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  • 11
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    Unknown
    PANGAEA
    In:  Supplement to: Bouimetarhan, Ilham; Dupont, Lydie M; Schefuß, Enno; Mollenhauer, Gesine; Mulitza, Stefan; Zonneveld, Karin A F (2009): Palynological evidence for climatic and oceanic variability off NW Africa during the late Holocene. Quaternary Research, 72(2), 188-197, https://doi.org/10.1016/j.yqres.2009.05.003
    Publication Date: 2023-06-27
    Description: Pollen and organic-walled dinoflagellate cyst assemblages from core GeoB 9503-5 retrieved from the mud-belt ( 50 m water depth) off the Senegal River mouth have been analyzed to reconstruct short-term palaeoceanographic and palaeoenvironmental changes in subtropical NW Africa during the time interval from ca. 4200 to 1200 cal yr BP. Our study emphasizes significant coeval changes in continental and oceanic environments in and off Senegal and shows that initial dry conditions were followed by a strong and rapid increase in humidity between ca. 2900 and 2500 cal yr BP. After ca. 2500 cal yr BP, the environment slowly became drier again as indicated by slight increases in Sahelian savannah and desert elements in the pollen record. Around ca. 2200 cal yr BP, this relatively dry period ended with periodic pulses of high terrigenous contributions and strong fluctuations in fern spore and river plume dinoflagellate cyst percentages as well as in the fluxes of pollen, dinoflagellate cysts, fresh-water algae and plant cuticles, suggesting "episodic flash flood" events of the Senegal River. The driest phase developed after about 2100 cal yr BP.
    Keywords: 288; Center for Marine Environmental Sciences; GeoB9503-5; Gravity corer (Kiel type); M65/1; MARUM; Meteor (1986); SL
    Type: Dataset
    Format: application/zip, 3 datasets
    Location Call Number Limitation Availability
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  • 12
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    Unknown
    PANGAEA
    In:  Supplement to: Bouimetarhan, Ilham; Prange, Matthias; Schefuß, Enno; Dupont, Lydie M; Lippold, Jörg; Mulitza, Stefan; Zonneveld, Karin A F (2012): Sahel megadrought during Heinrich Stadial 1: evidence for a three-phase evolution of the low- and mid-level West African wind system. Quaternary Science Reviews, 58, 66-76, https://doi.org/10.1016/j.quascirev.2012.10.015
    Publication Date: 2023-06-27
    Description: Millennial-scale dry events in the Northern Hemisphere monsoon regions during the last Glacial period are commonly attributed to southward shifts of the Intertropical Convergence Zone (ITCZ) associated with an intensification of the northeasterly (NE) trade wind system during intervals of reduced Atlantic meridional overturning circulation (AMOC). Through the use of high-resolution last deglaciation pollen records from the continental slope off Senegal, our data show that one of the longest and most extreme droughts in the western Sahel history, which occurred during the North Atlantic Heinrich Stadial 1 (HS1), displayed a succession of three major phases. These phases progressed from an interval of maximum pollen representation of Saharan elements between ~19 and 17.4 kyr BP indicating the onset of aridity and intensified NE trade winds, followed by a millennial interlude of reduced input of Saharan pollen and increased input of Sahelian pollen, to a final phase between ~16.2 and 15 kyr BP that was characterized by a second maximum of Saharan pollen abundances. This change in the pollen assemblage indicates a mid-HS1 interlude of NE trade wind relaxation, occurring between two distinct trade wind maxima, along with an intensified mid-tropospheric African Easterly Jet (AEJ) indicating a substantial change in West African atmospheric processes. The pollen data thus suggest that although the NE trades have weakened, the Sahel drought remained severe during this time interval. Therefore, a simple strengthening of trade winds and a southward shift of the West African monsoon trough alone cannot fully explain millennial-scale Sahel droughts during periods of AMOC weakening. Instead, we suggest that an intensification of the AEJ is needed to explain the persistence of the drought during HS1. Simulations with the Community Climate System Model indicate that an intensified AEJ during periods of reduced AMOC affected the North African climate by enhancing moisture divergence over the West African realm, thereby extending the Sahel drought for about 4000 years.
