ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • AWI_Paleo; Paleoenvironmental Reconstructions from Marine Sediments @ AWI  (4)
  • Compound-specific radiocarbon dating  (3)
  • (Aluminium+Iron)/(Silicon+Potassium+Titanium); 286; Age; AGE; Aluminium; Calcium; Calculated; Depth, composite; DEPTH, sediment/rock; GeoB; GeoB9501-4; Geosciences, University of Bremen; Intercore correlation; Iron; M65/1; Mauritania Canyon; Meteor (1986); MUC; MultiCorer; Potassium; Silicon; Titanium; X-ray fluorescence core scanner (XRF) II, Bremen, (AVAATECH)  (1)
Collection
Keywords
Publisher
Years
  • 1
    facet.materialart.
    Unknown
    Sea surface temperature calculated from UK37 and UK'37 in the Pacific sector of the Southern Ocean (2012)
    PANGAEA
    In:  Supplement to: Ho, Sze Ling; Mollenhauer, Gesine; Lamy, Frank; Martínez‐García, Alfredo; Mohtadi, Mahyar; Gersonde, Rainer; Hebbeln, Dierk; Nunez-Ricardo, Samuel; Rosell-Melé, Antoni; Tiedemann, Ralf (2012): Sea surface temperature variability in the Pacific sector of the Southern Ocean over the past 700 kyr. Paleoceanography, 27, PA4202, https://doi.org/10.1029/2012PA002317
    Details
    Publication Date: 2023-03-16
    Description: In spite of the important role played by the Southern Ocean in global climate, the few existing paleoceanographic records in the east Pacific sector do not extend beyond one glacial-interglacial cycle, hindering circumpolar comparison of past sea surface temperature (SST) evolution in the Southern Ocean. Here we present three alkenone-based Pleistocene SST records from the subantarctic and subtropical Pacific. We use a regional core top calibration data set to constrain the choice of calibrations for paleo SST estimation. Our core top data confirm that the alkenone-based UK37 and UK'37 values correlate linearly with the SST, in a similar fashion as the most commonly used laboratory culture-based calibrations even at low temperatures (down to ~1°C), rendering these calibrations appropriate for application in the subantarctic Pacific. However, these alkenone indices yield diverging temporal trends in the Pleistocene SST records. On the basis of the better agreement with d18O records and other SST records in the subantarctic Southern Ocean, we propose that the UK37 is a better index for SST reconstruction in this region than the more commonly used UK'37 index. The UK37-derived SST records suggest glacial cooling of ~8°C and ~4°C in the subantarctic and subtropical Pacific, respectively. Such extent of subantarctic glacial cooling is comparable to that in other sectors of the Southern Ocean, indicating a uniform circumpolar cooling during the Pleistocene. Furthermore, our SST records also imply massive equatorward migrations of the Antarctic Circumpolar Current (ACC) frontal systems and an enhanced transport of ACC water to lower latitudes during glacials by the Peru-Chile Current.
    Keywords: AWI_Paleo; Paleoenvironmental Reconstructions from Marine Sediments @ AWI
    Type: Dataset
    Format: application/zip, 6 datasets
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    DATA PANGAEA
  • 2
    facet.materialart.
    Unknown
    Fractional abundances and concentrations of branched glycerol dialkyl glycerol tetraethers (brGDGT) of core SO201-2-12KL (2017)
    PANGAEA
    In:  Supplement to: Meyer, Vera D; Hefter, Jens; Lohmann, Gerrit; Max, Lars; Tiedemann, Ralf; Mollenhauer, Gesine (2017): Summer temperature evolution on the Kamchatka Peninsula, Russian Far East, during the past 20000 years. Climate of the Past, 13(4), 359-377, https://doi.org/10.5194/cp-13-359-2017
    Details
    Publication Date: 2023-03-16
    Description: Little is known about the climate evolution on the Kamchatka Peninsula during the last glacial?interglacial transition as existing climate records do not reach beyond 12 ka BP. In this study, a summer temperature record for the past 20 kyr is presented. Branched glycerol dialkyl glycerol tetraethers, terrigenous biomarkers suitable for continental air temperature reconstructions, were analyzed in a sediment core from the western continental margin off Kamchatka in the marginal northwest Pacific (NW Pacific). The record suggests that summer temperatures on Kamchatka during the Last Glacial Maximum (LGM) equaled modern temperatures. We suggest that strong southerly winds associated with a pronounced North Pacific High pressure system over the subarctic NW Pacific accounted for the warm conditions. A comparison with an Earth system model reveals discrepancies between model and proxy-based reconstructions for the LGM temperature and atmospheric circulation in the NW Pacific realm. The deglacial temperature development is characterized by abrupt millennial-scale temperature oscillations. The Bølling?Allerød warm phase and the Younger Dryas cold spell are pronounced events, suggesting a connection to North Atlantic climate variability.
