclimatic evolution of the Arctic region from about 140 to 80 million years ago.   ìWe believe volcanism and tectonics, the motion of the Earthís plates and mountain building events, are intimately related to Earthís climate,î said Tarduno, who is also chair of the department.

Support from the National Science Foundation and the National Geographic Society allowed the undergraduates to take part in the expedition.   They participated in scientific collection and learned basic field techniques.   This year, Take-5 Scholar Matt Polizzatto, junior Matt Friedman, and sophomores Santo Marciano and Allyson OíKane journeyed to the Arctic along with teaching assistant Peter Lippert and postdoctoral fellow Rory Cottrell.   ìThis expedition gave me the chance to learn some of the basics of field geology, something that will likely come in very handy in the future,î Friedman said.   ìAlso, I enjoyed just being there and living for nearly a month out of a tent in the  Arctic.î

Because of the gradient between the equator and the poles of the earth, the Arctic is an ideal place to study paleoclimateó it is extremely sensitive to global change.   The researchers found evidence that the Arctic was not always the temperature that it is today.   At one location they found vertebrate fossils of dinosaurs and turtles, which suggest that the Arctic once had a climate similar to that of Florida today.   But in other rocks they found ice accumulation in mountainous regions, suggesting that the Arctic used to be much colder than it is now.

The weather was exceptionally good on this trip compared to past years, which allowed them to establish camps at much higher latitudes, going as far as 81.5 degrees north on Ellesmere Island.   Normally, this area is shrouded in fog or snow, which does not allow people to camp and work there or see sights such as Axel Heiberg Island, Nansen Sound and the Arctic Ocean sea ice beyond.

Tarduno and his team found a series of ammonites that will help them to determine the age of some of the rock formations.   They also found a series of lava flows at their highest latitude camp.   This lava has the potential to help them unravel the processes responsible for the anomalous rates of volcanic activity seen in the Arctic.

ìThe Arctic is a key area for understanding past climate change,î Tarduno said.   ìThis, together with the realization that you are working in an area where few or perhaps no people have visited previously, brings excitement to the research.î

Lippert agrees.   ìWhen I thought about the Arctic, I thought of hundreds of miles of snow and ice and bitter cold temperatures,î he said after his second trip to the Arctic.   ìThere was plenty of snow and it got very cold at times, but I discovered that the Arctic is a beautiful landscape of rugged mountains, glaciers and tundra.î

Lippert said he would jump at the chance to go to the Arctic again, but advises that it is not for everyone:  ìAn expedition thousands of miles from any real form of civilization is rigorous, the hours are long and hard and the weather can make or break it.   But if this sounds like it appeals to you, definitely try to do such a thing.î