Tempestite frequency curves: a key to Late Ordovician and Early Silurian subsidence, sea-level change, and orbital forcing in the Anticosti foreland basin, Quebec, Canada

2007 ◽  
Vol 44 (3) ◽  
pp. 413-431 ◽  
Author(s):  
D GF Long
Keyword(s):  
Sea Level ◽  
Foreland Basin ◽  
Sediment Flux ◽  
Sediment Loading ◽  
Orbital Eccentricity ◽  
The South ◽  
Storm Activity ◽  
Sea Levels ◽  
Anticosti Island ◽  
Frequency Curves

Following partial closure of the northern Iapetus Ocean along the Newfoundland segment of the St. Lawrence Promontory, subsidence along the Anticosti Platform was influenced by residual thermal subsidence, renewed tectonic loading by thrust sheets to the south, and sediment loading. Basement subsidence, calculated by removing the effects of sediment loading, was between 2 and 5 cm/ka in the Caradocian, increasing to 8.6 cm/ka in the Pusgillian and Cautleyan, and reaching a maximum of 17.7 cm/ka in the Rawtheyan, during deposition of the Princeton Lake and Vauréal Formations. A marked decline in subsidence, beginning in the Hirnantian and continuing into the Early Silurian, may reflect decoupling of thrust loads to the south, although a further stage of thrust loading may have occurred in the Aeronian during deposition of the lower part of the Jupiter Formation. Storm frequency curves, produced using tempestite abundance, thickness, and grain size through more than a kilometre of carbonate strata on Anticosti Island, allow recognition of long period, 3rd-order trends. These are in part similar to local sea-level trends deduced from direct interpretation of sedimentary structures, but depart significantly from paleontological-based sea-level curves. Shorter period 4th-order cycles appear to be related to orbital eccentricity with periods of 100 and 400 ka. These may reflect periods with falling sea levels, increasing storm activity, or enhanced sediment flux to the middle and outer shelf.

scholarly journals ANALYSIS OF MAXIMUM SEA LEVELS IN SOUTHERN ENGLAND

1978 ◽  
Vol 1 (16) ◽  
pp. 53
Author(s):  
J. Graff ◽  
D.L. Blackman
Keyword(s):  
Sample Size ◽  
Sea Level ◽  
Linear Trend ◽  
South Coast ◽  
Annual Maximum ◽  
Return Periods ◽  
The South ◽  
Mean Sea Level ◽  
Sea Levels ◽  
Southern England

Along the south coast of England, series of observed annual maximum sea levels, ranging from 16 years to 125 years have been analysed for each of 10 ports. The Jenkinson method of analysis was used to compute the frequency of recurrence of extreme levels. For a number of these ports the series of annual maxima are shown to have significant trends of the same order as those for mean sea level. The Jenkinson method can be simply adjusted to cope with maxima having a component linear trend, making it possible to allow for such trends in computing the frequency of recurrence of extreme levels. If a trend in the annual maxima varies throughout the sample of observations it is shown that difficulties arise in using the Jenkinson method to compute acceptable statistics. It is also shown that for certain ports having long series of observed annual maxima it may be necessary to restrict the sample size of observations in order to compute estimates of the recurrence of extreme levels within reasonable return periods.

scholarly journals A century of sea level data and the UK's 2013/14 storm surges: an assessment of extremes and clustering using the Newlyn tide gauge record

2014 ◽  
Vol 11 (4) ◽  
pp. 1995-2028 ◽  
Author(s):  
M. P. Wadey ◽  
I. D. Haigh ◽  
J. M. Brown
Keyword(s):  
Sea Level ◽  
Return Period ◽  
Tide Gauge ◽  
Storm Surges ◽  
High Water ◽  
Lower Probability ◽  
Tide Gauge Record ◽  
Storm Activity ◽  
Sea Levels ◽  
Level Data

