Pliocene glacial cyclicity in a deep-sea sediment drift (Antarctic Peninsula Pacific Margin)

Hepp, Daniel A.; Mörz, Tobias; Grützner, Jens

doi:10.1016/j.palaeo.2005.07.030

Cited by 47 publications

(59 citation statements)

References 36 publications

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“…Although microfossil assemblages found in the ODP Leg 178 drift sediments show no evidence of significantly warmer surface water temperatures than today (Hillenbrand and Fütterer, 2002), Hepp et al (2006) have suggested open ocean conditions in the warm Early Pliocene, even during glacials. In addition, diatom evidence from ODP site 1165 (in the Southern Ocean at 64.384°S) reported by Whitehead and Bohaty (2003) gives MATs at 4°C.…”

Section: Southern Ocean and Sea Icementioning

confidence: 83%

Climate and environment of a Pliocene warm world

Salzmann

Williams

Haywood

et al. 2011

Palaeogeography, Palaeoclimatology, Palaeoecology

146

100

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The Pliocene Epoch, 5.33 -2.58 million years ago (Ma), was a generally warmer and wetter interval with atmospheric CO 2 -concentrations at or slightly above modern levels. This paper provides an overview of Pliocene vegetation, sea surface temperatures and climate modelling outcomes.. Most prominent changes in Pliocene biome distribution compared to today include a northwards shift of temperate and boreal vegetation zones in response to a warmer and wetter climate as well as an expansion of tropical savannas and forests at the expense of deserts. Modelling experiments using the Hadley Centre climate model identified significantly higher Pliocene sea surface temperatures at the high-latitudes with only minor warming predicted in the tropics. Global mean annual surface temperatures (MAT) are estimated to have been 2 to 3ºC higher during the Piacenzian (3.6-2.58 Ma) than today with a reduced equator to pole gradient. The marine realm during the Pliocene was characterised by a reconfiguration of ocean gateways, particularly the narrowing of the Indonesian Seaway and closure of the Central American Isthmus, which produced essentially a modern pattern of ocean circulation. In the Southern Ocean a warm early Pliocene gave way to late Piacenzian cooling. Proxy data indicate a reduced east to west sea surface temperature gradient in the tropical Pacific during the Pliocene warmth. The Pliocene is one of the most intensively studied geological intervals of the pre-Quaternary. No other warm period in the geological past yields such a unique combination of near modern atmospheric CO 2 -concentrations, palaeogeography and palaeobiology. However, this paper also identifies data gaps and shortcomings in the reconstruction of Pliocene environments using proxy data and climate models on which future research should focus.

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Section: Southern Ocean and Sea Icementioning

confidence: 83%

Climate and environment of a Pliocene warm world

Salzmann

Williams

Haywood

et al. 2011

Palaeogeography, Palaeoclimatology, Palaeoecology

146

100

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“…The XRF core scanner allows nondestructive, nearly continuous, and relatively fast analysis of the elements from Aluminum (Al, atomic number 13) through to Uranium (U, atomic number 92) [Richter et al, 2006]. Detailed XRF core scans have already successfully been used for high-resolution time series, stratigraphic correlations, and detailed sedimentary and climatic reconstructions on various timescales [e.g., Haug et al, 2001;Lamy et al, 2001;Röhl et al, 2001;Kuhlmann et al, 2004;Bahr et al, 2005;Grützner et al, 2005;Hepp et al, 2006;Jaccard et al, 2005;Westerhold et al, 2005].…”

Section: Introductionmentioning

confidence: 99%

Influence of the water content on X‐ray fluorescence core‐scanning measurements in soft marine sediments

Tjallingii

Röhl

Kölling

et al. 2007

Geochem Geophys Geosyst

369

337

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[1] The X-ray fluorescence (XRF) core scanner provides bulk-sediment chemistry data measured nondestructively at the split core sediment surface. Although this method is widely accepted, there is little known about the effects of physical properties such as density and water content on XRF core scanner data. Comparison of XRF scanner measurements from the sediment surface and dry powder samples of sediment core GeoB7920 indicates strongly reduced element intensities for the lighter elements Al and Si. We relate the lower element intensities of the measurements taken at the sediment surface to the amount of water in the sample volume analyzed by the XRF core scanner. The heavier elements K, Ca, Ti, and Fe remain relatively unaffected by the variation of any physical property within sediment core GeoB7920. Additionally, we successfully use the elemental intensity of Cl as a proxy for the seawater content in the sample volume analyzed by the XRF core scanner. This enables the establishment of a correction function for the elements Al and Si that corrects for the radiation absorption of the water content in sediment core GeoB7920 off Cape Blanc, NW Africa.

