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September 25, 2020

Views of Kīlauea's growing summit water lake; Sulphur Banks and Steam Vents; gravity survey at Kīlauea summit

Views of Kīlauea's growing summit water lake

Color photographs of volcanic crater lake
HVO geologists made observations of Kīlauea's summit water lake from the east rim of Halema‘uma‘u. This view point is on the large downdropped block that subsided during the 2018 collapse events. From this spot, a view of the entire lake is possible, providing a new perspective on the growth of the lake. The last visit to this spot was on December 18, 2019, when the lake had a surface area of 1.1 hectares (2.7 acres). The lake has risen approximately 25 m (82 feet) since that time, and now has a surface area of 3.3 hectares (8.2 acres). The yellow circle in the left photo shows the normal observation site used by HVO geologists on the west caldera rim. Steaming is more apparent in the September 23, 2020, image due to the humid and rainy conditions on that day. USGS photos by K. Mulliken and M. Patrick.
Photograph of volcanic crater lake
This view shows Kīlauea's water lake from the east side of the crater. On September 23, 2020, the western portion of the lake (top of image) was the most varied in color, with patches of greenish and brown water. The majority of the lake surface, however, was the typical tan hue. USGS photo by M. Patrick.
Photograph of material floating on volcanic crater lake
Small patches of light-colored floating material were seen drifting on the surface of Kīlauea's summit water lake on September 23, 2020. The composition of this material is unknown, but future water sampling missions may provide insight. USGS photo by M. Patrick.


Color photograph of road and crater lake
Portions of Crater Rim Drive, within Hawai‘i Volcanoes National Park, appear cracked, offset, and down-dropped in this photo, taken during an overflight of Kīlauea’s summit on September 23, 2020. To the north, Kīlauea’s summit water lake, within Halema‘uma‘u, is visible. USGS photo by K. Mulliken.

Views of Sulphur Banks and Steam Vents

Photograph of trail and sulfur banks
Hawaiian Volcano Observatory geologists flew over the Sulphur Banks area and Ha‘akulamanu trail within Hawai‘i Volcanoes National Park on September 23, 2020. Fumaroles in the Sulphur Banks area are sampled approximately every three months by Hawaiian Volcano Observatory gas geochemists to track long-term changes in volcanic gas chemistry at Kīlauea. USGS photo by K. Mulliken.
Color photograph of steam vents
The weather was overcast during an overflight of Kīlauea's summit on September 23, 2020. This view shows Wahinekapu (Steaming Bluff) and the Steam Vents area within Hawai‘i Volcanoes National Park. Extensive cracks in the area allow heated groundwater to escape from underground. Cracks reach up to 63 degrees Celsius (145 degrees Fahrenheit), preventing trees from growing. USGS photo by K. Mulliken.



Gravity survey at Kīlauea summit

Photograph of scientists surveying caldera
On September 23, 2020, Hawaiian Volcano Observatory geophysicists and a geologist conducted a gravity survey of Kīlauea summit, as part of HVO's regular monitoring program. In this photo, scientists are carrying survey equipment westward along the remnants of the Halema‘uma‘u Trail on the down-dropped block of Kīlauea caldera. The fissure from the 1954 eruption can be seen in the distance. USGS photo by A. Flinders.
Photograph of scientists surveying caldera
During a gravity survey, HVO scientists measure the relative strength of gravity (gravimeter, bottom left corner of photo) between benchmarks. High-precision vertical positions from kinematic Global Positioning System (GPS, tripod and antenna middle of photo) help correct the gravity measurement for the effects of elevation changes. The south sulfur banks, exposed during the 2018 collapse events at Kīlauea summit are visible in the background of this image, to the right of the GPS antenna. USGS photo by A. Flinders.
Photograph of gravimeter in caldera
A gravimeter makes a measurement at a benchmark situated among lava flows erupted in 1919. The strength of gravity varies with both elevation and the amount of mass beneath the instrument. Changes in mass can indicate changes in the amount of magma entering Kīlauea's magma reservoirs. USGS photo by A. Flinders.
Photograph of scientist surveying gravity in caldera
An HVO geophysicist takes a gravity measurement at a benchmark near a continuous gravimeter (inside hutch). The continuous gravimeter takes gravity measurements once per second and relays the data via radio back to HVO. During the gravity survey on September 23, 2020, HVO scientists took measurements at multiple locations on the floor of Kīlauea caldera. By comparing the measurements made at these benchmarks with survey data from previous dates, HVO scientists can estimate the change of mass beneath the instrument. USGS photo by I. Johanson.