Abstract. For the UK's longest and most complete sea level record (Newlyn), we assess extreme high water events and their temporal clustering; prompted by the 2013/2014 winter of flooding and storms. These are set into context against this almost 100 yr record. We define annual periods for which storm activity, tides and sea levels can be compared on a year-by-year basis. Amongst the storms and high tides which affected Newlyn the recent winter produced the largest recorded high water (3 February 2014) and five others above a 1 in 1 yr return period. The large magnitude of tide and mean sea level, and the close inter-event spacings (of large return period high waters), suggests that the 2013/2014 high water "season" may be considered the most extreme on record. However, storm and sea level events may be classified in different ways. For example in the context of sea level rise (which we calculate linearly as 1.81 ± 0.1 mm yr−1 from 1915 to 2014), a lower probability combination of surge and tide occurred on 29 January 1948, whilst 1995/1996 storm surge season saw the most high waters of ≥ 1 in 1 yr return period. We provide a basic categorisation of five types of high water cluster, ranging from consecutive tidal cycles to multiple years. The assessment is extended to other UK sites (with shorter sea level records and different tide-surge characteristics), which suggests 2013/2014 was extreme, although further work should assess clustering mechanisms and flood system "memory".

scholarly journals Magnetostratigraphic dating of the Paleogene synorogenic sediments of the NE sector of the Ebro Foreland Basin (Spanish Pyrenees)

2021 ◽  
Author(s):  
Charlotte Peigney ◽  
Elisabet Beamud ◽  
Òscar Gratacós ◽  
Eduard Roca ◽  
Alberto Sáez ◽  
...  
Keyword(s):  
Regional Scale ◽  
Foreland Basin ◽  
Late Eocene ◽  
Tectonic Activity ◽  
Orbital Eccentricity ◽  
The South ◽  
Drainage Pattern ◽  
Ebro Basin ◽  
Alluvial Deposits ◽  
Thrust Sheets

<p>In foreland settings at the front of active orogens, the aggradation/progradation of fluvial fans and sedimentary changes in lacustrine systems depends greatly on the tectonic activity and the derived drainage pattern changes in the hinterland. As a result of the emplacement and erosion of the South-Pyrenean thrust sheets, a system of N-S fluvial fans prograded into the Ebro foreland basin from late Eocene to Oligocene times. After the synorogenic deposition of the Priabonian (late Eocene) marine evaporites of the Cardona Fm, the Ebro Basin was characterized by internal drainage, with the fluvial fans grading to lacustrine systems at the center of the basin, which developed and migrated in response to subsidence changes. All these deposits were deformed by variably oriented salt-detached folds, evidencing the basinwards propagation of the deformation. In this work, we study the Solsona-Sanaüja fluvial fan system by means of litostratigraphy and magnetostratigraphy aiming to determine the age of the transition from fluvial fan to lacustrine systems in the NE sector of the Ebro Basin. The precise dating of this succession reveals causal relationships between tectonic and climatic processes affecting the source-to-sink system, including changes in the depositional style linked to the evolution of the Pyrenean fold and thrust belt.</p><p>Our new magnetostratigraphic study consisted in the sampling and analysis of 195 samples along a ca. 1800m thick stratigraphic section of the late Eocene-Oligocene succession in the northern limb of the NW-SE oriented Sanaüja Anticline. Our results show overall Priabonian to Rupelian ages for the succession, considering an age of 36 Ma. (C16n) for the top of the Cardona Fm from previous magnetostratigraphic studies. This allows dating the end of the evaporitic sedimentation (top of the Barbastro Fm) as Priabonian and establishing a late Priabonian to early Rupelian (C13r) age for the transition from the younger lacustrine deposits (Torà Fm) to the continuous and most important fluvial fan episode of progradation in the study area. The final progradation of the fluvial fan system was coeval to a tectonically controlled reorganization of the drainage pattern of the basin responding to the emplacement of the South-Pyrenean thrust sheets. Meanwhile, smaller scale (hectometric-decametric) alternation between lacustrine and alluvial deposits was possibly driven by climatic changes related to orbital eccentricity cycles. The correlation and integration of these results with previous magnetostratigraphic studies in the area can help analyzing sedimentation patterns and architectural changes in the basin margins at a regional scale.</p>

Sediment flux across the south-Pyreneean foreland basin. A contribution to the S2S-Future network. 

