Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Volcanic eruptions, ancient global warming linked

27.04.2007
A team of scientists announced today confirmation of a link between massive volcanic eruptions along the east coast of Greenland and in the western British Isles about 55 million years ago and a period of global warming that raised sea surface temperatures by five degrees (Celsius) in the tropics and more than six degrees in the Arctic.

The findings were reported in this week’s edition of Science.

The study is important, experts say, because it documents the Earth’s response to the release of large amounts of greenhouse gases – carbon dioxide and methane – into the atmosphere, and definitively links a major volcanic event with a period of global warming.

"There has been evidence in the marine record of this period of global warming, and evidence in the geologic record of the eruptions at roughly the same time, but until now there has been no direct link between the two," said Robert A. Duncan, a professor in the College of Oceanic and Atmospheric Sciences at Oregon State University and one of the authors of the study.

Other authors are Michael Storey, from Roskilde University in Denmark, and Carl C. Swisher, from Rutgers University.

The Paleocene-Eocene thermal maximum, or PETM, was a period of intense warming that lasted roughly 220,000 years. In addition to the warming of sea surface waters, this event – characterized by scientists as a "planetary emergency" – also greatly increased the acidification of the world’s oceans and led to the extinction of numerous deep-sea species.

Warming periods in Earth’s history are of interest as analogs to today’s climate change, Duncan said.

The international science team was able to link the PETM with the breakup of Greenland from northern Europe through analyzing the ash layers deposited toward the end of the peak of the volcanic eruptions. Using chemical fingerprints and identical ages, they were able to positively match ash layers in east Greenland with those in marine sediments in the Atlantic Ocean.

"We think the first volcanic eruptions began about 61 million years ago and then it took another 5 million years for the mantle to weaken, the continent to thin and the molten material to rise to the surface," Duncan said. "It was like lifting a lid. The plate came apart and gave birth to the North Atlantic Ocean."

The link from the volcanism to the warming period came through correlations with the marine fossil record. Dramatic changes in the carbon-isotopic composition of the ocean, corroded plankton shells, and the extinction of some bottom-dwelling organisms characterize the PETM. This interval occurred about 300,000 years before the ash layer, at the peak of volcanic activity in east Greenland.

The scientists speculate that massive release of greenhouse gases – carbon dioxide and methane – from the "out-gassing" of the lava flows and heating of organic-rich sediments in basins along the east Greenland margin were responsible for the global warming and changes in ocean chemistry.

The breakthrough came from being able to find a marker – the ash eruption – that was distributed all over the North Atlantic, and showed up in the marine record as well, Duncan said.

The volcanic activity that took place in Greenland 55 to 61 million years ago brought up some 10 million cubic kilometers of magma from below the Earth’s surface. These lava flows can be plainly seen today in Greenland, western Scotland and the Faeroe Islands, where they cooled, leaving a layered sequence of lava flows as deep as six kilometers in some places. Duncan said the eruptions are similar in scale with the well-known Deccan Flood Basalts in India.

"They are also about 40 times as big as the Columbia River basalts in Oregon and Washington," he said.

The Columbia River basalts likely had few global impacts, but the Deccan Flood Basalts, the Siberian Traps, and the Parana Flood Basalts in South America all coincide with periods of global warming or changes in the ocean chemistry, Duncan pointed out. No conclusive links have been established, however, he added.

"Similarly large submarine volcanic events correlate with major marine anoxic events – periods of no oxygen in the deep-ocean water – which we think are triggered by high surface productivity of plankton that have responded to nutrients released into the ocean by hydrothermal activity," Duncan said.

Bob Duncan | EurekAlert!
Further information:
http://www.oregonstate.edu

More articles from Earth Sciences:

nachricht Climate satellite: Tracking methane with robust laser technology
22.06.2017 | Fraunhofer-Gesellschaft

nachricht How reliable are shells as climate archives?
21.06.2017 | Leibniz-Zentrum für Marine Tropenforschung (ZMT)

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Can we see monkeys from space? Emerging technologies to map biodiversity

An international team of scientists has proposed a new multi-disciplinary approach in which an array of new technologies will allow us to map biodiversity and the risks that wildlife is facing at the scale of whole landscapes. The findings are published in Nature Ecology and Evolution. This international research is led by the Kunming Institute of Zoology from China, University of East Anglia, University of Leicester and the Leibniz Institute for Zoo and Wildlife Research.

Using a combination of satellite and ground data, the team proposes that it is now possible to map biodiversity with an accuracy that has not been previously...

Im Focus: Climate satellite: Tracking methane with robust laser technology

Heatwaves in the Arctic, longer periods of vegetation in Europe, severe floods in West Africa – starting in 2021, scientists want to explore the emissions of the greenhouse gas methane with the German-French satellite MERLIN. This is made possible by a new robust laser system of the Fraunhofer Institute for Laser Technology ILT in Aachen, which achieves unprecedented measurement accuracy.

Methane is primarily the result of the decomposition of organic matter. The gas has a 25 times greater warming potential than carbon dioxide, but is not as...

Im Focus: How protons move through a fuel cell

Hydrogen is regarded as the energy source of the future: It is produced with solar power and can be used to generate heat and electricity in fuel cells. Empa researchers have now succeeded in decoding the movement of hydrogen ions in crystals – a key step towards more efficient energy conversion in the hydrogen industry of tomorrow.

As charge carriers, electrons and ions play the leading role in electrochemical energy storage devices and converters such as batteries and fuel cells. Proton...

Im Focus: A unique data centre for cosmological simulations

Scientists from the Excellence Cluster Universe at the Ludwig-Maximilians-Universität Munich have establised "Cosmowebportal", a unique data centre for cosmological simulations located at the Leibniz Supercomputing Centre (LRZ) of the Bavarian Academy of Sciences. The complete results of a series of large hydrodynamical cosmological simulations are available, with data volumes typically exceeding several hundred terabytes. Scientists worldwide can interactively explore these complex simulations via a web interface and directly access the results.

With current telescopes, scientists can observe our Universe’s galaxies and galaxy clusters and their distribution along an invisible cosmic web. From the...

Im Focus: Scientists develop molecular thermometer for contactless measurement using infrared light

Temperature measurements possible even on the smallest scale / Molecular ruby for use in material sciences, biology, and medicine

Chemists at Johannes Gutenberg University Mainz (JGU) in cooperation with researchers of the German Federal Institute for Materials Research and Testing (BAM)...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Plants are networkers

19.06.2017 | Event News

Digital Survival Training for Executives

13.06.2017 | Event News

Global Learning Council Summit 2017

13.06.2017 | Event News

 
Latest News

Quantum thermometer or optical refrigerator?

23.06.2017 | Physics and Astronomy

A 100-year-old physics problem has been solved at EPFL

23.06.2017 | Physics and Astronomy

Equipping form with function

23.06.2017 | Information Technology

VideoLinks
B2B-VideoLinks
More VideoLinks >>>