Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Deciphering Arctic climate puzzles - New findings from the Arctic Coring Expedition

17.11.2004


An international team of scientists is currently evaluating sediment cores collected during the Arctic Coring Expedition, ACEX, conducted under the auspices of the Integrated Ocean Drilling Program (IODP). ACEX, conducted in August and September this year, is an exploration success story. At a press conference in the University of Bremen, Germany, today (16 November 2004) the co-chief scientists of the expedition described the first results from this expedition.



Scientists from ten countries gathered in Bremen over the last two weeks. They analyzed sediment cores from 430 metres beneath the Arctic Ocean sea-floor. These cores reveal new insights into the past climate of the Arctic. Preliminary results show that the ACEX recovered the first ever climate record of the Arctic Ocean over the past 56 million years. Co-chief scientists Kate Moran, University of Rhode Island, and Jan Backman, Stockholm University, described key findings.

The Arctic Ocean was frozen much earlier than previoulsy thought. Professor Moran said that “we are trying to define the exact time when ice appeared but it seems clear that perennial ice existed as early as 15 million years ago”. Professor Jan Backman added that these results would become more precise over the next few months and “we have cores that will hopefully allow us to distinguish between seasonal (winter only) ice and perennial ice”.


Initial offshore results indicate that the upper hundred and sixty meters represent a record of the past ~15 million years comprised of sediment with ice-rafted debris and occasional small pebbles, suggesting that ice covered conditions extended at least this far back in time. Details of the ice cover, timing and characteristic (e.g., perennial vs. seasonal cover) awaits further study.

The sediment record during the late Eocene is of dark, organic-rich siliceous composition with a depositional environment dominated by ice-free, warmer surface ocean waters. An interval recovered around 49 million years ago reveals an abundance of a freshwater fern (Azolla spp.) suggesting that a surface fresh/low salinity water setting dominated the region during this time period. Although predictions had placed the base of the sediment column at 50 million years, drilling revealed that the latest Paleocene to earliest Eocene boundary interval was recovered. During this time, about 55 million years ago, the Arctic was subtropical with warm surface ocean temperatures.

ACEX also penetrated into the underlying sedimentary bedrock, confirming the hypothesis that the Lomonosov Ridge crust is of shallow-water, continental origin and of Cretaceous age.

Professor Jan Backman described operating in this challenging environment: “At times, the drillsite was covered with ice 2-3 metres thick. At one point we encountered an ice flow of multiyear ice (harder and denser than ice frozen only in one Arctic winter) hundred of metres across and over 4 metres thick which was like driving into a brick wall.” But, with the aid of the three ice-breaking vessels the coring operations were successfully completed. The scientists will take home samples and will undertake further investigations during the next months – with more exciting results to come.

Eva Grönlund | alfa
Further information:
http://www.iodp.de
http://www.polar.se

More articles from Earth Sciences:

nachricht NASA finds newly formed tropical storm lan over open waters
17.10.2017 | NASA/Goddard Space Flight Center

nachricht The melting ice makes the sea around Greenland less saline
16.10.2017 | Aarhus University

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Neutron star merger directly observed for the first time

University of Maryland researchers contribute to historic detection of gravitational waves and light created by event

On August 17, 2017, at 12:41:04 UTC, scientists made the first direct observation of a merger between two neutron stars--the dense, collapsed cores that remain...

Im Focus: Breaking: the first light from two neutron stars merging

Seven new papers describe the first-ever detection of light from a gravitational wave source. The event, caused by two neutron stars colliding and merging together, was dubbed GW170817 because it sent ripples through space-time that reached Earth on 2017 August 17. Around the world, hundreds of excited astronomers mobilized quickly and were able to observe the event using numerous telescopes, providing a wealth of new data.

Previous detections of gravitational waves have all involved the merger of two black holes, a feat that won the 2017 Nobel Prize in Physics earlier this month....

Im Focus: Smart sensors for efficient processes

Material defects in end products can quickly result in failures in many areas of industry, and have a massive impact on the safe use of their products. This is why, in the field of quality assurance, intelligent, nondestructive sensor systems play a key role. They allow testing components and parts in a rapid and cost-efficient manner without destroying the actual product or changing its surface. Experts from the Fraunhofer IZFP in Saarbrücken will be presenting two exhibits at the Blechexpo in Stuttgart from 7–10 November 2017 that allow fast, reliable, and automated characterization of materials and detection of defects (Hall 5, Booth 5306).

When quality testing uses time-consuming destructive test methods, it can result in enormous costs due to damaging or destroying the products. And given that...

Im Focus: Cold molecules on collision course

Using a new cooling technique MPQ scientists succeed at observing collisions in a dense beam of cold and slow dipolar molecules.

How do chemical reactions proceed at extremely low temperatures? The answer requires the investigation of molecular samples that are cold, dense, and slow at...

Im Focus: Shrinking the proton again!

Scientists from the Max Planck Institute of Quantum Optics, using high precision laser spectroscopy of atomic hydrogen, confirm the surprisingly small value of the proton radius determined from muonic hydrogen.

It was one of the breakthroughs of the year 2010: Laser spectroscopy of muonic hydrogen resulted in a value for the proton charge radius that was significantly...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ASEAN Member States discuss the future role of renewable energy

17.10.2017 | Event News

World Health Summit 2017: International experts set the course for the future of Global Health

10.10.2017 | Event News

Climate Engineering Conference 2017 Opens in Berlin

10.10.2017 | Event News

 
Latest News

Los Alamos researchers and supercomputers help interpret the latest LIGO findings

18.10.2017 | Physics and Astronomy

Study shows how water could have flowed on 'cold and icy' ancient Mars

18.10.2017 | Physics and Astronomy

Navigational view of the brain thanks to powerful X-rays

18.10.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>