    Keywords: AWI_Paleo; Paleoenvironmental Reconstructions from Marine Sediments @ AWI
    Type: Dataset
    Format: application/zip, 2 datasets
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    DATA PANGAEA
  • 3
    facet.materialart.
    Unknown
    Fractional abundances of isoprenoid and branched glycerol dialkyl glycerol tetraethers (GDGT) of cores SO201-2-12KL and SO201-2-114KL (2016)
    PANGAEA
    In:  Supplement to: Meyer, Vera D; Max, Lars; Hefter, Jens; Tiedemann, Ralf; Mollenhauer, Gesine (2016): Glacial-to-Holocene evolution of sea surface temperature and surface circulation in the subarctic northwest Pacific and the Western Bering Sea. Paleoceanography, 31, 12 pp, https://doi.org/10.1002/2015PA002877
    Details
    Publication Date: 2023-03-16
    Description: It has been proposed that North Pacific sea surface temperature (SST) evolution was intimately linked to North Atlantic climate oscillations during the last glacial-interglacial transition. However, during the early deglaciation and the Last Glacial Maximum, the SST development in the subarctic northwest Pacific and the Bering Sea is poorly constrained as most existing deglacial SST records are based on alkenone paleothermometry, which is limited prior to 15 ka B.P. in the subarctic North Pacific realm. By applying the TEXL86 temperature proxy we obtain glacial-Holocene-SST records for the marginal northwest Pacific and the Western Bering Sea. Our TEXL86-based records and existing alkenone data suggest that during the past 15.5 ka, SSTs in the northwest Pacific and the Western Bering Sea closely followed millennial-scale climate fluctuations known from Greenland ice cores, indicating rapid atmospheric teleconnections with abrupt climate changes in the North Atlantic. Our SST reconstructions indicate that in the Western Bering Sea SSTs drop significantly during Heinrich Stadial 1 (HS1), similar to the known North Atlantic climate history. In contrast, progressively rising SST in the northwest Pacific is different to the North Atlantic climate development during HS1. Similarities between the northwest Pacific SST and climate records from the Gulf of Alaska point to a stronger influence of Alaskan Stream waters connecting the eastern and western basin of the North Pacific during this time. During the Holocene, dissimilar climate trends point to reduced influence of the Alaskan Stream in the northwest Pacific.
    Keywords: AWI_Paleo; Paleoenvironmental Reconstructions from Marine Sediments @ AWI
    Type: Dataset
    Format: application/zip, 2 datasets
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    DATA PANGAEA
  • 4
    facet.materialart.
    Unknown
    Age models, color measurements, and calculated sea surface temperatures of sediment cores from the Bering Sea and the Sea of Okhotsk (2012)
    PANGAEA
    In:  Supplement to: Max, Lars; Riethdorf, Jan-Rainer; Tiedemann, Ralf; Smirnova, Maria; Lembke-Jene, Lester; Fahl, Kirsten; Nürnberg, Dirk; Matul, Alexander G; Mollenhauer, Gesine (2012): Sea surface temperature variability and sea-ice extent in the subarctic northwest Pacific during the past 15,000 years. Paleoceanography, 27(3), PA3213, https://doi.org/10.1029/2012PA002292
    Details
    Publication Date: 2023-05-12
    Description: Past changes in North Pacific sea surface temperatures and sea-ice conditions are proposed to play a crucial role in deglacial climate development and ocean circulation but are less well known than from the North Atlantic. Here, we present new alkenone-based sea surface temperature records from the subarctic northwest Pacific and its marginal seas (Bering Sea and Sea of Okhotsk) for the time interval of the last 15 kyr, indicating millennial-scale sea surface temperature fluctuations similar to short-term deglacial climate oscillations known from Greenland ice-core records. Past changes in sea-ice distribution are derived from relative percentage of specific diatom groups and qualitative assessment of the IP25 biomarker related to sea-ice diatoms. The deglacial variability in sea-ice extent matches the sea surface temperature fluctuations. These fluctuations suggest a linkage to deglacial variations in Atlantic meridional overturning circulation and a close atmospheric coupling between the North Pacific and North Atlantic. During the Holocene the subarctic North Pacific is marked by complex sea surface temperature trends, which do not support the hypothesis of a Holocene seesaw in temperature development between the North Atlantic and the North Pacific.
