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What are volcanic alert-levels? - Honolulu, Hawaii news, sports & weather - KITV Channel 4

What are volcanic alert-levels?

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Low-level eruption of lava continues from multiple points along the northeast end of the active fissure system on the Big Island. With a “WARNING” alert level and “RED” aviation color in place, both are the highest level in the alert system.

What does that mean?

The U.S. Geological Survey (USGS) has a nationwide volcano alert-level system to characterize conditions at U.S. volcanoes ranging from quiet, unrest and eruption.

The alert-level system for volcanic activity has two parts: ranked terms to inform people on the ground about a volcano's status and ranked colors to inform the aviation sector about airborne ash hazards.

Alert Level Terms

When the volcano alert-level is changed, a Volcano Activity Notice (VAN) is issued.

Normal: Volcano is in typical background, non-eruptive state or after a change from a higher level, volcanic activity has ceased and volcano has returned to non-eruptive background state.

Advisory: Volcano is exhibiting signs of elevated unrest above known background level or, after a change from a higher level, volcanic activity has decreased significantly but continues to be closely monitored for possible renewed increase.

Watch: Volcano is exhibiting heightened or escalating unrest with increased potential of eruption, time frame uncertain, OR eruption is underway but poses limited hazards.

Warning: Hazardous eruption is imminent, underway, or suspected.

Aviation Color Codes

When the volcano color code changes, a Volcano Observatory Notification for Aviation is issued.

Green: Volcano is in typical background, non-eruptive state or, after a change from a higher level, volcanic activity has ceased and volcano has returned to non-eruptive background state.

Yellow: Volcano is exhibiting signs of elevated unrest above known background level or, after a change from a higher level, volcanic activity has decreased significantly but continues to be closely monitored for possible renewed increase.

Orange: Volcano is exhibiting heightened or escalating unrest with increased potential of eruption, time frame uncertain, OR eruption is underway with no or minor volcanic-ash emissions. Ash-plume height would be specified if possible.

Red: Eruption is imminent with significant emission of volcanic ash into the atmosphere likely OR eruption is underway or suspected with significant emission of volcanic ash into the atmosphere. Ash-plume height would be specified if possible.

Source: USGS

Residents in lower Puna should remain informed and heed Hawaii County Civil Defense closures, warnings and messages.

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