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Canadian Cascade Arc
The Canadian Cascade Arc, also called the Canadian Cascades, is the Canadian segment of the North American Cascade Volcanic Arc. Located entirely within the Canadian province of British Columbia, it extends from the Cascade Mountains in the south to the Coast Mountains in the north. Specifically, the southern end of the Canadian Cascades begin at the Canada–United States border. However, the specific boundaries of the northern end are not precisely known and the geology in this part of the volcanic arc is poorly understood. It is widely accepted by geologists that the Canadian Cascade Arc extends through the Pacific Ranges of the Coast Mountains. However, others have expressed concern that the volcanic arc possibly extends further north into the Kitimat Ranges, another subdivision of the Coast Mountains, and even as far north as Haida Gwaii (formerly known as the Queen Charlotte Islands).
Over the last 29 million years, the Canadian Cascade Arc has been erupting a chain of volcanoes along the British Columbia Coast. At least four volcanic zones in British Columbia are related to Cascade Arc volcanism. This includes a large volcanic plateau in The Interior and three linear volcanic belts on The Coast. They were formed during different geological periods, separated by millions of years, and occur in three regions referred to as the ''back-arc'', ''main-arc'' and ''fore-arc''. The youngest of the three belts has been sporadically active over the last 4.0–3.0 million years, with the latest eruption having taken place possibly in the last 1,000 years. About 2,350 years ago, a major explosive eruption occurred, sending a massive ash column into the atmosphere. This is recognized as the largest volcanic eruption throughout Canada within the last 10,000 years.
In historical times, the Canadian Cascade Arc has been considerably less active than the American portion of the volcanic arc. It also has no records of historical eruptions. Nevertheless, the volcanic arc poses a threat to the surrounding region. Any volcanic hazard—ranging from landslides to eruptions—could pose a significant risk to humans and wildlife. Even though there are no historical eruptions in the Canadian Cascade Arc, eruptive activity is very likely to resume; if this were to happen, relief efforts would be quickly organized. Teams such as the Interagency Volcanic Event Notification Plan (IVENP) are prepared to notify people threatened by volcanic eruptions.
==Geology==
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