Science Current Events | Science News | Brightsurf.com
 

University of Pittsburgh Geologists Map Prehistoric Climate Changes in Canada's Yukon Territory

May 09, 2012
PITTSBURGH-Researchers at the University of Pittsburgh have joined an international group of scientists to study past climate changes in the Arctic. Comprising geologists from Pitt's Department of Geology and Planetary Science, the team has analyzed sedimentary and geochemical records of water-level changes in Rantin Lake, located in the boreal forest of Canada's southeastern Yukon Territory. The results were published online in the April issue of Journal of Paleolimnology as one of 18 articles dedicated to reconstructing Arctic lake sediments climate and environmental changes during the Holocene (about 12,000 years before present day).

"During the last 10,000 years, there have been certain times in which rapid climate change events occurred," said David Pompeani, lead author and a Pitt PhD geology student. "By analyzing Rantin Lake, we've contributed a piece of the puzzle toward mapping the timing and magnitude of these prehistoric events throughout the Arctic."

Rantin Lake is part of a watershed containing a series of small lakes hydrologically connected through groundwater flow. The regional climate is subarctic and characterized by warm, wet summers and dry, cold winters. The lake is located at 60 degrees north in the Canadian Arctic, only 30 degrees away from the North Pole, where climate change is expected to be amplified.

In July 2006, the Pitt team-including Mark Abbott, associate professor of geology and planetary science, and Byron Steinman, a former PhD geology student (now a postdoctoral researcher at Penn State University)-collected two sediment cores from the lake for analysis. The sediment cores were split and analyzed for paleoclimate proxy indicators, including geochemical composition, sedimentary structure, and macrofossil content (that which is visible without a microscope). The amount of water in a lake is directly related to its depth. Therefore, a loss in water during droughts is recorded by drop in lake levels, whereas wet periods are characterized by deep waters.

Using these proxy indicators, the researchers were able to make inferences about past variations in the balance between precipitation and evaporation in the southern Yukon. A comparison of the lake-level proxies with a previously developed fossil pollen record from the same lake found that rapid vegetation changes over the Holocene also occurred during shifts in the precipitation/evaporation balance, suggesting hydrologic conditions played an integral role in the evolution of the Yukon's ecosystem. The development of unique shallow-water sediment at the deep-water core site indicated that lake levels dropped significantly during a "megadrought" in the early Holocene.

"About 8,400 years ago, the lake almost dried out," said Pompeani. "We documented the timing of this drought and studied its transition to conditions more typical of what we observed in the late Holocene."

Pitt's study, says Pompeani, contributes to the long-term perspective on natural climate variability that is needed to understand historically unprecedented changes now occurring in the Arctic. Rapid changes in the Arctic climate system that occurred in the relatively recent past can be compared with climate models to improve the understanding of the processes responsible for such nonlinear changes.

Funding for this project was provided by the National Science Foundation.

The Holocene climate project focuses on climate records from the last 8,000 years, including two focus regions: eastern Beringia and the northwest Atlantic. For more information on the Holocene climate project, visit www.arcus.org/synthesis8k/index.php

University of Pittsburgh


Related Climate Change Current Events and Climate Change News Articles


Environmental 'tipping points' key to predicting extinctions
Researchers from North Carolina State University have created a model that mimics how differently adapted populations may respond to rapid climate change.

Underwater robot sheds new light on Antarctic sea ice
The first detailed, high-resolution 3-D maps of Antarctic sea ice have been developed using an underwater robot.

El Niño stunts children's growth in Peru
Extreme weather events, such as El Niño, can have long-lasting effects on health, according to research published in the open access journal Climate Change Responses.

New volume documents the science at the legendary snowmastodon fossil site in Colorado
Four years ago, a bulldozer operator turned over some bones during construction at Ziegler Reservoir near Snowmass Village, Colorado.

Climate Change Could Affect Future of Lake Michigan Basin
Climate change could lengthen the growing season, make soil drier and decrease winter snowpack in the Lake Michigan Basin by the turn of the century, among other hydrological effects.

