November 2018.
Has it already been six months since lava began flowing through Hawaii County’s lower Puna district?
Has it only been three months since activity at fissure 8 ended rather abruptly?
Similar questions can be asked about the onset and end of the dramatic collapse of Kilauea Volcano’s summit crater floor.
Interesting and important questions for the U.S. Geological Survey’s Hawaiian Volcano Observatory staff, our colleagues and the volcano research community relate to what happened within and beneath Kilauea. Ultimately, we also want to know what will happen next on the volcano.
Throughout the dramatic volcanic events of the summer, HVO’s work continued, as has the institution of HVO.
Fortuitously, as the summit began to shake with the regularity of large crater collapse events and as lava flows began their advance in lower Puna, the University of Hawaii at Hilo was in summer session. UH-Hilo and its Geology Department generously opened offices and labs to HVO staff — evacuated from Hawaii Volcanoes National Park upon its closure — where they could work in temporarily available space. Had university classes been in full session, this would not have been possible.
What made such a rapid move even thinkable was the thoughtful design of HVO’s data and information technology infrastructure. While HVO’s critical IT infrastructure remains in the national park, it was possible to reroute HVO monitoring data streams and processing to UH-Hilo. This was by no means a small accomplishment.
At the end of the summer session, it was necessary for HVO to move from UH-Hilo’s Geology Department. HVO staff and equipment are now in a second set of temporary work and storage spaces spread throughout five buildings and three locations, including UH-Hilo and the Port of Hilo.
In the near future, HVO will move to a third temporary location so a larger fraction of the staff will be able to work under a single roof. Like other displaced Hawaii residents, HVO staff continue to adapt and remain flexible in transient and challenging times.
Discussions and planning regarding HVO’s future permanent location are ongoing. There are many considerations and factors that will influence the eventual decisions.
Experiences gained from Kilauea’s 2018 episode also will inform these decisions, as they provided new insights, especially regarding data distribution, remote monitoring of volcanic activity and working collaboratively with partners throughout the whole country.
In the meantime, HVO continues to vigilantly watch Kilauea and Mauna Loa volcanoes.
Since the relatively abrupt end to Kilauea’s summit collapse sequence and lower East Rift Zone lava flows in early August, HVO has not noted any trends suggesting the volcano is building toward imminent renewed eruptive activity.
Typical of intervals without active eruptions, seismic activity is the primary indicator of what’s happening inside Hawaiian volcanoes. Seismicity at Kilauea continues beneath its summit and south flank. But, rather than the thousands of earthquakes that were recorded each week between June and August, recent earthquake rates have persisted at several hundred per week. Many of these earthquakes can be considered aftershocks of the magnitude-6.9 Kilauea south flank earthquake that occurred May 4.
Since early August, minor seismic activity has returned to the upper elevations of Mauna Loa. A brief flurry of small earthquakes began beneath the summit and uppermost Southwest Rift Zone in mid-September, followed by a sequence of earthquakes beneath the volcano’s upper west flank.
Seismicity beneath these regions continued through mid-October but has since decreased. Importantly, HVO notes no significant geodetic changes at Mauna Loa associated with this seismic activity.
Lo‘ihi, a submarine volcano south of Hawaii Island, and other earthquake source regions also have been seismically active.
As an institution, HVO is settling into a new “normal.” HVO’s future office moves should not be as sudden as those required this past summer nor will they adversely impact HVO’s monitoring of the island’s active volcanoes. Unlike volcanic eruptions that eventually end, HVO’s work continues nonstop.
Volcano activity updates
Kilauea is not erupting. Low rates of seismicity, deformation and gas release have not changed significantly during the past week.
Earthquakes continue to occur primarily at Kilauea’s summit area and south flank, with continued small aftershocks of the May 4 magnitude-6.9 quake. Seismicity remains low in the lower East Rift Zone.
Deformation signals are consistent with magma refilling the middle ERZ. At the summit, tiltmeters have shown little change this week, except for a small DI (deflation-inflation) event.
Sulfur dioxide gas emissions at the summit averaged 50 tonnes/day as reported Oct. 24, and 75 tonnes/day at Pu‘u ‘O‘o on Oct. 23. There was no sulfur dioxide detected by our instruments in the lower ERZ.
Hazardous conditions still exist at the lower ERZ and summit. Residents in the lower Puna District and Kilauea summit areas should stay informed and heed Hawaii County Civil Defense closures, warnings and messages (http://www.hawaiicounty.gov/active-alerts).
The USGS Volcano Alert level for Mauna Loa remains at Normal.
No Hawaii earthquakes received three or more felt reports (minimum to be recounted here) this past week.
Visit HVO’s website (https://volcanoes.usgs.gov/hvo) for past Volcano Watch articles, Kilauea and Mauna Loa updates, volcano photos, maps, recent earthquake info, and more. Call 808-967-8862 for weekly Kilauea updates. Email questions to askHVO@usgs.gov.
Volcano Watch (https://volcanoes.usgs.gov/hvo/hvo_volcano_watch.html) is a weekly article and activity update written by U.S. Geological Survey Hawaiian Volcano Observatory scientists and affiliates.