| Citation |
Schwab, J.W. and M. Kirk (2002) Sackungen on a Forested Slope, Kitnayakwa River, Forest Sciences, Prince Rupert Forest Region, BC Forest Service. Extension Note #47, March, 2002. |
| Abstract/Description or Keywords |
Anomalous linear features including uphill-facing (antislope) scarps and troughs trending parallel to slope contours were found on a forested slope adjacent to large bedrock landslides (54 25’ N; 127 52’ W) within the Kitnayakwa River watershed (Figure1). The German term “Sackung” denotes slope sagging, gravitational spreading or deepseated gravitational slope deformation to describe these linear features in mountainous landscapes. Numerous landslides have occurred in the vicinity over the last 450 years. The sackung features at Kitnayakwa indicate active slope movement and foreshadow another pending landslide. The sackung features at Kitnayakwa signify an unstable, sagging slope. Another catastrophic failure could occur at any time as a result of past glacial debuttressing and oversteepened slopes, water input through seasonal and climatic cycles, earthquake activity, or a combination of any three. Despite some existing theories sackungen remain enigmatic. To better understand sackung features, researchers must explore climatic and seasonal cyclic effects on ground water, the role of vegetation on hydrology within the contributing basin, the failure process, and bedrock properties. The sackungen found on the slopes above the Kitnayakwa show evidence of rapid movement in the past and continual ongoing slow movement. This persistent instability poses the question: should human activities, such as logging and road construction, take place on these slopes? |
