A collection of five crustal scale seismic refraction programs performed in Canada by the Geological Survey of Canada.

The data used in this compilation come from the Canadian Gravity Database (CGDB), which is managed by the Canadian Geodetic Survey (CGS), Surveyor General Branch. CGDB includes more than 755 000 observations, including some 232 000 observations on land. The distribution of the land data represents an average of one gravity point per 40 km². The gravity maps, which are gridded to a 2-km interval with a blanking radius of 20 km, currently include data acquired between 1944 and 2015. CGS and partners continue to supplement the CGDB each year. The surveys are conducted using relative gravimeters that measure the gravity difference between two locations. On the landmass, gravity has been measured primarily using static gravimeters. Although measurements at some offshore locations have been collected using static gravimeters on the ocean floor, most are acquired using dynamic gravimeters aboard moving vessels. The relative nature of the gravimeters require that surveys be tied to base (control) stations with known absolute gravity. The base stations are part of the Canadian Gravity Standardization Network (CGSN), which is tied to the International Gravity Standardization Network 1971 (IGSN71). Today, the traditional base stations are being replaced by new base stations that are measured with an absolute gravimeter having an accuracy of 2µGal (2x10-8 m/s²). All relative gravity measurements are integrated into the IGSN71 datum to create a coherent dataset at the global scale. Normal (theoretical) gravity is calculated using the Geodetic Reference System 1980 (GRS80; https://doi.org/10.1007%2FS001900050278). Bouguer anomalies, which include reductions of the elevation and topographical mass to sea level, are calculated using a vertical gravity gradient of ~0.3086 mGal/m (change slightly with latitude and elevation) and a crustal density of 2670 kg/m³.

Vertical seismic profiling (VSP) surveys done by the Geological Survey of Canada for research into downhole seismic imaging techniques for mineral exploration.

This data set is a compilation of data acquired mostly by airborne surveys in Canada, gridded at 200 m and 1 km resolutions. The Geological Survey of Canada has flown or supervised more than 700 surveys since 1947, generally with a flight-line spacing of 800 m and an altitude of 305 m above the ground, though since 2000 the majority of surveys have been flown with a line spacing of 400 m or less. These aeromagnetic surveys have been leveled to each other to correct for arbitrary datums, slow variations of Earth's magnetic field over time, and differing survey specifications. The magnetic character of a rock depends on its ferromagnetic mineral composition, its concentration and its deformational and metamorphic history. Variations in the magnetic character of Earth's crust cause small magnetic anomalies in the earth's magnetic field. These magnetic anomalies can show geological trends and structural boundaries. The first vertical derivative of magnetic anomalies is calculated from the residual magnetic field and enhances the short wavelength component of the field. It is often used to trace contacts between magnetic domains. These data have also been published as two Geological Survey of Canada Open File maps: Magnetic Anomaly Map, Canada, (Open File 7799) and the First Vertical Derivative of the Magnetic Anomalies Map, Canada, (Open File 7878).