Yellowknife Geoscience Forum

An ongoing challenge across the Northwest Territories (NWT) and western Canada for land managers and research scientists is a lack of attribute information for seismic lines and other linear features.  Often the locations of lines are known (either collected from maps, spatial data, or digitized from air or satellite imagery), but information about how and when those lines were cut are not.  Without those attribute data it is impossible to link a current line recovery state to severity of disturbance during initial construction or time since construction.  This in turn limits myriad subsequent actions like estimating animal response to lines with variable amounts of vegetation recovery or forecasting line recovery rates.  Such limitations often translate to keeping lines “on the books” forever which is unlikely to be ecologically realistic, but perhaps required from the perspective of a precautionary conservation strategy.

In this talk non-traditional sources of data were used to improve and attribute spatial datasets of known linear features in three different study sites across the NWT.  Companies that license seismic data often collect and catalogue various existing data and associated exploration program information into data libraries to market those data to interested parties.  Also, all seismic exploration programs conducted in the NWT are reported on to a governing agency (historically to the National Energy Board; currently to the NWT Land and Water Board system) with a Geophysical Report explaining a variety of program information.  These data streams were used to attribute line features in the official GNWT footprint dataset by assigning seismic line construction method, season, year, and width, updating converted seismic lines to new line type (e.g., pipeline, access, and road), and inferring whether a seismic line was reopened in a subsequent exploration program.  Also missing lines and line segments were infilled using recent (2015 – 2018) satellite imagery.  This work was done in the Checkpoint / Jean Marie River, Cameron Hills, and the Central Mackenzie Valley areas, selected because each were subject to different intensities of development pressure at different time periods.  In all study areas, known lines were well represented in available datasets, but line attributes were not.  For all study areas, attribute information was available for < 10% of lines in the official GNWT footprint dataset; using these methods the full suite of attributes was assigned to > 95% of all lines.  In the Cameron Hills, where development activity transitioned from exploration to production, transition from seismic lines to other line types was also captured for 17% of lines.