Victoria Strait Research Articles

C- and L-band SAR signatures of Arctic sea ice during freeze-up

Identifying sea ice types in the early stages of development from L-band SAR imagery remains an active research area during the Arctic freeze-up period. We used ScanSAR C- and L-band imagery from RADARSAT-2, ALOS PALSAR and ALOS-2 PALSAR-2, to identify ice types in the North Water Polynya (NOW) and Victoria Strait (VS) region of the Canadian Arctic. We investigated the HH-polarized microwave backscatter coefficient (σHH0) and its GLCM texture parameters for six ice classes and open water. We found very low σHH0 for nilas at both C- and L-band. Although similar σHH0 found for grey ice at both frequencies, σHH0 decrease with increasing ice thickness at L-band from grey ice, whereas, at C-band, σHH0 increases from grey to grey-white ice and then decreases as the ice grows. GLCM texture parameters show lower values for L-band than C-band; however, separability among classes was found only for a few selected parameters. We used the support vector machine (SVM) algorithm for ice type classification from SAR scenes using σHH0 and GLCM texture statistics. Due to overlapping σHH0 signatures at C-band, early-stage ice classes were substantially misclassified. L-band identified early-stage ice classes with higher accuracy compared to C-band but misclassified thicker ice types and open water. L-band alone provided very good classification results (~80% accuracy) and combining L- and C-band (i.e., dual-frequency approach) further increased accuracy to >90%. C-band alone resulted in the lowest accuracy of <60%. We acknowledge that developing a universal ice classification is still a challenge and requires some manual supervision to adopt variable ice conditions into the classification method. However, a dual-frequency approach can achieve higher classification accuracy than conventionally used single-frequency approaches. This research highlights the value of upcoming L-Band SAR missions to improve sea ice classification in regions where a variety of ice types exist, including many thinner types, which are now dominating an increasingly warming Arctic.

The Effect of Sea Ice on Tidal Propagation in the Kitikmeot Sea, Canadian Arctic Archipelago

AbstractThe tides in the Kitikmeot Sea, in the southern Canadian Arctic Archipelago, are found to be heavily influenced by seasonal sea‐ice formation and blocking in a strait. Data from a moored current profiler in Dease Strait exhibit strong tidal damping during wintertime seasonal sea‐ice cover, with 50%–60% reduction in tidal elevation and 65% reduction in tidal velocities. We used a 3D unstratified barotropic numerical tidal model of the region to show that the observed wintertime tidal damping likely requires both high sea‐ice friction and a partial sea‐ice blockage in Victoria Strait (VS), the eastern gateway of the Kitikmeot Sea, where tidal‐induced ridging causes thick, rough ice to accumulate over its shallow sill. Our analysis of the model shows different dynamics for the M2 and K1 tides. Both tidal constituents are dominated by the Atlantic tides entering through VS. Overall, ∼90% of the M2 tidal energy entering VS does not reach Dease Strait because, in addition to dissipation in VS (∼25%), it is significantly diverted into adjoining bays and around an amphidrome in eastern Queen Maud Gulf (∼65%). In contrast, the smaller K1 tide is less diverted into the subsidiary channels, after ∼20% dissipation in VS and only ∼25% in adjoining bays, it propagates far into the region and is amplified due to resonance in Dease Strait and Coronation Gulf, resulting in larger tidal height than the M2 tide in Coronation Gulf.

‘Sovereignty’ over submerged cultural heritage in the Canadian Arctic waters: case study from the Franklin expedition wrecks (1845-48)

ABSTRACTTransiting the Northwest Passage captured the imaginations of explorers and adventures for centuries. The idea of a shorter and more economical trade route through the frozen North resulted in hundreds of state and privately financed expeditions to the Canadian Arctic. Perhaps the most famous of the expeditions was the British-led Franklin voyage including the HMS Erebus and HMS Terror, which in April 1848 became stuck in ice and were abandoned in the Victoria Strait. Dozens of expeditions were subsequently commissioned to find the ships, but they would not be seen again until more than 150 years later when their wrecks were found on the sea floor of the Canadian Arctic. Despite the recent transfer of ownership of Franklin’s shipwrecks by the British to the Canadian Government, this case study illustrates the complexity of the identification of ownership over shipwrecks. Based on a literature review of international legal frameworks regarding submerged cultural heritage, claims and statements of various perspectives are documented. In a context of increasing marine tourism activity, in particular pleasure craft traffic, in the Canadian Arctic, efforts must be made to ensure nothing ends up in the hands of looters and private collectors who trade them on the black market.

