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The pattern of eruptions over the last 13,000 years suggest that the chances of a future eruption at Medicine Lake volcano are about 1 in 3,600 in any given year.

Weeks to months of heightened earthquake activity and ground deformation will probably precede the next eruption. The character of a future eruption is most likely to be effusive, with incandescent fountains of lava rising a several to hundreds of meters in the air (1 m = 3.28 ft). Over the course of weeks to months, a circular mound of cinder would form around the vent and slow-moving lava flows could impact areas many miles away. Such an eruption could occur anywhere on the volcano, including within Lava Beds National Monument. An explosive eruption, like that of 950 years ago at Glass Mountain, is also possible, particularly near the summit of the volcano.

Map showing caldera features and caldera-related hazards at Medicin...
Green line (gas hazard zone limit) indicates elevation contour that defines the closed basin within the caldera, including Medicine Lake. In the event of significant volcanic gas emissions, the gases, which are heavier than air, could accumulate and potentially result in asphyxiation for anyone within the zone. It is likely that warning signs would be posted in such an event. Orange dashed line (phreatomagmatic hazard zone limit) indicates likely extent of phreatomagmatic deposits of hot volcanic mud should a volcanic vent open under the lake. Lava flows shown in red are 5,200 years old and younger. Hot Spot (red “x”) is site of the volcano’s only fumarole.