Volcano Minute — Recent USGS work on El Salvador volcanoes

Aloha, it's your weekly Volcano Minute, brought to you by the USGS Hawaiian Volcano Observatory. 

Today, we’re heading to Central America, where a team of USGS scientists — including two from right here in Hawaii — spent March studying one of the most volcanically crowded countries on Earth: El Salvador. 

Although it’s only slightly larger than the Hawaiian Islands, El Salvador has more than 200 volcanoes. That’s because it sits on the Central American volcanic arc, where one tectonic plate dives beneath another, generating magma that can erupt almost anywhere along the landscape. 

The USGS, through its Volcano Disaster Assistance Program, has partnered with El Salvador’s environmental agency for decades. This year’s collaboration focused on two major projects: unraveling the eruptive history of Santa Ana volcano and building a national volcano atlas to map and characterize all of the country’s volcanic vents. 

During their fieldwork, scientists collected dozens of samples, cored coastal mangroves looking for ancient ash, and surveyed small single‑eruption volcanoes scattered across western El Salvador. They also led a week‑long workshop on lava‑flow hazards — crucial training, since the country hasn’t seen a lava flow since 1917. 

And while the USGS team shared expertise from Hawaii and Alaska, they also brought home valuable insights — from interpreting explosive deposits to understanding how lava interacts with older, weathered landscapes, similar to those here in Hawaii on Hualālai, Mauna Kea, and Haleakalā. 

Mahalo for listening, I’m Katie Mulliken and this was your weekly volcano minute brought to you by the USGS Hawaiian Volcano Observatory.