A reconnaissance survey of late Quaternary sea levels, Bella Bella/Bella Coola region, central British Columbia coast

1978 ◽  
Vol 15 (3) ◽  
pp. 341-350 ◽  
Author(s):  
J. T. Andrews ◽  
R. M. Retherford
Keyword(s):  
British Columbia ◽  
Sea Level ◽  
Late Quaternary ◽  
Middle Part ◽  
Relative Sea Level ◽  
Marine Transgression ◽  
Sea Levels ◽  
Reconnaissance Survey ◽  
Rate Of Emergence ◽  
Bella Coola

A preliminary relative sea level curve that covers the last 10 200 years is derived for the area of the islands and outer mainland centered on Bella Bella and Namu, the central coast of British Columbia. The curve shows postglacial emergence of 17 m over this period. The rate of emergence was ~0.6 m/100 year about 9000 BP, and present sea level was attained between 7000 and 8000 BP. Relative sea level continued to fall until the last few hundred to one thousand years BP when a marine transgression led to a rise of sea level and resultant erosion of many coastal Indian middens. Marine limits on the outer islands may reach 120 m asl, whereas in the middle part of the fiord country observed delta surfaces are lower (54–75 m asl). Elevations of raised deltas then attain ~150 m at fiord heads. A readvance of the ice front ≤ 12 210 ± 330 BP (GSC-1351) is suggested by the stratigraphy of one section.

scholarly journals Late Quaternary Relative Sea-Level Change on the West Coast of Newfoundland*

2007 ◽  
Vol 59 (2-3) ◽  
pp. 129-140 ◽  
Author(s):  
Trevor Bell ◽  
Julia Daly ◽  
Martin J. Batterson ◽  
David G.E. Liverman ◽  
John Shaw ◽  
...  
Keyword(s):  
Sea Level ◽  
West Coast ◽  
Late Quaternary ◽  
General Pattern ◽  
Laurentide Ice Sheet ◽  
The West ◽  
Relative Sea Level ◽  
Show Evidence ◽  
Rate Of Emergence ◽  
Harbour Area

Abstract Two revised relative sea-level (RSL) curves are presented for the Port au Choix to Daniel’s Harbour area of the Great Northern Peninsula, northwestern Newfoundland. Both curves are similar, showing continuous emergence of 120-140 m between 14 700 cal BP and present. The half-life of exponential curves fit to the RSL data is 1400 years and the rate of emergence varies from ~2.3 m per century prior to 10 000 cal BP to ~0.13 m per century since 5000 cal BP. The curves fit a general pattern of RSL history along the west coast of Newfoundland, where there is a southward transition from solely emergence to emergence followed by submergence. Isostatic depression curves are generated for four RSL records spanning the west coast. Almost double the crustal depression is recorded to the northwest, reflecting the greater glacioisostatic loading by the Laurentide Ice Sheet over southern Labrador and Québec compared to a smaller loading centre by a regional ice complex over Newfoundland. Only the St. George’s Bay RSL record in the southwest appears to show evidence for a proglacial forebulge, when at 6000 cal BP an isostatic ridge of 4 m amplitude begins to collapse.

Late Quaternary sea levels and crustal movements, coastal British Columbia

1982 ◽  
Vol 19 (3) ◽  
pp. 597-618 ◽  
Author(s):  
John Clague ◽  
John R. Harper ◽  
R. J. Hebda ◽  
D. E. Howes
Keyword(s):  
British Columbia ◽  
Sea Level ◽  
Late Holocene ◽  
Late Quaternary ◽  
Sea Level Change ◽  
Vancouver Island ◽  
Relative Sea Level ◽  
Crustal Movements ◽  
Level Change ◽  
Queen Charlotte Islands

