Analysis of the 29 November 2018 ML 4.5 Earthquake Near Fort St. John, BC

Date: 4/26/2019

Time: 06:00 PM

Room: Fifth Avenue

A ML 4.5 earthquake occurred at 18:27 local time on 29 November, 2018, approximately 16 km from Fort St. John, British Columbia. This event occurred in an area of drilling within the Septimus region of the Montney siltstone resource play and it has been linked to active hydraulic fracturing in the Lower Montney, leading to a halt in operations by the B.C. Oil and Gas Commission. The mainshock was felt to a distance of at least 200 km and was followed by two significant aftershocks of ML 4.0 and ML 3.4. The event is located within a region of moderate structural complexity near the southern edge of the Carboniferous-to-Permian Fort St. John graben complex and also near the foreland limit of the Late Cretaceous-Paleocene Rocky Mountain thrust belt. A compilation of data, including seismic profiles, well logs, stress information and waveform data from regional seismograph networks, provide a basis for an integrated interpretation of this induced sequence that incorporates geomechanical analysis, pre-existing faults and structural setting.

Presenting Author: David W. Eaton

Authors