scholarly journals Modelling of estuarine response to sea-level rise during the Holocene: Application to the Guadiana Estuary–SW Iberia

Geomorphology ◽  
2015 ◽  
Vol 232 ◽  
pp. 47-64 ◽  
Author(s):  
D.M.R. Sampath ◽  
T. Boski ◽  
C. Loureiro ◽  
C. Sousa
Keyword(s):  
Sea Level Rise ◽  
Sea Level ◽  
The Holocene ◽  
Guadiana Estuary

A radiocarbon chronology of Holocene climate change and sea-level rise at the Delmarva Peninsula, US Mid-Atlantic Coast

The Holocene ◽  
2021 ◽  
pp. 095968362110482
Author(s):  
Kelvin W Ramsey ◽  
Jaime L. Tomlinson ◽  
C. Robin Mattheus
Keyword(s):  
Climate Change ◽  
North America ◽  
Sea Level Rise ◽  
Sea Level ◽  
Early Holocene ◽  
Eastern North America ◽  
Delmarva Peninsula ◽  
The Holocene ◽  
Cool Climate ◽  
And Sea Level

Radiocarbon dates from 176 sites along the Delmarva Peninsula record the timing of deposition and sea-level rise, and non-marine wetland deposition. The dates provide confirmation of the boundaries of the Holocene subepochs (e.g. “early-middle-late” of Walker et al.) in the mid-Atlantic of eastern North America. These data record initial sea-level rise in the early Holocene, followed by a high rate of rise at the transition to the middle Holocene at 8.2 ka, and a leveling off and decrease in the late-Holocene. The dates, coupled to local and regional climate (pollen) records and fluvial activity, allow regional subdivision of the Holocene into six depositional and climate phases. Phase A (>10 ka) is the end of periglacial activity and transition of cold/cool climate to a warmer early Holocene. Phase B (10.2–8.2 ka) records rise of sea level in the region, a transition to Pinus-dominated forest, and decreased non-marine deposition on the uplands. Phase C (8.2–5.6 ka) shows rapid rates of sea-level rise, expansion of estuaries, and a decrease in non-marine deposition with cool and dry climate. Phase D (5.6–4.2 ka) is a time of high rates of sea-level rise, expanding estuaries, and dry and cool climate; the Atlantic shoreline transgressed rapidly and there was little to no deposition on the uplands. Phase E (4.2–1.1 ka) is a time of lowering sea-level rise rates, Atlantic shorelines nearing their present position, and marine shoal deposition; widespread non-marine deposition resumed with a wetter and warmer climate. Phase F (1.1 ka-present) incorporates the Medieval Climate Anomaly and European settlement on the Delmarva Peninsula. Chronology of depositional phases and coastal changes related to sea-level rise is useful for archeological studies of human occupation in relation to climate change in eastern North America, and provides an important dataset for future regional and global sea-level reconstructions.

scholarly journals Holocene sea level and climate interactions on wet dune slack evolution in SW Portugal: A model for future scenarios?

The Holocene ◽  
2018 ◽  
Vol 29 (1) ◽  
pp. 26-44 ◽  
Author(s):  
Manel Leira ◽  
Maria C Freitas ◽  
Tania Ferreira ◽  
Anabela Cruces ◽  
Simon Connor ◽  
...  
Keyword(s):  
Sea Level Rise ◽  
Sea Level ◽  
Environmental Changes ◽  
Sediment Accumulation ◽  
High Energy ◽  
Sediment Supply ◽  
Dune Slack ◽  
Ecological Stability ◽  
The Holocene ◽  
Climate Interactions

We examine the Holocene environmental changes in a wet dune slack of the Portuguese coast, Poço do Barbarroxa de Baixo. Lithology, organic matter, biological proxies and high-resolution chronology provide estimations of sediment accumulation rates and changes in environmental conditions in relation to sea-level change and climate variability during the Holocene. Results show that the wet dune slack was formed 7.5 cal. ka BP, contemporaneous with the last stages of the rapid sea-level rise. This depositional environment formed under frequent freshwater flooding and water ponding that allowed the development and post-mortem accumulation of abundant plant remains. The wetland evolved into mostly palustrine conditions over the next 2000 years, until a phase of stabilization in relative sea-level rise, when sedimentation rates slowed down to 0.04 mm yr−1, between 5.3 and 2.5 cal. ka BP. Later, about 0.8 cal. ka BP, high-energy events, likely due to enhanced storminess and more frequent onshore winds, caused the collapse of the foredune above the wetlands’ seaward margin. The delicate balance between hydrology (controlled by sea-level rise and climate change), sediment supply and storminess modulates the habitat’s resilience and ecological stability. This underpins the relevance of integrating past records in coastal wet dune slacks management in a scenario of constant adaptation processes.

