Data Accuracy

Geophysical Survey location data accuracy and completeness

Please note that all survey location data in BASIN should be considered to be approximate. A large portion of the data has been digitized from paper shot-point maps of various scales and are therefore only as accurate as the source map. Also note that our survey location coverage is not complete and is limited to surveys for which we have obtained maps and are of interest to the research programs of the Earth Science Sector. Therefore we have no coverage at all for several (mostly recent) surveys, and partial coverage for many of the surveys (tracks/lines lists and maps) in BASIN.

Well location data accuracy

NAD27 latitudes and longitudes in BASIN are taken from either the well history report (wells for which the confidentiality period has expired) or from the Canada-Nova Scotia Offshore Petroleum Board (CNSOPB)/Canada-Newfoundland and Labrador Offshore Petroleum Board (CNLOPB) (newer wells).

NAD83 latitudes and longitudes were provided by the CNLOPB (for Grand Banks, East Newfoundland Shelf, Labrador Shelf and West Newfoundland wells). Most other NAD83 latitudes and longitudes were converted by the GSCA from the NAD27 positions by utilizing the conversion program NTV2 (available on the Natural Resources Canada - Geodetic Survey Division NTV2 web page). NAD83 latitudes and longitudes for wells south of 40 degrees north were converted by the GSCA from the NAD27 positions by using the conversion program NADCON (may be downloaded from the U.S. National Geodetic Survey NADCON web page).

NAD27 UTM conversions were done using the Clarke 1866 Ellipsoid, NAD83 UTM conversions employed the GRS 1980 Ellipsoid, both with a Zone width of 6 degrees.