scholarly journals Insights into Holocene relative sea‐level changes in the southern North Sea using an improved microfauna‐based transfer function

2021 ◽  
Author(s):  
Juliane Scheder ◽  
Friederike Bungenstock ◽  
Kristin Haynert ◽  
Anna Pint ◽  
Frank Schlütz ◽  
...  
Keyword(s):  
Transfer Function ◽  
Sea Level ◽  
North Sea ◽  
Sea Level Changes ◽  
Relative Sea Level ◽  
Southern North Sea

scholarly journals Land–sea coupling of early Pleistocene glacial cycles in the southern North Sea exhibit dominant Northern Hemisphere forcing

2018 ◽  
Vol 14 (3) ◽  
pp. 397-411 ◽  
Author(s):  
Timme H. Donders ◽  
Niels A. G. M. van Helmond ◽  
Roel Verreussel ◽  
Dirk Munsterman ◽  
Johan ten Veen ◽  
...  
Keyword(s):  
Surface Water ◽  
Sea Level ◽  
Northern Hemisphere ◽  
North Sea ◽  
River Flow ◽  
Meridional Overturning Circulation ◽  
Early Pleistocene ◽  
Sea Level Changes ◽  
Relative Sea Level ◽  
Southern North Sea

Abstract. We assess the disputed phase relations between forcing and climatic response in the early Pleistocene with a spliced Gelasian (∼2.6–1.8 Ma) multi-proxy record from the southern North Sea basin. The cored sections couple climate evolution on both land and sea during the intensification of Northern Hemisphere glaciation (NHG) in NW Europe, providing the first well-constrained stratigraphic sequence of the classic terrestrial Praetiglian stage. Terrestrial signals were derived from the Eridanos paleoriver, a major fluvial system that contributed a large amount of freshwater to the northeast Atlantic. Due to its latitudinal position, the Eridanos catchment was likely affected by early Pleistocene NHG, leading to intermittent shutdown and reactivation of river flow and sediment transport. Here we apply organic geochemistry, palynology, carbonate isotope geochemistry, and seismostratigraphy to document both vegetation changes in the Eridanos catchment and regional surface water conditions and relate them to early Pleistocene glacial–interglacial cycles and relative sea level changes. Paleomagnetic and palynological data provide a solid integrated timeframe that ties the obliquity cycles, expressed in the borehole geophysical logs, to Marine Isotope Stages (MIS) 103 to 92, independently confirmed by a local benthic oxygen isotope record. Marine and terrestrial palynological and organic geochemical records provide high-resolution reconstructions of relative terrestrial and sea surface temperature (TT and SST), vegetation, relative sea level, and coastal influence. During the prominent cold stages MIS 98 and 96, as well as 94, the record indicates increased non-arboreal vegetation, low SST and TT, and low relative sea level. During the warm stages MIS 99, 97, and 95 we infer increased stratification of the water column together with a higher percentage of arboreal vegetation, high SST, and relative sea level maxima. The early Pleistocene distinct warm–cold alterations are synchronous between land and sea, but lead the relative sea level change by 3000–8000 years. The record provides evidence for a dominantly Northern Hemisphere-driven cooling that leads the glacial buildup and varies on the obliquity timescale. Southward migration of Arctic surface water masses during glacials, indicated by cool-water dinoflagellate cyst assemblages, is furthermore relevant for the discussion on the relation between the intensity of the Atlantic meridional overturning circulation and ice sheet growth.

scholarly journals Land–sea coupling of Early Pleistocene glacial cycles in the southern North Sea exhibit dominant Northern Hemisphere forcing

2017 ◽  
Author(s):  
Timme Donders ◽  
Niels A. G. M. van Helmond ◽  
Roel Verreussel ◽  
Dirk Munsterman ◽  
Johan Ten Veen ◽  
...  
Keyword(s):  
Surface Water ◽  
Sea Level ◽  
Northern Hemisphere ◽  
North Sea ◽  
River Flow ◽  
Meridional Overturning Circulation ◽  
Early Pleistocene ◽  
Sea Level Changes ◽  
Relative Sea Level ◽  
Southern North Sea

