Kīlauea Weekly Update, June 29th

U.S. Geological Survey - Hawaiian Volcano Observatory, June 29, 2021 -- Activity Summary: Kīlauea Volcano is no longer erupting. No surface activity has been observed by field crews or webcam images since May 23, 2021. Seismicity has slowly increased in recent weeks in the summit region, with continued gradual summit inflation over the past several months. Sulfur dioxide emission rates remain slightly elevated. It is possible that the Halema‘uma‘u vent could resume eruption or that Kīlauea is entering a longer period of quiescence prior to the next eruption. Summit Observations: The most recent sulfur dioxide (SO2) emission rates, measured on June 16, 2021, were 70 tonnes per day (t/d) (updated). SO2 emission rates are approaching levels associated with the non-eruptive period from late 2018 to late 2020 (30-35 t/d) and are significantly lower than emission rates that averaged over 800 t/d from mid-February to mid-April. Summit tiltmeters recorded three deflation-inflation cycles over the past week, along with continued gradual inflation in recent months. Seismicity has been slowly increasing in recent weeks, with a small swarm of earthquakes in the summit region on June 23. Halemaʻumaʻu Lava Lake Observations: The lake’s surface is completely covered by solidified lava crust. No surface activity or evidence of recent surface activity has been observed over the past week. Near-real time webcam views of the lava lake can be found in the webcam link below. 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. Hazard Analysis: Levels of volcanic gas—SO2 and carbon dioxide (CO2)—can remain locally hazardous even though Kīlauea is no longer erupting. SO2 gas emissions have greatly decreased. However, local concentrations of SO2 or hydrogen sulfide (H2S) may persist in downwind areas, and residents may from time to time notice odors of these gasses. Significant hazards also remain around Halemaʻumaʻu from crater wall instability, ground cracking, and rockfalls that can be enhanced by earthquakes within the area closed to the public. Even with decreased effusion rates and no signs of lava lake activity, conditions around Halema‘uma‘u crater remain hazardous. Image from USGS, KPcam: "View from Mauna Loa Strip Road looking at the Kīlauea summit to document volcanic eruption plumes."