Late Holocene vertical land motion and relative sea-level changes: lessons from the British Isles

2011 ◽  
Vol 27 (1) ◽  
pp. 64-70 ◽  
Author(s):  
Ian Shennan ◽  
Glenn Milne ◽  
Sarah Bradley
Keyword(s):  
Sea Level ◽  
Late Holocene ◽  
British Isles ◽  
Sea Level Changes ◽  
Relative Sea Level ◽  
Vertical Land Motion

Late Holocene sea-level changes and isostasy in western Denmark

2006 ◽  
Vol 66 (2) ◽  
pp. 288-302 ◽  
Author(s):  
W. Roland Gehrels ◽  
Katie Szkornik ◽  
Jesper Bartholdy ◽  
Jason R. Kirby ◽  
Sarah L. Bradley ◽  
...  
Keyword(s):  
Salt Marsh ◽  
Sea Level ◽  
Salt Marshes ◽  
Late Holocene ◽  
Glacial Isostatic Adjustment ◽  
Sea Level Changes ◽  
Relative Sea Level ◽  
Isostatic Adjustment ◽  
Tidal Embayment ◽  
Made In

AbstractCores and exposed cliff sections in salt marshes around Ho Bugt, a tidal embayment in the northernmost part of the Danish Wadden Sea, were subjected to 14C dating and litho- and biostratigraphical analyses to reconstruct paleoenvironmental changes and to establish a late Holocene relative sea-level history. Four stages in the late Holocene development of Ho Bugt can be identified: (1) groundwater-table rise and growth of basal peat (from at least 2300 BC to AD 0); (2) salt-marsh formation (0 to AD 250); (3) a freshening phase (AD 250 to AD 1600?), culminating in the drying out of the marshes and producing a distinct black horizon followed by an aeolian phase with sand deposition; and (4) renewed salt-marsh deposition (AD 1600? to present). From 16 calibrated AMS radiocarbon ages on fossil plant fragments and 4 calibrated conventional radiocarbon ages on peat, we reconstructed a local relative sea-level history that shows a steady sea-level rise of 4 m since 4000 cal yr BP. Contrary to suggestions made in the literature, the relative sea-level record of Ho Bugt does not contain a late Holocene highstand. Relative sea-level changes at Ho Bugt are controlled by glacio-isostatic subsidence and can be duplicated by a glacial isostatic adjustment model in which no water is added to the world's oceans after ca. 5000 cal yr BP.

A relative sea-level history for Arviat, Nunavut, and implications for Laurentide Ice Sheet thickness west of Hudson Bay

2014 ◽  
Vol 82 (1) ◽  
pp. 185-197 ◽  
Author(s):  
Karen M. Simon ◽  
Thomas S. James ◽  
Donald L. Forbes ◽  
Alice M. Telka ◽  
Arthur S. Dyke ◽  
...  
Keyword(s):  
Sea Level ◽  
Late Holocene ◽  
Ice Sheet ◽  
Tidal Range ◽  
Laurentide Ice Sheet ◽  
Hudson Bay ◽  
Level Curve ◽  
Relative Sea Level ◽  
Vertical Land Motion ◽  
Crustal Uplift

AbstractThirty-six new and previously published radiocarbon dates constrain the relative sea-level history of Arviat on the west coast of Hudson Bay. As a result of glacial isostatic adjustment (GIA) following deglaciation, sea level fell rapidly from a high-stand of nearly 170 m elevation just after 8000 cal yr BP to 60 m elevation by the mid Holocene (~ 5200 cal yr BP). The rate of sea-level fall decreased in the mid and late Holocene, with sea level falling 30 m since 3000 cal yr BP. Several late Holocene sea-level measurements are interpreted to originate from the upper end of the tidal range and place tight constraints on sea level. A preliminary measurement of present-day vertical land motion obtained by repeat Global Positioning System (GPS) occupations indicates ongoing crustal uplift at Arviat of 9.3 ± 1.5 mm/yr, in close agreement with the crustal uplift rate inferred from the inferred sea-level curve. Predictions of numerical GIA models indicate that the new sea-level curve is best fit by a Laurentide Ice Sheet reconstruction with a last glacial maximum peak thickness of ~ 3.4 km. This is a 30–35% thickness reduction of the ICE-5G ice-sheet history west of Hudson Bay.

