Images

On Tuesday, August 31, Hawaiian Volcano Observatory (HVO) scientists and technicians visited the Keller Well in Kīlauea's south caldera region. Water from the well is typically sampled and analyzed quarterly to monitor how magma supply to Kīlauea's summit reservoirs might impact regional ground water.

This map depicts the detected intrusive activity over the past week at Kīlauea Volcano. The initial swarm of small earthquakes from August 23–25 was centered in the south caldera region, as labelled on the map.

Pore waters from Yellowstone Lake sediment cores collected in August 2021 are extracted through filtration devices into plastic syringes.  Note that the second core from the left appears light in color because the plastic core liner was etched by very hot 91°C (196°F) fluids.

Gravity coring device on the rear deck of the R/V Annie after coring the floor of Yellowstone Lake, with dark mud coating the outside of the corer.  The 100-lb. green coring head is at the top, and the bottom of the barrel has a tapered stainless steel core cutter.

View to the aft of the R/V Annie as it leaves Bridge Bay Marina early in the morning of August 26, 2021.

Map showing the seismic activity beneath the south part of Kīlauea caldera, within Hawaiʻi Volcanoes National Park, from August 23, 2021, at noon through the same time on August 25, 2021. The earthquake swarm began in that region at around 4:30 p.m. HST on August 23 and continued until the morning of August 25, 2021.

A hand-sample photo of what is known to be Lava Creek Tuff “unit 2.”  Small black scoria pieces are distinctive of this unit compared to the previously recognized Member A and Member B of the Lava Creek Tuff.  Photo by Ray Salazar (Montana State University) on August 16, 2021.

An HVO scientist uses a syringe to capture a sample from an area within Kīlauea caldera that was identified as emitting elevated levels of the volcanic gas carbon dioxide. The sample is transferred to a gas sample bag, which will later be taken to a lab for chemical analyses. USGS photo by K. Mulliken on August 3, 2021.

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.

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.

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.

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

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

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.