Complex sentence: An eruption in the foreseeable future is probably more likely along the Northern Cordilleran Volcanic Province than in an unrelated volcanic zone outside the province because this volcanic area, which includes the Iskut-Unuk River Cones, is the most active volcanic zone in Canada.
Split into simpler sentences: An eruption in the foreseeable future is probably more likely along the Northern Cordilleran Volcanic Province than in an unrelated volcanic zone outside the province. This is because the Northern Cordilleran Volcanic Province, which includes the Iskut-Unuk River Cones, is the most active volcanic zone in Canada.