scholarly journals Subarctic tidal flats in areas of large tidal range, southern Baffin Island, eastern Canada

2011 ◽  
Vol 35 (2) ◽  
pp. 183-204 ◽  
Author(s):  
S. B. McCann ◽  
J. E. Dale ◽  
P. B. Hale
Keyword(s):  
Sea Ice ◽  
Intertidal Zone ◽  
Tidal Flats ◽  
Tidal Range ◽  
Baffin Island ◽  
Eastern Canada ◽  
Ice Breakup ◽  
Cumberland Sound ◽  
Ice Floes ◽  
Mode Of Transport

Wide, boulder-strewn intertidal flats occur around the head of Frobisher Bay and along parts of the shoreline of Cumberland Sound, in southeast Baffin Island. The coastal environment is characterized by large tidal ranges, severe winter sea ice conditions, and a relative sea level history which involves rapid and then decreasing land emergence during the earlier part of the Holocene, succeeded by slight recent submergence. Summer field investigations were carried out at two sites, Koojesse Inlet on Frobisher Bay, where ice breakup conditions were also monitored, and Pangnirtung Fiord off Cumberland Sound. The results are summarized under three headings: physical and biological zonation across the tidal flats; tidal action and sea ice processes; and geological evolution of the tidal flats. Comparisons are made with similar settings described by others in Labrador and Ungava Bay. The sedimentary shores at both Baffin Island sites exhibit a distinct physical zonation, most evident in the concentration of boulders in the middle tidal flat zone at Koojesse Inlet and in the boulder barricade at the seaward margin of the Pangnirtung flats. Biological observations show a zonation of intertidal flora and fauna across the intertidal zone at Koojesse Inlet. An outstanding problem concerns the mode of transport of very large boulders. Pushing and rolling, by ice floes which are confined to the intertidal zone by the solid ice in the offshore zone during the critical early phase of breakup may be more appropriate processes than ice rafting.

scholarly journals Boulder-strewn flats in a high-latitude macrotidal embayment, Baffin Island: geomorphology, formation, and future stability

2021 ◽  
Author(s):  
Scott Vincent Hatcher ◽  
Donald L. Forbes ◽  
Gavin K. Manson
Keyword(s):  
Sea Ice ◽  
Sea Level ◽  
High Latitude ◽  
Open Water ◽  
Tidal Flats ◽  
Sediment Supply ◽  
Tidal Range ◽  
Baffin Island ◽  
Relative Sea Level ◽  
Sand And Gravel

Tidal flats are widely distributed on high-latitude coasts, where sea ice processes have been invoked to explain the abundance and distribution of boulders. This study documents the surface morphology and sediment dynamics of a low-Arctic macrotidal system, the boulder-rich tidal flats of Koojesse Inlet, fronting the Nunavut capital, Iqaluit, on Baffin Island. This is a region of postglacial isostatic uplift and forced regression, with raised littoral, deltaic, and glaciomarine deposits. The spring-tidal range is 11.1 m and sea ice cover lasts roughly 9 months of the year. The extensive intertidal flats are up to 1 km wide, with a veneer of sand and gravel (including large boulders) resting on an erosional unconformity truncating the underlying glaciomarine mud, forming a terrace within the present tidal range. Over a three-year study, no consistent pattern of erosion or deposition was evident. Over a longer time scale, the concave hypsometry, low sediment supply, slight ebb-dominance of weak tidal currents, abrasion by wave-entrained sand, ebb-oriented ripples formed under subaerial drainage, and slumps on the terrace flanks are consistent with seaward hydraulic and gravitational sediment transport. These processes may be of greater importance than shoreward ice transport. This study underlines the importance of relict glaciomarine deposits, postglacial uplift, and falling relative sea level in the erosional development of these high-latitude tidal flats. Relative sea-level projections for Iqaluit are ambiguous, but a switch to rising sea level, if it occurs, combined with more open water and wave energy, could alter the foreshore dynamics of the system.

