Know What Hazards A Volcano Delivers

Volcanic Hazards:

Air quality/volcanic gas plume (fissure eruption):High levels of volcanic gas, including sulfur dioxide (SO₂) , are emitted from the fissure vents. As SO₂ is released from the eruption, it will react in the atmosphere with oxygen, sunlight, moisture, and other gases and particles and within hours to days, convert to fine particles. The particles scatter sunlight and cause the visible haze, known as vog (volcanic air pollution, from “volcanic smog”). Vog creates the potential for airborne health hazards to residents and visitors, damages agricultural crops and other plants, and affects livestock operations. 

Lava flows:Hawaiian lava flows generally advance slowly enough that people can avoid them. They can destroy everything in their paths, including vegetation and infrastructure—which can cut off road access and utilities. Hazards associated with active or recent lava flows include hot and glassy (sharp) surfaces that can cause severe burns, abrasions, and lacerations upon contact with unprotected or exposed skin; uneven and rough terrain can lead to falls and other injuries; hot temperatures that can cause heat exhaustion or dehydration, or in heavy rain can produce steamy ground-fog that can be acidic, severely limiting visibility and sometimes causing difficulty breathing.  

Tephra fall:Pele’s hair and other lightweight volcanic glass fragments from lava fountains and spattering will fall downwind, dusting the ground within a few hundred meters (yards) of the vent. High winds may waft lighter particles and transport them greater distances downwind.  These particles are sharp and can irritate the skin and eyes and could be respiratory health hazard.

Secondary hazards: Lava flow advance into vegetated areas may generate secondary hazards by igniting small fires in vegetation adjacent to lava flow margins. Lava flows that cover and burn vegetation and soil also introduce the hazard of subsurface natural gas pockets igniting, which can cause methane explosions. These explosions can blast lava fragments up to several meters (yards) away and can be hazardous to observers. 