The hazard zones for Hawai'i Island are based on:
- The locations of probable eruption sites (which are based on past eruption sites)
- The likely paths of lava flows erupted from those sites (based on topography and the paths of previous lava flows)
- The frequency of lava flow inundation of an area over the past several thousand years.
The hazard zones also take into account structural and topographic features that would affect the direction of lava flows.
Our knowledge of past eruptions is based on written records beginning in the early 1800s, oral Hawaiian traditions, and the geologic mapping of--and age-date determinations for--lava flows on each volcano.
Learn more: Hawaiian Volcano Observatory Frequently Asked Questions and Answers about Lava-Flow Hazards