Kilauea topped a nationwide list of dangerous volcanoes and was one of 18 considered to be “very high risk,” according to a report released this week by the U.S. Geological Survey.

The USGS updated its volcano threat assessment for the first time since 2005, taking into consideration new research to determine which ones should be added or removed from the list of potentially active volcanic systems.

Kilauea, which has been erupting for more than 30 years — including this year at and around Leilani Estates — was No. 1 on the list, followed by Mount St. Helens and Mount Rainier in Washington, Alaska’s Redoubt Volcano and California’s Mount Shasta.

“Now, as in 2005, Kilauea ranked as the U.S. volcano with the highest threat score,” said John Ewert, USGS volcanologist and lead author of the report. “Kilauea is the most active U.S. volcano. It erupts mainly lava flows but is also capable of producing explosive eruptions, and there are highly developed and populated areas on its flanks. Eruptive activity in 2018 and the impacts we saw from that to Hawaii are clear examples of why Kilauea is one of our very high threat volcanoes.”

A total of 161 volcanoes in the U.S., or about 10 percent of earth’s geologically active volcanoes, are ranked by the report based on 24 factors, including the type of volcano, the level of explosiveness, how recently it has been active, the frequency of eruptions, the number of people who live nearby, seismic activity, evacuations and disruptions to air traffic.

The volcanoes are then sorted into five threat levels, ranging from very low to low, moderate, high and very high.

The revised threat assessment includes 18 very high-threat volcanoes, 39 high- threat volcanoes, 49 moderate-threat volcanoes, 34 low-threat volcanoes and 21 very low-threat volcanoes.

Kilauea garnered the highest overall threat score of 263. Mauna Loa joined Kilauea in the very high-threat category, at No. 16, with an overall threat score of 131. The other volcanoes in the category were in Washington, Oregon, California and Alaska.

Hualalai on the Big Island was categorized as a high threat, at No. 23. Haleakala and Mauna Kea were categorized as moderate, at No. 86 and No. 106 respectively.

The USGS said that the threat rankings are not an indication of which volcanoes will erupt next, but the potential severity of impacts that could result from future eruptions, and are used to help guide risk mitigation efforts.

The new report dropped several volcanoes, including Mount Washington in Oregon and Twin Buttes in California. Other volcanoes were added to the list, including several from the Commonwealth of the Northern Mariana Islands, Soda Lakes in Nevada and the Red Hill-Quemado volcanic field in New Mexico.

The USGS said a dozen volcanoes have jumped in threat level since 2005. Twenty others dropped in threat level.

Among those where the threat score — but not the threat level — is higher are Alaska’s Redoubt, Mount Okmok, Akutan Island and Mount Spurr. Threat scores also rose for Oregon’s Newberry Volcano and Wyoming’s Yellowstone.

None of the Big 18 changed in overall threat levels, even though the overall threat scores of 11 dropped.

Besides the top five, the rest of the Big 18 are Mount Hood, Three Sisters and Crater Lake in Oregon; Akutan Island, Makushin, Mount Spurr and Augustine in Alaska; Lassen and Long Valley in California; Mount Baker and Glacier Peak in Washington; and Mauna Loa in Hawaii.

Since 1980 there have been 120 eruptions and 52 episodes of notable volcanic unrest as indicated by increased seismicity, observed ground deformations and gas emissions at 44 U.S. volcanoes.

Kilauea began erupting in early May, but activity slowed in early August. It is no longer erupting, and rates of seismicity, deformation and gas release, which remain low, have not changed significantly over the past week, according to the USGS.

However, USGS officials cautioned hazards are still present, and residents and visitors should heed Hawaii County Civil Defense warnings.

THREAT RANKING FOR HAWAII VOLCANOES

>> No. 1: Kilauea, overall threat score: 263 (very high)

>> No. 16: Mauna Loa, overall threat score: 131 (very high)

>> No. 23: Hualalai, overall threat score: 109 (high)

>> No. 86: Haleakala, overall threat score: 45 (moderate)

>> No. 106: Mauna Kea, overall threat score: 30 (moderate)

The Associated Press contributed to this report.