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Micropaleontology at the North Pole: an Introduction

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Micropaleontology at the North Pole: an Introduction Micropaleontology at the North Pole: An introduction Michael A. Kaminski1 and Kozo Takahashi2 1Department of Earth Sciences, University College London, Gower Street, London WC1E 6BT, U.K. 2Department of Earth & Planetary Sciences, Graduate School of Sciences, Kyushu University, 812-8581, Japan The Arctic Coring Expedition (ACEX) is unequalled in the • improve knowledge of past climates and forcing functions scope of research carried out within the span of only a few • improve knowledge of evolutionary patterns of marine biota weeks. In August 2004, the first ever multi-ship drilling expe- • reconstruct the poorly-known Arctic and circum-Arctic dition to the Central Arctic provided a unique opportunity to paleogeography and paleobathymetry sample the modern Arctic Ocean and its “deep time” environ- • improve knowledge and estimates of hydrocarbon resources ments. A series of Ocean Drilling cores were drilled on the In 1999 the Ocean Drilling Program called together the Arctic Lomonosov Ridge, an aseismic ridge between Greenland and Drilling Program Planning Group and in 2000 JOIDES Arctic Siberia that represents a sliver of continental crust that rifted Detailed Planning Group, whose mandate was to draw up de- away from the Siberian Margin during the early Paleogene. tailed scientific justification and plans for an ODP expedition to The ACEX cruise was a culmination of nearly 20 years of plan- the Central Arctic. The planning group met on three occasions – ning. In 1989 and 1990 a group of scientists gathered at the in Stavanger, Calgary, and Stockholm and produced a white pa- Geological Congress and again in Bremen to draw up the scien- per on Arctic Ocean Drilling. The overall scientific goal of Arc- tific justification to take a drilling ship to the Arctic Ocean. tic drilling was to determine the paleoenvironmental evolution Known as the “Nansen Arctic Drilling Initiative”, the scientific in the Central Arctic during post-Paleocene times and to deci- objectives were published in a mission statement by Thiede et pher its role in global climatic evolution. A secondary goal was al. (1992). The stated goals of the Nansen Arctic Drilling Initia- to acquire information about the early tectonic evolution of the tive document were to: Eurasian Basin. Some of the specific scientific objectives in- • provide new data and models for predicting global change cluded determining: and its effects • the history of ice rafting and sea ice • assess potential release of greenhouse gases and dissolution • the land-sea links and the response of the Arctic to Pliocene of clathrate horizons warm events TEXT-FIGURE 1 Scientific Party and Technical teams from the drill ship Vidar Viking and the icebreaker Oden at the North Pole, August 6, 2004. This group includes what was perhaps the largest group of micropaleontologists that have ever visited the North Pole at the same time. Photo by Martin Jacobsson. micropaleontology, vol. 55, nos. 2-3, pp. 97-100, text-figures 1-3, 2009 97 Michael A. Kaminski and Kozo Takahashi: Micropaleontology at the North Pole: An introduction TEXT-FIGURE 2 The Vidar Viking on station over the Lomonosov Ridge during drilling operations. Photo by Michael A. Kaminski • the timing and consequences of the opening of the Bering We set off from Tromsø just before midnight on August 7th, and and Fram straits two days later we rendezvoused with the Murmansk-based ice- • the history of biogenic sedimentation breaker Sovietskiy Soyuz at the edge of the Polar Ice. The 75,000 hp nuclear-powered Sovietskiy Soyuz was an essential part of the operation, leading the convoy through the polar ice. The The opportunity to undertake drilling operations in the high Oden and Vidar Viking followed behind at a good pace. Arctic finally took form in the summer of 2004. The European Consortium for Ocean Drilling Research funded and organised During the transit to the Pole, there were times when the ship the first “Mission Specific Platform” operation for the IODP as slowed down enough to enable our micropaleontologists to their contribution to the programme for that year. Mission Spe- sample some of the Polar ice, using a plastic bucket tied to the cific Platform operations make use of vessels that are not pri- end of a length of rope. This was a tricky operation on a cold marily drillships. In the case of the ACEX Expedition, the and slippery deck, but some fragments of diatom-rich sea ice assembled fleet consisted of three icebreakers: the Swedish reg- made it successfully back to the lab on board the Oden. The sci- istered Vidar Viking as the coring platform and two protecting entific results of this ad-hoc undertaking are presented in this icebreakers, the Oden and the Sovietskiy