BASc Thesis 1987 – Fraser delta submarine landslides

Fraser Titan Dredge 2012

The Fraser Titan — a dredge, working at the mouth of the Fraser River near Vancouver BC. August 2012

 

 

The late John Luternauer of the Geological Survey of Canada took me under his wing when I was looking for a topic for my undergraduate thesis for the geological engineering program at UBC. He had copies of about 100 bathymetic blueprints with dredging surveys at the mouth of the Fraser River, near Vancouver, BC (Canada), and word from the crews that occassionally there were massive slumps at the mouth of the river, near the Sand Heads lighthouse, about 10km offshore. We analyzed the changes in depths and found five significant submarine landslides, and worked to try to explain the mechanisms and triggers.

Fraser River Submarine Canyon 1985

Side scan sonar of the Fraser River delta Canyon (main arm)

My colleages often suggest I’m tempting fate, as I live on the Fraser River delta, about 17km east of these landslides, and I’m only 270m from the nearest dyke. A geologist living below sea level on a river that likes to flood and a loose sandy delta deposit prone to liquefaction in earthquakes. But we love living in Ladner this past 12 years, and we’re hoping to stay at least another 10 years before moving to higher ground.

 

Sandheads Lighthouse c1985

Sand Heads Lighthouse at the mouth of the Fraser River. c1985

 

References:

 

McKenna, GT, 1987. Evidence of large-scale mass wasting on the Fraser River delta front at Sand Heads, British Columbia, Unpublished undergraduate thesis, University of British Columbia, 62p.

McKenna, GT and Luternauer, JL, 1987. First documented large failure at the Fraser River delta front, British Columbia, Current Research, Part A, Geological Survey of Canada, Paper 87-1A, p919-924.

McKenna, GT. and Kostaschuk, RA, 1990. Submarine slope failures at the mouth of the Fraser River, British Columbia, Abstract and presentation, Geological Association of Canada Annual Meeting, Vancouver.

McKenna, GT, Luternauer, JL, and Kostaschuk, RA, 1992. Large-scale mass-wasting events on the Fraser River delta front near Sand Heads, British Columbia, Canadian Geotechnical Journal, Vol 29, Number 1, p151-156.

Kostaschuck, RA, Luternauer, JL, McKenna, GT, and Moslow, TF, 1992.  Sediment transport in a submarine channel system, Fraser River delta, Canada, Journal of Sedimentary Petrology, Vol 62, No 2, p283-282.

 

Ladner fields 2008

Ladner is a suburb of Vancouver on the Fraser Delta.