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“…Indeed, results from SHALDRIL cores and other data from the eastern Antarctic Peninsula shelf indicate progressive cooling and associated decline in vegetation over the past 37 My, culminating in early Pliocene ice sheet expansion onto the continental shelf . Results from Leg 178 cores from the western Antarctic Peninsula margin are consistent with repeated ice sheet advances throughout the Pliocene (Eyles et al, 2001;Hillenbrand and Ehrmann, 2005;Hepp et al, 2006;Bart, 2001) but also indicate significant oceanic warming during Pliocene interglacials (Hillenbrand and Cortese, 2006;Escutia et al, 2009;Hepp et al, 2009;Bart and Iwai, 2012). The proposed drill cores from the ASE will decipher whether the WAIS responded directly to the orbitally paced climatic cycles of the Pliocene and Quaternary or it varied at periods determined by its internal dynamics, as findings from Leg 178 suggest for the Antarctic Peninsula Ice Sheet (Barker et al, 2002).…”

Section: Hypothesis H2: Ice-proximal Records Of Ice Sheet Dynamics Inmentioning

confidence: 58%

“…To obtain complete sedimentary sequences, at least one site will core deep-sea drifts on the continental rise offshore from the ASE. Similar drift sediments drilled on the western Antarctic Peninsula continental rise during Leg 178 provided excellent archives of Neogene to Quaternary ice sheet dynamics and paleoenvironmental changes (e.g., Hillenbrand and Ehrmann, 2005;Hepp et al, 2006Hepp et al, , 2009Escutia et al, 2009;Bart and Iwai, 2012). A comparable potential has already been demonstrated for Pleistocene drift sediments recovered from the Amundsen Sea continental rise In model experiments, incursions of relatively warm CDW onto the West Antarctic continental shelf have been implicated in regulating WAIS behavior on orbital and suborbital timescales (Thoma et al, 2008;Pollard and DeConto, 2009).…”

Section: Hypothesis H2: Ice-proximal Records Of Ice Sheet Dynamics Inmentioning

confidence: 62%

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Gohl¹,

Wellner²,

Klaus³

2017

International Ocean Discovery Program Scientific Prospectus

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The West Antarctic Ice Sheet (WAIS) is largely marine based and thus highly sensitive to both climatic and oceanographic changes. Therefore, the WAIS has likely had a very dynamic history over the last several million years. A complete collapse of the WAIS would result in a global sea level rise of 3.3-4.3 m, yet the world's scientific community is not able to predict its future behavior. Moreover, knowledge about past behavior of the WAIS is poor, in particular during geological times with climatic conditions similar to those expected for the near and distant future. Reconstructions and quantifications of partial or complete WAIS collapses in the past are urgently needed for constraining and testing ice sheet models that aim to predict future WAIS behavior and the potential contribution of the WAIS to global sea level rise. Large uncertainties exist regarding the chronology, extent, rates, and spatial and temporal variability of past advances and retreats of the WAIS across the continental shelves. These uncertainties largely result from the fundamental lack of data from drill cores recovered proximal to the WAIS. The continental shelf and rise of the Amundsen Sea are prime targets for drilling because the records are expected to yield archives of pure WAIS dynamics unaffected by other ice sheets and the WAIS sector draining into the Amundsen Sea Embayment (ASE) currently experiences the largest ice loss in Antarctica (Paolo et al., 2015).We propose a series of drill sites for the ASE shelf where seismic data reveal seaward-dipping sedimentary sequences that span from the preglacial depositional phase to the most recent glacial periods. Our strategy is to drill a transect from the oldest sequences close to the bedrock/basin boundary at the middle-inner shelf transition to the youngest sequences on the outer shelf in the eastern ASE. If the eastern ASE is inaccessible due to sea ice cover, a similar transect of sites can be drilled on the western ASE. The core transect will provide a detailed history of the glacial cycles in the Amundsen Sea region and allow comparison to the glacial history from the Ross Sea sector. In addition, deep-water sites on the continental rise of the Amundsen Sea are selected for recovering continuous records of glacially transported sediments and detailed archives of climatic and oceanographic changes throughout glacial-interglacial cycles. We will apply a broad suite of analytical techniques, including multiproxy analyses, to address our objectives of reconstructing the onset of glaciation in the greenhouse to icehouse transition, processes of dynamic ice sheet behavior during the Neogene and Quaternary, and ocean conditions associated with the glacial cycles.The five principal objectives of Expedition 379 are as follows:1. To reconstruct the glacial history of West Antarctica from the Paleogene to recent times and the dynamic behavior of the WAIS during the Neogene and Quaternary, especially possible partial or full WAIS collapses, and the WAIS contribution to past sea level...

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Pliocene glacial cyclicity in a deep-sea sediment drift (Antarctic Peninsula Pacific Margin)

Cited by 47 publications

References 36 publications

Climate and environment of a Pliocene warm world

Climate and environment of a Pliocene warm world

Influence of the water content on X‐ray fluorescence core‐scanning measurements in soft marine sediments

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