Kīlauea Report: Quakes Slow, Gradual Swelling

One week shy of three months since lava was last visible at Kīlauea’s surface, the volcano has slowed its earthquakes over the past few days but continues to show gradual swelling on its GPS monitors, according to the latest weekly update from the USGS Hawaiian Volcano Observatory. Ground-tilt exhibits little net change over the past week due to two small deflationary cycles but appears to have resumed its inflationary trend, while the latest gas measurement on August 12th is the lowest in over a month at 50-55 tonnes per day of SO2, remaining well within the background non-eruptive range. “The slight increase in the rates of seismicity around the summit and upper East Rift Zone early last week has not persisted, and has since decreased,” according to USGS-HVO. Specifically, daily earthquake counts on Kīlauea exceeded 100 per day on August 5th, then for four straight days from August 8th, but then dropped back to less than 60 per day for the next four days. At the tail end of the slightly elevated activity, a small swarm under Kīlauea Iki crater peaked with a magnitude 2.4 on August 11th. More recently within the last week, seismic activity appears to be greatly reduced especially in the East Rift between the summit and Puʻuʻōʻō, but also around the caldera and on the south flank. The past week has offered a short-term slowdown in multiple monitoring signals as underground adjustments continue around and within the magma reservoirs. Variations in individual monitoring streams have been common ahead of previous eruptions, so just as was the case last week during the heightened earthquake activity, more time is needed to reveal if the longer-term trend is affected by their decrease this week. Lacking significant changes in other monitoring signals, the long-term prognosis is unchanged: it’s only a matter of time before the volcano erupts again, and given the build-up thus far it is fair to expect it to do so sooner than later -- but apparently, not quite yet. To support our productions please like, share and subscribe! Mahalo! --- Join our weekly live video review of Kīlauea and Maunaloa volcanoes, at 5pm Hawaiʻi time Thursdays! To support our productions please like, share and subscribe! Mahalo! #Kilauea2021 [Image: On the morning of August 13, HVO geologists made observations from the western rim of Halema‘uma‘u, at the summit of Kīlauea. No active lava has been visible since May. This photo was taken from an area of Hawai‘i Volcanoes National Park that remains closed to the public due to safety reasons. USGS photo taken by D. Downs.]