Soyuz. volume (Katsuki et al.; Takahashi et al.). The Vidar Viking was a bare-decked supply vessel until it was The speed of the transit to the drill sites exceeded all expecta- converted into a drill ship by adding a moon pool and a 34 me- tions, and we took up position over the Lomonosov Ridge, ter high Seacore drilling rig in the Aberdeen shipyard. A about 240km from the North Pole on August 13th. The polar ice helideck and a stern notch were added in Sweden before the cap is in constant motion owing to wind and currents, and the ship proceeded to meet up with the Oden in Tromsø in northern Vidar Viking most of the time needed to steam ahead at half a Norway, where the scientific party and support crews boarded knot or more just to maintain position (text-fig. 2). This meant a the ships. The Oden had been newly fitted with a purpose-built continuous and active ice-breaking and monitoring operation laboratory on the front deck of the ship, and this new addition had to be maintained during coring. The Sovietskiy Soyuz took became home for the shipboard Micropaleontologists and up lead position cutting through the most difficult ice, while the Sedimentologists for the duration of the expedition. Oden did figure-8’s in front of the Vidar Viking to break up the 98 Micropaleontology, vol. 55, nos. 2-3, 2009 TEXT-FIGURE 3 Icebreaking operations on station over the Lomonosov Ridge. The Sovietskiy Soyuz acts as the leading vessel, while the icebreaker Oden clears ice from the path of the Vidar Viking. Photo by Martin Jacobsson. ice further and push it out of the way of the drill ship. Some of Maytag Repairman. This unfortunately meant that no biogenic the most iconic images from the expedition were taken from the carbonate was available for studies of plankton evolution or ship’s helicopter and show the three ships breaking ice (text- paleoclimatic proxies. Nevertheless, the Cenozoic sediments figure 3). on the Lomonosov Ridge yielded a number of very exciting findings, many of which are published in this volume. Scientists and samples were ferried back and forth between the Vidar Viking and Oden by helicopter, and the shipboard With the initial drilling objectives now completed, we pulled up micropaleontologists received a regular stream of core-catcher the drill stem on September 6th, refuelled the Vidar Viking, and samples at the beginning of each shift. Samples were first de- made preparations for the transit back to Tromsø. Because we scribed lithologically, then subdivided between the Micro- had saved some time during the initial transit, the Captain of the paleontologists and Sedimentologists for lithological analysis Oden made the very popular decision to make a slight detour in of smear slides, calcareous nannofossils, siliceous microfossils, our return voyage and stop the ship at the North Pole. Thus, af- palynology, and foraminifera. ter a champagne reception on the bridge of the Oden, the 10 micropaleontologists and the ship’s company were able to dis- Drilling operations on the Lomonosov Ridge lasted 16 days, embark at the North Pole for a couple of hours of social activity and four holes were drilled at three sites. Ultimately, drilling and enjoy the midnight sun during the “night” of August 6/7. achieved the initial plan, and reached a maximum depth of 429 We were offered a tour of the Sovietskiy Soyuz while the Rus- meters below sea bed, penetrating the whole Cenozoic sediment sian crew of that ship visited the Oden. The group photograph of column into Cretaceous pre-rift sediments beneath the break-up the crew and scientific party of the Oden and Vidar Viking unconformity. In the process, a total of 330 metres of core were (text-fig. 1) documented the occasion, and stands in evidence collected with a recovery rate of 68% - quite an accomplish- that we likely had the greatest number of micropaleontologists ment for a location that had only been previously sampled using who had ever stood together on the North Pole at the same time. piston cores. As drilling progressed, we had a number of sur- During the transit back we met up with the Yemal, the sister ship prises – the fact that calcium carbonate was restricted to the up- of the Sovietskiy Soyuz, which was ferrying a group of tourists permost 26 meters of the sediment column meant that our to the Pole. A BBC news crew met the Oden upon its return to nannofossil specialist had about as much to do as the iconic Tromsø just before midnight on September 13, 2004. 99 Michael A. Kaminski and Kozo Takahashi: Micropaleontology at the North Pole: An introduction A unique feature of the expedition was the fact that much of the reports in the National Geographic and other popular maga- detailed scientific research was carried out by the full scientific zines, several Nature papers including the cover story of the issue party at the IODP Core repository later that year.
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