Volcano Watch: How does HVO determine which regions are most threatened by lava flows?

During HVO’s July 10, 2018, overfligh, the dramatic difference in landscapes on the northern and southern sides of the fissure 8 lava channel was readily apparent. With dominant trade winds blowing heat and volcanic gases to the southwest, the north side of the lava channel remains verdant, while, in stark contrast, vegetation on the south side has been severely impacted and appears brown and yellow. The fissure 8 cone is obscured by a cloud of steam (top center). (USGS/Special to West Hawaii Today)

Most residents of the Island of Hawaii live on one of four potentially active volcanoes and probably have wondered about the threat of lava flows at one time or another. Interestingly, determining future threats relies on knowledge of the past. The long-term likelihood of an area being invaded by lava in the future, is estimated in two different ways based on the history of lava flow activity.