An earthquake with an initially reported magnitude of 4.0 has struck the Nahanni National Park Reserve.
The quake had its epicentre virtually on the border between the NWT and Yukon, around 100 km west of Nahanni Butte, Earthquakes Canada reported.
Residents of either territory were unlikely to have felt the quake, which struck an uninhabited area of wilderness. There were no immediate reports of any damage or injury.
The US Geological Survey gave the quake a slightly higher magnitude of 4.2 in its own initial report.
Both US and Canadian authorities gave the time of the earthquake as 5:32pm MT on Thursday.
A quake of similar size struck farther to the north of the Nahanni region in mid-June. Together, the two form the NWT's most significant quakes since two struck northwest of Fort Good Hope in quick succession six months ago.
Earthquakes of magnitude 4.0 or above in the Northwest Territories are not uncommon, but equally are not an everyday occurrence.
According to Earthquakes Canada, the NWT's largest earthquake of the past half-century registered a magnitude of 5.7 west of Tulita in the Mackenzie mountains in 2006.
Though there are several variables affecting an earthquake's impact – such as the depth at which it strikes – in general, only magnitudes of 5.5 or above cause damage of note.
As they ordinarily strike remote regions around the Mackenzies, rarely do NWT earthquakes cause injury or trigger reports of damage to property.