Subtropical Arctic

8 September 2004

The North Pole, synonymous with all things very cold, once had a subtropical climate according to scientists now returning from the Arctic.

The international scientific team, taking part in the Integrated Ocean Drilling Program's Arctic Coring Expedition (ACEX), has discovered that prehistoric global warming meant the Arctic Ocean once was ice-free.

The scientific team from eight nations and partly funded by the Natural Environment Research Council has recovered sediment cores from nearly 400 metres below the seafloor, in waters 1300 metres deep.

One of the co-chief scientists onboard, Professor Jan Backman, Stockholm University, said, "The early history of the Arctic Basin will be re-evaluated based on the scientific results collected on this expedition."

The cores show evidence of subtropical, shallow seas in the form of tiny fossils-extinct marine plant and animals. These date back to a period known as the "Palaeocene-Eocene thermal maximum", a brief period that occurred around 55m years ago characterised by an extremely warm climate that created a natural greenhouse effect causing massive carbon input to sea and air. Scientists identified the interval through specific algae, which lived only in subtropical conditions. The algae fossils reveal that the Arctic ocean once were much warmer - around 20°C, similar to the waters around New York in August compared with today's freezing temperatures that average -1·5°C.

"We're seeing a mass extinction of sea-bottom-living organisms caused by these conditions," said palaeontologist Dr. Michael Kaminski, University College London on board the icebreaker Oden. "Moving forward in time, we see many species disappear. Only a few hardy survivors endure the thermal maximum."

Professor Backman added, "We were surprised to find fresh water conditions and periods of extreme warmth. This indicates environmental conditions were more variable than anticipated. We have now sediment records going back to 56m years, which are resting on 80m years old bedrock."

The expedition returns to Tromsø, Norway on 14 September 2004. The scientists will meet again in November at the University of Bremen, Germany, to examine the data collected. Further study will help explain the changes in the Arctic's climate, from greenhouse conditions to today's icy environment.

Further information

Albert Gerdes
University of Bremen
Tel: +49 421 218-7761 (office)
Mob: +49 172 43 77 986

Eva Grönlund
Information Officer
Swedish Polar Research Secretariat
Tel: +46 86739730 (office)
Mob: +46 703449251

Andy Kingdon
British Geological Survey
Tel: 0115 936 3415 (office)
Mob: 07779 616 602

NERC Press Office
Natural Environment Research Council
Polaris House, North Star Avenue
Swindon, SN2 1EU
Tel: 01793 411561
Mob: 07917 557215

Notes

1. Interviews can be arranged with any members of the scientific team. Please contact the NERC Press Office, Andy Kingdon or any of the contact persons above.

2. The Integrated Ocean Drilling Program (IODP) is an international scientific endeavour that supports basic research into the history of the ocean basins, the nature of climate change, the composition and structure of ocean crust and sediments and life that exists beneath the seafloor. IODP conducts technologically advanced ocean drilling expeditions which investigate regions beneath the seafloor that are inaccessible by any other technology.

3. European Consortium for Ocean Research Drilling (ECORD) represents and funds international ocean drilling at a European level. ECORD Science Operator is a group of scientific institutions which conduct drilling operations on behalf of ECORD. Coordinated by British Geological Survey, this includes University of Bremen, European Petrophysics Consortium (Universities of Leicester, Montpellier, Aachen and Amsterdam) and Swedish Polar Research Secretariat.

4. The British Geological Survey, BGS, is the world's first geological survey, formed in 1835. It is the nation's principal supplier of geoscience expertise and custodian of much of the country's geoscientific information. The BGS provides objective, impartial and up-to-date geoscientific information, advice and services which meet the needs of customers in the commercial, governmental and scientific communities of Great Britain and overseas, thereby contributing to the economic competitiveness of the country, the effectiveness of public services and policy, and quality of life.

5. NERC is the UK member of IODP. The Natural Environment Research Council (NERC) is one of the UK's research councils. It uses a budget of about £300m a year to fund and carry out impartial scientific research in the sciences of the environment. NERC trains the next generation of independent environmental scientists. It is addressing some of the key questions facing mankind such as global warming, renewable energy and sustainable economic development.

6. The $12·5m Arctic Coring Expedition (ACEX) is conducted under the auspices of the Integrated Ocean Drilling Program (IODP) by the European Consortium for Ocean Research Drilling. A consortium of European scientific institutions, ECORD Science Operator, are responsible for fleet management, ice and weather monitoring, and science operations.

More information concerning ACEX can be found at the expedition web site. A logbook with reports and pictures can also be found on this page.

Press release: 30/04

Subtropical Arctic

External links

Press links

Recent press news