scholarly journals The zone of influence: matching sea level variability from coastal altimetry and tide gauges for vertical land motion estimation

Ocean Science ◽  
2021 ◽  
Vol 17 (1) ◽  
pp. 35-57
Author(s):  
Julius Oelsmann ◽  
Marcello Passaro ◽  
Denise Dettmering ◽  
Christian Schwatke ◽  
Laura Sánchez ◽  
...  
Keyword(s):  
Sea Level ◽  
Spatial Scales ◽  
Tide Gauges ◽  
Sea Level Changes ◽  
Relative Sea Level ◽  
Sea Level Variability ◽  
Vertical Land Motion ◽  
Spatial Coverage ◽  
Coupling Procedure ◽  
Zone Of Influence

Abstract. Vertical land motion (VLM) at the coast is a substantial contributor to relative sea level change. In this work, we present a refined method for its determination, which is based on the combination of absolute satellite altimetry (SAT) sea level measurements and relative sea level changes recorded by tide gauges (TGs). These measurements complement VLM estimates from the GNSS (Global Navigation Satellite System) by increasing their spatial coverage. Trend estimates from the SAT and TG combination are particularly sensitive to the quality and resolution of applied altimetry data as well as to the coupling procedure of altimetry and TGs. Hence, a multi-mission, dedicated coastal along-track altimetry dataset is coupled with high-frequency TG measurements at 58 stations. To improve the coupling procedure, a so-called “zone of influence” (ZOI) is defined, which confines coherent zones of sea level variability on the basis of relative levels of comparability between TG and altimetry observations. Selecting 20 % of the most representative absolute sea level observations in a 300 km radius around the TGs results in the best VLM estimates in terms of accuracy and uncertainty. At this threshold, VLMSAT-TG estimates have median formal uncertainties of 0.58 mm yr−1. Validation against GNSS VLM estimates yields a root mean square (rmsΔVLM) of VLMSAT-TG and VLMGNSS differences of 1.28 mm yr−1, demonstrating the level of accuracy of our approach. Compared to a reference 250 km radius selection, the 300 km zone of influence improves trend accuracies by 15 % and uncertainties by 35 %. With increasing record lengths, the spatial scales of the coherency in coastal sea level trends increase. Therefore, the relevance of the ZOI for improving VLMSAT-TG accuracy decreases. Further individual zone of influence adaptations offer the prospect of bringing the accuracy of the estimates below 1 mm yr−1.

scholarly journals Geomorphology of the Coastal Sand Dune Fields and Their Association with the Palaeolandscape Evolution of Akrotiri Peninsula, Lemesos, Cyprus

Geosciences ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 448
Author(s):  
Miltiadis Polidorou ◽  
Niki Evelpidou
Keyword(s):  
Sea Level ◽  
Late Holocene ◽  
Sand Dune ◽  
Salt Lake ◽  
Sea Level Changes ◽  
Coastal Sand Dune ◽  
Relative Sea Level ◽  
Upper Pleistocene ◽  
Dune Field ◽  
Coastal Sand

Two well-developed late Pleistocene dune fields have been identified on the western and eastern side of Akrotiri promontory (Lemesos, Cyprus). The dune fields extend immediately from the low level of their source beaches onto higher ground (>48 m amsl). Geomorphic observations supported by OSL dating and sedimentological data provided evidence of the dune development and for the palaeogeographic reconstruction of the area. Relative sea level changes and wave action during the upper Pleistocene and Holocene played an important role into the development of the palaeolandscape and affected the formation of the dunes. From the collected data the development of the western dune field started at 56.2 ± 5.5 ka when the relative sea level was at approximately −60 m and contributed to the development of the western tombolo of the area whereas the eastern dune field developed in the late Holocene, after the formation of the eastern spit that resulted in the formation of the Akrotiri Salt lake.