SEA ICE BREAKUP AND TIDAL FLAT PROCESSES, FROBISHER BAY, BAFFIN ISLAND

1986 ◽  
Vol 7 (2) ◽  
pp. 168-180 ◽  
Author(s):  
S. B. McCann ◽  
J. E. Dale
Keyword(s):  
Sea Ice ◽  
Tidal Flat ◽  
Baffin Island ◽  
Ice Breakup

scholarly journals Understanding Melting due to Ocean Eddy Heat Fluxes at the Edge of Sea-Ice Floes

2018 ◽  
Vol 45 (18) ◽  
pp. 9721-9730 ◽  
Author(s):  
Christopher Horvat ◽  
Eli Tziperman
Keyword(s):  
Sea Ice ◽  
Heat Fluxes ◽  
Ice Floes

scholarly journals Airborne observations and simulations of three-dimensional radiative interactions between Arctic boundary layer clouds and ice floes

2015 ◽  
Vol 15 (14) ◽  
pp. 8147-8163 ◽  
Author(s):  
M. Schäfer ◽  
E. Bierwirth ◽  
A. Ehrlich ◽  
E. Jäkel ◽  
M. Wendisch
Keyword(s):  
Boundary Layer ◽  
Radiative Transfer ◽  
Sea Ice ◽  
Three Dimensional ◽  
Open Water ◽  
Radiative Effects ◽  
Arctic Boundary Layer ◽  
Boundary Layer Clouds ◽  
Ice Edge ◽  
Ice Floes

Abstract. Based on airborne spectral imaging observations, three-dimensional (3-D) radiative effects between Arctic boundary layer clouds and highly variable Arctic surfaces were identified and quantified. A method is presented to discriminate between sea ice and open water under cloudy conditions based on airborne nadir reflectivity γλ measurements in the visible spectral range. In cloudy cases the transition of γλ from open water to sea ice is not instantaneous but horizontally smoothed. In general, clouds reduce γλ above bright surfaces in the vicinity of open water, while γλ above open sea is enhanced. With the help of observations and 3-D radiative transfer simulations, this effect was quantified to range between 0 and 2200 m distance to the sea ice edge (for a dark-ocean albedo of αwater = 0.042 and a sea-ice albedo of αice = 0.91 at 645 nm wavelength). The affected distance Δ L was found to depend on both cloud and sea ice properties. For a low-level cloud at 0–200 m altitude, as observed during the Arctic field campaign VERtical Distribution of Ice in Arctic clouds (VERDI) in 2012, an increase in the cloud optical thickness τ from 1 to 10 leads to a decrease in Δ L from 600 to 250 m. An increase in the cloud base altitude or cloud geometrical thickness results in an increase in Δ L; for τ = 1/10 Δ L = 2200 m/1250 m in case of a cloud at 500–1000 m altitude. To quantify the effect for different shapes and sizes of ice floes, radiative transfer simulations were performed with various albedo fields (infinitely long straight ice edge, circular ice floes, squares, realistic ice floe field). The simulations show that Δ L increases with increasing radius of the ice floe and reaches maximum values for ice floes with radii larger than 6 km (500–1000 m cloud altitude), which matches the results found for an infinitely long, straight ice edge. Furthermore, the influence of these 3-D radiative effects on the retrieved cloud optical properties was investigated. The enhanced brightness of a dark pixel next to an ice edge results in uncertainties of up to 90 and 30 % in retrievals of τ and effective radius reff, respectively. With the help of Δ L, an estimate of the distance to the ice edge is given, where the retrieval uncertainties due to 3-D radiative effects are negligible.

scholarly journals An analytical model for wind-driven Arctic summer sea ice drift

2016 ◽  
Vol 10 (1) ◽  
pp. 227-244 ◽  
Author(s):  
H.-S. Park ◽  
A. L. Stewart
Keyword(s):  
Sea Ice ◽  
Analytical Model ◽  
Surface Wind ◽  
Open Water ◽  
Sea Ice Concentration ◽  
Efficient Calculation ◽  
Sea Ice Drift ◽  
Wind Input ◽  
Ice Floes ◽  
Arctic Summer

