Garibaldi volcano is one of the three major composite volcanoes in Canada located in the Garibaldi Volcanic Belt. Rising to an elevation of 2678 meters, the Garibaldi volcano is made up of Mount Garibaldi and its adjacent peaks, the Dalton Dome and Atwell Peak. These peaks are located roughly 20 kilometers NE of Downtown Squamish and 30 kilometers south of Whistler.
Garibaldi volcano is built on crystalline basement rock in the southern Coast Mountains of British Columbia. Garibaldi volcano was in-built by the Peléan eruption, the idetincal mechanism that builds Mount Pelee on the Caribbean Island. Series of explosives of andesitic to dacitic flow or during the waning stages of the last glacial epoch in Pleistocene, 12 000- 10 000 BP ago (Mathews, 1952a). These explosions built an apron of blocky, unconsolidated material around the vent area and out onto the encircling sheet of thick glacial ice. This unconsolidated material was intruded by the growing domes and capped by a lava flow.
The foremost recent eruptive activity is represented by the Ring Creek Lava flow, issued from Opal cone on the southeast flank of Mount Garibaldi. The dacitic lava flow extends 15 km down the Mamquam River Valley and is found to be between 10000 and 9000 years old based on stratigraphy and radioactive dating (Brooks and Friele, 1992). However, such a period of dormancy, in volcanology, is not long enough to establish the extinction of the volcano.
In 2006, Mt Garibaldi was listed as one of the top 10 Canadian volcanoes selected based on recent seismic activities, alongside volcanoes such as Mt Cayley and Mt Meager from the Garibaldi Volcanic Belt (Hickson & Ulmi, 2006). There are local anomalous high heat flow in Table Meadows (Woodsworth, 2003) which hints at possible activity underground.
Given the signs of potential volcanic activity, a geospatial investigation was carried out to analyze how potential eruptions of Garibaldi volcano would impact the populations of Squamish and Whistler, and to devise contingency plans for safe evacuation.