Regional Magnetic Anomalies of the Canadian Arctic

1973 ◽  
Vol 10 (2) ◽  
pp. 157-163 ◽  
Author(s):  
R. P. Riddihough ◽  
G. V. Haines ◽  
W. Hannaford
Keyword(s):  
Magnetic Field ◽  
Sea Level ◽  
Canadian Arctic ◽  
Arctic Basin ◽  
Magnetic Anomalies ◽  
Canadian Shield ◽  
The Arctic ◽  
Vertical Magnetic Field ◽  
Broad View

A contoured residual map of the vertical magnetic field, observed at an altitude of 3.5 km above sea level, provides a broad view of major tectonic patterns and relations between the Canadian Shield, the Innuitian Region, and the oceanic ridges of the Arctic Basin.

Magnetic Anomalies over British Columbia and the Adjacent Pacific Ocean

1971 ◽  
Vol 8 (3) ◽  
pp. 387-391 ◽  
Author(s):  
G. V. Haines ◽  
W. Hannaford ◽  
R. P. Riddihough
Keyword(s):  
Magnetic Field ◽  
British Columbia ◽  
Pacific Ocean ◽  
Sea Level ◽  
Magnetic Anomalies ◽  
Canadian Shield ◽  
Vertical Magnetic Field ◽  
Northeast Pacific ◽  
Broad View ◽  
Northeast Pacific Ocean

A contoured residual map of the vertical magnetic field, observed at approximately 5 km altitude above sea level, provides a broad view of the major structures of the buried Canadian Shield, the Cordilleran Region, and the northeast Pacific Ocean.

Large scale magnetic anomalies over western Canada and the Arctic: a discussion

1976 ◽  
Vol 13 (6) ◽  
pp. 790-802 ◽  
Author(s):  
R. L. Coles ◽  
G. V. Haines ◽  
W. Hannaford
Keyword(s):  
Magnetic Field ◽  
Large Scale ◽  
Elevated Temperatures ◽  
Magnetic Anomalies ◽  
The Arctic ◽  
Evolutionary Development ◽  
Magnetic Feature ◽  
Western Canada ◽  
Arctic Regions ◽  
The Magnetic Field

A contoured map of vertical magnetic field residuals (relative to the IGRF) over western Canada and adjacent Arctic regions has been produced by amalgamating new data with those from previous surveys. The measurements were made at altitudes between 3.5 and 5.5 km above sea level. The map shows the form of the magnetic field within the waveband 30 to 5000 km. A magnetic feature of several thousand kilometres wavelength dominates the map, and is probably due in major part to sources in the earth's core. Superimposed on this are several groups of anomalies which contain wavelengths of the order of a thousand kilometres. The patterns of the short wavelength anomalies provide a broad view of major structures and indicate several regimes of distinctive evolutionary development. Enhancement of viscous magnetization at elevated temperatures may account for the concentration of intense anomalies observed near the western edge of the craton.

Geomorphic diversity and complexity of the inner shelf, Canadian Arctic Archipelago, based on LiDAR and multibeam sonar surveys

2020 ◽  
Vol 57 (1) ◽  
pp. 123-132
Author(s):  
John Shaw ◽  
D. Patrick Potter ◽  
Yongsheng Wu
Keyword(s):  
Sea Level ◽  
Gas Hydrate ◽  
Canadian Arctic ◽  
Slight Modification ◽  
The Arctic ◽  
Canadian Arctic Archipelago ◽  
Beach Ridge ◽  
Terrestrial Lidar ◽  
Sea Levels ◽  
Glacial Landforms

Data from two surveys by multi-beam sonar and two by marine/terrestrial LiDAR are used to evaluate the geomorphology of the seafloor in littoral areas of the Canadian Arctic Channels, near King William Island, Nunavut. Submarine terrains show well-preserved glacial landforms (drumlins, mega-scale glacial lineations, iceberg-turbated terrain, recessional moraines, and glaciofluvial landforms) with only slight modification by modern processes (wave action and sea-ice activity). At Gjoa Haven the seafloor is imprinted by fields of pits 2 m wide and 0.15 m deep. They may result from gas hydrate dissolution triggered by falling relative sea levels. The Arctic Archipelago displays what might be termed inverted terrains: marine terrains, chiefly beach ridge complexes, exist above modern sea level and well-preserved glacial terrains are present below modern sea level. This is the inverse of the submerging regimes of Atlantic Canada, where glacial terrains exist on land, but below sea level they have been effaced and modified by marine processes down to the lowstand depth.

