Many geometrical schemes - or map projections - are used to represent the curved surface of the Earth on map sheets. Canada uses the **Universal Transverse Mercator** (UTM) system. It is called transverse because the strips run north-south rather than east-west along the equator. This data class shows a 5 km x 5 km grid coordinate system based on the UTM projection using the North American Datum 83 (NAD83). It includes a UTM Map Sheet Number.

BCGS 1:2,500 scale grid, North Amercian Datum 1983. The British Columbia Geographic System is a geographic system in which the coverage in minutes and seconds of longitude is double the coverage in minutes and seconds of latitude for sheets at all scales

The Canadian Gravity Anomaly Data Base consists of approximately 660 000 gravity observations, including 165 000 on land, acquired between 1944 and the present. The data spacing ranges from less than 1 km to over 20 km, with an average spacing between 5 and 10 km. All measurements were reduced to the IGSN71 datum. Theoretical gravity values were calculated from the Geodetic Reference System 1967 (GRS67) gravity formula. Bouguer anomalies were calculated using a vertical gravity gradient of 0.3086 mGal·m-1 and a crustal density of 2 670 kg·m-3.

All 1:50,000 NTDB transportation features including roads, trails, and railways Based on Edition 2.x.Distributed from [GeoYukon](https://yukon.ca/geoyukon) by the [Government of Yukon](https://yukon.ca/maps) . Discover more digital map data and interactive maps from Yukon's digital map data collection.For more information: [geomatics.help@yukon.ca](mailto:geomatics.help@yukon.ca)

All 1:250,000 NTDB Transportation features including roads, trails, and railways.Distributed from [GeoYukon](https://yukon.ca/geoyukon) by the [Government of Yukon](https://yukon.ca/maps) . Discover more digital map data and interactive maps from Yukon's digital map data collection.For more information: [geomatics.help@yukon.ca](mailto:geomatics.help@yukon.ca)

In 2015, a magnitude 4.7 earthquake occurred 60 km beneath Sidney, BC. This scenario visualizes the effects of that event if it had a magnitude of 7.1.

This layer is part of the Geological Survey of Canada's earthquake monitoring network. There are some blank fields toward the beginning of the listing, from the time the network was being installed and hence parameters were often unknown. Also, all depths in the table are "fixed" to a depth which is an integer multiple of 5km, according to lowest obtainable residuals and known crustal structure. The number and magnitude of located events are also dependent on the time recorded, as the magnitude threshold lowered as more stations were installed. The larger, potentially damaging earthquakes, however, were likely recorded from the inception of the network as these events produce waves which reach the entire western network.Distributed from [GeoYukon](https://yukon.ca/geoyukon) by the [Government of Yukon](https://yukon.ca/maps) . Discover more digital map data and interactive maps from Yukon's digital map data collection.For more information: [geomatics.help@yukon.ca](mailto:geomatics.help@yukon.ca)

Description:Chlorophyll-a concentration (a proxy for phytoplankton biomass) was retrieved from the MODIS instrument on the Aqua satellite, with data distributed by the NASA Ocean Biology Processing Group, and averaged into monthly climatological composites. The data span the years 2003-2020 and this record includes data at 4 km pixel resolution.Methods:MODIS-Aqua Chlorophyll-a (Chl-a) was acquired from the NASA Ocean Biology Processing Group at processing Level-3 (version 2018), 4-km resolution, where Chl-a concentration was calculated using the OC3/OCI method. The months of January and December were excluded from this dataset, as data in the winter months at higher latitudes are missing due to low sun angle preventing acquisition. The monthly geometric mean value at all pixels was calculated for individual years, then the geometric mean and geometric standard deviation factor of chlorophyll-a were calculated by month from these images. These methods of calculating mean and standard deviation were used due to the log-normal distribution of chlorophyll-a. The geometric standard deviation is a unitless factor, where the lower bound is the ratio of the geometric mean and geometric standard deviation, and the upper bound is the multiplication of the two. In addition to the geometric mean and geometric standard deviation factor the number of occurrences of valid data at each pixel over the period of observation were calculated. Pixels with fewer than two occurrences over the entire period of observation were removed from these maps, and set to a NaN value in the tif files. All resulting rasters were cropped to the Canadian Exclusive Economic Zone and assigned to the NAD83 geographic coordinate reference system (EPSG:4269), and have a final pixel resolution of approximately 0.0417 degrees. The monthly geometric mean, monthly geometric standard deviation factor, and number of occurrences for all pixels are provided.Data Sources:NASA Ocean Biology Processing Group. (2017). MODIS-Aqua Level 2 Ocean Color Data Version R2018.0. NASA Ocean Biology Distributed Active Archive Center. https://doi.org/10.5067/AQUA/MODIS/L2/OC/2018Uncertainties:Satellite values have been evaluated against global datasets, and datasets of samples in the Pacific region (see references). However, uncertainties are introduced when averaging together images over time as each pixel has a differing number of observations. Short-lived or spatially limited events may be missed.