Abstract. The authors present an analytical model for wind-driven free drift of sea ice that allows for an arbitrary mixture of ice and open water. The model includes an ice–ocean boundary layer with an Ekman spiral, forced by transfers of wind-input momentum both through the sea ice and directly into the open water between the ice floes. The analytical tractability of this model allows efficient calculation of the ice velocity provided that the surface wind field is known and that the ocean geostrophic velocity is relatively weak. The model predicts that variations in the ice thickness or concentration should substantially modify the rotation of the velocity between the 10 m winds, the sea ice, and the ocean. Compared to recent observational data from the first ice-tethered profiler with a velocity sensor (ITP-V), the model is able to capture the dependencies of the ice speed and the wind/ice/ocean turning angles on the wind speed. The model is used to derive responses to intensified southerlies on Arctic summer sea ice concentration, and the results are shown to compare closely with satellite observations.

Miniature mud volcanoes and other injection features in tidal flats, James Bay, Québec

1976 ◽  
Vol 13 (3) ◽  
pp. 422-428 ◽  
Author(s):  
Jean-Claude Dionne
Keyword(s):  
East Coast ◽  
Fine Sand ◽  
Tidal Flats ◽  
Mud Volcanoes ◽  
James Bay ◽  
Marine Clay ◽  
Ice Floes ◽  
Mud Deposit

Miniature injection features, including mud volcanoes, dikes forming polygonal patterns, and isolated patches of clay, occur in tidal flats along the east coast of James Bay. They are formed by localized upward ejection of a mixture of fluidized marine clay, silt, and fine sand through a surficial recent mud deposit. Liquefaction is related to the melting of ice in the clayey deposit. Upward flowing of clay, silt, and fine sand seems to result from overloading by the overlying sediments having a higher degree of density, and possibly also by pressures of ice floes or/and icefoot.

scholarly journals Winter-to-summer transition of Arctic sea ice breakup and floe size distribution in the Beaufort Sea

Elem Sci Anth ◽  
2017 ◽  
Vol 5 (0) ◽  
pp. 40 ◽  
Author(s):  
Byongjun Hwang ◽  
Jeremy Wilkinson ◽  
Edward Maksym ◽  
Hans C. Graber ◽  
Axel Schweiger ◽  
...  
Keyword(s):  
Sea Ice ◽  
Size Distribution ◽  
Beaufort Sea ◽  
Arctic Sea Ice ◽  
Ice Breakup ◽  
Arctic Sea

Food of Shorthorn Sculpin, Myoxocephalus scorpius, in the Cumberland Sound Area of Baffin Island

1974 ◽  
Vol 31 (3) ◽  
pp. 355-359 ◽  
Author(s):  
I. A. Moore ◽  
J. W. Moore
Keyword(s):  
Dry Weight ◽  
Abundant Species ◽  
The Other ◽  
Gut Contents ◽  
Baffin Island ◽  
Littorina Saxatilis ◽  
Shorthorn Sculpin ◽  
Cumberland Sound ◽  
Myoxocephalus Scorpius ◽  
Benthic Prey

One hundred shorthorn sculpins, Myoxocephalus scorpius, over 15 cm in length captured from June to October, 1972, in Cumberland Sound, Baffin Island, fed almost exclusively (90% by both numbers and dry weight) on the planktonic amphipods Pseudalibrotus glacialis and Parathemisto libellula. In contrast, 140 fish captured about the same times from nearby Pangnirtung Fjord fed heavily on the benthic gastropods Littorina saxatilis and Margarites umbilicalis (each 34% by numbers and 22% by weight) and the bivalve Modiolaria discors (16% by both). Drifting ice on Cumberland Sound probably reduced the level of illumination making the detection of benthic prey difficult and causing the sculpins in this area to feed entirely on the better illuminated, brightly colored plankton. At both localities, the most abundant species in the plankton and the epifauna were also the most frequently encountered in gut contents. On the other hand, coelenterates, planktonic gastropods, copepods, and infauna, all of which were abundant in the environment, were rarely eaten.

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