Expanding the Cenozoic paleoceanographic record in the Central Arctic Ocean: IODP Expedition 302 Synthesis

Backman, Jan; Moran, Kathryn

doi:10.2478/v10085-009-0015-6

Cited by 41 publications

(43 citation statements)

References 93 publications

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“…It was only in 2004, when the Integrated Ocean Drilling Program (IODP) Expedition 302, the Arctic Coring Expedition (ACEX), retrieved the first long drill core from the central Arctic Ocean, that proposed tectonic models with palaeoceanographic implications could be compared with geological ground truth ). The 428 m long sediment record retrieved from the Lomonosov Ridge unveiled a range of novel results (e.g., Brinkhuis et al 2006;Moran et al 2006;Pagani et al 2006;Jakobsson et al 2007;Haley et al 2008;Backman & Moran 2009). One of these results suggests that the Arctic Ocean transformed from a poorly oxygenated ''lake stage'' to a fully oxygenated ''ocean stage'' during late early Miocene (17.5 Mya; Jakobsson et al 2007).…”

Section: Introductionmentioning

confidence: 94%

A model study of the first ventilated regime of the Arctic Ocean during the early Miocene

Thompson¹,

Nilsson²,

Nycander³

et al. 2012

Polar Research

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The tectonic opening of Fram Strait during the Neogene was a significant geological event that transferred the Arctic Ocean from a poorly ventilated enclosed basin, with weak exchange with the North Atlantic, to a fully ventilated “ocean stage”. Previous tectonic and physical oceanographic analyses suggest that the early Miocene Fram Strait was likely several times narrower and less than half as deep as the present-day 400 km wide and 2550 m deep strait. Here we use an ocean general circulation model with a passive age tracer included to further address the effect of the Fram Strait opening on the early Miocene Arctic Ocean circulation. The model tracer age exhibits strong spatial gradient between the two major Arctic Ocean deep basins: the Eurasian and Amerasian basins. There is a two-layer stratification and the exchange flow through Fram Strait shows a bi-layer structure with a low salinity outflow from the Arctic confined to a relatively thin upper layer and a saline inflow from the North Atlantic below. Our study suggests that although Fram Strait was significantly narrower and shallower during early Miocene, and the ventilation mechanism quite different in our model, the estimated ventilation rates are comparable to the chemical tracer estimates in the present-day Arctic Ocean. Since we achieved ventilation of the Arctic Ocean with a prescribed Fram Strait width of 100 km and sill depth of 1000 m, ventilation may have preceded the timing of a full ocean depth connection between the Arctic Ocean and North Atlantic established through seafloor spreading and the development of the Lena Trough

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Section: Introductionmentioning

confidence: 94%

A model study of the first ventilated regime of the Arctic Ocean during the early Miocene

Thompson¹,

Nilsson²,

Nycander³

et al. 2012

Polar Research

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“…The Integrated Ocean Drilling Program (IODP) Arctic Coring Expedition (ACEX), drilled a 428 m long sediment record from the Lomonosov Ridge in the central Arctic Ocean (Backman and Moran, 2009) (Fig. 1).…”

Section: Arctic Ocean Sea Icementioning

confidence: 99%

New insights on Arctic Quaternary climate variability from palaeo-records and numerical modelling

Jakobsson

Long

Inǵólfsson

et al. 2010

Quaternary Science Reviews

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a b s t r a c tTerrestrial and marine geological archives in the Arctic contain information on environmental change through Quaternary interglacialeglacial cycles. The Arctic Palaeoclimate and its Extremes (APEX) scientific network aims to better understand the magnitude and frequency of past Arctic climate variability, with focus on the "extreme" versus the "normal" conditions of the climate system. One important motivation for studying the amplitude of past natural environmental changes in the Arctic is to better understand the role of this region in a global perspective and provide base-line conditions against which to explore potential future changes in Arctic climate under scenarios of global warming. In this review we identify several areas that are distinct to the present programme and highlight some recent advances presented in this special issue concerning Arctic palaeo-records and natural variability, including spatial and temporal variability of the Greenland Ice Sheet, Arctic Ocean sediment stratigraphy, past ice shelves and marginal marine ice sheets, and the Cenozoic history of Arctic Ocean sea ice in general and Holocene oscillations in sea ice concentrations in particular. The combined sea ice data suggest that the seasonal Arctic sea ice cover was strongly reduced during most of the early Holocene and there appear to have been periods of ice free summers in the central Arctic Ocean. This has important consequences for our understanding of the recent trend of declining sea ice, and calls for further research on causal links between Arctic climate and sea ice.