    Keywords: AWI_Paleo; Paleoenvironmental Reconstructions from Marine Sediments @ AWI
    Type: Dataset
    Format: application/zip, 25 datasets
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    DATA PANGAEA
  • 5
    facet.materialart.
    Unknown
    (Figure S3) Bulk element concentrations from multicore GeoB9501-4 measured with EDP-XRF spectroscopy (2010)
    PANGAEA
    Details
    Publication Date: 2023-07-10
    Keywords: (Aluminium+Iron)/(Silicon+Potassium+Titanium); 286; Age; AGE; Aluminium; Calcium; Calculated; Depth, composite; DEPTH, sediment/rock; GeoB; GeoB9501-4; Geosciences, University of Bremen; Intercore correlation; Iron; M65/1; Mauritania Canyon; Meteor (1986); MUC; MultiCorer; Potassium; Silicon; Titanium; X-ray fluorescence core scanner (XRF) II, Bremen, (AVAATECH)
    Type: Dataset
    Format: text/tab-separated-values, 378 data points
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    DATA PANGAEA
  • 6
    facet.materialart.
    Unknown
    Timescales of lateral sediment transport in the Panama Basin as revealed by radiocarbon ages of alkenones, total organic carbon and foraminifera (2010)
    Details
    Publication Date: 2022-05-25
    Description: Author Posting. © The Author(s), 2009. This is the author's version of the work. It is posted here by permission of Elsevier B.V. for personal use, not for redistribution. The definitive version was published in Earth and Planetary Science Letters 290 (2010): 340-350, doi:10.1016/j.epsl.2009.12.030.
    Description: Paired radiocarbon measurements on haptophyte biomarkers (alkenones) and on cooccurring tests of planktic foraminifera (Neogloboquadrina dutertrei and Globogerinoides sacculifer) from late glacial to Holocene sediments at core locations ME0005-24JC, Y69- 71P, and MC16 from the south-western and central Panama Basin indicate no significant addition of pre-aged alkenones by lateral advection. The strong temporal correspondence between alkenones, foraminifera and total organic carbon (TOC) also implies negligible contributions of aged terrigenous material. Considering controversial evidence for sediment redistribution in previous studies of these sites, our data imply that the laterally supplied material cannot stem from remobilization of substantially aged sediments. Transport, if any, requires syn-depositional nepheloid layer transport and redistribution of low-density or fine-grained components within decades of particle formation. Such rapid and local transport minimizes the potential for temporal decoupling of proxies residing in different grain size fractions and thus facilitates comparison of various proxies for paleoceanographic reconstructions in this study area. Anomalously old foraminiferal tests from a glacial depth interval of core Y69-71P may result from episodic spillover of fast bottom currents across the Carnegie Ridge transporting foraminiferal sands towards the north.
    Description: This study was funded by the Helmholtz Young Investigators Group „Applications of molecular 14C analysis for the study of sedimentation processes and carbon cycling in marine sediments”. G.M. acknowledges financial support from WHOI postdoctoral scholarship program. T.I.E. was supported by NSF grant OCE-0526268. A.C.M. was supported by NSF grant ATM0602395.
    Keywords: Compound-specific radiocarbon dating ; Alkenones ; Lateral sediment transport ; Panama Basin ; Eastern Equatorial Pacific
    Repository Name: Woods Hole Open Access Server
    Type: Preprint
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 7
    facet.materialart.