Abstract. We assess the disputed phase relations between forcing and climatic response in the Early Pleistocene with a spliced Gelasian (~ 2.6–1.8 Ma) multi-proxy record from the southern North Sea. The cored sections couple climate evolution on both land and sea during the onset of Northern Hemisphere Glaciations (NHG) in NW Europe, providing the first well-constrained stratigraphic sequence of the classic terrestrial Praetiglian Stage. Terrestrial signals were derived from the Eridanos paleoriver, a major fluvial system that contributed a large amount of freshwater to the northeast Atlantic. Due to its latitudinal position, the Eridanos catchment was likely affected by Early Pleistocene NHG, leading to intermittent shutdown and reactivation of river flow and sediment transport. Here we apply organic geochemistry, palynology, carbonate isotope geochemistry, and seismostratigraphy to document both vegetation changes in the Eridanos catchment and regional surface water conditions and relate them to Early Pleistocene glacial–interglacial cycles, and relative sea level changes. Paleomagnetic and palynological data provide a solid integrated timeframe that ties the obliquity cycles, expressed in the borehole geophysical logs, to Marine Isotope Stages (MIS) 103 to 92, independently confirmed by a local benthic oxygen isotope record. Marine and terrestrial palynological and organic geochemical records provide high resolution reconstructions of relative Terrestrial and Sea Surface Temperature (TT and SST), vegetation, relative sea level, and coastal influence. During the prominent cold stages MIS 100, 98 and 96, the record indicates increased non-arboreal vegetation, and low SST and TT, and low relative sea level. During the warm stages MIS 99, 97 and 95 we infer freshwater influx increases causing stratification of the water column together with higher % arboreal vegetation, high SST and relative sea level maxima. The Early Pleistocene distinct warm–cold alterations are synchronous between land and sea, but lead the relative sea level change. The record provides evidence for a dominantly NH driven cooling and glacial build up which is obliquity driven. Timing of southward migration of Arctic surface water masses, indicated by relative SST, are furthermore relevant for the discussion on the relation between the intensity of the Atlantic meridional overturning circulation and ice sheet growth in order to identify lead-lags between forcing and response of Early Pleistocene glaciations.

The sedimentary record of climatic variation in the southern North Sea

1988 ◽  
Vol 318 (1191) ◽  
pp. 523-537 ◽  
Keyword(s):  
Sea Level ◽  
North Sea ◽  
Climatic Changes ◽  
Sea Level Changes ◽  
Offshore Area ◽  
Sea Levels ◽  
Indirect Response ◽  
Southern North Sea ◽  
Sedimentary Sequences ◽  
Glaciofluvial Deposits

The sedimentary sequence on the shelf of the southern North Sea records Quaternary climatic changes in two ways. They are indicated directly by moraine and glaciofluvial deposits from the Elsterian, Saalian and Weichselian glacial periods when the British and the Scandinavian ice sheets covered parts of the area. An indirect response to the climate is indicated by sea-level changes. Phases of cooling are characterized by regressions and low sea-level stands; phases of warming are indicated by marine transgressions and high sea levels during the Holsteinian, Eemian and Holocene periods. The seismic characteristics of the different lithological units, the sedimentary sequences and their fossil content are described for the offshore area and the adjacent coastal zone. This provides a record of the interaction of sedimentary processes and the palaeogeographic development as a response to climatic changes.

scholarly journals Holocene relative sea-level data for the East Frisian barrier coast, NW Germany, southern North Sea

2021 ◽  
Vol 100 ◽  
Author(s):  
Friederike Bungenstock ◽  
Holger Freund ◽  
Alexander Bartholomä
Keyword(s):  
Sea Level ◽  
North Sea ◽  
Level Curve ◽  
Relative Sea Level ◽  
Southern North Sea ◽  
Isostatic Adjustment ◽  
Landscape Reconstruction ◽  
Time Period ◽  
Level Data ◽  
Age Constraints

Abstract Collecting sea-level data from restricted coastal areas is essential for understanding local effects on relative sea level. Here, a revised relative mean sea-level curve for the area of the East Frisian island Langeoog, northwestern Germany, for the time period from 7200 cal BP until Recent is presented. The revision is based on the reinterpretation of previously published and unpublished data following the HOLSEA standardisation of data handling. Altogether 68 sea-level data taken from 32 cores and outcrops from Langeoog, its back-barrier and the adjacent mainland, which have been collected since the 1950s for mapping and landscape reconstruction purposes, are presented. The age constraints, derived from radiocarbon ages of basal peat, intercalated peat and molluscs and optical dating of tidal deposits, were evaluated in terms of the HOLSEA sea-level protocol and their stratigraphic context. For 7200 cal BP until modern times, 30 sea-level index points with different uncertainty ranges were defined. Additionally, a factor of decompaction was estimated for the remaining basal peat samples as well as for the underlying sediments of intercalated peat samples. The comparison of the Langeoog relative sea-level curve with the relative sea-level curve from the western Netherlands shows that the Langeoog curve lies up to 0.80 m lower than the Dutch curve and diverges for the time before 6000 cal BP. Though the offset coincides with the overall predicted trend of glacial-isostatic adjustment, it is less than predicted. Our study provides a useful assessment of legacy data and contributes to an improved sea-level index dataset for the southern North Sea coast.

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