Broad-scale magnetic anomalies over central and eastern Canada: a discussion

1981 ◽  
Vol 18 (3) ◽  
pp. 657-661 ◽  
Author(s):  
R. L. Coles ◽  
G. V. Haines ◽  
W. Hannaford
Keyword(s):  
Magnetic Field ◽  
Sea Level ◽  
Vertical Component ◽  
Magnetic Anomalies ◽  
Superior Province ◽  
The South ◽  
Earth’S Magnetic Field ◽  
Eastern Canada ◽  
Earth's Magnetic Field ◽  
Broad Scale

Profiles of anomalies in the vertical component of the Earth's magnetic field over central and eastern Canada, observed at an average altitude of 4 km above sea level, show broad regions with distinctive anomaly character. These subdivisions indicate major differences in the evolutions of regions within individual structural provinces. Particularly notable is a region of intense anomalies in the northern part of the Superior Province in Quebec, contrasting with much weaker anomaly relief to the south and east.

scholarly journals The nature of regional magnetic anomalies in the northeast of the Barents-Kara continental margin based on the results of seismic data interpretation

2021 ◽  
Vol 11 (2) ◽  
pp. 195-204
Author(s):  
E.V. Shipilov ◽  
◽  
L.I. Lobkovsky ◽  
S.I. Shkarubo ◽  
◽  
...  
Keyword(s):  
Arctic Basin ◽  
Data Interpretation ◽  
Magnetic Anomalies ◽  
The Arctic ◽  
The North ◽  
Franz Josef Land ◽  
Seismic Reflection Method ◽  
Anna Trough ◽  
Seismic Sections ◽  
Severnaya Zemlya

Based on the interpretation of seismic sections via seismic reflection method, the lines of which intersect the positive magnetic anomalies in the St. Anna Trough and on the North Kara Shelf, the authors have substantiated the position of the Early Cretaceous dike belt in the north of the Barents-Kara platform for the first time. They traced the belt from the arch-block elevation of arch. Franz Josef Land, which belongs to the Svalbard platе through the Saint Anna Trough and further into the Kara platе to arch. Severnaya Zemlya. The distinguished dyke belt has discordant relationships with the structural-tectonic plan of the region under consideration. The authors illustrate the manifestations of dyke magmatism in the marked tectonic elements in seismic sections, and conclude that the dyke belt relates to the formation of the structural system of the Arctic basin.

Dating stratigraphic variations of ions and oxygen isotopes in a high-altitude snowpack by comparison with daily variations of precipitation chemistry at a low-altitude site

2008 ◽  
Vol 39 (2) ◽  
pp. 101-112 ◽  
Author(s):  
W.H. Theakstone
Keyword(s):  
Sea Level ◽  
Oxygen Isotopes ◽  
Arctic Basin ◽  
Precipitation Chemistry ◽  
Temporal Variations ◽  
Climatic Conditions ◽  
The Arctic ◽  
Atmospheric Circulation Patterns ◽  
Ionic Concentrations ◽  
North East

Daily precipitation at Tustervatn (65°83′N, 13°92′E, 439 m above sea level) was analysed for ions and oxygen isotopes. Seven-day air mass trajectories provided information about the precipitation source and history. The highest Na+ loads were associated with air masses which had crossed the Norwegian Sea and the highest non-sea-salt SO42− loads with trajectories crossing Scandinavia or the United Kingdom; high SO42− loads in late April reflected decreasing snow cover. Trajectories from the Arctic basin resulted in the lowest δ18O values. During the winter, 4.8 m of snow accumulated at 1470 m above sea level on the glacier Austre Okstindbreen, 25 km north-east of Tustervatn. Mean ionic concentrations were lower than at Tustervatn, but loads were higher, as the total precipitation was three times greater. At both sites, ionic loads were closely related to ionic concentrations but not to sample water-equivalent values/precipitation amounts. Dates could be assigned to much of the snowpack on the basis of similarities between its chemical stratigraphy and temporal variations of precipitation chemistry at Tustervatn. Examination of the influence of individual storms on δ18O variations and the relationship between those variations and atmospheric circulation patterns has potential importance in relation to understanding past, present and possible future climatic conditions.

Geological history and tectonic implication of the Kucherov Terrace (East Siberian Arctic shelf).

2020 ◽  
Author(s):  
Sergei Freiman ◽  
Anatoly Nikishin
Keyword(s):  
Sea Level ◽  
Chukchi Sea ◽  
Sedimentary Cover ◽  
Arctic Basin ◽  
Water Area ◽  
The Arctic ◽  
Shelf Area ◽  
Geological History ◽  
Shallow Marine ◽  
History Of

<p>The Kucherov Terrace is a prominent flat platform lies on a depth about 1200 meters below sea level between shelf area of the Chukchi Sea and deep-water area of Podvodnikov Basin and Mendeleev Rise. Due to location between main tectonic features of the East Arctic basin this territory carries some important insights to the tectonic history of the Arctic. By available seismic data and regional seismic correlation, we outlined series of the key moments of the geological history and estimated ancient geomorphological features of the territory.   </p><p>Based on our interpretation we suppose main rifting event took place on the territory in Aptian-Albian ages. After the rifting stage thermal subsidence lead to increasing of water depth and infilling of the basin by sediments from the Siberia territory. Two main stages of sedimentary history of the area were identified: Late Cretacerous-Paleocene and Eocene-Recent.    </p><p>By presence of obvious clinoform sequences in a sedimentary cover of the Kucherov terrace, we interpret the terrace itself as submerged ancient shelf was formed not later than end of Paleocene. Using clinoform geometry we calculated paleodepth of the Podvodnikov and Toll basins as around 800-1000 meters below sea level in Paleocene. At the same time adjacent to the shelf area seamounts of the Mendeleev Rise already existed in this time and played a role of a natural barrier to the prograding shallow-marine clastic wedges.  By shelf-edge position of a clinoform sets we estimated mean subsidence rates as 15-22 meters/myr in an area with preceding sediment loading less than 3 km.  The obtained estimates can be used as good constraints during further subsidence modelling.</p><p>During Eocene-Recent stage existence of flat platform led to a peculiar pattern of a sedimentation in a Chukchi shelf. Shallow-marine circumstances led to a very fast descending profile with less or absence of basin-floor fans. Formation of the mass wasting deposits starts in this area only in the Miocene unlike adjacent territories.</p><p>The study was funded by RFBR ‐ projects № 18-05-70011 and 18-05-00495.</p><div> <div> </div> </div>

