There are several different types of natural hazards in Sea to Sky Country.
Below are descriptions of some of them.
Rockfall : rocks commonly fall off the steep slopes above the Sea to Sky Highway. At least $1 million is spent annually to do safety work and the Ministry of Transportation plans on spending $18 million as part of the current upgrade to address safety issues.
Landslides as you travel from Horseshoe Bay to Pemberton:
M Creek :There are no known landslides at the southern end of the corridor although a "crack" in the land has been noted above M Creek. In 1981 a debris flow swept down and took out the bridge. Nine people died.
Mount Garibaldi: Recurrent landslides from this steep scarp have produced a huge debris fan at the mouth of the Cheekye River just north of Brackendale.
The Barrier: The fractured face of The Barrier has repeatedly collapsed, producing landslides along Rubble Creek, mostly recently in 1855-56. Its likely this event will happen every 1,500 years.
The Fitzsimmons Landslip: An area 2.5 kilometres upstream from the village on Whistler Mountain threatens to send one million cubic metres of earth into Fitzsimmons Creek temporarily blocking it before bursting the damn and sending a debris flow down into the day skier parking lots and the local bus loop.
Between Wedgemont Lake trail and Green River crossing: Scientists know there was a massive rock avalanche probably in the order of 8 million cubic metres. There are currently some huge cracks in the mountain ridge above it so there is at least some possibility that there could be a future event but no studies have been done to assess risk.
Mystery Creek: This was a rock avalanche with about 30-50 million cubic metres of rock. It happened at least 900 years ago.
Mount Currie: There is a one-kilometre crack across its face.
Debris Flows : Most of the creeks along Howe Sound have now been assessed and steps taken to prevent debris flows which could injure people or cause property damage. However, as the washing away of the Rutherford Creek Bridge last October proved, Mother Nature usually has the last word.
Floods : Pemberton and Squamish most at risk.
Earthquakes : Damage will depend on how close it is to the corridor. At the very least lose or unstable rock will be shaken free above the highway and it is likely the road will be closed, possibly for several days as crews deal with multiple rockfalls.
It could also trigger massive landslides at weak points like the Barrier. Big earthquakes in this region usually take place every 300 to 500 years. The last earthquake was Jan. 26, 1700.
Volcanoes : Of the three in the area, Mount Garibaldi, Mount Cayley and Mount Meager, only the later is considered potentially active. If any of them were to erupt they would not only send ash as far as Alberta they could also cause massive flooding problems due to river blockages by debris. Mount Meager last erupted 2,400 years ago.