FORT ST. JOHN, B.C. – Geologists that have been contracted by the Peace River Regional District in its response to the landslide above the community of Old Fort say that the landslide appears to be slowing down.
In an update today the PRRD said that over the past few days the geotechnical team has found signs of movement on the slopes to the east of the large bedrock ‘knob’ in the hillside above Old Fort.
Geologists said that the movement is related to movement on the upslope portion of the active slide, and that no recent slope movement was noted in the hillside above most homes in the Old Fort subdivision.
The PRRD’s geotechnical team also conducted an aerial assessment of the off-road vehicle trail running along the ridge on the eastern edge of the ancient slide complex above most subdivision houses.
Geologists say that while they did not see any signs of recent slope movement, they will be conducting more examinations of that portion of the hillside on Thursday to confirm the findings.
The Regional District said that the geotechnical team spent time in the field discussing various landslide initiation models, as well as the direction their investigation would focus on over the coming days.
Over the past several days, the geotechnical team also had a good look at the slopes above Old Fort Road to the east of the active slide complex, and could not see any significant signs of recent slope movement – which supports data collected during aerial LiDAR surveys.
Lateral tension cracks that had recently appeared on the hillside immediately east of the active slide complex have now started to turn downslope, which means the lateral shear zone on this side of the slide may be developing.
The PRRD explained that those findings indicate that, at this point, the surface of the original Old Fort Slide does not appear to have been impacted by the recent slope movement.