On February 6, 2024, HVO geologists conducted an overflight of the Koa‘e fault system, south of Kīlauea caldera, and the Southwest Rift Zone to assess cracks observed by ground crews in the area over the weekend. This view shows lava flows from the 1971 Southwest Rift Zone eruption; Kīlauea caldera is visible to the northeast. USGS photo by H. Winslow.

Pu‘ukoa‘e, on the Southwest Rift Zone of Kīlauea, is prominent in this aerial photo taken on February 6, 2024. The slopes of Mauna Loa and the Nīnole Hills are visible in the background. USGS photo by H. Winslow.

HVO geologists conducted an overflight of Halema‘uma‘u, Kaluapele (Kīlauea summit caldera), the Koa‘e fault system, and the upper Southwest Rift Zone of Kīlauea on February 6, 2024. This aerial view of Halema‘uma‘u shows the fumarolic areas marked by white alteration that have developed on the lava flows that make up the floor of Halema‘uma‘u. USGS photo by H. Winslow.

An aerial view of Mauna Loa, taken from the Southwest Rift Zone of Kīlauea during a Hawaiian Volcano Observatory monitoring overflight on February 6, 2024. USGS photo by H. Winslow.

Aerial view of Halema‘uma‘u, a crater within Kaluapele, the summit caldera of Kīlauea. Most of the crater has been filled in by lava erupted since 2020. The flanks of Mauna Loa are visible in the background of this southeast-facing view. USGS photo by K. Mulliken.

An aerial view of the Twin Pit Craters near Maunaiki trail in the Ka‘ū Desert of Hawaii Volcanoes National Park. USGS photo by K. Mulliken.

University of Hawai‘i at Hilo geology professor Steve Lundblad takes a level reading during a survey of the Koa‘e fault system on Saturday, February 7, 2024. The KAOE fault system connects Kīlauea's East and Southwest Rift Zones south of the caldera, and a recent intrusion occurred in this area. Faults here appear as low cliffs, or “scarps” along Hilina Pali Road in Hawai‘i Volcanoes National Park. Learn more about the Koa‘e fault system here: https://www.usgs.gov/news/volcano-watch-crack-team-geologists-measure-koae-fault-system. USGS photo by M. Warren.

On Saturday, February 3, University of Hawai‘i at Hilo scientists and students, and Hawaiian Volcano Observatory staff, conducted a survey of the Koa‘e fault system to measure changes during the recent intrusive activity southwest of Kīlauea summit caldera. In this photo, two people brace the leveling rod against the strong winds that day. USGS photo by M. Warren.

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.

This photo shows where some recent cracks cut across the Maunaiki trail within Hawai‘i Volcanoes National Park as a result of the intrusive activity southwest of Kīlauea summit. On the trail, the cracks are less distinct because of foot traffic has moved the tephra around and started to fill in the cracks. USGS photo by N. Deligne.

On February 3, 2024, a team of HVO scientists documented new ground cracks along the Maunaiki Trail in Hawai‘i Volcanoes National Park, caused by the recent intrusion southwest of Kaluapele (Kīlauea caldera). These cracks primarily cut the loose Keanakāko‘i tephra which blanketed the region in 1790 CE. Some cracks were over 100 feet (30 meters) long. Note the person for scale in the right upper portion of the photo. USGS photo by N. Deligne.

This photo shows a crack in spatter and lava previously erupted on the Southwest Rift Zone of Kīlauea, with a geologist for scale. The crack likely widened during the recent intrusion southwest of the summit of Kīlauea. New cracks in loose Keanakāko‘i tephra, which blanketed the region in 1790 CE, can be seen in the bottom portion of the photo leading the crack in the lava. USGS photo by N. Deligne.

On February 3, 2024, a team of HVO scientists documented new ground cracks caused by the intrusion at Kīlauea southwest of the summit caldera. These cracks were observed along the Maunaiki Trail in the Ka‘ū Desert region of Hawai‘i Volcanoes National Park. USGS photo by N. Deligne.

On February 3, 2024, a team of HVO scientists documented new ground cracks in three areas of the Maunaiki Trail in the Ka‘ū Desert, caused by the intrusion at Kīlauea south of the summit caldera. These cracks primarily cut the loose Keanakāko‘i tephra which blanketed the region in 1790 CE. Some cracks were over 100 feet (30 meters) long. Note the person for scale in the right upper portion of the photo. USGS photo by N. Deligne.

On February 3, 2024, a team of HVO scientists documented ground cracks in three areas, caused by ground deformation from the intrusion at Kīlauea south of the summit caldera. There were many new cracks and some pre-existing cracks in the area widened. This photo shows a fern which was growing in a pre-existing crack (going from left to right), which had its roots disturbed as the cracks widened during the intrusion event. USGS photo by N. Deligne. 

HVO deployed two temporary GPS monitoring instruments in the Ka‘ū Desert, with permission from Hawai‘i Volcanoes National Park. These sites will improve monitoring, hazard analysis, event response, and situational awareness in response to the volcanic unrest at Kīlauea that starting late January 2024.

One instrument location is at a pre-existing benchmark that HVO visits for annual GPS surveys. These data will be combined with previous measurements to continue monitoring and modeling. The second instrument is at a new location a couple of kilometers (about a mile) further southwest and co-located with other geophysical instrumentation. Both sites are telemetered, meaning HVO is able to download the data remotely from their office, eliminating the time and physical effort of needing to visit the sites in-person to collect the data. USGS photo by A. Ellis.

Hawaiian Volcano Observatory staff deployed a temporary GPS monitoring instruments in the Ka‘ū Desert, with permission from Hawai‘i Volcanoes National Park, on February 2, 2024. The site will improve monitoring, hazard analysis, event response, and situational awareness in response to the volcanic unrest at Kīlauea that starting late January 2024. USGS photo by A. Ellis.

USGS Hawaiian Volcano Observatory lead electronics technician Kevan Kamibayashi helps to deploy a temporary GPS monitoring instrument in the Ka‘ū Desert of Hawai‘i Volcanoes National Park. With permission from the National Park Service, this station will enhance HVO's pre-existing ground deformation monitoring network given the recent intrusive event southwest of Kīlauea's summit. USGS photo by A. Ellis.

On February 2, 2024, a temporary GPS monitoring instrument was deployed at a location with existing HVO geophysical volcano monitoring instrumentation. The site is telemetered and will transmit data back to HVO that will aid in monitoring the Southwest Rift Zone region of Kīlauea volcano. USGS photo by A. Ellis.

One of the temporary GPS stations deployed in response to the intrusive activity southwest of Kīlauea summit. The metal disk on the ground beneath the tripod is the benchmark, which is cemented to the lava flow surface. A high-precision GPS unit is centered over the benchmark to collect data. Its position will be compared to data collected during previous GPS deployments on the benchmark to discern subtle patterns of ground deformation. USGS photo by A. Ellis.