scholarly journals The impact of Sea level rise in the guadiana estuary

2020 ◽  
Vol 44 ◽  
pp. 101169 ◽  
Author(s):  
Lara Mills ◽  
João Janeiro ◽  
Antonio Augusto Sepp Neves ◽  
Flávio Martins
Keyword(s):  
Sea Level Rise ◽  
Sea Level ◽  
The Impact ◽  
Guadiana Estuary

Sedimentary conditioning of a rocky strait during the Holocene transgression: Ría de Ferrol (NW Spain)

2020 ◽  
Author(s):  
Soledad García-Gil ◽  
Víctor Cartelle ◽  
Castor Muñoz-Sobrino ◽  
Natalia Martínez-Carreño ◽  
Iria García-Moreiras
Keyword(s):  
Sea Level Rise ◽  
Sea Level ◽  
Late Pleistocene ◽  
Nw Spain ◽  
The Holocene ◽  
Incised Valley ◽  
Sedimentary Evolution ◽  
Holocene Transgression ◽  
The Last Glacial Maximum ◽  
The Last Glacial

<p>Understanding coastal responses to relative sea level rise is key to be able to plan for future changes and develop a suitable managing strategy. The sedimentary record of the Late-Pleistocene and Holocene transgression provides a natural laboratory to study the long-term changes induced in coastal landscapes by the rapid sea level rise. As sea level rises, coastal morphology continually adapts towards equilibrium changing the landscape and reshaping the distribution of sedimentary environments.<br>The Ría de Ferrol is a confined tide-dominated incised valley located in the mesotidal passive Atlantic margin of western Galicia (NW Spain).  A multidisciplinary approach was used to identify the elements of sedimentary architecture within its sedimentary record since the Last Glacial Maximum. The sedimentary evolution was reconstructed combining seismic and sedimentary facies analysis with radiocarbon, geochemical and pollen data.<br>The Ría de Ferrol is characterised by a particular morphology with a rock-incised narrow channel in the middle of the basin (the Ferrol Strait) connecting an inner shallower sector with an outer deeper sector. The inner sector is characterised by low energetic conditions and is where the main fluvial inputs occur. The outer sector is connected to the shelf.<br>The main factor influencing the sedimentary evolution of the Ría de Ferrol incised valley was Late Pleistocene and Holocene sea-level rise. However, this evolution was modulated by the antecedent morphology, particularly once the middle strait became flooded during the Holocene transgression. Three main phases of evolution are distinguished: a fluvial valley drained by a braided river system, a tide-dominated estuary and a shallow marine basin (ria).<br>During the lowstand of the Last Glacial Maximum (ca 20 kyr BP), the ria was a fluvial valley whose sediments are mainly preserved in the inner sector. Sediments cores recovered sediments from ponds and stagnant areas, dated to be older than 10790-11170 cal yr BP.<br>During the Holocene, the basin turned into a tide-dominated estuary whose facies distribution was conditioned by the strait. The strait acted as a rock-bounded tidal inlet enhancing tidal erosion and deposition at both ends, where an ebb-tidal delta and tidal sandbanks appear. At this time, extensive tidal flats occupied most of the inner sector, dissected by estuarine channels of varied dimensions. Radiocarbon data showed ages from 8610-8910 to 5760-5940 cal yr BP.<br>An erosive episode is identified after 6 cal kyr BP with the formation of a ravinement surface. Wave and tidal energy were split by the middle strait. A wave ravinement surface is identified in the outer sector, while a coetaneous tidal ravinement surface occurs in the inner sector.<br>Slow sea-level rise after ca 4 ka BP finally forced rivers to retreat to the present position, causing the dispersion of their energy and leading to the final evolution of the area into a fully marine system.</p>

Holocene sea-level history of the Canadian Beaufort shelf

1993 ◽  
Vol 30 (1) ◽  
pp. 103-108 ◽  
Author(s):  
Philip R. Hill ◽  
Arnaud Héquette ◽  
Marie-Hélène Ruz
Keyword(s):  
Sea Level Rise ◽  
Sea Level ◽  
Coastal Zone ◽  
Marine Sediments ◽  
Tidal Marsh ◽  
Relative Sea Level ◽  
The Holocene ◽  
Single Piece ◽  
History Of ◽  
Holocene Sea Level