Biology trumps chemistry in open ocean
Single-cell phytoplankton in the ocean are responsible for roughly half of global oxygen production, despite vast tracts of the open ocean that are devoid of life-sustaining nutrients.

CT scans of coral skeletons reveal ocean acidity increases reef erosion
Coral reefs persist in a balance between reef construction and reef breakdown. As corals grow, they construct the complex calcium carbonate framework that provides habitat for fish and other reef organisms.

Livermore Lab scientists show salinity matters when it comes to sea level changes
Using ocean observations and a large suite of climate models, Lawrence Livermore National Laboratory scientists have found that long-term salinity changes have a stronger influence on regional sea level changes than previously thought.

Time-lapse photos and synched weather data unlock Antarctic secrets
Brown researchers use remote data-gathering equipment to study long-term meteorological and geological forces at work in Antarctica. Time-lapse photography synched with weather data also helps understand natural forces on the surface of Mars.

Crops help to drive greater seasonal change in CO2 cycle
Each year in the Northern Hemisphere, levels of atmospheric carbon dioxide (CO2) drop in the summer as plants inhale, and then climb again as they exhale and decompose after their growing season.
More Climate Change Current Events and Climate Change News Articles

Climate Change: Evidence and Causes (PDF Booklet)

Climate Change: Evidence and Causes (PDF Booklet)
by National Academies Press


Climate Change: Evidence and Causes is a jointly produced publication of The US National Academy of Sciences and The Royal Society. Written by a UK-US team of leading climate scientists and reviewed by climate scientists and others, the publication is intended as a brief, readable reference document for decision makers, policy makers, educators, and other individuals seeking authoritative information on the some of the questions that continue to be asked. Climate Change makes clear what is well-established and where understanding is still developing. It echoes and builds upon the long history of climate-related work from both national academies, as well as on the newest climate-change assessment from the United Nations' Intergovernmental Panel on Climate Change. It touches on current...

This Changes Everything: Capitalism vs. The Climate

This Changes Everything: Capitalism vs. The Climate
by Naomi Klein (Author)


The most important book yet from the author of the international bestseller The Shock Doctrine, a brilliant explanation of why the climate crisis challenges us to abandon the core “free market” ideology of our time, restructure the global economy, and remake our political systems.

In short, either we embrace radical change ourselves or radical changes will be visited upon our physical world. The status quo is no longer an option.

In This Changes Everything Naomi Klein argues that climate change isn’t just another issue to be neatly filed between taxes and health care. It’s an alarm that calls us to fix an economic system that is already failing us in many ways. Klein meticulously builds the case for how massively reducing our greenhouse emissions is our best chance...

Climate Change: A Very Short Introduction (Very Short Introductions)

Climate Change: A Very Short Introduction (Very Short Introductions)
by Mark Maslin (Author)


Climate change is still, arguably, the most critical and controversial issue facing the world in the twenty-first century. Previously published as Global Warming: A Very Short Introduction, the new edition has been renamed Climate Change: A Very Short introduction, to reflect the important change in the terminology of the last decade.

In the third edition, Mark Maslin includes crucial updates from the last few years, including the results of the 2013 IPCC Fifth Assessment Report, the effects of ocean acidification, and the impact of changes to global population and health. Exploring key topics in the debate, Maslin makes sense of the complexities of climate change, from political and social issues to environmental and scientific ones. Looking at its predicated impacts, he explores...

Don't Even Think About It: Why Our Brains Are Wired to Ignore Climate Change

Don't Even Think About It: Why Our Brains Are Wired to Ignore Climate Change
by George Marshall (Author)


Most of us recognize that climate change is real, and yet we do nothing to stop it. What is this psychological mechanism that allows us to know something is true but act as if it is not? George Marshall’s search for the answers brings him face to face with Nobel Prize-winning psychologists and the activists of the Texas Tea Party; the world’s leading climate scientists and the people who denounce them; liberal environmentalists and conservative evangelicals. What he discovered is that our values, assumptions, and prejudices can take on lives of their own, gaining authority as they are shared, dividing people in their wake.

With engaging stories and drawing on years of his own research, Marshall argues that the answers do not lie in the things that make us different and drive...

