| Comments | Khyex River BC, November 28, 2003. The Khyex River Landslide occurred on November 28, between 00:20 and 00:30 PST. This is when Pacific Northern Gas Ltd noticed a pressure loss in the pipeline. Approximately 300 metres of 8-inch pipeline was lost. As a result, most of Prince Rupert residents were without natural gas or heat for 10 days. A few days after the landslide occurred, a temporary 2-inch gas line was installed to restore partial service. The spectacular landslide flowed downstream, crossed the river and flowed upstream for hundreds of metres. This type of landslide took place in very sensitive glaciomarine muds, and is called a retrogressive earthflow. The estimated volume of material displaced by the landslide is up to 4.7 million cubic metres. It is thought that the slope failure was triggered by erosion of the riverbank. |