On April 29, 1903 at 4:10 a.m., a mass of limestone rock estimated to weigh 82 million tonnes (8.2 x 1010 kg) failed on the flank of Turtle Mountain near the community of Frank, Alberta. The rockslide was initiated at an elevation of 2300 metres above sea level (a.s.l.). The rock mass crashed onto the valley floor at an elevation of 1600 metres a.s.l. and came to an abrupt halt on the opposite valley wall at an elevation of 1800 metres a.s.l. It took only 90 seconds for the rock mass to travel 1.5 kilometres (km) and to cover an area of 3 km2 to a depth of more than 30 metres (m). This is Canada's deadliest rockslide; a portion of the community of Frank was buried by the rock debris and more than 70 fatalities were reported (https://publications.gc.ca/collections/collection_2008rcan/M4-59-2- 2008E.pdf). Please view the YouTube video titled "1903: 90 seconds of terror" produced by the Canadian Broadcasting Corporation in 2003 before proceeding to complete this exercise (https://www.youtube.com/watch?v=M2fDOdNzX_U). As the rock mass moved down the mountainside, its potential energy was converted into kinetic energy. What force was applied to this moving rock mass?

GEOG 120 Introduction to Global Environmental Systems Lab Exercise #4 Landslide Hazard Analysis 7 F = m x g Where F = force m = mass of rock (kilograms, kg) g = acceleration due to gravity = 9.8 m/s2

9. Compute the force applied to the moving rock mass?