Quiet at the surface, rumblings underground
Update Wed 16 Jun 2021 04:26
A third week of relative quiet passes on Kīlauea, though earthquakes remain slightly elevated near the volcano's summit, upper east rift, and nearby south flank. No glow is visible from the recent eruption's West Vent, nor from the crusted lava lake surface, though temperatures from the vent and a handful of small spots “around the rim and in local cavities” remain hotter than their surroundings, though still well below molten lava temperatures according to this week's USGS Hawaiian Volcano Observatory update.
This Unoccupied Aircraft Systems (UAS) photo, looking straight down into the inactive western fissure within Halema'uma'u at the summit of Kīlauea, was captured on Thursday, June 3, 2021. One of the objectives of the UAS mission was to get a close-up look into the fissure to see if any incandescent lava was still visible. As evidenced by the darkness within the opening atop the fissure (center of frame), no active lava was observed. For scale, the height and width of this photo each span approximately 40 m (131 ft) laterally. (USGS image & caption.)
The baseline ground tilt continues to slowly increase as it has over the past month, occasionally interrupted by less frequent deflation-inflation cycles, with one event in each of the past two weeks. The summit continues to swell based on the GPS cross-caldera distance measurement, also at a slightly increased rate for the past two weeks, and together with the ongoing seismicity intensely focused in the summit and upper east rift connector, indicates that magma is still building underground.
The upper east rift between Maunaulu and Puʻuʻōʻō, still within Hawaiʻi Volcanoes National Park, is also refilling with magma according to USGS-HVO monitoring data and reports, and does show some seismicity within the rift zone during the past week, but much less focused than in areas up-rift. Instead, there are earthquakes dispersed across the nearby south flank, suggesting that growing pressure in that part of the rift is pushing the mobile flank and distributes the seismicity across its wider base as a consequence. On the south flank, a magnitude 3.7 earthquake on June 12th occurred in the same area as the magnitudes 3.6, 3.4 and 4.2 on May 23rd, a seeming catch point at the western edge of the currently mobile area.
This pattern of adjustment is not imminently alarming, as the volcano can sustain slightly elevated activity for weeks to months before a larger change occurs, including the possibility of an eruption near the summit or currently active rift areas. The current level of seismicity is approaching that observed in the months ahead of the 2020 eruption, though it is still roughly half of the rate of the final pre-eruption weeks. The wait and watch continues, as the transition to Kīlauea's next lava showing slowly advances.
Join our weekly live video review of Kīlauea's eruption! Broadcast at 5pm HST Thursdays as of June 2021 and archived, along with short video updates, on the Hawaiʻi PODD channel - including monitoring signals, photos & videos, time-lapses, geologic context and annotation, and discussion of live viewer questions.
Source: Compilation and summary of USGS Hawaiian Volcano Observatory activity updates & online data, June 2021
"Kīlauea Volcano is no longer erupting", says USGS-HVO
Update Wed 26 May 2021 22:04
"Observations indicate that the eruption in Halema'uma'u at the summit of Kīlauea Volcano has paused. It is possible that the Halema'uma'u vent could resume eruption or that Kīlauea is entering a period of quiescence prior the next eruption."
During an eruption monitoring shift on May 25, HVO field crews did not observe any active surface lava or incandescent areas within Halema'uma'u crater, at the summit of Kīlauea. (USGS photo by K. Mulliken.)
Excerpt from the USGS Hawaiian Volcano Observatory's May 26, 2021 Daily Update:
Activity Summary: Kīlauea Volcano is no longer erupting. Observations indicate that the eruption in Halema'uma'u at the summit of Kīlauea Volcano has paused. This morning, May 26, the lava lake is 229 m (751 ft) deep and is stagnant across its surface. Within the past 48 hours, no active lava was observed in webcam images of the Halema'uma'u crater lava lake surface. Field crews on May 25 did not observe any signs of lava lake activity, and reported no signs of recently active surface lava. Sulfur dioxide emission rates remain slightly elevated.
HVO will issue a Volcano Activity Notice (VAN) lowering the Volcano Alert Level for ground based hazards from WATCH to ADVISORY and the Aviation Color Code from ORANGE to YELLOW. HVO continues to monitor Kīlauea Volcano closely for additional signs of changes in activity.
Summit Observations: The most recent sulfur dioxide (SO2) emission rates, measured on May 23, were 100 tonnes per day, continuing a trend of decreased emission rates that began in mid-April. The SO2 emission rates are now nearly at levels associated with the recent non-eruptive period from late 2018 to late 2020 (less than 50 tonnes per day), and are significantly lower than emission rates that averaged over 800 tonnes per day from mid-February to mid-April. Summit tiltmeters recorded slight but continuous deflation over the past 24 hours. Seismicity remains stable, with elevated tremor.
East Rift Zone Observations: No unusual activity noted in the region. Geodetic monitors indicate that the summit and upper East Rift Zone—between the summit and Puʻuʻōʻō—is refilling at rates similar to those measured over the past 2 years and before the December 2020 eruption. SO2 and hydrogen sulfide (H2S) emissions from Puʻuʻōʻō were below instrumental detection levels when last measured on January 7 2021.