Late Quaternary sea-level fluctuations on the British Columbia coast have been established from studies of terrestrial and marine sediments and landforms. These studies indicate that the sea-level history of mainland British Columbia and eastern Vancouver Island is very different from that of the Queen Charlotte Islands and western Vancouver Island. Specifically, in the former areas, there was a rapid rise of submerged coastal lowlands between about 13 000 and 10 000 years ago. Emergence culminated about 6000–9000 years ago, depending on the locality, when the sea, relative to the land, was 12 m or more lower than at present in some areas. During middle and late Holocene time, relative sea level rose on the mainland coast and at least locally on eastern Vancouver Island, resulting in inundation of coastal archaeological sites and low-lying terrestrial vegetation. Tidal records and precise levelling suggest ongoing submergence of at least part of this region.In contrast, shorelines on the Queen Charlotte Islands were below present from before 13 700 years ago until approximately 9500–10 000 years ago. A transgression at the close of the Pleistocene climaxed about 7500–8500 years ago when relative sea level probably was about 15 m above present in most areas. Most of the emergence that followed apparently occurred in the last 5000–6000 years. There has been a similar pattern of emergence on the west coast of Vancouver Island during late Holocene time.The above patterns of late Quaternary sea-level change are attributed to complex isostatic response to downwasting and retreat of the late Wisconsin Cordilleran Ice Sheet, to transfers of water from melting ice sheets to oceans, and to plate interactions on the British Columbia continental margin. Late Pleistocene and early Holocene crustal movements were dominantly isostatic. Although the recent regression on the outer coast likely is due, at least in part, to tectonic uplift, some late Holocene sea-level change in this area and elsewhere on the British Columbia coast may be either eustatic in nature or a residual isostatic response to deglaciation, which occurred thousands of years earlier.

Multiple drivers of extreme sea levels in the northern Adriatic Sea

2021 ◽  
Author(s):  
Christian Ferrarin ◽  
Piero Lionello ◽  
Mirko Orlic ◽  
Fabio Raicich ◽  
Gianfausto Salvadori
Keyword(s):  
Sea Level Rise ◽  
Sea Level ◽  
Adriatic Sea ◽  
Driving Factors ◽  
Northern Adriatic Sea ◽  
Relative Sea Level ◽  
Northern Adriatic ◽  
Sea Levels ◽  
Extreme Sea Levels ◽  
Relative Sea Level Rise

<p><span><span>Extreme sea levels at the coast result from the combination of astronomical tides with atmospherically forced fluctuations at multiple time scales. Seiches, river floods, waves, inter-annual and inter-decad</span></span><span><span>al dynamics and relative sea-level rise can also contribute to the total sea level. While tides are usually well described and predicted, the effect of the different atmospheric contributions to the sea level and their trends are still not well understood. Meso-scale atmospheric disturbances, synoptic-scale phenomena and planetary atmospheric waves (PAW) act at different temporal and spatial scales and thus generate sea-level disturbances at different frequencies. In this study, we analyze the 1872-2019 sea-level time series in Venice (northern Adriatic Sea, Italy) to investigate the relative role of the different driving factors in the extreme sea levels distribution. The adopted approach consists in 1) isolating the different contributions to the sea level by applying least-squares fitting and Fourier decomposition; 2) performing a multivariate statistical analysis which enables the dependencies among driving factors and their joint probability of occurrence to be described; 3) analyzing temporal changes in extreme sea levels and extrapolating possible future tendencies. The results highlight the fact that the most extreme sea levels are mainly dominated by the non-tidal residual, while the tide plays a secondary role. The non-tidal residual of the extreme sea levels is attributed mostly to PAW surge and storm surge, with the latter component becoming dominant for the most extreme events. The results of temporal evolution analysis confirm previous studies according to which the relative sea-level rise is the major driver of the increase in the frequency of floods in Venice over the last century. However, also long term variability in the storm activity impacted the frequency and intensity of extreme sea levels and have contributed to an increase of floods in Venice during the fall and winter months of the last three decades.</span></span></p>

scholarly journals Late Quaternary Deglaciation, Glaciomarine Sedimentation and Glacioisostatic Recovery in the Rivière Nastapoka Area, Eastern Hudson Bay, Northern Québec