scholarly journals SEISMIC STRATIGRAPHY OF TRAPANDÉ BAY (SOUTHERN BRAZIL) TO STUDY SEA-LEVEL CHANGES AND DEPOSITION EVOLUTION IN THE UPPER QUATERNARY

2019 ◽  
Vol 37 (4) ◽  
Author(s):  
Vinicius S. Rodrigues ◽  
Daniel P. V. Alves ◽  
Luigi Jovane ◽  
Luis A. P. De Souza
Keyword(s):  
Sea Level ◽  
Late Holocene ◽  
Seismic Stratigraphy ◽  
Sao Paulo ◽  
São Paulo ◽  
Sea Level Changes ◽  
Relative Sea Level ◽  
Bathymetric Data ◽  
Depositional Evolution ◽  
Seismic Sections

ABSTRACT. The Quaternary relative sea-level in the Southeastern Brazilian margin is mostly studied using a sedimentary approach. In this work, we used high-resolution seismic and bathymetric data to study the depositional evolution in the Quaternary of Trapandé Bay, in São Paulo State, Brazil. Using seismic stratigraphy, we have analyzed over 198 km of seismic sections and we interpreted 6 seismic horizons which defined 5 seismic units. The oldest unit (U1) is related to the highstand deposits developed during Marine Isotope Stages (MIS) 5. The horizon H1 represents the erosional surface formed during the regression that culminated in the Last Glacial Maximum (LGM). After that, during the first stabilization period of sea-level rise, unit U2 formed and was subsequently eroded by a rapid flood of the bay, forming the erosional surface H2. During middle and late Holocene, it was identified a transgressive tract in the unit U3 and a progradational facies in unit U4, limited to the more coastal regions. Finally, unit U5 developed in Late Holocene, with depositional characteristics similar to those of present time. We found none seismic expression of Late Holocene high-frequency relative sea- level oscillations.Keywords: seismic stratigraphy, Quaternary oceanography, paleochannels, Cananéia-Iguape, Holocene transgression, relative sea-level.RESUMO.As variações relativas do nível do mar na margem sudeste do Brasil são estudadas principalmente a partir de uma abordagem sedimentológica. Neste trabalho, foram utilizados dados batimétricos e sísmicos de alta resolução para o estudo da evolução deposicional do Quaternário na Baía de Trapandé, no Estado de São Paulo, Brasil. Utilizando uma análise sismoestratigráfica, foram analisados mais de 198 km de seções sísmicas e interpretados 6 horizontes sísmicos que definiram 5 unidades sísmicas. A unidade mais antiga (U1) está relacionada com os depósitos de mar alto desenvolvidos durante o Estátio Isotópico 5. O horizonte H1 representa a superfície erosiva formada durante a regressão marinha que culminou no Último Máximo Glacial. Em seguida, durante a primeira estabilização da subida do nível do mar, a unidade U2 se depositou e em seguida foi erodida por um rápido afogamento da baía, formando a superfície erosiva H2. Durante o Holoceno médio e tardio, foram identificados um trato transgressivo na unidade U3 e fácies progradacionais na unidade U4, sendo estas últimas limitadas às áreas mais costeiras. Finalmente, a unidade U5 se desenvolveu durante o Holoceno tardio, com características deposicionais similares àquelas atuais. Não foram encontradas expressões sísmicas das oscilações de alta frequência do nível do mar do Holoceno tardio.Palavras-chave: Sismoestratigrafia, oceanografia do Quaternário, paleocanais, Cananéia-Iguape, Holoceno, transgressão, nível do mar relativo

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