Geomorphology and Quaternary geology of Codroy Lowland and adjacent plateaus, southwest Newfoundland

1977 ◽  
Vol 14 (9) ◽  
pp. 2101-2120 ◽  
Author(s):  
Ian A. Brookes
Keyword(s):  
Sea Level Rise ◽  
Sea Level ◽  
Long Range ◽  
Quaternary Geology ◽  
Quaternary Sediments ◽  
Isostatic Rebound ◽  
Quaternary Glaciation ◽  
Late Wisconsinan ◽  
Glacial Landforms ◽  
Rising Sea Level

The paper presents an interpretation of preglacial and glacial landforms and Quaternary sediments of approximately 2000 km2 of southwest Newfoundland. The area comprises lithologically controlled Codroy Lowland, floored by Late Wisconsinan glacial deposits, flanked by Long Range and Anguille Mountains plateaus, which bear pre-Quaternary fluvial denudation surfaces and evidence in weathering zones of multiple Quaternary glaciation. Part of Long Range Mountains bears no evidence of glaciation, and extensive areas there, including all of the Anguille Mountains, were ice-free at the Late Wisconsinan glacial maximum. The maximum glacial condition for which evidence is preserved prevailed some time before the Late Wisconsinan and surfaces exposed since then have not passed through an interglacial weathering regime, so that this condition probably can be assigned to an Early Wisconsinan glacial stade.Coastal cliffs on Cabot Strait expose a Late Wisconsinan drift sequence which indicates: (1) advancing ice moved perpendicular to the coast, striating rock and depositing till; (2) subsequently the coast was deglaciated and marine overlap ensued, approximately 14 000 years ago; (3) ice readvanced, probably down Codroy Lowland with a halt near the present coast, and deposited moraines at about 12 600 years ago.Total postglacial isostatic rebound has raised marine features only 5–10 m above rising sea level. The shoreline has likely been submerging since about 11 000 years BP under the combined influences of eustatic sea level rise, dominant over rebound, and possible subsidence beneath the load of more than 500 m of water in Laurentian Channel, only 30 km offshore.

Late Wisconsinan Glaciation of the Central Sector of the Canadian High Arctic

2000 ◽  
Vol 54 (2) ◽  
pp. 182-188 ◽  
Author(s):  
Scott F. Lamoureux ◽  
John H. England
Keyword(s):  
Sea Level Rise ◽  
Sea Level ◽  
Direct Evidence ◽  
Ice Sheet ◽  
Strong Support ◽  
High Arctic ◽  
Canadian High Arctic ◽  
Northern Flank ◽  
Late Wisconsinan ◽  
Glacial Landforms

Geomorphic and chronological evidence from Cornwall Island in the Canadian High Arctic Archipelago provides direct evidence for the age and dynamics of the center and northern flank of the Innuitian Ice Sheet that covered the islands during the Late Wisconsonian glacial maximum. Dispersal of erratics and glacial landforms indicate that ice flowed north across the island and converged with ice flowing northwest from Norwegian Bay. Cornwall Island was initially deglaciated at 9000 14C yr B.P. in near synchrony with widely separated sites in adjacent parts of the archipelago. This regional chronology suggests rapid breakup of a marine-based Innuitian Ice Sheet that was destabilized by rapid eustatic sea-level rise and ice thinning during the early Holocene. This evidence provides strong support for a recently proposed ice divide spanning the central part of the Canadian High Arctic and indicates that most, if not all, of the region was glaciated during the Late Wisconsinan.

scholarly journals Late Holocene sea-level change around Newfoundland

2007 ◽  
Vol 44 (10) ◽  
pp. 1453-1465 ◽  
Author(s):  
Julia F Daly ◽  
Daniel F Belknap ◽  
Joseph T Kelley ◽  
Trevor Bell
Keyword(s):  
Salt Marsh ◽  
Sea Level Rise ◽  
Sea Level ◽  
Late Holocene ◽  
Sea Level Change ◽  
Laurentide Ice Sheet ◽  
Change Analysis ◽  
Level Change ◽  
Rising Sea Level ◽  
Holocene Sea Level