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“…Ryan et al, 2009). Observed sulfatemethane transitions during the MITAS 1 expedition shown in black diamonds (Coffin et al, 2013) and Arctic Coring Expedition (ACEX) shown as red squares (Backman and Moran, 2009). …”

Section: East Siberian Margin Geologymentioning

confidence: 99%

“…So far, no deep drilling has occurred along SNESS. However, the 2004 Arctic Coring Expedition (ACEX; Backman et al, 2009) drilled and cored the central Lomonosov Ridge (Fig. 1).…”

Section: Current Speculation On Gas Hydrates In the Arcticmentioning

confidence: 99%

“…Arctic slopes may contain high POC contents, which accumulated (a) in shallow platform environments prior to the opening of the Amerasian Basin, (Spencer et al, 2011) (b) during periods of high surface water productivity and oxygen poor bottom water conditions that persisted across much of the Arctic un- til the opening of the Fram Strait in the Neogene (Jakobsson et al, 2007;Stein et al, 2006;O'Regan et al, 2011;Jokat and Ickrath, 2015), or (c) as terrigenous material carried to or deposited along the slopes during interglacial intervals of the Quaternary (Danyushevskaya et al, 1980;Darby et al, 1989;Archer, 2015). Certainly, organic-rich Cretaceous and Eocene sediments have been documented on other Arctic margins and in the ACEX cores on the Lomonosov Ridge (Moran et al, 2006;Backman and Moran, 2009;O'Regan et al, 2011). The second reason is that the thickness of the gas hydrate stability zone depends on bottom water temperature and the geothermal gradient (Dickens, 2001).…”

Section: Current Speculation On Gas Hydrates In the Arcticmentioning

confidence: 99%

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Pore water geochemistry along continental slopes north of the East Siberian Sea: inference of low methane concentrations

et al. 2017

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Abstract. Continental slopes north of the East Siberian Sea potentially hold large amounts of methane (CH 4 ) in sediments as gas hydrate and free gas. Although release of this CH 4 to the ocean and atmosphere has become a topic of discussion, the region remains sparingly explored. Here we present pore water chemistry results from 32 sediment cores taken during Leg 2 of the 2014 joint Swedish-Russian-US Arctic Ocean Investigation of Climate-Cryosphere-Carbon Interactions (SWERUS-C3) expedition. The cores come from depth transects across the slope and rise extending between the Mendeleev and the Lomonosov ridges, north of Wrangel Island and the New Siberian Islands, respectively. Upward CH 4 flux towards the seafloor, as inferred from profiles of dissolved sulfate (SO 2− 4 ), alkalinity, and the δ 13 C of dissolved inorganic carbon (DIC), is negligible at all stations east of 143 • E longitude. In the upper 8 m of these cores, downward SO 2− 4 flux never exceeds 6.2 mol m −2 kyr −1 , the upward alkalinity flux never exceeds 6.8 mol m −2 kyr −1 , and δ 13 C composition of DIC (δ 13 C-DIC) only moderately decreases with depth (−3.6 ‰ m −1 on average). Moreover, upon addition of Zn acetate to pore water samples, ZnS did not precipitate, indicating a lack of dissolved H 2 S. Phosphate, ammonium, and metal profiles reveal that metal oxide reduction by organic carbon dominates the geochemical environment and supports very low organic carbon turnover rates. A single core on the Lomonosov Ridge differs, as diffusive fluxes for SO 2− 4 and alkalinity were 13.9 and 11.3 mol m −2 kyr −1 , respectively, the δ 13 C-DIC gradient was 5.6 ‰ m −1 , and Mn 2+ reduction terminated within 1.3 m of the seafloor. These are among the first pore water results generated from this vast climatically sensitive region, and they imply that abundant CH 4 , including gas hydrates, do not characterize the East Siberian Sea slope or rise along the investigated depth transects. This contradicts previous modeling and discussions, which due to the lack of data are almost entirely based on assumption.

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Expanding the Cenozoic paleoceanographic record in the Central Arctic Ocean: IODP Expedition 302 Synthesis

Cited by 41 publications

References 93 publications

A model study of the first ventilated regime of the Arctic Ocean during the early Miocene

A model study of the first ventilated regime of the Arctic Ocean during the early Miocene

New insights on Arctic Quaternary climate variability from palaeo-records and numerical modelling

Pore water geochemistry along continental slopes north of the East Siberian Sea: inference of low methane concentrations

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