HVO UPDATE: Hazards are Still Present

The U.S. Geological Survey released the following weekly update on Tuesday, Oct. 17, 2018.

Low sulfur dioxide gas emissions on Kīlauea have resulted in greatly diminished vog (volcanic air pollution) in Hawai‘i, giving rise to spectacular views on the island. Here, looking across the field of lava erupted from Kīlauea’s lower East Rift Zone this past summer, the shield-shaped profiles of Mauna Loa (left) and Mauna Kea (right) can be clearly seen in the far distance. Click to enlarge. PC: USGS

Kīlauea Volcano is not erupting. Rates of seismicity, deformation, and gas release have not changed significantly over the past week. Deformation signals are consistent with refilling of the middle East Rift Zone.

Observations: HVO monitoring during the past week shows low rates of seismicity at the summit and East Rift Zone (ERZ). Earthquakes continue to occur primarily at Kīlauea’s summit area and south flank (magnitude-2.5 was the largest) with continued small aftershocks of the magnitude-6.9 quake on May 4, 2018. Seismicity remains low in the lower ERZ.

In the ERZ, tiltmeters near Puʻu ʻŌʻō and farther east continue to record an inflationary trend, consistent with refilling of the middle East Rift Zone. At the summit, tiltmeters have recorded a slight inflationary trend; however, this signal is small and could be due to heavy rainfall.

Sulfur dioxide gas emissions at the summit, Puʻu ʻŌʻō, and the ERZ remain drastically reduced. The most recent SO2 emission measurements, from late September, show a combined rate of less than 300 tonnes/day. Bad weather has prevented new SO2 emission rate measurements; however, downwind SO2 concentrations suggest that no major changes have occurred over the last week.

Hazards are still present in the Lower East Rift Zone (LERZ) eruption area and at the Kīlauea summit. Residents and visitors near recently active fissures and lava flows should stay informed, heed Hawai‘i County Civil Defense and National Park warnings, and be prepared, if necessary, to self-evacuate in the unlikely event of renewed activity. Note that Hawai‘i County maintains a closure of the entire flow field and the vents and prohibits access to the area unless authorized through Civil Defense.

The Hawaiian Volcano Observatory (HVO) continues to closely monitor Kīlauea’s seismicity, deformation, and gas emissions for any sign of reactivation, and maintains visual surveillance of the summit and the East Rift Zone. HVO will continue to issue a weekly update every Tuesday and additional messages as warranted by changing activity.