scholarly journals The Younger Dryas and the Sea of Ancient Ice

2008 ◽  
Vol 70 (1) ◽  
pp. 1-10 ◽  
Author(s):  
Raymond S. Bradley ◽  
John H. England
Keyword(s):  
Sea Ice ◽  
Arctic Ocean ◽  
Sea Level ◽  
Barents Sea ◽  
Younger Dryas ◽  
Arctic Basin ◽  
Arctic Sea Ice ◽  
The Arctic ◽  
Floating Body ◽  
The Arctic Ocean

AbstractWe propose that prior to the Younger Dryas period, the Arctic Ocean supported extremely thick multi-year fast ice overlain by superimposed ice and firn. We re-introduce the historical term paleocrystic ice to describe this. The ice was independent of continental (glacier) ice and formed a massive floating body trapped within the almost closed Arctic Basin, when sea-level was lower during the last glacial maximum. As sea-level rose and the Barents Sea Shelf became deglaciated, the volume of warm Atlantic water entering the Arctic Ocean increased, as did the corresponding egress, driving the paleocrystic ice towards Fram Strait. New evidence shows that Bering Strait was resubmerged around the same time, providing further dynamical forcing of the ice as the Transpolar Drift became established. Additional freshwater entered the Arctic Basin from Siberia and North America, from proglacial lakes and meltwater derived from the Laurentide Ice Sheet. Collectively, these forces drove large volumes of thick paleocrystic ice and relatively fresh water from the Arctic Ocean into the Greenland Sea, shutting down deepwater formation and creating conditions conducive for extensive sea-ice to form and persist as far south as 60°N. We propose that the forcing responsible for the Younger Dryas cold episode was thus the result of extremely thick sea-ice being driven from the Arctic Ocean, dampening or shutting off the thermohaline circulation, as sea-level rose and Atlantic and Pacific waters entered the Arctic Basin. This hypothesis focuses attention on the potential role of Arctic sea-ice in causing the Younger Dryas episode, but does not preclude other factors that may also have played a role.

scholarly journals Estimating the contribution of Arctic glaciers to sea-level change in the next 100 years

2005 ◽  
Vol 42 ◽  
pp. 230-236 ◽  
Author(s):  
J. Oerlemans ◽  
R.P. Bassford ◽  
W. Chapman ◽  
J.A. Dowdeswell ◽  
A.F. Glazovsky ◽  
...  
Keyword(s):  
Sea Level ◽  
Climate Models ◽  
Ice Sheet ◽  
Canadian Arctic ◽  
Greenland Ice Sheet ◽  
Sea Level Change ◽  
The Arctic ◽  
Climate Change Scenarios ◽  
Regional Patterns ◽  
Level Change

AbstractIn this paper, we report on an approach to estimate the contribution of Arctic glaciers to sea-level change. In our calculation we assume that a static approach is feasible. We only calculate changes in the surface balance from modelled sensitivities. These sensitivities, summarized in the seasonal sensitivity characteristic, can be used to calculate the change in the surface mass budget for given anomalies of monthly temperature and precipitation. We have based our calculations on a subdivision of all Arctic ice into 13 regions: four sectors of the Greenland ice sheet; the Canadian Arctic >74˚N; the Canadian Arctic <74˚N; Alaska, USA; Iceland; Svalbard; Zemlya Frantsa Iosifa, Russia; Novaya Zemlya, Russia; Severnaya Zemlya, Russia; and Norway/Sweden >60˚N. As forcing for the calculations, we have used the output from five climate models, for the period 2000–2100. These models were forced by the same greenhouse-gas scenario (IPCC-B2). The calculated contributions to sea-level rise in the year 2100 vary from almost zero to about 6 cm. The differences among the models stem first of all from differences in the precipitation. The largest contribution to sea-level change comes from the Greenland ice sheet. The glaciers in Alaska also make a large contribution, not because of the area they cover, but because they are more sensitive than other glaciers in the Arctic. The climate models do not agree on regional patterns. The runoff from Svalbard glaciers, for instance, increases for two models and decreases for the three other models. We conclude that the uncertainty due to a simple representation of the glaciological processes is probably smaller than the uncertainty induced by the differences in the climate-change scenarios produced by the models.

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