The U.S. Geological Survey update on the danger of active volcanoes in the U.S. maintained Haleakala’s assessment at “moderate threat.”
The “2018 Update to the U.S. Geological Survey National Volcanic Threat Assessment” released Wednesday uses new research to add or remove volcanoes and to rescore the threat of active volcanoes. The last report was was in 2005.
A 24-factor, hazard-and-exposure matrix was used to place threat assessments into five categories — very low, low, moderate, high and very high, the report explains.
A total of 161 volcanoes made the list with 18 a very high threat, 39 a high threat, 49 a moderate threat, 34 a low threat, and 21 a very low threat.
Kilauea was listed as the highest threat volcano in the survey, and Mauna Loa also was considered a very high threat. An eruption at Kilauea that began in May destroyed scores of homes and wiped out landmarks and shorelines.
Hualalai on the Big Island was listed as a high threat volcano.
Haleakala and Mauna Kea were listed as moderate threat volcanoes. There was no change to the threat levels of Hawaii volcanoes in the updated report.
Each volcano was scored based on 15 hazard and nine exposure factors, which were added within the two categories and multiplied to generate a threat score.
Haleakala’s threat score was 45, which ranked it 86th in terms of threat level in the U.S. By comparison, Kilauea’s threat score was 263.
Haleakala, rising more than 10,000 feet from sea level, erupts every 200 to 500 years, according to the USGS Hawaiian Volcano Observatory. The last lava flow between 1420 and 1620 created the ‘Ahihi-Kina’u Natural Area Reserve from the lower southwest rift zone, volcano observatory officials said.
Based on past volcanic activity, the mostly likely next eruption will occur along the southwest rift zone, a line of vents that crosses Haleakala Crater and descends to La Perouse and Keone’oi’o.
“Future eruptions should be expected,” the volcano observatory said in a 2010 publication.
While the likelihood exists for eruptions, one does not appear in the offing, and there would be precursor events, such as micro-earthquakes, volcano observatory officials say. There have been no earthquakes or ground deformations in the last couple of decades, they added.
The Haleakala web page says that another 500 years or more may pass before the next eruption, though it is possible that new eruptions will occur in the lifetimes of current residents.
The volcanic activity that began building Haleakala started about 2 million years ago, the volcano observatory said.
Maui’s other main mountain, the West Maui Mountains, is considered extinct.
* Lee Imada can be reached at leeimada@mauinews.com.
Today's breaking news and more in your inbox
ncG1vNJzZmivp6x7rq3UoqWer6NjsLC5jqecsKtfobykrctmpZ6vo2R%2FcX2XaGhpZ5iWuaatypqjmmWmpLmkrc2oZKudnZa2r7%2BMmmSmp5Sav6LAxGaroaqVlsFuss6rZJ6qpaXBqrvNaA%3D%3D