Two explosions in as many days were triggered by rocks falling into KÄ«lauea Volcano’s summit lava lake. The event shown above occurred around 12:26 p.m., HST, today (Thursday, October 20). The other explosion happened around 7:45 a.m. on Wednesday, October 19. Both events are reminders why the area around HalemaÊ»umaÊ»u Crater remains closed to the public. Photo taken Thursday, October 20, 2016 courtesy of USGS/HVO

Today’s explosion, triggered by a rockfall from the south-southeast wall of the summit vent within HalemaÊ»umaÊ»u Crater, blasted spatter (molten lava) and rock fragments on to the rim of HalemaÊ»umaÊ»u Crater, as well as on to the closed section of Crater Rim Drive, about a quarter-mile from the vent. Photo taken Thursday, October 20, 2016 courtesy of USGS/HVO

Following today’s explosion, spatter (bit of molten lava) and fragments of solid rock littered this closed section of Crater Rim Drive in HawaiÊ»i Volcanoes National Park. This section of the road, adjacent to the former HalemaÊ»umaÊ»u Crater parking area, has been closed since 2008 due to elevated sulfur dioxide emissions and other ongoing volcanic hazards, such as today’s rockfall-triggered explosion. Photo taken Thursday, October 20, 2016 courtesy of USGS/HVO

Spatter and “ribbon bombs” (stretched fragments of molten lava) up to 30 cm (about 12 inches) long fell to the ground surface on the rim of HalemaÊ»umaÊ»u Crater during the two most recent explosions from KÄ«lauea’s summit lava lake. The black, glassy lava fragment shown here, about the size of a standard donut, landed amidst smaller, solid pieces of rock blasted from the vent. Photo taken Thursday, October 20, 2016 courtesy of USGS/HVO

A marking pen is shown for scale to indicate the size of this solid rock fragment hurled from the vent during the explosion. Photo taken Thursday, October 20, 2016 courtesy of USGS/HVO

A close-up of spatter and rock fragments blasted from the summit vent during the recent explosions. These pieces of rock and lava, now scattered among the Pele’s hair that blankets the rim of HalemaÊ»umaÊ»u Crater, remind us of the hazards that still exist in this area. Photo taken Thursday, October 20, 2016 courtesy of USGS/HVO

Time-lapse movie of Halemaumau Overlook Vent with tilt graph overlay. October 13-20, 2016. Images courtesy of USGS/HVO

Time-lapse thermal image movie of Halemaumau Overlook Vent. October 13-20, 2016. Images courtesy of USGS/HVO

Time-lapse movie of Halemaʻumaʻu Overlook Vent from Hawaiian Volcano Observatory. October 13-20, 2016. Images courtesy of USGS/HVO

Time-lapse movie of KÄ«lauea Caldera from Hawaiian Volcano Observatory. October 13-20, 2016. Images courtesy of USGS/HVO

Time-lapse movie of Halemaumau Crater looking Southwest. October 13-20, 2016. Images courtesy of Hawaii Volcanoes National Park

(Activity updates are written by scientists at the U.S. Geological Survey’s Hawaiian Volcano Observatory.)

Kīlauea continues to erupt at its summit and East Rift Zone. This past week, the summit lava lake level rose and fell in concert with summit inflation and deflation, varying mostly between 5 m and 17 m (16–56 ft) below the vent rim, but briefly overflowing the vent on October 15. The 61g lava flow continued to enter the ocean near Kamokuna. The lava flow does not pose an immediate threat to nearby communities.

Mauna Loa is not erupting. Seismicity remains elevated relative to the long-term background rate, with small earthquakes occurring mostly in the volcano’s south caldera and upper Southwest Rift Zone at depths less than 5 km (3 mi). Deformation related to inflation of a magma reservoir beneath the summit and upper Southwest Rift Zone continues, with inflation occurring mainly in the southwestern part of the magma storage complex.

No earthquakes were reported felt on the Island of Hawaiʻi this past week.

Please visit the HVO website (http://hvo.wr.usgs.gov) for past Volcano Watch articles, KÄ«lauea daily eruption updates, Mauna Loa weekly updates, volcano photos, recent earthquakes info, and more; call for summary updates at 808-967-8862 (KÄ«lauea) or 808-967-8866 (Mauna Loa); email questions to askHVO@usgs.gov.

On Saturday, October 15, KÄ«lauea Volcano’s summit lava lake overflowed the vent rim between 1-2 p.m., and again around 6:30 p.m., HST. In this image, captured by HVO’s K2 webcam, you can see small spill-overs (shiny black lava) on the east (far left) and west (right) sides of the vent rim.
In recent weeks, the lava lake level has been rising and falling in concert with summit inflation and deflation (DI-events), with the lake surface often in view of Hawaiʻi Volcanoes National Park overlooks. On September 22, the lake level rose to within 10 m (33 ft) of the vent rim, the highest level reached since the previous lake overflow in April-May 2015. Since then, the lake level has risen and fallen with multiple DI-events.
A switch to summit inflation on October 13 led to Saturday’s brief overflow, which was soon followed by a return to summit deflation and a drop in the lake level. As of this morning, October 17, the summit lava lake level was 17 m (56 ft) below the vent rim. Photo taken Saturday, October 15, 2016 courtesy of USGS/HVO