    Keywords: 293; Center for Marine Environmental Sciences; GeoB9508-5; Gravity corer (Kiel type); M65/1; MARUM; Meteor (1986); SL
    Type: Dataset
    Format: application/zip, 5 datasets
    Location Call Number Limitation Availability
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  • 13
    Publication Date: 2023-06-27
    Keywords: 293; Age model; Calculated from Mg/Ca ratios (Elderfield & Ganssen, 2000); Calculated from Mg/Ca ratios (Groeneveld and Chiessi, 2011); Center for Marine Environmental Sciences; DEPTH, sediment/rock; GeoB9508-5; Globigerina bulloides, Magnesium/Calcium ratio; Globigerina bulloides, δ13C; Globorotalia inflata, Magnesium/Calcium ratio; Globorotalia inflata, δ13C; Gravity corer (Kiel type); ICP-OES, Perkin-Elmer, Optima 3300RL; M65/1; MARUM; Mass spectrometer Finnigan MAT 251; Meteor (1986); SL; Temperature, calculated
    Type: Dataset
    Format: text/tab-separated-values, 210 data points
    Location Call Number Limitation Availability
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  • 14
    Publication Date: 2023-11-01
    Keywords: 293; Acacia; AGE; Algae; Amaranthaceae/Chenopodiaceae; Artemisia; Asteroideae; Balanites; Borreria; Boscia-type; Calculated, see reference(s); Caryophyllaceae; Celtis; Center for Marine Environmental Sciences; Clematis; Counting, palynology; Cuticles; Cyperaceae; Depth, bottom/max; DEPTH, sediment/rock; Depth, top/min; Ephedra distachya-type; Ephedra fragilis-type; Euphorbia-type; Fraxinus; Galium; GeoB9508-5; Gramineae; Gravity corer (Kiel type); Lycopodium; M65/1; MARUM; Mass; Meteor (1986); Mimosa-type; Mitracarpus; Olea; Pinus; Pollen, total; Pollen and spores; Psydrax-type subcordata; Rhamnaceae; Rhizophora; Rubiaceae; Sedimentation rate; SL; Spores; Sporomorphes, total; Typha; Uapaca; Vernonia-type; Volume; Ziziphus
    Type: Dataset
    Format: text/tab-separated-values, 1352 data points
    Location Call Number Limitation Availability
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  • 15
    Publication Date: 2023-07-10
    Keywords: 288; Acacia; AGE; Algae; Amaranthaceae/Chenopodiaceae; Anonaceae; Artemisia; Asteroideae; Boreria spermacore; Boscia-type; Butyrospermum; Canthium subcordatum; Center for Marine Environmental Sciences; Clematis; Counting, palynology; Cuviera; Cyperaceae; DEPTH, sediment/rock; Euphorbia-type; Fraximus; Galium; GeoB9503-5; Gramineae; Gravity corer (Kiel type); Indeterminata; Indigofera; M65/1; MARUM; Meteor (1986); Mimosa; Mitracarpus; Olea; Phoenix; Pinus; Pliostigma; Pollen, total; Pollen indeterminata; Pterocarpus; Rhizophora; Rubeacea; SL; Spores; Stereospermum; Tamarindus; Typha; Uapaca; Vernonia; Zizyphus
    Type: Dataset
    Format: text/tab-separated-values, 2184 data points
    Location Call Number Limitation Availability
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  • 16
    Publication Date: 2023-07-10
    Keywords: 293; Acacia; AGE; Alchornea; Amaranthaceae; Annonaceae; Artemisia; Asteroideae; Balanites; Borreria; Boscia-type; Butyrospermum; Caryophyllaceae; Cassia-type; Celtis; Center for Marine Environmental Sciences; Clematis; Combretaceae; Counting, palynology; Cuviera; Cyperaceae; Depth, bottom/max; DEPTH, sediment/rock; Depth, top/min; Ephedra distachya-type; Ephedra fragilis-type; Euphorbia-type; Fraxinus; Galium; GeoB9508-5; Gramineae; Gravity corer (Kiel type); Indigofera; Lamnea; M65/1; MARUM; Meteor (1986); Mimosa-type; Mitracarpus; Olea; Phoenix-type; Piliostigma; Pinus; Pollen, total; Psydrax-type subcordatum; Pterocarpus-type; Rhamnaceae; Rhizophora; Rubiaceae; Sedimentation rate; SL; Stereospermum-type; Tamarindus-type indica; Typha; Uapaca; Vernonia-type; Ziziphus