Differential sea-level change in formerly glaciated areas is predicted owing to variability in extent and timing of glacial coverage. Newfoundland is situated close to the margin of the former Laurentide ice sheet, and the orientation of the shoreline affords the opportunity to investigate variable rates and magnitudes of sea-level change. Analysis of salt-marsh records at four sites around the island yields late Holocene sea-level trends. These trends indicate differential sea-level change in recent millennia. A north–south geographic trend reflects submergence in the south, very slow sea-level rise in the northeast, and a recent transition from falling to rising sea-level at the base of the Northern Peninsula. This variability is best explained as a continued isostatic response to deglaciation.

scholarly journals Late glacial to early Holocene development of southern Kattegat

1969 ◽  
Vol 28 ◽  
pp. 21-24 ◽  
Author(s):  
Carina Bendixen ◽  
Jørn Bo Jensen ◽  
Ole Bennike ◽  
Lars Ole Boldreel
Keyword(s):  
Sea Level Rise ◽  
Sea Level ◽  
Late Glacial ◽  
Last Deglaciation ◽  
Isostatic Rebound ◽  
North East ◽  
The North ◽  
Tectonically Active ◽  
The Last Deglaciation ◽  
The Øresund Region

The Kattegat region is located in the wrench zone between the Fennoscandian shield and the Danish Basin that has repeatedly been tectonically active. The latest ice advances during the Quaternary in the southern part of Kattegat were from the north-east, east and south-east (Larsen et al. 2009). The last deglaciation took place at c. 18 to 17 ka BP (Lagerlund & Houmark-Nielsen 1993; Houmark-Nielsen et al. 2012) and was followed by inundation of the sea that formed a palaeo-Kattegat (Conradsen 1995) with a sea level that was relatively high because of glacio-isostatic depression. Around 17 ka BP, the ice margin retreated to the Øresund region and meltwater from the retreating ice drained into Kattegat. Over the next millennia, the region was characterised by regression because the isostatic rebound of the crust surpassed the ongoing eustatic sea-level rise, and a regional lowstand followed at the late glacial to Holocene transition (Mörner 1969; Thiede 1987; Lagerlund & Houmark-Nielsen 1993; Jensen et al. 2002a, b).

scholarly journals Statistical modeling of the long-range-dependent structure of barrier island framework geology and surface geomorphology

2018 ◽  
Vol 6 (2) ◽  
pp. 431-450 ◽  
Author(s):  
Bradley A. Weymer ◽  
Phillipe Wernette ◽  
Mark E. Everett ◽  
Chris Houser
Keyword(s):  
Sea Level Rise ◽  
Sea Level ◽  
Long Range ◽  
Moving Average ◽  
Quantitative Measure ◽  
Barrier Island ◽  
Barrier Islands ◽  
Wave Number ◽  
Statistical Parameters ◽  
Padre Island

Abstract. Shorelines exhibit long-range dependence (LRD) and have been shown in some environments to be described in the wave number domain by a power-law characteristic of scale independence. Recent evidence suggests that the geomorphology of barrier islands can, however, exhibit scale dependence as a result of systematic variations in the underlying framework geology. The LRD of framework geology, which influences island geomorphology and its response to storms and sea level rise, has not been previously examined. Electromagnetic induction (EMI) surveys conducted along Padre Island National Seashore (PAIS), Texas, United States, reveal that the EMI apparent conductivity (σa) signal and, by inference, the framework geology exhibits LRD at scales of up to 101 to 102 km. Our study demonstrates the utility of describing EMI σa and lidar spatial series by a fractional autoregressive integrated moving average (ARIMA) process that specifically models LRD. This method offers a robust and compact way of quantifying the geological variations along a barrier island shoreline using three statistical parameters (p, d, q). We discuss how ARIMA models that use a single parameter d provide a quantitative measure for determining free and forced barrier island evolutionary behavior across different scales. Statistical analyses at regional, intermediate, and local scales suggest that the geologic framework within an area of paleo-channels exhibits a first-order control on dune height. The exchange of sediment amongst nearshore, beach, and dune in areas outside this region are scale independent, implying that barrier islands like PAIS exhibit a combination of free and forced behaviors that affect the response of the island to sea level rise.

