Meager

Geography & Climate

Meager is located in Canada, within the Garibaldi Volcanic Arc of the broader North America Volcanic Regions. Situated at 50.63° N, 123.50° W in the Northern Hemisphere, the volcano lies within a temperate climate zone. At 2,680 meters above sea level, Meager rises above the surrounding terrain into montane or subalpine conditions. The elevation creates distinct ecological zones along its flanks, from forested lower slopes to exposed rocky terrain near the summit. The volcanic landform is characterized as a composite, which describes the physical shape and structure of the volcanic edifice as observed from the surface.

Geological Context

Meager sits in a subduction zone, where one tectonic plate dives beneath another, creating intense heat and pressure that generates magma. Subduction zones are responsible for many of the world's most explosive volcanoes and deadliest eruptions. For communities in Canada near Meager, this tectonic setting means the volcano is capable of producing powerful explosive eruptions, pyroclastic flows, and lahars that can threaten populated areas within tens of kilometers of the summit. The dominant rock type is dacite, an intermediate to silica-rich volcanic rock. This composition typically produces more viscous magma, leading to more explosive eruptions with ash columns and pyroclastic flows. Andesitic and dacitic magmas build pressure before erupting, which is why volcanoes with this rock chemistry are often associated with Plinian-style eruptions that can send ash tens of kilometers into the atmosphere and disrupt aviation across entire regions.

Eruption History Summary

Meager has 1 recorded eruption in the geological database, spanning from 410 BCE to 410 BCE. The most powerful recorded event was a paroxysmal eruption with devastating regional consequences in 410 BCE, reaching VEI 5 on the Volcanic Explosivity Index.

Significance

With a maximum recorded VEI of 5, Meager has demonstrated the capacity for paroxysmal eruptions comparable to the 1980 eruption of Mount St. Helens. Eruptions of this scale can devastate areas within 20-30 kilometers and produce ash fall that disrupts aviation and agriculture across hundreds of kilometers.

GVP Reference Summary

Mount Meager volcanic complex, of Pliocene-to-Holocene age, forms a dissected andesitic-to-rhyodacitic stratovolcano with multiple eroded summit lava domes and volcanic necks. It lies in the Garibaldi volcanic belt and is the northernmost volcano of the Cascade arc that extends to northern California. The summit of the complex consists of overlapping piles of andesitic lava flows and younger dacitic lava domes and flows. Quaternary basalts underlying the uppermost 22 km of the Elaho valley originated at the 1375 m level in the South Fork Meager River. The most recent activity, about 2350 years ago, produced Canada's largest known Holocene explosive eruption and an associated welded block-and-ash flow and a lava flow from a vent on the NE flank of Plinth Peak. Two clusters of hot springs occur within the complex, which has been investigated for potential geothermal power.

— Smithsonian Institution, Global Volcanism Program