Kīlauea Caldera Collapse July 12th equivalent to a M5.3 earthquake


U.S. Geological Survey
Tuesday, July 17, 2018, 1:43 PM HST (Tuesday, July 17, 2018, 23:43 UTC)

19°25'16" N 155°17'13" W, Summit Elevation 4091 ft (1247 m)
Current Volcano Alert Level: WARNING
Current Aviation Color Code: ORANGE

Kīlauea Volcano Lower East Rift Zone

Fissure 8 continues to erupt lava into the perched channel leading northeastward from the vent. Surging was noted at the Fissure 8 cone during the overflight but had stopped by the time ground crews arrived to verify it. Lava in the channel is a bit lower this morning and there were no significant overflows. The southern margin of the flow was located about 750 m (0.5 mi) from the boat ramp at Isaac Hale Park this morning. Despite no visible surface connection to the fissure 8 channel, lava continues to ooze out at several points on the 6 km (3.7 mi) wide flow front into the ocean.

No other fissures are active this morning.

Pele's hair and other lightweight volcanic glass fragments from the lava fountain at Fissure 8 continue to fall downwind of the fissure, dusting the ground within a few hundred meters (yards) of the vent. High winds may waft lighter particles to greater distances. Residents are urged to minimize exposure to these volcanic particles, which can cause skin and eye irritation similar to volcanic ash.

The most recent map of lava flows can be found at https://volcanoes.usgs.gov/volcanoes/kilauea/multimedia_maps.html

HVO field crews are on site tracking activity as conditions allow and are reporting information to Hawaii County Civil Defense. Observations are also collected on a daily basis from cracks in the area of Highway 130; no changes in temperature, crack width, or gas emissions have been noted for several days.

Volcanic gas emissions remain very high and continue to increase. VOG information can be found at https://vog.ivhhn.org/

The ocean entry is a hazardous area. The interaction of lava with the ocean creates "laze", a corrosive seawater plume laden with hydrochloric acid and fine volcanic particles that drifts downwind and can irritate the skin, eyes, and lungs. Close to the ocean entry, flying debris from explosive interaction between lava and water is a primary hazard. Additionally, submarine magma-water interaction can result in explosive activity beyond the visible lava delta, creating a hazard that extends offshore. The lava delta is unstable because it is built up to 800 m (0.5 mi) from the former coastline on unconsolidated lava fragments and sand. This loose material can easily be eroded away by surf, causing the new land to become unsupported and slide into the sea.

Magma continues to be supplied to the Lower East Rift Zone. Seismicity remains relatively low although higher amplitude tremor is occasionally being recorded on seismic stations close to the ocean entry.

Additional ground cracking and outbreaks of lava in the area of the active fissures are possible at any time. Residents downslope of the region of fissures should remain informed and heed all Hawaii County Civil Defense messages and warnings.

Kīlauea Volcano Summit

Seismicity has increased as has been the pattern leading up to collapse/explosion events beneath the summit. The last event occurred at 11:42 a.m. HST July 16 with energy equivalent to a magnitude-5.3 earthquake. We expect a high rate of earthquakes (25-35 per hour) to continue until the next collapse/explosion event occurs later today. Inward slumping of the rim and walls of Halemaʻumaʻu continues in response to the ongoing subsidence at the summit.

Sulfur dioxide emissions from the volcano's summit are very low. This gas and minor amounts of ash resuspended by wind are being transported downwind. Small bursts of ash and gas may coincide with the summit collapse/explosion events. The summit region is occasionally impacted by sulfur dioxide from the lower East Rift Zone eruption.

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