Finding the dead: bodies, bones and burials from the 1845 Franklin northwest passage Expedition

AbstractOn 22 April 1848, after three years in the Arctic, and 19 months spent ice-bound in northern Victoria Strait, the 105 surviving officers and crew of the Franklin Northwest Passage expedition deserted HMSErebusand HMSTerroras the first step of their escape plan. They assembled at a camp south of Victory Point on the northwest coast of King William Island and made the final preparations for the next step, a 400 km trek along the frozen seashores of King William Island and Adelaide Peninsula to the Back River. All of the men died before reaching their destination, and their remains have been found at 35 locations along the route of the retreat. These discoveries have played a central role in reenactments of events thought to have occurred during the failed attempt to reach the Back River and to the disastrous outcome of the expedition. This paper presents a summary of these findings and examines the criteria used to attribute them to the Franklin expedition. It is suggested that approximately one-third of the identifications have been based on information that is inadequate to confidently assign the human remains as those of Franklin expedition personnel.

Navegación e historia de la ciencia: Hielo, hambre y plomo. La expedición perdida de Franklin

The Franklin’s lost expedition was a British voyage of Arctic exploration led by Captain Sir John Franklin. They sailed from England in 1845 aboard two ships, the HMS Erebus and the HMS Terror. The mission was to cross the last non-navigated section of the so-called Northwest Passage in the Arctic. After various vicissitudes and losses of men, the two ships were trapped in the ice in the Victoria Strait, near King William Island in the Canadian Arctic. The entire expedition, 129 men including Franklin, was lost. Infections, lead poisoning, malnutrition, scurvy, hypothermia and cannibalism ended the expedition.

Navigable windows of the Northwest Passage

Artic sea ice loss trends support a greater potential for Arctic shipping. The information of sea ice conditions is important for utilizing Arctic passages. Based on the shipping routes given by “Arctic Marine Shipping Assessment 2009 Report”, the navigable windows of these routes and the constituent legs were calculated by using sea ice concentration product data from 2006 to 2015, by which a comprehensive knowledge of the sea ice condition of the Northwest Passage was achieved. The results showed that Route 4 (Lancaster Sound – Barrow Strait – Prince Regent Inlet and Bellot Strait – Franklin Strait – Larsen Sound – Victoria Strait – Queen Maud Gulf – Dease Strait – Coronation Gulf – Dolphin and Union Strait – Amundsen Gulf) had the best navigable expectation, Route 2 (Parry Channel - M'Clure Strait) had the worst, and the critical legs affecting the navigation of Northwest Passage were Viscount Melville Sound, Franklin Strait, Victoria Strait, Bellot Strait, M'Clure Strait and Prince of Wales Strait. The shortest navigable period of the routes of Northwest Passage was up to 69 days. The methods used and the results of the study can help the selection and evaluation of Arctic commercial routes.

Dietary tracers in Bathyarca glacialis from contrasting trophic regions in the Canadian Arctic

This study used fatty acid trophic markers (FATMs) to assess carbon sources of the bivalve Bathyarca glacialis and describe the pelagic-benthic coupling in the Canadian Arctic Archipelago. Four regions characterized by contrasting trophic environments were investigated: Southeastern Beaufort Sea, Victoria Strait, Lancaster Sound and Northern Baffin Bay. Our results suggest that B. glacialis is a non-selective filter feeder, feeding on microalgae, zooplankton, and bacteria. Diet was based mainly on microalgae, especially for coastal populations of the Southeast- ern Beaufort Sea. However, zooplankton and bacteria contributed more significantly to the diet of B. glacialis in bathyal populations than the coastal populations. Local and seasonal environmental conditions likely explain these differences in diet between populations. Furthermore, non- methylene- interrupted (NMI) fatty acids were present in the polar lipids of B. glacialis, which could be produced de novo when access to essential fatty acids (EFAs), required for maintaining membrane structure and function, is limited. This physiological response could help the bivalve to modulate its membrane fluidity in the face of constraints of the deep-sea environment such as low temperatures, high pressure, and when EFAs are less available in its diet. This bivalve species thus has certain attributes that could help it to cope with expected strong modifications in primary production dynamics due to climate-induced changes in the Arctic marine system.