2021 ◽  
Author(s):  
Philémon Juvany ◽  
Miguel Garcés
Keyword(s):  
Foreland Basin ◽  
Sediment Flux ◽  
Provenance Analysis ◽  
The South ◽  
Flexural Response ◽  
Eastern Pyrenees ◽  
Sediment Routing ◽  
Sedimentary Provenance ◽  
Source To Sink ◽  
Volumetric Quantification

<div> </div><div> <p>The early Eocene was a period of the intense collision during the formation of the Pyrenees. The flexural response to loading of the overriding European plate led to the formation of an elongated foredeep on the subducting Iberian plate which connected westward to the Atlantic Ocean. A thrust salient formed in the central Pyrenees, where Mesozoic Cover units travelled southwards on top of Triassic salt detachment. This process resulted in the sequencing of the foreland basin in different isolated sub-basins such as the Ripoll basin in the East, the Tremp-Graus and Ainsa-Jaca basins in central and western south Pyrenees and the Ager basin located south of the Tremp-Graus basin.  The precise timing and surface processes associated to this reorganization of the sedimentary routing system remains not totally understood. Indeed, various sedimentary provenance studies show that the sediments of the Tremp-Graus basin were sourced from a different catchment zone than those of the Ager basin. Besides, the Ripoll basin sediments provenance analysis shows major similarities with the Ager basin, suggesting a common catchment area in the Eastern Pyrenees. However, it has been pointed out that the clastic systems feeding the rapidly subsiding sink of the Ripoll through could not find their way towards the shallower Ager basin. In this PhD project we aim at providing further constraints to the paleogeographic reconstruction and sediment routing systems of the South Eastern Pyrenees in the light of a revised chronostratigraphic scheme. A Source-to-Sink approach will be followed to study the sediment Routing Systems and to decode the climatic and tectonic signal from the sedimentary record. It will follow a volumetric quantification of the sediment budget over the entire foreland, and a comparison with eroded rock volumes of the whole Pyrenees. The resulting revised scenario will seek conciliation of all available data from the stratigraphic, structural, petrologic, geochronologic and sedimentologic datasets with new radiogenic isotopes sedimentary provenance analysis.  </p> </div>

Last Interglacial Sea Levels and Coastal Caves in the Cape Province, South Africa

1986 ◽  
Vol 25 (2) ◽  
pp. 189-198 ◽  
Author(s):  
Q. B. Hendey ◽  
T. P. Volman
Keyword(s):  
South Africa ◽  
Sea Level ◽  
Southern Africa ◽  
River Mouth ◽  
South Coast ◽  
Early Pleistocene ◽  
Last Interglacial ◽  
The South ◽  
Sea Levels

The dating of the 6 to 8-m shoreline in southern Africa as early Pleistocene prompted a reassessment of evidence from archaeological cave sites on the south coast of the Cape Province which had suggested that this shoreline is of last interglacial age. The successions in the caves at Klasies River Mouth and Die Kelders have been misinterpreted. In fact, they confirm a pre-last interglacial age for this feature. These sites, together with Herolds Bay Cave, indicate that in southern Africa the only last interglacial shoreline above present sea level is at about 4 m, and that it dates from isotope substage 5e.

scholarly journals Quantifying Thresholds of Barrier Geomorphic Change in a Cross-Shore Sediment Partitioning Model

2020 ◽  
Author(s):  
Daniel J. Ciarletta ◽  
Jennifer L. Miselis ◽  
Justin L. Shawler ◽  
Christopher J. Hein
Keyword(s):  
Sea Level Rise ◽  
Sea Level ◽  
Cross Sections ◽  
Sediment Flux ◽  
State Transitions ◽  
Morphologic Change ◽  
Relative Sea Level ◽  
Coastal System ◽  
Sea Levels ◽  
Relative Sea Level Rise

