HAWAIIAN VOLCANO OBSERVATORY WEEKLY UPDATE
U.S. Geological Survey
Tuesday, December 4, 2018, 4:01 PM HST (Wednesday, December 5, 2018, 02:01 UTC)
19°25'16" N 155°17'13" W,
Summit Elevation 4091 ft (1247 m)
Current Volcano Alert Level: ADVISORY
Current Aviation Color Code: YELLOW
Activity Summary: 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 and south flank areas.
In the ERZ, tiltmeters reveal little change over the last week, with GPS indicating some inflation downrift from Puʻu ʻŌʻō. At the summit, tiltmeters recorded a small DI (deflation-inflation) sequence over the weekend; the current trend is minor deflation.
Sulfur dioxide emission rates have been below detection limits in the LERZ since early September, though minor amounts of volcanic gas are still present. Last week, sulfur dioxide emission rates measured ~35 t/d at the summit as well as ~35 t/d in the ERZ. These most recent measurements are consistent with the extremely low emissions from Kīlauea over the past few months.
September 4 was the last time active lava was observed along the LERZ; tomorrow (December 5) will mark three months with no eruptive activity at the surface. According to the Smithsonian Institution’s Global Volcanism Program (https://volcano.si.edu/), volcanoes with no eruptive activity over a three-month period are no longer classified as having a “continuing” eruption. Based on this Global Volcanism Program criterion, the LERZ eruption could be considered to be over. However, there is one known example (Mauna Ulu, 1969-74) in which Kilauea’s rift zone activity resumed after more than three months had passed. Although this phase of Kīlauea’s activity has now reached this three-month threshold, it is important to note that it is still an active volcano that could erupt in the near future and associated hazards have not changed. Magma is being supplied to Kīlauea and geophysical datasets continue to show evidence for movement of material through the magma system, including the refilling of the ERZ.
Hazards are still present in the LERZ eruption area and at the Kīlauea summit. Residents and visitors near recently active fissures and lava flows should stay informed, heed Hawaii County Civil Defense and National Park warnings, and be prepared, if necessary, to self-evacuate in the unlikely event of renewed activity. Please note that Hawaii 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.
Activity summary also available by phone: (808) 967-8862
Subscribe to these messages: https://volcanoes.usgs.gov/vns2/
Webcam images: https://volcanoes.usgs.gov/volcanoes/kilauea/multimedia_webcams.html
Lava flow maps: https://volcanoes.usgs.gov/volcanoes/kilauea/multimedia_maps.html
Definitions of terms used in update: https://volcanoes.usgs.gov/volcanoes/kilauea/extra/definitions.pdf
Overview of Kīlauea summit (Halemaʻumaʻu) and East Rift Zone (Puʻu ʻŌʻō ) eruptions:
Summary of volcanic hazards from Kīlauea eruptions:
Recent earthquakes in Hawaiʻi (map and list):
Explanation of Volcano Alert Levels and Aviation Color Codes:
The Hawaiian Volcano Observatory is one of five volcano observatories within the U.S. Geological Survey and is responsible for monitoring volcanoes and earthquakes in Hawaiʻi.