Core Time Travel: 40 Million Years Ago the Arctic Was Warm

STOCKHOLM, Sweden, August 31, 2004 (ENS) - The first 40 million years of Arctic climate history were recovered from beneath the Arctic seafloor by an international team last week before extreme sea ice forced their research ship to abandon its position.

The expedition left Tromso, Norway August 7 and sailed to a point above the Lomonosov Ridge in the central Arctic Ocean. After four days of working in hazardous conditions, the Integrated Ocean Drilling Program's Arctic Coring Expedition (ACEX) retrieved 272 meters (884 feet) of core.

The cores were raised from ocean depths of about 600 meters (1,950 feet), coring depths unprecedented in Arctic waters.

Shifting ice in the Central Arctic Ocean (Photo courtesy Arctic Coring Expedition)

But coring of the Arctic's first scientific borehole - located roughly 145 miles (233 kilometres) from the North Pole - was interrupted when thick, moving ice floes threatened the expedition's safety.

Even one of the world's most powerful ice breakers, the Russian Sovetskiy Soyuz, employed to protect the coring ship Vidar Viking from harsh Arctic elements, could not safeguard operations at the first coring site.

Scientists on board the Vidar Viking have examined microfossils in the retrieved core. Initial analyses suggest that some of the material in the core's sediments could be 40 million years old, originating in the Middle Eocene period.

The expedition's co-chief scientist, Professor Jan Backman at Stockholm University's Department of Geology and Geochemistry, is thrilled to have come up from the depths with a fossil record of such a distant past.

"This is very exciting," he said. "For the first time, we are beginning to get information about the history of ice in the central Arctic Ocean."

"This core goes back to a time when there was no ice on the planet - it was too warm. It will tell us a great deal about the climate of the region. It will tell us when it changed from hot to cold, and hopefully, why."

Backman explains that in prehistoric times when the Arctic was warmer and free from ice, marine life thrived in the Arctic Ocean. The retrieved Arctic sediments will indicate the type and abundance of marine creatures that lived there back then.

Some of the sediment cores from beneath the seafloor of the Central Arctic Ocean. (Photo courtesy ACEX)

The six week ACEX project is the inaugural effort of the Integrated Ocean Drilling Program, a program of scientific discovery sponsored by 16 countries.

It is funded by the U.S. National Science Foundation, the Japanese Ministry of Education, Culture, Sports, Science and Technology, and the European Consortium for Ocean Research Drilling.

Five sites are proposed to be drilled on the ridge crest of the Lomonosov Ridge in the central Arctic Ocean, all located in international waters.

The Arctic Ocean and its marginal seas play "a fundamental role" in the global ocean/climate system, the authors say in their research proposal. "The dense cold bottom waters of most of the world's oceans, which originate in the Nordic seas, strongly influence global thermohaline circulation, driving world climate."

The permanent Arctic sea ice cover influences the distribution of fresh water on Earth. It varies both seasonally and over longer time periods and has a direct influence on global heat distribution and climate, the international scientific team states.

The complex history of this basin, which receives surface water from the North Pacific, the North Atlantic and the large rivers which drain northern Eurasia and North America, where water exists in all three phases year round, can only be studied by direct sampling of the sediments which record its history, the scientists said.

The sediment has captured a record of the development of the Fram and Bering Straits, varying fluxes of fresh water into the basin, the development of the Arctic sea ice and the history of the high latitude effects of the ancient glaciation.

This information is necessary to fully understand the climate of the Northern Hemisphere, providing a data set that complements ice and sediment cores collected at lower latitudes, the scientists said.

The expedition team now is searching for another favorable site from which to do some more coring before the expedition ends on September 19.

The program, overseen by Integrated Ocean Drilling Program Management International with offices in Sapporo, Japan, and Washington, DC, coordinates all program planning, administration, and educational outreach.

Visit the Integrated Ocean Drilling Program online at: www.iodp.org

ACEX is found at: http://www.rcom-bremen.de/English/IODP.html

Read the expedition logbook at: http://www.rcom-bremen.de/English/Expedition_Logbook.html

The European Consortium for Ocean Research Drilling represents and funds international ocean drilling at the European level.