Mount Redoubt (Alaska volcano)

Physical characteristics

Redoubt is a steep, conical volcano typical of stratovolcanoes, with a summit crater and substantial ice and snow cover at higher elevations. Its relief above the surrounding valleys is on the order of 9,147 feet (2,788 m). The summit area contains glacial ice that can be melted during eruptions, raising the risk of volcanic mudflows (lahars) and sediment-laden floods.

Eruptive history and hazards

Redoubt has a history of intermittent eruptions. Recorded activity in modern times includes eruptions in 1902, 1922, 1966, 1989, and a notable series of events beginning in 2009. Eruptions commonly produce ash clouds, pyroclastic material, explosive activity and, where heat melts snow or ice, lahars that travel down river valleys. Volcanic ash can spread many miles downwind and pose hazards to aviation, infrastructure and public health.

Impact, monitoring and response

The 2009 activity at Mount Redoubt sent ash high into the atmosphere and resulted in widespread ashfall across mountain areas and communities; airport operations in the Anchorage area were disrupted. Because of these threats, Redoubt is closely monitored by geophysical agencies that track seismicity, gas emissions and deformation. Monitoring helps authorities issue warnings and coordinate responses with local governments and transportation agencies.

Uses, significance and notable facts

• Geological significance: Redoubt is part of the Aleutian arc, offering insight into subduction-related volcanism and mountain-building processes.
• Hazard example: Its combination of explosive activity and summit ice makes it a classic example of volcanoes that can generate destructive lahars.
• Accessibility: The volcano lies in a sparsely populated region; although few people live nearby, ash and air traffic impacts can extend to distant communities.

For plain-language background and updates, see a general volcano information resource. For regional context about Alaska and its volcanoes, consult an Alaska-focused page at Alaska resources. For local or logistical details such as distance from Anchorage and transportation impacts, a travel or regional planning source may be helpful: local planning.