Abstract. Barrier coasts, including barrier islands, beach-ridge plains, and associated landforms, can assume a broad spectrum of morphologies over decadal scales that reflect conditions of sediment availability, accommodation, and relative sea-level rise. However, the quantitative thresholds of these controls on barrier-system behavior remain largely unexplored, even as modern sea-level rise and anthropogenic modification of sediment availability increasingly reshape the world’s sandy coastlines. In this study, we conceptualize barrier coasts as sediment partitioning frameworks, distributing sand delivered from the shoreface to the subaqueous and subaerial components of the coastal system. Using an idealized morphodynamic model, we explore thresholds of behavioral/morphologic change over decadal to centennial timescales, simulating barrier evolution within quasi-stratigraphic morphological cross-sections. Our results indicate a wide diversity of barrier behaviors can be explained by the balance of fluxes delivered to the beach versus the dune/backbarrier, including previously understudied forms of transgression that allow the subaerial system to continue accumulating sediment during landward migration. Most importantly, our results show that barrier state transitions between progradation, cross-shore amalgamation, aggradation, and transgression are controlled largely through balances within a narrow range of relative sea-level rise and sediment flux. This suggests that, in the face of rising sea levels, subtle changes in sediment fluxes could result in significant changes in barrier morphology. We also demonstrate that modeled barriers with reduced vertical sediment accommodation are highly sensitive to the magnitude and direction of shoreface fluxes. Therefore, natural barriers with limited sediment accommodation could allow for exploration of the future effects of sea-level rise and changing flux magnitudes over a period of years as opposed to the decades required for similar responses in sediment-rich barrier systems. Finally, because our model creates stratigraphy generated under different input parameters, we propose it could be used in combination with stratigraphic data to hindcast the sensitivity of existing barriers and infer changes in pre-historic morphology, which we anticipate will provide a baseline to assess the reliability of forward modeling predictions.

scholarly journals Quantifying thresholds of barrier geomorphic change in a cross-shore sediment-partitioning model

2021 ◽  
Vol 9 (2) ◽  
pp. 183-203
Author(s):  
Daniel J. Ciarletta ◽  
Jennifer L. Miselis ◽  
Justin L. Shawler ◽  
Christopher J. Hein
Keyword(s):  
Sea Level Rise ◽  
Sea Level ◽  
Cross Sections ◽  
Sediment Flux ◽  
State Transitions ◽  
Morphologic Change ◽  
Relative Sea Level ◽  
Coastal System ◽  
Sea Levels ◽  
Relative Sea Level Rise

Abstract. Barrier coasts, including barrier islands, beach-ridge plains, and associated landforms, can assume a broad spectrum of morphologies over multi-decadal scales that reflect conditions of sediment availability, accommodation, and relative sea-level rise. However, the quantitative thresholds of these controls on barrier-system behavior remain largely unexplored, even as modern sea-level rise and anthropogenic modification of sediment availability increasingly reshape the world's sandy coastlines. In this study, we conceptualize barrier coasts as sediment-partitioning frameworks, distributing sand delivered from the shoreface to the subaqueous and subaerial components of the coastal system. Using an idealized morphodynamic model, we explore thresholds of behavioral and morphologic change over decadal to centennial timescales, simulating barrier evolution within quasi-stratigraphic morphological cross sections. Our results indicate a wide diversity of barrier behaviors can be explained by the balance of fluxes delivered to the beach vs. the dune or backbarrier, including previously understudied forms of transgression that allow the subaerial system to continue accumulating sediment during landward migration. Most importantly, our results show that barrier state transitions between progradation, cross-shore amalgamation, aggradation, and transgression are controlled largely through balances within a narrow range of relative sea-level rise and sediment flux. This suggests that, in the face of rising sea levels, subtle changes in sediment fluxes could result in significant changes in barrier morphology. We also demonstrate that modeled barriers with reduced vertical sediment accommodation are highly sensitive to the magnitude and direction of shoreface fluxes. Therefore, natural barriers with limited sediment accommodation could allow for exploration of the future effects of sea-level rise and changing flux magnitudes over a period of years as opposed to the decades required for similar responses in sediment-rich barrier systems. Finally, because our model creates stratigraphy generated under different input parameters, we propose that it could be used in combination with stratigraphic data to hindcast the sensitivity of existing barriers and infer changes in prehistoric morphology, which we anticipate will provide a baseline to assess the reliability of forward modeling predictions.