Climate Change: Picturing the Science

Climate Change: Picturing the Science
by Gavin Schmidt (Author), Joshua Wolfe (Author), Jeffrey D. Sachs (Foreword)


An unprecedented union of scientific analysis and stunning photography illustrating the effects of climate change on the global ecosystem. Going beyond the headlines, this work by leading NASA climate scientist Gavin Schmidt and master photographer Joshua Wolfe illustrates as never before the ramifications of shifting climate. Photographic spreads show retreating glaciers, sinking villages in Alaska’s tundra, and drying lakes. The text follows adventurous scientists through the ice caps at the poles to the coral reefs of the tropical seas. Marshaling data spanning centuries and continents, the book sparkles with cutting-edge research and visual records, including contributions from experts on atmospheric science, oceanography, paleoclimatology, technology, politics, and the polar...

The Deliberate Corruption of Climate Science

The Deliberate Corruption of Climate Science
by Tim Ball (Author)


Dr. Tim Ball exposes the malicious misuse of climate science as it was distorted by dishonest brokers to advance the political aspirations of the progressive left.

Climate Change: What the Science Tells Us

Climate Change: What the Science Tells Us
by Charles Fletcher (Author)


Fletcher's 1st edition of "Climate Change: What the Science Tells Us" places strong emphasis on the peer-reviewed literature in reporting the impacts of climate change on the ocean, terrestrial ecosystems, the water cycle, human communities, dangerous weather patterns, and potential future Earth systems. The book offers detailed discussion of greenhouse gases, oceanic and atmospheric processes, Pleistocene and Holocene paleoclimate, the human fingerprints of climate change, modeling climate, sea level rise, climate impacts on economic sectors, and dangerous weather patterns associated with climate change.Fletcher offers the first real textbook to present the science surrounding climate change at the right level for an undergraduate student. His polished writing style makes this an...

The Thinking Person's Guide to Climate Change

The Thinking Person's Guide to Climate Change
by Robert Henson (Author)


Everybody can be a thinking person when it comes to climate change, and this book is a perfect roadmap.  Start a web search for “climate change” and the first three suggestions are “facts,” “news,” and “hoax.” The Thinking Person's Guide to Climate Change is rooted in the first, up to date on the second, and anything but the last. Produced by one of the most venerable atmospheric science organizations, it is a must-read for anyone looking for the full story on climate change.

Using global research and written with nonscientists in mind, the Guide breaks down the issues into straightforward categories: “Symptoms” covers signs such as melting ice and extreme weather, while “Science” lays out what we know and how we figured it out....

The Collapse of Western Civilization: A View from the Future

The Collapse of Western Civilization: A View from the Future
by Naomi Oreskes (Author), Erik M. Conway (Author)


The year is 2393, and the world is almost unrecognizable. Clear warnings of climate catastrophe went ignored for decades, leading to soaring temperatures, rising sea levels, widespread drought and -- finally -- the disaster now known as the Great Collapse of 2093, when the disintegration of the West Antarctica Ice Sheet led to mass migration and a complete reshuffling of the global order. Writing from the Second People's Republic of China on the 300th anniversary of the Great Collapse, a senior scholar presents a gripping and deeply disturbing account of how the children of the Enlightenment -- the political and economic elites of the so-called advanced industrial societies -- failed to act, and so brought about the collapse of Western civilization. In this haunting, provocative work of...

The Global Warming Reader: A Century of Writing About Climate Change

The Global Warming Reader: A Century of Writing About Climate Change
by Bill McKibben (Author)


Our most widely respected environmental writer brings together the essential voices on global warming, from its 19th-century discovery to the present
With the rise of extreme weather events worldwide--witness the devastation wrought by Hurricanes Sandy, Irene, and Katrina, and the sustained drought across the American West--global warming has become increasingly difficult to deny.

What is happening to our planet? And what can we do about it? The Global Warming Reader provides more than thirty-five answers to these burning questions, from more than one hundred years of engagement with the topic. Here is Elizabeth Kolbert's groundbreaking essay "The Darkening Sea," Michael Crichton's skeptical view of climate change, George Monbiot's biting indictment of those who are...

© 2014 BrightSurf.com