Katherine (Katie) M. Mulliken

This video, taken around 6:30 a.m. HST on July 9, 2025, shows the fan-shaped lava fountain being erupted during episode 28 of the ongoing Kīlauea summit eruption. This perspective is from the north rim of Kaluapele, near Kīlauea Overlook within Hawaiʻi Volcanoes National Park. Episode 28 was active for 9 hours, the final 8 of which consisted of high fountaining.

On the night of September 15, USGS Hawaiian Volcano Observatory geophysical data indicated that an eruption could be occurring a remote area of Kīlauea’s middle East Rift Zone, within Hawaiʻi Volcanoes National Park.

This two-minute video summarizes the 1924 explosive eruption at the summit of Kīlauea, which occurred 100 years ago this year. The video is narrated by Thomas Jaggar, who founded the Hawaiian Volcano Observatory in 1912. His description of the 1924 eruption was recorded in 1951 by Hawaiʻi Volcanoes National Park. 

This video summarizes changes to the summit Kīlauea volcano since the 2018 caldera collapse. In the year after the 2018 collapse, a water lake began to rise from the bottom. It evaporated during about 90 minutes when an eruption started in Halemaʻumaʻu crater on the night of December 20, 2020.

Six Eruptions at Two Volcanoes Over the Past Three Years

How the Hawaiian Volcano Observatory monitors some of Earth’s most active volcanoes

by Katie Mulliken, Geologist, Research Corporation of the University of Hawai‘i and USGS Hawaiian Volcano Observatory

Mauna Loa 2022 eruption anniversary video. Mauna Loa is Earth's largest active volcano and covers just over half of the Island of Hawaiʻi. It erupted most recently in November-December 2022, and it will erupt again.

An overflight on November 30, 2022, provided aerial views of the Northeast Rift Zone eruption of Mauna Loa. On the ground, Hawaiian Volcano Observatory scientists deploy a new webcam and measure fissure 3. USGS video by K. Mulliken. 

HVO volcanic gas specialists make sulfur dioxide (SO~2~) emission rate measurements downwind of the eruption within Halema‘uma‘u crater, Kīlauea summit. This video shows the typical fieldwork involved with measuring SO2 emission rates, during which HVO scientists drive traverses beneath the plume in the closed area of Hawai‘i Volcanoes National Park.

Kīlauea volcano's summit eruption, within Hawai‘i Volcanoes National Park, began one year ago—on September 29, 2021. This three-minute video, produced by the Hawaiian Volcano Observatory, features footage from the past year and summarizes the eruption.

On January 28, the USGS-Hawaiian Volcano Observatory conducted Unoccupied Aerial Systems (UAS) missions at the summit of Kīlauea, within Hawai‘i Volcanoes National Park.

Mauna Loa is an active volcano, though it has been quiet for almost 30 years. An eruption is not imminent, but patterns of ground deformation on Mauna Loa over the past year may indicate that new, previously unobserved processes may have occurred. Mauna Loa lava flows have the capacity to disrupt lives and commerce throughout the Island of Hawai‘i.

2021 was an interesting year for deformation at both Kīlauea and Mauna Loa volcanoes. At Kīlauea, 2021 provided a glimpse of what the future might hold as the system recovers from the large collapses that accompanied the 2018 lower East Rift Zone eruption.

The past ten years have seen historic changes on Kīlauea volcano, spanning from the summit, down the East Rift Zone, and to the coast.

Communities on the Island of Hawai‘i continue to recover from Kīlauea’s 2018 lower East Rift Zone eruption and summit collapse as does the USGS Hawaiian Volcano Observatory (HVO). During the events of 2018, HVO instruments were lost, monitoring infrastructure was impacted, and HVO staff had to evacuate the observatory, which was damaged beyond repair.

Incredibly high sulfur dioxide (SO2) emission rates were measured during the lower East Rift Zone of Kīlauea in 2018—nearly 200,000 tonnes per day. Emissions dropped to only about 30 tonnes per day during Kīlauea’s non-eruptive quiet period from 2018–2020.

Following the lower East Rift Zone eruption and summit collapse of Kīlauea in 2018, the volcano remained quiet for more than two years. Lava returned to Kīlauea in December 2020, boiling off the water lake that had been present at the base of Halema‘uma‘u crater, and starting a five-month long eruption in Hawai‘i Volcanoes National Park.

The last year has been a busy one for seismologists at the USGS Hawaiian Volcano Observatory. Earthquake activity at Kīlauea summit has varied over the past year, with upticks in a variety of seismic signals providing clues to the start of the December 2020 and September 2021 Kīlauea summit eruptions.

Structure-from-motion techniques use photographs taken from different angles to reconstruct the three-dimensional shape of an object. At Kīlauea, this technique has been used to rapidly generate maps of eruption activity from aerial imagery, allowing scientists to quantify changes over time such as the volume of lava erupted and surface area covered by lava.

Olivine—the green mineral found in Hawaiian lavas—and its chemistry can tell us a lot about how, when, and where magmas move inside volcanoes before they erupt. Join Hawaiian Volcano Observatory geologist Kendra J.

Join USGS Hawaiian Volcano Observatory retired geologist Don Swanson on a virtual field visit to an exposure of the Keanakāko‘i Tephra near the summit of Kīlauea as part of Volcano Awareness Month.

Because Mauna Loa has been quiet for almost 30 years, residents may not be aware that Mauna Loa is an active volcano. When Mauna Loa erupts, it is capable of disrupting lives and commerce throughout the Island of Hawai‘i. What can we learn from Mauna Loa’s past eruptions?