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


Underground fungi detected from space
Just as a person's skin indicates if s/he has a healthy diet, colored satellite images of forests in the Smithsonian's Forest Global Earth Observatory (ForestGEO) indicate if a forest has a healthy diet.

As global temperatures rise, children must be central climate change debates
Rising temperatures, rising sea levels and the increasing likelihood of extreme weather will all alter children's lives and the lives of their own children.

Influence of sea-ice loss on Arctic warming is shaped by temperatures in the Pacific Ocean
Influence of sea-ice loss on Arctic warming is shaped by varying temperatures in the Pacific Ocean, new study shows

How much does groundwater contribute to sea level rise?
Groundwater extraction and other land water contribute about three times less to sea level rise than previous estimates, according to a new study published in the journal Nature Climate Change.

Demographic changes increase the risk of natural fires
In many parts of the world, grass and forest fires pose a threat to animals and humans. According to a new study from Lund University in Sweden, while climate change is likely to cause more and larger fires, in the future, more and more people will become directly affected as a result of demographic changes.

Hydropeaking extirpates river insects
Hydropower produces 19% of the world's electricity--far more than all other renewable sources combined. In the face of mounting climate-change effects, the rush to this profuse energy source is expected to continue. However, hydroelectric dams can also produce a number of environmental consequences, many of which are unrecognized or understudied.

Maryland climate and health report identifies state's vulnerabilities to climate change
As world leaders convene in Washington, DC this week for the Climate Action 2016 summit, a new report by Maryland public health leaders, the Maryland Climate and Health Profile report, details the impacts of climate change on the health of Marylanders now and in the future.

Hurricanes key to carbon uptake by forests
While hurricanes are a constant source of worry for residents of the southeastern United States, new research suggests that they have a major upside -- counteracting global warming.

Reef system with 10,000 km2 found at the Amazon River mouth
The changes that the Amazon River promotes in the tropical North Atlantic ocean water make an unfavorable environment for reef development.

Microbes make tubular microtunnels on earth and perhaps on mars
Tubular microtunnels believed to be the trace fossils formed by microbes inhabiting volcanic rock interiors have only been reported in oceanic and subglacial settings.
More Climate Change Current Events and Climate Change News Articles

Climate Change: The Facts

Climate Change: The Facts
by J.Abbot (Author), J.S. Armstrong (Author), A.Bolt (Author), R.Carter (Author), R.Darwall (Author), J.Delingpole (Author), C.Essex (Author), S.Franks (Author), K.Green (Author), D.Laframboise (Author), N.Lawson (Author), B.Lewin (Author), R.Lindzen (Author), J.Marohasy (Author), R.McKitrick (Author), P.Michaels (Author), A.Moran (Author), J.Nova (Author), G.Paltridge (Author), I.Plimer (Author), W.Soon (Author), M.Steyn (Author), A.Watts (Author), Alan Moran (Editor)


Tirelessly promoted by princes, presidents, actors and activists, "climate change" has become a dominant theme of global politics. But what's really going on as the "pause" in global warming prepares to enter its third decade? In this new anthology, leading scientists and commentators from the United States, the United Kingdom, Canada and Australia consider the climate from every angle - the science, the policy and the politics.

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: What Everyone Needs to Know®

Climate Change: What Everyone Needs to Know®
by Joseph Romm (Author)


Climate change will have a bigger impact on humanity than the Internet has had. The last decade's spate of superstorms, wildfires, heat waves, and droughts has accelerated the public discourse on this topic and lent credence to climatologist Lonnie Thomson's 2010 statement that climate change "represents a clear and present danger to civilization." In June 2015, the Pope declared that action on climate change is a moral issue.

This book offers the most up-to-date examination of climate change's foundational science, its implications for our future, and the core clean energy solutions. Alongside detailed but highly accessible descriptions of what is causing climate change, this entry in the What Everyone Needs to Know series answers questions about the practical implications of this...

The Sixth Extinction: An Unnatural History

The Sixth Extinction: An Unnatural History
by Elizabeth Kolbert (Author)


WINNER OF THE PULITZER PRIZE
ONE OF THE NEW YORK TIMES BOOK REVIEW'S 10 BEST BOOKS OF THE YEAR
A NEW YORK TIMES BESTSELLER
A NATIONAL BOOK CRITICS CIRCLE AWARD FINALISTA major book about the future of the world, blending intellectual and natural history and field reporting into a powerful account of the mass extinction unfolding before our eyes

Over the last half-billion years, there have been Five mass extinctions, when the diversity of life on earth suddenly and dramatically contracted. Scientists around the world are currently monitoring the sixth extinction, predicted to be the most devastating extinction event since the asteroid impact that wiped out the dinosaurs. This time around, the cataclysm is us. In prose that is at once frank, entertaining, and deeply...

Climate Change: The Climate Change Agenda - World Government, Carbon Taxes & Population Control (Climate Change, Global Warming, World Government)

Climate Change: The Climate Change Agenda - World Government, Carbon Taxes & Population Control (Climate Change, Global Warming, World Government)


Understand the New Global Realities of Climate Change!
☆★☆ Read this book for FREE on Kindle Unlimited - Download Now! ☆★☆
What Is Climate Change? How Did We Cause It? What is the Climate Change Agenda?
When you download Climate Change: The Climate Change Agenda - World Government, Carbon Taxes and Population Control, you’ll dive into a complex and exciting real-world adventure.
This book helps you understand the science, politics, and future projection of climate change – and how to survive it!
From Carbon Taxing to “Cap and Trade”, Climate Change: The Climate Change Agenda - World Government, Carbon Taxes and Population Control explains the political myths, realities surrounding climate change, the effects of climate change on food...

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. “Debates” tackles the...

Dire Predictions, 2nd Edition: Understanding Climate Change

Dire Predictions, 2nd Edition: Understanding Climate Change
by Michael E. Mann (Author), Lee R. Kump (Author)


Explore global warming with graphics, illustrations, and charts that separate climate change fact from fiction, presenting the truth about global warming in a way that's both accurate and easy to understand. Respected climate scientists Michael E. Mann and Lee R. Kump address important questions about global warming and climate change, diving into the information documented by the IPCC (Intergovernmental Panel on Climate Change) and breaking it down into clear graphics that explain complex climate questions in simple illustrations that present the truth of the global warming problem clearly. These experts take scientific findings about climate change and global warming and use analogies, striking images, and understandable graphics to make the global warming question clear to both...

Global Warming-Alarmists, Skeptics and Deniers: A Geoscientist Looks at the Science of Climate Change

Global Warming-Alarmists, Skeptics and Deniers: A Geoscientist Looks at the Science of Climate Change
by G. Dedrick Robinson (Author), Gene D. Robinson III (Author)


Global Warming-Alarmists, Skeptics & Deniers: A Geoscientist looks at the Science of Climate Change, brings a unique geological perspective to this politically charged issue, a perspective that has been ignored far too long. Written by a father-son team of geoscientist and attorney, it is the concise guide to the global warming controversy that has been long needed. As a university professor and research geologist for thirty years, Dr. Robinson knows that geological science is essential for placing the global warming controversy in proper prospective. One cannot hope to understand how humans might be causing climate change without an understanding of the magnitude and speed natural processed are capable of when it comes to climate change. Earth history is the only yardstick we have to...

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 yet we do nothing to stop it. What is the 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 Texas Tea Party activists; the world’s leading climate scientists and those who denounce them; liberal environmentalists and conservative evangelicals. What he discovers 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, but rather in what we share: how our human...

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...

© 2016 BrightSurf.com