Description:Chlorophyll-a concentration (a proxy for phytoplankton biomass) was retrieved from the MODIS instrument on the Aqua satellite, with data distributed by the NASA Ocean Biology Processing Group, and averaged into monthly climatological composites. The data span the years 2003-2020 and this record includes data at 1 km pixel resolution.Methods:MODIS-Aqua Chlorophyll-a (Chl-a) was acquired from the NASA Ocean Biology Processing Group at processing Level-2 (version 2018), 1-km resolution, where Chl-a concentration was calculated using the OC3/OCI method. The months of January and December were excluded from this dataset, as data in the winter months at higher latitudes are missing due to low sun angle preventing acquisition. The pixels were aligned on a regular grid using the SeaDAS program, after which the monthly geometric mean value at all pixels was calculated for individual years. Finally, the geometric mean and geometric standard deviation factor of chlorophyll-a were calculated by month from these images. These methods of calculating mean and standard deviation were used due to the log-normal distribution of chlorophyll-a. The geometric standard deviation is a unitless factor, where the lower bound is the ratio of the geometric mean and geometric standard deviation, and the upper bound is the multiplication of the two. In addition to these variables, the number of occurrences of valid data at each pixel over the period of observation were calculated. Pixels with fewer than two occurrences over the entire period of observation were removed from these maps, and set to a NaN value in the tif files. A few small gaps between pixels (near the edges of individual images) were filled using the median value of surrounding pixels, provided there were greater than 4 values. Finally, all rasters were cropped to the Canadian Exclusive Economic Zone and assigned to the NAD83 geographic coordinate reference system (EPSG:4269), and have a final pixel resolution of approximately 0.01 degrees. The monthly geometric mean, monthly geometric standard deviation factor, and number of occurrences for all pixels are provided.Data Sources:NASA Ocean Biology Processing Group. (2017). MODIS-Aqua Level 2 Ocean Color Data Version R2018.0. NASA Ocean Biology Distributed Active Archive Center. https://doi.org/10.5067/AQUA/MODIS/L2/OC/2018Uncertainties:Satellite values have been evaluated against global datasets, and datasets of samples in the Pacific region (see references). However, uncertainties are introduced when averaging together images over time as each pixel has a differing number of observations. Short-lived or spatially limited events may be missed.

Curie point depth (CPD) mapping in Yukon was done using public domain aeromagnetic data from Natural Resources Canada. In this study, two different CPD methodologies were employed using two different window sizes (200 km and 300 km). Qualitatively, the results were broadly consistent regardless of the method or window size. South-central Yukon exhibits shallow CPD values while northern and southeastern Yukon have deeper CPD values. This suggests that south-central Yukon has higher levels of heat flow in the mid-to-lower crust compared to the rest of the territory. The CPD results are largely consistent with heat flow measurements from the near surface. Specifically, regions with shallow CPD estimates correspond to areas with elevated heat flow measurements. Geologically, the regions with shallow CPD correspond to the Cordillera, while deep CPD areas appear to be co-located with continental platform rocks of Ancestral North America. Comparison with Yukon-specific crustal geotherms derived from other data suggest that the CPD estimates for south-central Yukon are systematically too deep by 2 to 12 km. The discrepancy is likely caused by the need to better understand and account for the fractal distribution of magnetization in the crust in Yukon. The results of this CPD study are valuable in that 95% of Yukon has been demarcated into regions of shallow CPD (higher heat flow) and deep CPD (lower heat flow). These findings should be combined with other data, such as heat generation and sediment thickness estimates, to identify the most prospective regions of elevated subsurface heat in Yukon. Contours have been created for the gridded curie point depth at 1 km intervals and are presented along with the grid.Distributed from [GeoYukon](https://mapservices.gov.yk.ca/GeoYukon/) by the [Government of Yukon](https://yukon.ca/) . Discover more digital map data and interactive maps from Yukon's digital map data collection. For more information: [geomatics.help@yukon.ca](mailto:geomatics.help@yukon.ca)