Identification of the Franklin expedition wreck

The wreck discovered by the Victoria Strait expedition in early September (Barr 2014) has now been positively identified as that of HMS Erebus. This identification was based on a thorough analysis of the acoustic imagery (side-scan and multi-beam sonar),comparison with the plans for both Erebus and Terror from the National Maritime Museum, Greenwich, visual measurements made during inspection dives by Parks Canada personnel on the site (particularly with regard to the 1845 modifications to the stern), as well as certain telling details which were captured with photo and video. The fact that Erebus was a longer and beamier vessel than Terror is readily discernible from the acoustic data. The locations of various deck fixtures such as the fore and main hatchways, forward suction pumps, bowsprit partners, deck illuminators, and ringbolts, as compared to the same fixtures shown on the plans, all offer very strong correlation with Erebus (and not Terror) (Ryan Harris, Parks Canada, personal communication, 3 November 2014).

A Most Inhospitable Coast: The Report of Lieutenant William Hobson’s 1859 Search for the Franklin Expedition on King William Island

Lieutenant William R. Hobson’s 1859 search for traces of the Franklin expedition on the west coast of King William Island resulted in several major discoveries that include an official record containing the dates of Sir John Franklin’s death, of the abandonment of HMS Erebus and HMS Terror , and of the departure of the ship’s company for the Back River. Information derived from Hobson’s report appeared in McClintock’s published account of the expedition, and it has been referenced in other works, but the report itself was never published. Recent investigations of Franklin archaeological sites on the Victoria Strait coast of King William Island by the Government of Nunavut, including sites first discovered by Hobson, served as a catalyst for locating Hobson’s full descriptions of his findings. The report includes general observations on weather, ice conditions, and wildlife encountered, and his detailed descriptions of several Franklin expedition sites are potentially valuable sources of information for ongoing archaeological investigations.

Discovery of one of Sir John Franklin's ships

In the summer of 2014 a major search was mounted in the Canadian Arctic for H.M.S.ErebusandTerror, the ships of Sir John Franklin's expedition, the aim of which was to make a transit of the northwest passage. Beset in the ice to the northwest of King William Island in the summer of 1846, they were abandoned there by the 105 surviving members of their crews in the summer of 1848. The officers and men hoped to walk south to the mouth of the Back River, presumably to ascend that river in the hope of reaching the nearest Hudson's Bay Company's post at Fort Resolution on Great Slave Lake. None of them survived. The 2014 expedition, the Victoria Strait Expedition, mounted by a consortium which included Parks Canada, the Canadian Coast Guard, the Canadian Navy, the Royal Canadian Geographical Society, the Arctic Research Foundation, and One Ocean Adventure, had four ships at its disposal including the Canadian Coast Guard's icebreakerSir Wilfrid Laurier(Captain Bill Noon) and the Navy's HMCSKingston.

Striking similarities in temporal changes to spring sea ice occurrence across the central Canadian Arctic Archipelago over the last 7000 years