Late Wisconsinan glaciation of Amund and Ellef Ringnes islands, Nunavut: evidence for the configuration, dynamics, and deglacial chronology of the northwest sector of the Innuitian Ice Sheet

2003 ◽  
Vol 40 (3) ◽  
pp. 351-363 ◽  
Author(s):  
Nigel Atkinson
Keyword(s):  
Sea Level ◽  
Ice Sheet ◽  
Marine Fauna ◽  
Ice Flow ◽  
Ice Caps ◽  
Ice Cap ◽  
Sequential Entry ◽  
Data Record ◽  
Late Wisconsinan ◽  
Glacial Landforms

Geomorphic and chronologic evidence from Amund and Ellef Ringnes islands documents the configuration, dynamics, and collapse of the northwest sector of the Innuitian Ice Sheet. These data record the inundation of the Ringnes Islands by northwestward-flowing ice from divides spanning the alpine and lowland sectors of the Innuitian Ice Sheet. Ice-flow indicators and granite dispersal along eastern Amund Ringnes Island suggest Massey Sound was filled by an ice stream discharging coalescent alpine and lowland ice from Norwegian Bay. In contrast, the interior of Amund Ringnes Island was overridden by predominantly non-erosive, granite-free ice from a divide in the lowland sector of the ice sheet. Glacial landforms on Ellef Ringnes Island record coverage by largely non-erosive ice, but it remains uncertain whether these features relate to northward-flowing lowland ice or a cold-based local ice cap. Deglaciation of the Ringnes Islands commenced ~10 000 14C years ago. Deglacial dates between 9.7 and 9.2 ka BP record the sequential entry of marine fauna along Massey and Hassel sounds, concomitant with the southward retreat of trunk ice towards Norwegian Bay. These data suggest marine-based trunk glaciers were vulnerable to calving during pre-Holocene eustatic sea-level rise. However, deglacial dates from inner embayments indicate that residual ice caps persisted on Amund and Ellef Ringnes islands for 800 to 1400 14C years after retreat of trunk ice from the adjacent marine channels. Lateral meltwater channels record the subsequent retreat of these ice caps, which became increasingly confined within upland valleys after 8.6 ka BP.

scholarly journals COMBINING COASTAL DESIGN-FLOOD ELEVATIONS AND SEA LEVEL RISE PROJECTIONS

2012 ◽  
Vol 1 (33) ◽  
pp. 26
Author(s):  
James Houston
Keyword(s):  
Climate Change ◽  
Sea Level Rise ◽  
Sea Level ◽  
Design Consideration ◽  
Design Flood ◽  
Intergovernmental Panel ◽  
Flood Level ◽  
Rising Sea Level ◽  
And Sea Level

Design-flood elevations with associated exceedance probabilities are often determined for coastal projects. Rising sea level introduces another design consideration that needs to be combined with the design-flood level. However, most sea level projections do not have exceedance probabilities that can be used in conjunction with the design flood to obtain total flood elevations with exceedance probabilities. This paper shows how to combine design-flood elevations with sea level rise projections that have exceedance probabilities, such as those of the Intergovernmental Panel for Climate Change (Bindoff et al 2007) or Houston (2012a), to obtain total elevations at desired exceedance probabilities over particular intervals.

Glacial isostatic adjustment near the center of the former Patagonian Ice Sheet (48°S) during the last 16.5 kyr

2021 ◽  
Author(s):  
Matthias Troch ◽  
Sebastien Bertrand ◽  
Carina B. Lange ◽  
Paola Cardenas ◽  
Helge Arz ◽  
...  
Keyword(s):  
Sea Level Rise ◽  
Sea Level ◽  
Average Rate ◽  
Ice Sheet ◽  
Late Glacial ◽  
Glacial Isostatic Adjustment ◽  
Isostatic Rebound ◽  
Isostatic Adjustment ◽  
Modelling Studies ◽  
Global Sea Level

