Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Arctic Coring Expedition Continues to Yield New Clues About Climate Change

11.08.2006
For the second time in as many months, the IODP Arctic Coring Expedition (ACEX) is making news with new analysis of ocean-floor sediments. In the Aug. 10 issue of Nature, an article authored by several of the expedition scientists summarizes their findings: more evidence that the Arctic was extremely warm, unusually wet, and ice-free up to the time the last massive amounts of greenhouse gases were released into the Earth's atmosphere – a period calculated to have occurred 55 million years ago, and known as the Paleocene/Eocene thermal maximum, or PETM.

Researchers have long recognized that a massive release of greenhouse gases, probably carbon dioxide or methane, occurred during the PETM. Surface temperatures also rose in many places by as much as 15 degrees Fahrenheit in the (relative) geological instant of about 100,000 years.

Arctic sediment samples were largely unavailable until 2004, when ACEX scientists recovered the first deep-ocean sediment samples from beneath the ice-laden waters near the North Pole. ACEX, only the second scientific expedition to be conducted by the Integrated Ocean Drilling Program (established in late 2003), recovered 339 meters of subseafloor sediment samples.

"Building a picture of ancient climatic events is a lot like putting together a jigsaw puzzle, and what ACEX allowed us to do was fill in a blank section of the PETM picture," said Gerald Dickens, a Rice University geochemist and co-author, who conducted the initial, shipboard chemical analyses of all the ACEX core samples.

"The ACEX cores clearly show that the Arctic got very warm and wet during the PETM," Dickens said. "Even tropical marine plants thrived in the balmy conditions."

In today's oceans, certain species of microscopic plants are known to rapidly multiply and create algal blooms. Dickens said that fossils of these plants – known only to originate in the tropics before the PETM – are commonly seen in the ACEX cores. Furthermore, the chemistry of the organic carbon in the ACEX cores may rule out some earlier theories about what caused the PETM. The diminution of these alternate explanations strongly suggests that an enormous amount of carbon entered the atmosphere at the beginning of the PETM, either from volcanic eruptions or the melting of oceanic gas hydrates – mixtures of methane and ice on the seafloor.

ACEX co-authors include Mark Pagani and Nikolai Pedentchouk of Yale University, Matthew Huber of Purdue University, Appy Sluijs and Henk Brinkhuis of Utrecht University (Netherlands), and Stefan Schouten and Jaap Sinninghe Damsté of the Royal Netherlands Institute for Sea Research.

The ACEX expedition was an operation of the Integrated Ocean Drilling Program (IODP), an international marine research program primarily funded by the National Science Foundation, and Japan’s Ministry of Education, Culture, Sports, Science and Technology. The Arctic Coring Expedition was led by the European Consortium on Ocean Research Drilling (ECORD), an IODP contributing member that represents 17 nations. ECORD is responsible for managing all IODP mission-specific operations, i.e. scientific expeditions conducted in unusual or demanding environments in which specific platform requirements must be used to meet specific science objectives. In all, 21 countries participate in IODP.

Nancy Light | EurekAlert!
Further information:
http://www.iodp.org

More articles from Earth Sciences:

nachricht Diving robots find Antarctic winter seas exhale surprising amounts of carbon dioxide
15.08.2018 | University of Washington

nachricht Algorithm provides early warning system for tracking groundwater contamination
14.08.2018 | DOE/Lawrence Berkeley National Laboratory

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Unraveling the nature of 'whistlers' from space in the lab

A new study sheds light on how ultralow frequency radio waves and plasmas interact

Scientists at the University of California, Los Angeles present new research on a curious cosmic phenomenon known as "whistlers" -- very low frequency packets...

Im Focus: New interactive machine learning tool makes car designs more aerodynamic

Scientists develop first tool to use machine learning methods to compute flow around interactively designable 3D objects. Tool will be presented at this year’s prestigious SIGGRAPH conference.

When engineers or designers want to test the aerodynamic properties of the newly designed shape of a car, airplane, or other object, they would normally model...

Im Focus: Robots as 'pump attendants': TU Graz develops robot-controlled rapid charging system for e-vehicles

Researchers from TU Graz and their industry partners have unveiled a world first: the prototype of a robot-controlled, high-speed combined charging system (CCS) for electric vehicles that enables series charging of cars in various parking positions.

Global demand for electric vehicles is forecast to rise sharply: by 2025, the number of new vehicle registrations is expected to reach 25 million per year....

Im Focus: The “TRiC” to folding actin

Proteins must be folded correctly to fulfill their molecular functions in cells. Molecular assistants called chaperones help proteins exploit their inbuilt folding potential and reach the correct three-dimensional structure. Researchers at the Max Planck Institute of Biochemistry (MPIB) have demonstrated that actin, the most abundant protein in higher developed cells, does not have the inbuilt potential to fold and instead requires special assistance to fold into its active state. The chaperone TRiC uses a previously undescribed mechanism to perform actin folding. The study was recently published in the journal Cell.

Actin is the most abundant protein in highly developed cells and has diverse functions in processes like cell stabilization, cell division and muscle...

Im Focus: Lining up surprising behaviors of superconductor with one of the world's strongest magnets

Scientists have discovered that the electrical resistance of a copper-oxide compound depends on the magnetic field in a very unusual way -- a finding that could help direct the search for materials that can perfectly conduct electricity at room temperatur

What happens when really powerful magnets--capable of producing magnetic fields nearly two million times stronger than Earth's--are applied to materials that...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Within reach of the Universe

08.08.2018 | Event News

A journey through the history of microscopy – new exhibition opens at the MDC

27.07.2018 | Event News

2018 Work Research Conference

25.07.2018 | Event News

 
Latest News

Unraveling the nature of 'whistlers' from space in the lab

15.08.2018 | Physics and Astronomy

Diving robots find Antarctic winter seas exhale surprising amounts of carbon dioxide

15.08.2018 | Earth Sciences

Early opaque universe linked to galaxy scarcity

15.08.2018 | Physics and Astronomy

VideoLinks
Science & Research
Overview of more VideoLinks >>>