Halemaʻumaʻu Lava Lake Observations: Observations indicate that the eruption in Halema'uma'u at the summit of Kīlauea Volcano has paused. It is possible that the Halema'uma'u vent could resume eruption or that Kīlauea is entering a period of quiescence prior the next eruption. The total depth of the lake is 229 m (751 ft) as measured by a continuous laser rangefinder on the western portion of the lake near the west vent area, and is unchanged since May 11, 2021. The total volume of the lake is approximately 41.2 million cubic meters (11 billion gallons). Within the past 48 hours, no active lava was observed in webcam images of the Halema'uma'u crater lava lake surface. Field crews on May 25 observed no signs of lava lake activity, no incandescence, and no signs of recently active surface lava. Small incandescent spots visible in thermal webcam imagery since May 23 persist, but have become much fainter. The lake's surface is covered by stagnant and solidified lava crust.
Source: USGS Hawaiian Volcano Observatory Daily Update, May 26, 2021
Kilauea volcano (Hawai'i): earthquake beneath southern flank
Mon, 24 May 2021, 06:5406:54 AM | BY: MARTIN
The seismic network of the Hawaiian Volcano Observatory (HVO) recorded a volcano-tectonic earthquake with magnitude M 4.2 at 7,5 km depth beneath the southern flank of the volcano yesterday at 11:41 local time. The earthquake was centered about 15 km (9 miles) south of Volcano, under the Hilina Pali area of Hawai'i Volcanoes National Park.
Distribution of earthquakes beneath Kilauea volcano including the latest M 4.2 event as red arrow shows (image: HVO)
Weak to light shaking, with maximum Intensity of IV on the Modified Mercalli Intensity Scale, has been reported across the Island of Hawai'i.
According to HVO Scientist-in-Charge Ken Hon, the earthquake had no apparent effect on Kīlauea or Mauna Loa volcanoes. “We see no detectable changes in activity at the summits or along the rift zones of Kīlauea or Mauna Loa as a result of this earthquake. Aftershocks are possible and could be felt.”
Source: Hawaiian Volcano Observatory volcano activity update 24 May 2021
Lava Lake Almost Fully Crusted After 5-Months of Eruption
Update Fri 21 May 2021 07:40
The final opening in the previously liquid 112-acre molten lake is only spattering lava intermittently, with USGS Hawaiian Volcano Observatory scientists reporting that “during an approximately one-hour visit to the crater rim, [the] only observation of active lava was [...] crustal foundering [...] which lasted approximately five minutes” on May 18th.
Thermal image loop (24 hours) from the USGS-HVO F1 camera on May 20, 2021, the 5-month milestone since the start of the eruption.
Has Kīlauea volcano stopped erupting lava, 5 months to the day after it began? The nearly complete crusting over of the open lava lake surface has made it difficult to tell, but live monitoring data of the lava lake's depth by the USGS HVO suggest no signs of injection beneath the cooling crust. Continuous measurements by a novel laser rangefinder shows no lifting of the hardened lava since one week ago on May 13th.
Beneath the crust, the core of the 229 m (752-ft) deep lava lake would remain liquid for over a century if left undisturbed, though that stability is unlikely in this dynamic volcanic landscape which exactly three years ago was in the midst of a 3-month, 500 m (1600-ft) collapse. That liquid will continue degassing, and the moving gas bubbles will carry and eject lava if they can, as is currently evident in these waning stages of eruptive activity.
Even after the crust is fully solidified, a rejuvenation of activity is still possible and fairly common among historical eruptions. Most recently, the 2018 vent in the Lower East Rift Zone now officially named Ahuʻailāʻau, ceased the bulk of its lava output on August 4th. After activity ceased within its crater, lava re-appeared briefly from September 1st to 6th, marking the final effusion of the 2018 eruption.
The volcano continues to slowly swell, and the pressure building underground could also reactivate the vent or shift the ground beneath the lake before resuming the eruption. The most recent USGS-HVO update states that based on reduced SO2 emission rates, “this implies a decrease in lava effusion rate that may indicate a coming pause in eruptive activity.” Only time will tell whether the current trend means the end of the eruption or only a temporary pause.
Join our weekly live video review of Kīlauea's eruption! Broadcast at 5pm HST Tuesdays and archived, along with short video updates, on the Hawaiʻi PODD channel - including monitoring signals, photos & videos, time-lapses, geologic context and annotation, and discussion of live viewer questions.
Source: Compilation and summary of USGS Hawaiian Volcano Observatory activity updates & online data, May 2021
Kilauea volcano (Hawai'i): lava lake crusting continues
Tue, 18 May 2021, 07:2907:29 AM | BY: MARTIN
The effusive eruption of the volcano continues characterized by the transformation of Kīlauea's lava lake into continuous crusting.
Lava lake surface within Halema‘uma‘u crater continues crusting (image: HVO)
The lava lake within Halema'uma'u crater remains active, although surface incandescence has become less frequent over the last few days.
As can be seen in the attached image, two elongated lobes oriented west (left) to east (right) with a relatively smooth shiny grey surface are visible in the center of the photo. These two lobes comprise the active area of the current lava lake. A tiny red glow is visible along the southern (bottom) margin of the northern (top) elongated lobe, toward the middle.
The lava flow, feeding from the western fissure vent, continues to effuse into the lava lake. The current lava lake depth is 751 ft (229 m).
Gas emissions and seismic activity remain at elevated levels.
Source: Hawaiian Volcano Observatory volcano activity update 18 May 2021