Anahim hotspot

Anahim hotspot

Anahim hotspot (British Columbia) Location of the Anahim hotspot in British Columbia
Country	Canada
Province	British Columbia
Region	Interior Plateau
Coordinates	52°56′N 123°44′W / 52.93°N 123.73°W / 52.93; -123.73—Nazko Cone
Latest activity	Carbon dioxide emissions
Last eruption	7,200 years ago

The Anahim hotspot is a hypothesized hotspot in the Central Interior of British Columbia, Canada. It has been proposed as the candidate source for volcanism in the Anahim Volcanic Belt, a 300 kilometres (190 miles) long chain of volcanoes and other magmatic features that have undergone erosion. This chain extends from the community of Bella Bella in the west to near the small city of Quesnel in the east. While most volcanoes are created by geological activity at tectonic plate boundaries, the Anahim hotspot is located hundreds of kilometres away from the nearest plate boundary.

The hotspot was first proposed in the 1970s by three scientists who used John Tuzo Wilson's classic hotspot theory. This theory proposes that a single, fixed mantle plume builds volcanoes that then, cut off from their source by the movement of the North American Plate, become increasingly inactive and eventually erode over millions of years. A more recent theory, published in 2001 by the Geological Society of America, suggests that the Anahim hotspot might be supplied by a mantle plume from the upper mantle rather than a deep-seated plume proposed by Wilson. Tomographic imaging has since identified a low-velocity anomaly, indicative of an upwelling plume, that measures roughly 400 kilometres (250 miles) deep. This measurement, however, could be an underestimate as the anomaly might originate deeper inside Earth.

Volcanism as early as 14.5 million years ago has been linked to the Anahim hotspot, with the latest eruption having taken place in the last 8,000 years. This volcanic activity has produced rocks that show a bimodal distribution in composition. While these rocks were being deposited, the hotspot coincided with periods of crustal extension and uplift. Activity in modern times has been limited to earthquakes and volcanic gas emissions.