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.