    Type: Dataset
    Format: text/tab-separated-values, 1776 data points
    Location Call Number Limitation Availability
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  • 17
    Publication Date: 2023-12-07
    Description: Dinoflagellate cysts are useful for reconstructing upper water conditions. For adequate reconstructions detailed information is required about the relationship between modern day environmental conditions and the geographic distribution of cysts in sediments. This Atlas summarises the modern global distribution of 71 organicwalled dinoflagellate cyst species. The synthesis is based on the integration of literature sources together with data of 2405 globally distributed surface sediment samples that have been preparedwith a comparable methodology and taxonomy. The distribution patterns of individual cyst species are being comparedwith environmental factors that are knownto influence dinoflagellate growth, gamete production, encystment, excystment and preservation of their organic-walled cysts: surface water temperature, salinity, nitrate, phosphate, chlorophyll-a concentrations and bottom water oxygen concentrations. Graphs are provided for every species depicting the relationship between seasonal and annual variations of these parameters and the relative abundance of the species. Results have been compared with previously published records; an overview of the ecological significance as well as information about the seasonal production of each individual species is presented. The relationship between the cyst distribution and variation in the aforementioned environmental parameters was analysed by performing a canonical correspondence analysis. All tested variables showed a positive relationship on the 99% confidence level. Sea-surface temperature represents the parameter corresponding to the largest amount of variance within the dataset (40%) followed by nitrate, salinity, phosphate and bottom-water oxygen concentration, which correspond to 34%, 33%, 25% and 24% of the variance, respectively. Characterisations of selected environments as well as a discussion about how these factors could have influenced the final cyst yield in sediments are included.
    Keywords: Alexandrium tamarense; Ataxiodinium choane; Bitectatodinium spongium; Bitectatodinium tepikiense; Brigantedinium spp.; Calculated; Caspidinium rugosum; Center for Marine Environmental Sciences; Chlorophyll a, interpolated; Cryodinium meridianum; Dalella chathamensis; DEPTH, sediment/rock; Dinoflagellate cyst; Dinoflagellate cyst, reworked; Dissolved oxygen, in water, interpolated; Dubridinium caperatum; Echinidinium aculeatum; Echinidinium bispiniformum; Echinidinium delicatum; Echinidinium granulatum; Echinidinium karaense; Echinidinium spp.; Echinidinium transparantum; Glaphyrocysta semitecta; Gymnodinium catenatum; Gymnodinium nolleri; Impagidinium aculeatum; Impagidinium caspienense; Impagidinium pallidum; Impagidinium paradoxum; Impagidinium patulum; Impagidinium plicatum; Impagidinium sphaericum; Impagidinium strialatum; Impagidinium variaseptum; Impagidinium velorum; Islandinium cezare; Islandinium minutum; LATITUDE; Lejeunecysta oliva; Lejeunecysta sabrina; Lingulodinium machaerophorum; LONGITUDE; MARUM; Nematosphaeropsis labyrinthus; Nitrate, in water, interpolated; Operculodinium centrocarpum; Operculodinium israelianum; Operculodinium janduchenei; Operculodinium longispinigerum; Operculodinium spp.; Pentapharsodinium dalei; Peridinium ponticum; Phosphate, in water, interpolated; Polykrikos kofoidii; Polykrikos schwarzii; Polykrikos var. arctica; Polysphaeridium