Source: US Geological Survey
A USGS Hawaiian Volcano Observatory geologist collects high-precision ground positions using a kinematic GPS instrument that measures its vertical and horizontal position. Once processed, these measurements will help scientists determine the thickness of the tephra deposit downwind of the ongoing Halema‘uma‘u eruption at Kīlauea summit. The tephra has primarily been falling in a closed area of Hawai‘i Volcanoes National Park, an area that HVO scientists access with permission from, and in coordination with, the National Park Service. USGS photo taken on May 29, 2025, by L. DeSmither.
During the pause after episode 23 of the ongoing Kīlauea summit eruption, a USGS Hawaiian Volcano Observatory scientist collects data on the tephra deposits. Buckets are used to collect tephra, and emptied between episodes, to ensure that samples from each episode are isolated to track geochemical changes and determine the amount of tephra that fell at each site. The steak also helps scientists measure the thickness of tephra fall in that area. USGS photo taken by L. DeSmither on May 29, 2025.