A 7000 year spring sea ice record for Victoria Strait (ARC-4) and Dease Strait (ARC-5) in the Canadian Arctic Archipelago (CAA) has been determined by quantification of the sea ice diatom-derived biomarker IP 25 in two marine sediment piston cores obtained in 2005. The chronologies of the ARC-4 and ARC-5 cores were determined using a combination of 14C AMS dates obtained from macrobenthic fossils and magnetic susceptibility measurements. The ages of the tops of the piston cores were estimated by matching chemical and physical parameters with those obtained from corresponding box cores. These analyses revealed that, while the top of the ARC-4 piston core was estimated to be essentially modern (ca. 60 cal yr BP), a few hundred years of sediment appeared to be absent from the ARC-5 piston core. Downcore changes to IP 25 fluxes for both cores were interpreted in terms of variations in spring sea ice occurrence, and correlations between the individual IP 25 flux profiles for Victoria Strait, Dease Strait and Barrow Strait (reported previously) were shown to be statistically significant at both 50 and 100-year resolutions. The IP 25 data indicate lower spring sea ice occurrences during the early part of the record (ca. 7.0–3.0 cal kyr BP) and for parts of the late Holocene (ca. 1.5–0.8 cal kyr BP), especially for the two lower latitude study locations. In contrast, higher spring sea ice occurrences existed during ca. 3.0–1.5 cal kyr BP and after ca. 800 cal yr BP. The observation of, consecutively, lower and higher spring sea ice occurrence during two periods of the late Holocene, coincides broadly with the Medieval Warm Period and Little Ice Age epochs, respectively. The IP 25 data are complemented by particle size and mineralogical data, although these may alternatively reflect changes in sea level at the study sites. The IP 25 data are also compared to previous proxy-based determinations of palaeo sea ice and palaeoclimate for the CAA, including those based on bowhead whale remains and dinocyst assemblages. The spatial consistency in the proxy data which, most notably, indicates an increase in spring sea ice occurrence around 3 cal kyr BP, provides a potentially useful benchmark for the termination of the Holocene Thermal Maximum for the central CAA.

Arches and basins of the Southern Arctic Islands of Canada

In the southern islands of the Canadian arctic archipelago and on the adjacent mainland three types of terrain predominate-uplands of crystalline rocks, plateaux of flat-lying strata, and lowlands of younger, relatively undisturbed strata. Forming the eastern boundary of the region lie the Baffin-Ellesmere mountains adjacent to Baffin Bay and Davis Strait, and to the north-west are the arctic ocean lowlands. Each of these major areas is profoundly different from the others in its geology, and these differences reflect crustal behaviour since Pre-Cambrian time. In the southern arctic islands region, several major northerly projecting basement features, the Minto, Wellington, Boothia and Melville-Southampton Arches separate the shallow Palaeozoic accumulations of the Wollaston, Victoria Strait, JonesLancaster and Foxe Basins. The Minto and Wellington Arches contain Pre-Cambrian sedimentary strata with some lavas and sills which are relatively little disturbed. In contrast, the Boothia and Melville-Southampton Arches are largely composed of granitic gneisses and greenschists much folded along north-south and north-eastsouth-west lines respectively. Early ‘post-Archaean’ sediments and numerous basic intrusives of uncertain age also occur. The rocks of these arches have a complex Pre-Cambrian history and the Boothia Arch was elevated dramatically in late Silurian –early Devonian and again possibly in Tertiary times. Facies variation within the strata of the basins gives little indication of positive movement of the arches in early Palaeozoic time. The influence of the Canadian Shield to the south and the developing Franklinian Geosyncline to the north were more important in facies control. Much of the deposition within the basins was of shallow water carbonates with some fine clastics and, at least locally, evaporites. Many kinds of lime-secreting and other organisms influenced sedimentation and biogenic rocks are common. This region seems also to have been occupied by some of the earliest-known vertebrate faunas, and it may have been a centre of Silurian agnathan radiation. In late Silurian–early Devonian time an orogeny sharply elevated the Boothia Arch and may have established the Cornwallis Fold Belt. The Siluro-Devonian Peel Sound Formation, spreading from the Boothia Arch into the Victoria Strait, ?Melville and Jones-Lancaster Basins, exhibits lateral facies changes from alluvial fans through fluvial to marine strata. Little is known of the geological history of the area from Devonian until Quaternary times. It is thought to have been a broadly positive area undergoing denudation and shedding sediment northward to the Sverdrup Basin. Nevertheless, CretaceousTertiary sediments occur in a few small outcrops far north of what has been regarded as the shoreline of those times. On Somerset Island the presence of Lingula in such strata may indicate a connexion with the Sverdrup Basin sea or with open water to the south. Sediment transport southward from the northern side of Barrow Strait is suggested near the axis of the Boothia Arch in southern Somerset Island. Fault activity at a later date is perhaps a rejuvenation of earlier trends of movement. The recently suggested isostatic origin of these arches or uplifts seems to be in accord with the facts, and appears to indicate that a wide area of relative isostatic equilibrium now exists between the Franklinian Geosyncline and the (Canadian Shield) craton, but that this was not the case in Palaeozoic time.