zoharyi; Priority Programme 1158 Antarctic Research with Comparable Investigations in Arctic Sea Ice Areas; Protoperidiniaceae; Protoperidinium americanum; Protoperidinium monospinum; Pyxidinopsis psilata; Pyxidinopsis reticulata; Quinquecuspis concreta; Reference/source; Selenopemphix antarctica; Selenopemphix nephroides; Selenopemphix quanta; Spiniferites bentori; Spiniferites cruciformis; Spiniferites delicatus; Spiniferites elongatus; Spiniferites lazus; Spiniferites membranaceus; Spiniferites mirabilis; Spiniferites pachydermus; Spiniferites ramosus; Spiniferites spp.; SPP1158; Station label; Stelladinium robustum; Stelladinium stellatum; Tectatodinium pellitum; Temperature, annular; Temperature, autumn; Temperature, spring; Temperature, summer; Temperature, winter; Trinovantedinium applanatum; Tuberculodinium vancampoae; Uniform resource locator/link to file; Votadinium calvum; Votadinium spinosum; Xandarodinium xanthum
    Type: Dataset
    Format: text/tab-separated-values, 230152 data points
    Location Call Number Limitation Availability
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  • 18
    Publication Date: 2023-11-28
    Keywords: 293; AGE; Bitectatodinium spongium; Bitectatodinium tepikiense; Brigantedinium spp.; Center for Marine Environmental Sciences; Counting, palynology; Crustacea, planktic, eggs; Dalella chathamensis; Depth, bottom/max; DEPTH, sediment/rock; Depth, top/min; Dinoflagellate cyst; Dinoflagellate cyst indeterminata; Dinoflagellates, total; Dubridinium spp.; Echinidinium aculeatum; Echinidinium bispiniformum; Echinidinium delicatum; Echinidinium granulatum; Echinidinium spp.; Echinidinium transparantum; Foraminifera, linings; GeoB9508-5; Gravity corer (Kiel type); Impagidinium aculeatum; Impagidinium paradoxum; Impagidinium patulum; Impagidinium spp.; Impagidinium strialatum; Islandinium cezare; Islandinium minutum; Leipokatium invisitatum; Lejeunecysta oliva; Lejeunecysta sabrina; Lejeunecysta spp.; Lingulodinium machaerophorum; Lingulodinium machaerophorum short; Lycopodium (added); Lycopodium (counted); M65/1; MARUM; Mass; Meteor (1986); Nematosphaeropsis labyrinthus; Operculodinium centrocarpum; Operculodinium centrocarpum sensu Wall and Dale (1966); Operculodinium israelianum; Operculodinium spp.; Pentapharsodinium dalei; Polykrikos kofoidii; Polykrikos schwarzii; Polysphaeridium zoharyi; Protoperidinium americanum; Protoperidinium monospinum; Protoperidinium spp.; Protoperidinium stellatum; Pyxidinopsis psilata; Pyxidinopsis reticulata; Pyxidinopsis spp.; Quinquecuspis concreta; Scolecodonta; Sedimentation rate; Selenopemphix antarctica; Selenopemphix nephroides; Selenopemphix quanta; Selenopemphix spp.; SL; Spiniferites bentori; Spiniferites bulloides; Spiniferites delicatus; Spiniferites elongatus; Spiniferites hyperacanthus; Spiniferites lazus; Spiniferites membranaceus; Spiniferites mirabilis; Spiniferites pachydermus; Spiniferites ramosus; Spiniferites spp.; Stelladinium reidii; Stelladinium robustum; Stelladinium spp.; Tectatodinium pellitum; Trinovantedinium applanatum; Tuberculodinium vancampoae; Volume; Votadinium calvum; Votadinium spinosum; Xandarodinium xanthum
    Type: Dataset
    Format: text/tab-separated-values, 2923 data points
    Location Call Number Limitation Availability
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  • 19
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    Unknown
    PANGAEA
    In:  Supplement to: Zhao, Xueqin; Dupont, Lydie M; Schefuß, Enno; Bouimetarhan, Ilham; Wefer, Gerold (2017): Palynological evidence for Holocene climatic and oceanographic changes off western South Africa. Quaternary Science Reviews, 165, 88-101, https://doi.org/10.1016/j.quascirev.2017.04.022