New radiocarbon ages pertaining to the Holocene sea-level history of the Canadian Beaufort shelf are presented. The ages were obtained on samples of freshwater and tidal-marsh peat beds from offshore boreholes and shallow cores in the coastal zone and on molluscs and a single piece of wood deposited in foraminifera-bearing marine sediments. Although none of the samples record directly the position of relative sea level, the suite of ages constrains the regional curve sufficiently to suggest a faster rate of mid Holocene sea level rise (7–14 mm/a) than previously thought. The rate of relative rise slowed markedly in the last 3000 years, approaching the present at a maximum probable rate of 2.5 mm/a.

scholarly journals In Anticipation of Extirpation

2020 ◽  
Vol 12 (1) ◽  
pp. 113-131 ◽  
Author(s):  
Patrick D. Nunn
Keyword(s):  
Sea Level Rise ◽  
Sea Level ◽  
Ice Age ◽  
Optimal Solutions ◽  
The Holocene ◽  
The Past ◽  
Coastal Cities ◽  
The People ◽  
Northwest Europe ◽  
Last Ice Age

Abstract As concern about sea level rise grows and optimal solutions are sought to address its causes and effects, little attention has been given to past analogs. This article argues that valuable insights into contemporary discussions about future sea level rise can be gained from understanding those of the past, specifically the ways in which coastal peoples and societies reacted during the period of postglacial sea level rise. For much of the Holocene, most continental people eschewed coastal living in favor of inland areas. In many places large coastal settlements appeared only after the development of polities and associated crosswater networks. Postglacial sea level rise affected coastal living in ways about which we remain largely ignorant. Yet, millennia-old stories from Australia and northwest Europe show how people responded, from which we can plausibly infer their motivations. Stories from Australia say the people have succeeded in halting sea level rise, whereas those from northwest Europe indicate that people have failed, leading to the drowning of coastal cities such as Ys (Brittany) and Cantre’r Gwaelod (Wales). This distinction is explained by the contrasting duration of postglacial sea level rise in these regions; around Australia, sea level stopped rising 7,000 years ago, while along many coasts of northwest Europe it has risen unceasingly since the last ice age ended. The nature of past human and societal responses to postglacial sea level rise holds important insights for the future.

scholarly journals Geomorphology of Canyon Outlets in Zrmanja River Estuary and Its Effect on the Holocene Flooding of Semi-enclosed Basins (the Novigrad and Karin Seas, Eastern Adriatic)

Water ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 2807
Author(s):  
Ozren Hasan ◽  
Slobodan Miko ◽  
Dea Brunović ◽  
George Papatheodorou ◽  
Dimitris Christodolou ◽  
...  
Keyword(s):  
High Resolution ◽  
Sea Level Rise ◽  
Sea Level ◽  
Geophysical Methods ◽  
River Estuary ◽  
Side Scan Sonar ◽  
The Holocene ◽  
Karst Environment ◽  
Gis Environment ◽  
Holocene Sea Level

Detailed multi-beam bathymetry, sub-bottom acoustic, and side-scan sonar observations of submerged canyons with tufa barriers were used to characterize the Zrmanja River karst estuary on the eastern Adriatic coast, Croatia. This unique karst environment consists of two submerged karst basins (Novigrad Sea and Karin Sea) that are connected with river canyons named Novsko Ždrilo and Karinsko Ždrilo. The combined use of high-resolution geophysical data with legacy topography and bathymetry data in a GIS environment allowed for the description and interpretation of this geomorphological setting in relation to the Holocene sea-level rise. The tufa barriers had a predominant influence on the Holocene flooding dynamics of the canyons and karst basins. Here, we describe the possible river pathways from the basins during the lowstand and the formation of a lengthening estuary during the Holocene sea-level rise. Based on the analyzed morphologies and the relative sea-level curve for the Adriatic Sea, the flooding of the Novsko Ždrilo occurred 9200 years before present (BP) and Karinsko Ždrilo was flooded after 8400 years BP. The combination of high-resolution geophysical methods gave an accurate representation of the karst estuarine seafloor and the flooding of semi-isolated basins due to sea-level rise.

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