Images

On the north margin of the south sulfur bank, which was exposed during the Kīlauea summit collapse events in 2018, light-colored deposits are evidence of the ongoing alteration from volcanic gas emissions.

Spatter ramparts from the April 30, 1982, Kīlauea summit eruption remain visible on the floor of Kīlauea caldera. During this brief eruption, which lasted approximately 19 hours, lava erupted from a 1-km-long (0.6 mile) fissure that extended to the northeast of Halema‘uma‘u.

On Tuesday, August 10, HVO scientists traversed the west and south rims of Halema‘uma‘u, at the summit of Kīlauea, to collect photos of the inactive lava lake from many different angles. Such a collection of photos will enable the construction of a three-dimensional model of the crusted lake surface using structure-from-motion software.

During the gas survey of Kīlauea caldera, HVO scientists walk transects in a grid-like pattern. As they traverse, the MultiGAS instruments that they are carrying on their backs measure the amount of carbon dioxide (CO₂), sulfur dioxide (SO₂), water vapor (H₂O), and hydrogen sulfide (H₂S).

From the northwest corner of the largest down-dropped block within Kīlauea caldera, HVO scientists were able to spot the southern edge of the lava lake that was recently active, from December 2020 to May 2021. The ongoing Kīlauea caldera gas survey is being conducted with permission from Hawai‘i Volcanoes National Park.

Schematic displaying the general processes associated with collapse of Yellowstone Caldera.  (A) Pre-caldera volcanism includes the eruption of dome complexes from the underlying magma chambers.  (B) The caldera-forming eruption evacuates a significant amount of magma from the chamber, causing the overlying crustal block to subside into the void space.&nbs

In recent weeks, HVO geophysicists have been undertaking a Global Positioning System (GPS) campaign across Kīlauea.

HVO scientists continue their survey of Kīlauea caldera floor, including the down-dropped block, for ​diffuse volcanic gas emissions. This photo shows a large crack, on a portion of the caldera floor that subsided in 2018, that is emitting volcanic gas and steam.

Over the past few months, HVO geophysicists have been conducting the annual high-precision Global Positioning System (GPS) survey of Kīlauea. The annual survey supplements HVO's continuous GPS monitoring stations and provides information on vertical and horizontal deformation of the ground surface.

Stacked lava flows are visible in the wall of the down-dropped block, which was exposed during the Kīlauea summit collapse events in 2018. A small exposure of lighter-colored volcanic ash, likely the Keanakāko‘i tephra deposits erupted during Kīlauea's last explosive phase several hundred years ago, is visible beneath tens of meters (yards) of lava flows.

Typical exposure of tabular blocks of layered ash in a matrix of cross-bedded ash. The tabular blocks were deposited, rapidly hardened, and ripped up and transported downstream along the ancestral Missouri River system with another pulse of ash and water, forming the cross-bedded matrix.

A view looking north into Halema‘uma‘u on July 30, 2021. Although eruptive activity has paused at the summit of Kīlauea, HVO geologists still monitor the lava lake and summit area weekly. Lava lake surface depths remain the same since mid to late May when active lava was last observed at the surface. USGS photo by N. Deligne. 

Eruptive activity paused within Halema‘uma‘u, at Kīlauea's summit, a bit more than 2 months ago. In that time, the spatter cone at the western fissure complex has slowly degraded due to numerous small scale collapses, leaving a debris apron (fresh looking rubble) and exposing the interior of the spatter cone. USGS photo by N. Deligne.

While mapping volcanic gasses in Kīlauea caldera, HVO scientists got a view (looking west) of Halema‘uma‘u and the down-dropped block. The steep crater walls of Halema‘uma‘u are visible in the upper center and right portions of this photo, but the recently active lava lake is out of view below the eastern crater rim.

A USGS scientist calibrates two MultiGas instruments to prepare for mapping volcanic gasses on the floor of Kīlauea caldera. With the MultiGas strapped to metal backpack frames, the scientists traverse across the caldera floor to collect gas data which will be compared to the last survey.

HVO geologists measure the depth to the water table at the Keller Well, located south of Halema‘uma‘u crater. The Keller Well is a borehole drilled in 1973 to a depth of 4,140 ft (1,262 m) that has been used to monitor the hydrology of the summit region of Kīlauea volcano. Photo taken on July 27, 2021, at 9:30 a.m. HST. USGS photo by J.M. Chang.

An HVO geologist conducts maintenance on the S1cam web camera located along the southern rim of Halema‘uma‘u, at the summit of Kīlauea.

The Yellowstone borehole geophysical network, installed by UNAVCO in 2007–2008. The placement of the boreholes is focused primarily around the caldera, and the boreholes contain a mix of instruments, including strainmeters, seismometers, tiltmeters, and pore pressure sensors.

HVO scientists walk transects along the down-dropped portion of Kīlauea caldera floor as part of a gas survey conducted on July 22.

This aerial photo of the inactive lava lake within Halema‘uma‘u at the summit of Kīlauea was captured during a routine helicopter overflight by HVO geologists on Thursday, July 22, 2021.

An HVO geologist conducts a routine high-precision survey of the inactive lava lake in Halema‘uma‘u, at the summit of Kīlauea volcano. Mist moving across the caldera on the morning of July 22 produced a rainbow over the lake. No significant changes have occurred in Halema‘uma‘u in recent weeks. USGS photo by M. Patrick.