    Publication Date: 2023-11-28
    Description: Atmospheric and oceanographic interactions between the Atlantic and Indian Oceans influence upwelling in the southern Benguela upwelling system. In order to obtain a better knowledge of paleoceanographic and paleoenvironmental changes in the southern Benguela region during the Holocene, 12 marine surface sediment samples and one gravity core GeoB8331-4 from the Namaqualand mudbelt off the west coast of South Africa have been studied for organic-walled dinoflagellate cysts in high temporal resolution. The results are compared with pollen and geochemical records from the same samples. Our study emphasizes significantly distinct histories in upwelling intensity as well as the influence of fluvial input during the Holocene. Three main phases were identified for the Holocene. High percentages of cysts produced by autotrophic taxa like Operculodinium centrocarpum and Spiniferites spp. indicate warmer and stratified conditions during the early Holocene (9900-8400 cal. yr BP), suggesting reduced upwelling likely due to a northward shift of the southern westerlies. In contrast, the middle Holocene (8400-3100 cal. yr BP) is characterized by a strong increase in heterotrophic taxa in particular Lejeunecysta paratenella and Echinidinium spp. at the expense of autotrophic taxa. This indicates cool and nutrient-rich waters with active upwelling probably caused by a southward shift of the southern westerlies. During the late Holocene (3100 cal. yr BP to modern), Brigantedinium spp. and other abundant taxa interpreted to indicate fluvial nutrient input such as cyst of Protoperidinium americanum and Lejeunecysta oliva imply strong river discharge with high nutrient supply between 3100 and 640 cal. yr BP.
    Keywords: Center for Marine Environmental Sciences; MARUM; RAiN; Regional Archives for Integrated iNvestigations
    Type: Dataset
    Format: application/zip, 2 datasets
    Location Call Number Limitation Availability
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  • 20
    Publication Date: 2023-11-28
    Keywords: 288; AGE; Bitectatodinium spongium; Bitectatodinium spp.; Brigantedinium spp.; Center for Marine Environmental Sciences; Counting, palynology; DEPTH, sediment/rock; Dinoflagellate cyst; Dinoflagellates, total; Dinoflagellate spp.; Diplopelta symmetrica; Dubridinium spp.; Echinidinium aculeatum; Echinidinium delicatum; Echinidinium granulatum; Echinidinium spp.; Echinidinium transparantum; Echinidinium zonneveldiae; GeoB9503-5; Gravity corer (Kiel type); Impagidinium aculeatum; Leujeunocysta oliva; Leujeunocysta sabrina; Lingulodinium machaerophorum; M65/1; MARUM; Meteor (1986); Nematosphaeropsis labyrinthus; Operculodinium centrocarpum; Operculodinium israelianum; Pentaspharsodinium dalei; Polykrikos kofoidii; Polykrikos schwarzii; Polysphaeridium zoharyi; Protoperidinium americanum; Protoperidinium cf. americanum; Protoperidinium monospinum; Protoperidinium spp.; Quinquecuspis concreta; Selenopemphix nephroides; Selenopemphix quanta; SL; Spiniferites bentori; Spiniferites bulloides; Spiniferites hyperacanthus; Spiniferites membranaceus; Spiniferites mirabilis; Spiniferites pachydermus; Spiniferites ramosus; Spiniferites spp.; Stelladinium stellatum; Trinovantedinium applanatum; Tuberculodinium vancampoae; Votadinium calvum; Votadinium spinosum; Xandarodinium xanthum; Zygabikodinium lenticulatum
    Type: Dataset
    Format: text/tab-separated-values, 2912 data points
    Location Call Number Limitation Availability
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