|Title||One-dimensional layered Earth models of Canada for GIC applications, part 1: General description|
|Licence||Please note the adoption of the Open Government Licence - Canada
supersedes any previous licences.|
Fernberg, P A; Boteler, D H|
|Source||Geological Survey of Canada, Open File 8594, 2019, 66 pages, https://doi.org/10.4095/314804 Open Access|
|Publisher||Natural Resources Canada|
|Related||This publication is related to One-dimensional layered Earth
models of Canada for GIC applications, part 2: Detailed description |
|File format||pdf (Adobe® Reader®)|
|Province||Canada; British Columbia; Alberta; Saskatchewan; Manitoba; Ontario; Quebec; New Brunswick; Nova Scotia; Prince Edward Island; Newfoundland and Labrador|
|NTS||1; 2; 3; 10; 11; 12; 13; 14; 15; 20; 21; 22; 23; 24; 25; 30; 31; 32; 33; 34; 35; 40; 41; 42; 43; 44; 52; 53; 54; 62; 63; 64; 72; 73; 74; 82; 83; 84; 92; 93; 94; 102; 103; 104; 114|
|Lat/Long WENS||-141.0000 -50.0000 63.0000 41.7500|
|Subjects||geophysics; regional geology; surficial geology/geomorphology; Science and Technology; Nature and Environment; geomagnetism; geomagnetic fields; models; modelling; geoelectric variations; resistivity;
magnetotelluric interpretations; bedrock geology; lithology; structural features; sediments; groundwater; aquifers; anomalies; conductivity; weathering; stratification; electric power; Canadian Magnetic Observatories; Infrastructures|
|Illustrations||location maps; tables; flow diagrams; plots; schematic representations; schematic cross-sections; geoscientific sketch maps; models|
|Program||Public Safety Geoscience Northern Canada Geohazards Project|
|Released||2019 07 18|
Evaluation of the impacts of space weather on ground infrastructure requires information on the size of geomagnetically induced (telluric) currents. For estimation of these currents
in places where they are/were not recorded, numerical modelling needs to be employed. The most common approach in the modelling of geomagnetically induced currents is based on the knowledge of the geoelectric field driving these currents. Because
there are no continuous measurements of the geoelectric fields in many areas where the power networks are located, the common method is based on utilisation of the available geomagnetic observations recorded in the area together with the surface
impedance of the Earth, derived from the short-duration magnetotelluric surveys.
The compilation of two reports (current, main Part 1 and supplementary Part 2)present one-dimensional resistivity models and corresponding surface impedance
variations for 10 Canadian provinces (located below 60 degrees in latitude), as derived from the available publications. The supplementary report provides a set of 10 Appendices with the detailed description of the geological settings of each
province, justification for choice of the one-dimensional areas (zones) for each province and values of resistivities and depths.
The presented main part summarises the one-dimensional Earth resistivity models and obtained surface impedance for
each province including maps with identification of different Zones, as well as Tables and plots, showing the resistivity variations with depths and plots presenting the variations of surface impedance amplitude and phase with frequency. Thus,
information presented in the main part can be immediately used for modelling of the geoelectric fields in each province.
Detailed descriptions with justification for values of layered Earths resistivity models for each province, as well as
details on the locations of the identified zones, together with the list of references are presented in: Trichtchenko, L., Fernberg, P.A., Boteler, D.H., 2019. One-dimensional Layered Earth Models of Canada for GIC Applications. Part 2. Detailed
Description; Geological Survey of Canada, Open File 8595, 587 pp. https://doi.org/10.4095/314805. In the following text this reference is cited as OF 8595. This detailed description can be used for better justification of the presented geoelectrical
parameters and location of defined zones and give the opportunity to update the specific parameters when the new information becomes available.
|Summary||(Plain Language Summary, not published)|
Space weather refers to the dynamic conditions on the Sun and in the space environment, in particular, in the near-Earth environment, that can affect
critical infrastructure. NRCan operates the Canadian Space Weather Forecast Centre and conducts research into space weather effects on power systems, pipelines, radio communications and GNSS positioning to help Canadian industry understand and
mitigate the effects of space weather. The report presents the set of Earth conductivity models for Canadian provinces. These new models are important for assessment of the space weather hazards on the power grids.