scholarly journals Economic damages from Hurricane Sandy attributable to sea level rise caused by anthropogenic climate change

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Benjamin H. Strauss ◽  
Philip M. Orton ◽  
Klaus Bittermann ◽  
Maya K. Buchanan ◽  
Daniel M. Gilford ◽  
...  
Keyword(s):  
Climate Change ◽  
Sea Level Rise ◽  
Sea Level ◽  
East Coast ◽  
The United States ◽  
Hurricane Sandy ◽  
Water Levels ◽  
Anthropogenic Climate Change ◽  
Economic Damage ◽  
Sea Levels

AbstractIn 2012, Hurricane Sandy hit the East Coast of the United States, creating widespread coastal flooding and over $60 billion in reported economic damage. The potential influence of climate change on the storm itself has been debated, but sea level rise driven by anthropogenic climate change more clearly contributed to damages. To quantify this effect, here we simulate water levels and damage both as they occurred and as they would have occurred across a range of lower sea levels corresponding to different estimates of attributable sea level rise. We find that approximately $8.1B ($4.7B–$14.0B, 5th–95th percentiles) of Sandy’s damages are attributable to climate-mediated anthropogenic sea level rise, as is extension of the flood area to affect 71 (40–131) thousand additional people. The same general approach demonstrated here may be applied to impact assessments for other past and future coastal storms.

Records of sea-level highstand over the Meghalayan age/late Holocene from uranium-series ages of beachrock in Weizhou Island, northern South China Sea

The Holocene ◽  
2021 ◽  
pp. 095968362110332
Author(s):  
Tingli Yan ◽  
Kefu Yu ◽  
Rui Wang ◽  
Wenhui Liu ◽  
Leilei Jiang
Keyword(s):  
South China Sea ◽  
Sea Level ◽  
South China ◽  
Intertidal Zone ◽  
Meteoric Water ◽  
Northern South China Sea ◽  
Water Environment ◽  
Sea Levels ◽  
China Sea ◽  
Micro Structures

Beachrock is considered a good archive for past sea-levels because of its unique formation position (intertidal zone). To evaluate sea-level history in the northern South China Sea, three well-preserved beachrock outcrops (Beigang, Gongshanbei, and Hengling) at Weizhou Island, northern South China Sea were selected to examine their relative elevation, sedimentological, mineralogical, and geochemical characteristics. Acropora branches with well-preserved surface micro-structures were selected from the beachrocks and used to determine the ages of these beachrocks via U-series dating. The results show that the beachrocks are composed of coral reef sediments, terrigenous clastics, volcanic clastics, and various calcite cements. These sediments accumulated in the intertidal zone of Weizhou Island were then cemented in a meteoric water environment. The U-series ages of beachrocks from Beigang, Gongshanbei, and Hengling are 1712–768 ca. BP, 1766–1070 ca. BP, and 1493–604 ca. BP (before 1950 AD) respectively. Their elevations are 0.91–1.16 m, 0.95–1.24 m, and 0.82–1.17 m higher than the modern homologous sedimentary zones, respectively. Therefore, we concluded that the sea-level in the Meghalayan age (1766–604 ca. BP) was 0.82–1.24 m higher than the present, and that the sea-level over this period showed a declining trend.

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