Frank Slide

The Frank Slide is a natural landslide feature in the southern Rocky Mountains of Canada, and a significant historical event in western Canada.

Frank, Alberta is a coal mining town in the Crowsnest Pass, Alberta. On April 29, 1903, at 4:10 a.m., 74 million tonnes (30 million cubic metres) of limestone crashed from the east face of Turtle Mountain and covered approximately three square kilometres of the valley floor. The slab of rock that broke free was approximately 650 m high, 900 m wide and 150 m thickcite book|last=Dawson|first=Brian|title=Crowsnest: An Illustrated History and Guide to the Crowsnest Pass|pages=54|year=1995|publisher=Altitude Publishing Canada|isbn=1-55153-075-9] (87,750,000 cu.m.). The slide dammed the Crowsnest River and formed a small lake, covered 2km of the Canadian Pacific Railway, destroyed most of the coal mine's surface infrastructure, and buried seven houses on the outskirts of the sleeping town of Frank, as well as several rural buildings. Frank was home to approximately 600 people in 1903; of the roughly 100 individuals who lived in the path of the slide, more than 70 were killed. The town was evacuated, but people were soon allowed to return and both the mine and the railway were back in operation within a month. The town of Frank continued to grow, until a report on the mountain’s stability resulted in the provincial government ordering the closure of the south part of the town in 1911. Studies and monitoring continue today.

Geology

Turtle Mountain is an anticline of Paleozoic Rundle Group carbonates thrust over weaker Mesozoic clastics and coals. Summit fissures at the apex of the anticline likely allowed water to infiltrate and weaken the slightly-soluble carbonates within the mountain face, while the supporting underlying clastics were undermined by valley glaciation followed by erosion from the Crowsnest River.

The slide removed the top of Turtle Mountain, leaving a present elevation of convert|2109|m|ft|0 for the north peak and convert|2200|m|ft|0|abbr=on for the south peak.

The primary cause of the slide was the mountain's unstable geological structure, although it was thought at the time that an earthquake on the Aleutian Islands in 1901 may have contributed; the theory was later dismissed. The mining at the base of the mountain may have been a small factor in the event's generation, but is not considered to be the primary cause. [CBC Archives, "On This Day - April 29, 1903" [http://archives.cbc.ca/souvenirs/date.asp?mois=04&jour=29&IDLan=1&IDClip=13371] ] It is believed that the weather was the final trigger of the slide.

Historical notes

* Only twelve bodies were recovered from the debris at the time of the slide. In 1922, a road construction crew uncovered the remains of seven more people.
* Several people in the direct path of the slide survived, including three young girls. Fernie Watkins was found amongst the debris. Marion Leitch, 15 months old, was thrown from her house to safety on a pile of hay. Gladys Ennis, 27 months old, was found choking in a pile of mud by her mother, Lucy Ennis (Gladys died in 1995 at age 94, the last survivor of the slide).
* Warnings were telegraphed westward to Cranbrook, but the eastern lines were severed. Two railway brakemen set out across the rockslide to flag down the Spokane Flyer, but only Sid Choquette made it across in time to flag down the train.
* Seventeen men trapped in the Frank mine escaped by tunneling through virgin coal to the surface, which was easier than trying to clear the debris at the entrance. They dug through 6 metres (20 ft) of coal and 2.7 metres (9 ft) of limestone boulders. The effort took them 14 hours. [ [http://www.collectionscanada.ca/sos/002028-2300-e.html?PHPSESSID=gjc8q31s0iq0rurk1v815uqg66 SOS! Canadian Disasters] , a virtual museum exhibition at Library and Archives Canada]
* A mine horse named Charlie survived alone in the mine for a month, but succumbed to its rescuers' kindness from overeating, without ever seeing daylight.

Popular culture

, features a song about the Turtle Mountain disaster called "How The Mountain Came Down". The song was also included in 2001 compilation "Sings Canadian History". The Canadian Indie Rock Band "The Rural Alberta Advantage" released a song about the disaster on their 2007 album "Hometowns", entitled, Frank, AB.

References

*Anderson, Frank W. "The Frank Slide Story". Frontier Books, 1968.
*Kerr, J. W. "Frank Slide". Barker, 1990.
*"Crowsnest and its People". Crowsnest Pass Historical Society, 1979.
*"On the Edge of Destruction" National Film Board of Canada, ID 153C0103256, 2003.
* [http://www.collectionscanada.ca/sos/ SOS! Canadian Disasters] , a virtual museum exhibition at Library and Archives Canada

Footnotes

External links

* [http://www.frankslide.com/ Frank Slide Interpretive Centre]
* [http://www3.sympatico.ca/goweezer/canada/frank.htm Neil Simpson's Frank Slide website]
* [http://www.ags.gov.ab.ca/activities/Turtle_Mountain/mainpage.htm Turtle Mountain Monitoring Project]
* [http://www.cseg.ca/conferences/2000/2000abstracts/860.PDF Geotechnical Hazard Assessment, 2000]