    Unknown
    An evaluation of 14C age relationships between co-occurring foraminifera, alkenones, and total organic carbon in continental margin sediments (2006)
    American Geophysical Union
    Details
    Publication Date: 2022-05-25
    Description: Author Posting. © American Geophysical Union, 2005. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Paleoceanography 20 (2005): PA1016, doi:10.1029/2004PA001103.
    Description: Radiocarbon age relationships between co-occurring planktic foraminifera, alkenones and total organic carbon in sediments from the continental margins of Southern Chile, Northwest Africa and the South China Sea were compared with published results from the Namibian margin. Age relationships between the sediment components are site-specific and relatively constant over time. Similar to the Namibian slope, where alkenones have been reported to be 1000 to 4500 years older than co-occurring foraminifera, alkenones were significantly (~1000 yrs) older than co-occurring foraminifera in the Chilean margin sediments. In contrast, alkenones and foraminifera were of similar age (within 2σ error or better) in the NW African and South China Sea sediments. Total-organic-matter and alkenone ages were similar off Namibia (age difference TOC-alkenones: 200-700 years), Chile (100-450 years), and NW Africa (360-770 years), suggesting minor contributions of pre-aged terrigenous material. In the South China Sea total organic carbon is significantly (2000-3000 yrs) older due to greater inputs of pre-aged terrigenous material. Age offsets between alkenones and planktic foraminifera are attributed to lateral advection of organic matter. Physical characteristics of the depositional setting, such as sea-floor morphology, shelf width, and sediment composition, may control the age of co-occurring 2 sediment components. In particular, offsets between alkenones and foraminifera appear to be greatest in deposition centers in morphologic depressions. Aging of organic matter is promoted by transport. Age offsets are correlated with organic richness, suggesting that formation of organic aggregate is a key process.
    Description: GM and MK acknowledge financial support from the WHOI postdoctoral scholarship program. This work was funded by NSF grant OCE-0327405.
    Keywords: Compound-specific radiocarbon dating ; Alkenones ; High accumulation rate sediments
    Repository Name: Woods Hole Open Access Server
    Type: Article
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 8
    facet.materialart.
    Unknown
    Aging of marine organic matter during cross-shelf lateral transport in the Benguela upwelling system revealed by compound-specific radiocarbon dating (2010)
    American Geophysical Union
    Details
    Publication Date: 2022-05-25
    Description: Author Posting. © American Geophysical Union, 2007. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Geochemistry Geophysics Geosystems 8 (2007): Q09004, doi:10.1029/2007GC001603.
    Description: Organic matter accumulation and burial on the Namibian shelf and upper slope are spatially heterogeneous and strongly controlled by lateral transport in subsurface nepheloid layers. Much of the material deposited in depo-centers on the slope ultimately derives from the shelf. Supply of organic matter from the shelf involves selective transport of organic matter. We studied these selective transport processes by analyzing the radiocarbon content of co-occurring sediment fractions. Here we present radiocarbon data for total organic carbon as well as three tracers of surface ocean productivity (phytoplankton-derived alkenones, membrane lipids of pelagic crenarchaeota (crenarchaeol), and calcareous microfossils of planktic foraminifera) in core-top and near-surface sediment samples. The samples were collected on the Namibian margin along a shelf-slope transect (85 to 1040 m) at 24°S and from the upper slope depo-center at 25.5°S. In core-top sediments, alkenone ages gradually increased from modern to 3490 radiocarbon years with distance from shore and with water depth. Crenarchaeol, while younger than alkenones, also increased in age with distance offshore. It was concluded that the observed ages were a consequence of cross-shelf transport and associated aging of organic matter. Radiocarbon ages of preserved lipid biomarkers in sediments thus at least partially depend on the relative amount of laterally supplied, pre-aged material present in a sample, highlighting the importance of nepheloid transport for the sedimentation of organic matter over the Namibian margin.
    Description: This work was funded by NSF grant OCE- 0327405 to T.I.E. and by a Spinoza grant to J.S.S.D. from NWO.
    Keywords: Compound-specific radiocarbon dating ; Sediment transport
    Repository Name: Woods Hole Open Access Server
    Type: Article
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...