2005 ◽  
Vol 57 (1) ◽  
pp. 65-83 ◽  
Author(s):  
Patrick Lajeunesse ◽  
Michel Allard
Keyword(s):  
Sea Level ◽  
Late Quaternary ◽  
Phase 1 ◽  
Second Phase ◽  
Hudson Bay ◽  
Silty Clay ◽  
Paleoenvironmental Reconstruction ◽  
Relative Sea Level ◽  
Radiocarbon Dates ◽  
Fluvial Terraces

Abstract This study presents a paleoenvironmental reconstruction of deglaciation dynamics and chronology, glaciomarine and postglacial sedimentation, as well as glacioisostatic recovery in the Rivière Nastapoka area, eastern Hudson Bay. Results indicate that the retreat of Québec-Labrador ice was mainly controlled by topography and was marked by four phases. Radiocarbon dates indicate that deglaciation began about 8.3 ka cal. BP and was characterized by a stillstand of the ice margin in the Nastapoka Hills that lead to the deposition of a drift belt in a high relative sea-level (Phase 1). After this stabilisation, the ice margin retreated rapidly eastward in a region of low relief and deposited a drape of silty clay in a falling relative sea-level (Phase 2). A second phase of stabilization of the ice margin lasted until at least 7.2 ka cal.BP on the higher shield peneplaine east of the limit of the Tyrrell Sea (Phase 3). This lead to the deposition of a belt of glaciofluvial deltas in a lower relative sea-level. Following this stillstand, the eastward retreat and subsequent ablation of the ice in central Québec-Labrador generated meltwater that transported large volumes of glacial sediments by fluvial processes and downcutting of fluvial terraces in previously deposited glaciofluvial and marine sediments (Phase 4). Glacioisostatic rebound reached 0.07 m/yr during the early phase of deglaciation and decreased to 0.04 m/yr between 6 and 5 ka cal. BP and 0.016 m/yr in the last 1000 years.

Late Quaternary relative sea-level changes and vertical movements at Lipari (Aeolian Islands)

2002 ◽  
Vol 17 (5-6) ◽  
pp. 459-467 ◽  
Author(s):  
N. Calanchi ◽  
F. Lucchi ◽  
P. A. Pirazzoli ◽  
C. Romagnoli ◽  
C. A. Tranne ◽  
...  
Keyword(s):  
Sea Level ◽  
Late Quaternary ◽  
Sea Level Changes ◽  
Relative Sea Level ◽  
Vertical Movements ◽  
Aeolian Islands

scholarly journals Relative sea-level changes in crete: reassessment of radiocarbon dates from Sphakia and west Crete

2002 ◽  
Vol 97 ◽  
pp. 171-200 ◽  
Author(s):  
Simon Price ◽  
Tom Higham ◽  
Lucia Nixon ◽  
Jennifer Moody
Keyword(s):  
Sea Level ◽  
Late Antiquity ◽  
Isotopic Fractionation ◽  
Sea Level Changes ◽  
Relative Sea Level ◽  
Radiocarbon Dates ◽  
Sea Levels ◽  
Catastrophic Earthquake ◽  
Radiocarbon Data ◽  
Calendar Dates

This article is concerned with the recognition and dating of Holocene relative sea-level changes along the coast of west Crete (an island located in the active Hellenic subduction arc of the southern Aegean) and in particular in Sphakia. Radiocarbon data for changes in sea levels collected and analysed previously must (a) be recorrected to take into account isotopic fractionation, and (b) recalibrated by using the new marine reservoir value. These new radiocarbon dates are analysed using Bayesian statistics. The resulting calendar dates for changes in sea level are younger than previously assumed. In particular the Great Uplift in western Crete in late antiquity must be dated to the fifth or sixth century AD, not to AD 365. Moreover, recent work on tectonics suggests that the Great Uplift need not have been accompanied by a catastrophic earthquake. Finally, we consider the consequences of the Great Uplift for some coastal sites in Sphakia.

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