GG231 Chapter Notes - Chapter 6: Landslide, Frank Slide, Cordillera Blanca
Document Summary
The frank slide ca(cid:374)ada"s (cid:271)est k(cid:374)o(cid:449)(cid:374) la(cid:374)dslide. Rock avalanche: sudden failure at a large mass of rock that rapidly fragments and travels as a streaming mass at high speeds. Frank alberta april 29th 1903 @ 4:10 am. 900m wide by 650m wide by 150m thick. Causes vs. triggers: cause = internal or external factor that overtime reduces stability of slope and brings to point of failure, trigger = e(cid:448)e(cid:374)t that sets off the la(cid:374)dslide (cid:862)fi(cid:374)al stra(cid:449)(cid:863, geology. Deeply eroded anticline of limestone over weaker coal bearing shale. Water slowly dissolved the carbonates and decreased stability: glaciation. Glacial erosion steepened the slope, reducing its strength: human interaction. Coal mining at base reduced stability high up: weather (cid:862)fi(cid:374)al stra(cid:449)(cid:863) Heavy snow fall in march 1903 and farm weather in late april. Water entered fissures and then froze, forcing the rock mass of the mountain. Lessons learnt from frank landslide: large la(cid:374)dslides (cid:272)a(cid:374)"t (cid:271)e pre(cid:448)e(cid:374)ted. Difficult/impossible to predict: geology is important.