<p>Our understanding of glacial isostatic rebound across Patagonia is highly limited, despite its importance to constrain past ice volume estimates and better comprehend relative sea-level variations. With this in mind, our research objective is to reconstruct the magnitude and rate of Late Glacial to Holocene glacial isostatic adjustment near the center of the former Patagonian Ice Sheet. We focus on Larenas Bay (48°S; 1.26 km<sup>2</sup>), which is connected to Baker Channel through a shallow (<em>ca.</em> 7.4 m) and narrow (<em>ca.</em> 150 m across) inlet, and hence has the potential to record periods of basin isolation and marine ingression. The paleoenvironmental evolution of the bay was investigated through a sedimentological analysis of a 9.2 m long, radiocarbon-dated, sediment core covering the last 16.8 cal. kyr BP. Salinity indicators, including diatom paleoecology, alkenone concentrations and CaCO<sub>3</sub> content, were used to reconstruct the bay’s connectivity to the fjord. Results indicate that Larenas Bay was a marine environment before 16.5 cal. kyr BP and after 9.1 cal. kyr BP, but that it was disconnected from Baker Channel in-between. We infer that glacial isostatic adjustment outpaced global sea-level rise between 16.5 – 9.1 cal. kyr BP. During the Late Glacial - Holocene transition, the center of the former Patagonian Ice Sheet rose <em>ca.</em> 96 m, at an average rate of 1.30 cm/year. During the remainder of the Holocene, glacial isostatic adjustment continued (<em>ca.</em> 19.5 m), but at a slower average pace of 0.21 cm/year. Comparisons between multi-centennial variations in the salinity indicators and existing records of global sea-level rise suggest that the glacial isostatic adjustment rate fluctuated during these time intervals, in agreement with local glacier dynamics. More specifically, most of the glacial isostatic adjustment registered between 16.5 – 9.1 cal. kyr BP seems to have occurred before meltwater pulse 1A (14.5 – 14.0 kyr BP). Likewise, it appears that the highest Holocene glacial isostatic rebound rates occurred during the last 1.4 kyr, most likely in response to glacier recession from Neoglacial maxima. This implies a relatively rapid response of the local solid earth to ice unloading, which agrees with independent modelling studies investigating contemporary uplift. We conclude that the center of the former Patagonian Ice Sheet experienced a glacial isostatic adjustment of <em>ca.</em> 115 m over the last 16.5 kyr, and that >80% occurred during the Late Glacial and early Holocene.</p>

Evidence for a Postglacial Low Relative Sea-Level Stand in the Drowned Delta of the Merrimack River, Western Gulf of Maine

1983 ◽  
Vol 19 (3) ◽  
pp. 325-336 ◽  
Author(s):  
R. N. Oldale ◽  
L. E. Wommack ◽  
A. B. Whitney
Keyword(s):  
Sea Level Rise ◽  
Sea Level ◽  
New Hampshire ◽  
Gulf Of Maine ◽  
Relative Sea Level ◽  
Radiocarbon Dates ◽  
Late Wisconsinan

AbstractA submerged delta of the Merrimack River, located offshore between Cape Ann, Massachusetts, and the New Hampshire border, indicates a postglacial low relative see-level stand of about −47 m. The low stand is inferred to date to 10,500 yr B.P., but a lack of age control makes this assignment uncertain. A curve based on a late Wisconsinan, high relative sea-level stand of +32m at 13,000 yr B.P., a low stand of −47m at 10,500 yr B.P., and younger radiocarbon dates related to sea-level rise indicates an early postglacial crustal rise of at least 5 m per century.

A 10,000 yr B.P. Extensive Ice Shelf over Viscount Melville Sound, Arctic Canada

1984 ◽  
Vol 22 (1) ◽  
pp. 18-30 ◽  
Author(s):  
Douglas A. Hodgson ◽  
Jean-Serge Vincent
Keyword(s):  
Sea Level ◽  
North Coast ◽  
Major Advance ◽  
Ice Shelf ◽  
The North ◽  
Minimum Age ◽  
Western Arctic ◽  
Late Wisconsinan ◽  
Victoria Island ◽  
Glacial Landforms

Late Wisconsinan age glacial landforms and deposits indicate that an ice shelf of at least 60,000 km2 flowed northwestward into Viscount Melville Sound, probably from the M'Clintock Dome of the Laurentide Ice Sheet. The ice shelf overlapped coastal areas and laid Winter Harbour Till up to 125 m above present sea level on the southern coast of Melville Island, to 135 m on Byam Martin Island, to possibly 90 m on the northeast tip of Banks Island, and to 150 m on the north coast of Victoria Island. The contemporary sea level was 50 to 100 m higher than present (it now rises eastward). A maximum age of 10,340 ± 150 yr B.P. for the till, and thus the ice-shelf advance, is provided by shells in marine sediments which underlie it, whereas a minimum age of 9880 ± 150 yr B.P. is provided by overlying shells that postdate the ice advance. The major advance of shelf ice into Viscount Melville Sound may be the result of the rapid disintegration of the M'Clintock Dome while the climate ameliorated in the western Arctic.

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