February 3, 2024 — Kīlauea Koa‘e fault system survey

University of Hawai‘i at Hilo geology professors and students, along with scientists from the Hawaiian Volcano Observatory, conducted a survey of the Koa‘e fault system on February 3, 2024. Despite very windy conditions, the group was able to make measurements showing ground changes resulting from the recent intrusion in this area. Leveling uses telescopes aimed at giant vertical rulers (called stadia rods) being held on specific locations on the ground surface, marked by stainless steel bolts cemented into bedrock. Precise elevation differences between stations are measured using the stadia rods, and horizontal distances between stations can be measured using ordinary measuring tapes. Repeat leveling can detect changes on the millimeter scale (much smaller than an inch) over time! USGS photo by M. Warren.