VOLCANO WATCH: Kīlauea Offers Premier Viewing

Map of Kīlauea’s active lava flow as of July 19, 2016. Red shows the extent of new breakouts since July 8; pink shows the flow prior as of July 8, and gray shows areas covered by earlier Pu‘u ‘Ō‘ō lava flows (1983–2016). As of July 20, the flow front was about 850 m (0.5 mi) from the ocean and making little forward progress, but active lava breakouts upslope of the flow front continued to widen the flow margins. USGS map.

What an exciting time for Kīlauea volcano-watchers!

Simultaneous eruptions at the summit and along the East Rift Zone of Kīlauea might be old news, but a change in late May has created some excitement: A new vent opened on the eastern flank of Pu‘u ‘Ō‘ō and is now sending lava down the south flank of Kīlauea and across the coastal plain for the first time since 2013.

The active lava flow continues to creep across the coastal plain on Kīlauea’s south flank. Breakouts of pāhoehoe (foreground) are fed by lava traveling through lava tubes from the Pu‘u ‘Ō‘ō vent and down Pulama pali (top background). USGS photo.

At Kīlauea’s summit, the sloshing, splashing lava lake within the Halemaʻumaʻu Crater vent has been high enough at times that spatter (bits of molten lava) is occasionally visible from the Jaggar Museum overlook in Hawai‘i Volcanoes National Park. At night, spectacular views of reddish glow against the dark sky and Milky Way have enthralled visitors.

The new Pu‘u ‘Ō‘ō lava flow has been informally named “61g,” as it is the 7th flow (g) in the 61st episode of the ongoing Kīlauea East Rift Zone eruption, which began in 1983. The flow now extends roughly 10 km (6 miles) from the vent, and is advancing to the southeast along the eastern border of Hawai‘i Volcanoes National Park.

Visitors who happened to be at Jaggar Museum in Hawaiʻi Volcanoes National Park midday on July 20, 2016, got spectacular views of spattering lava within Kīlauea Volcano’s summit vent, captured here with a zoomed-in camera. Views like this occasionally occur when the lava lake level is high and the spattering area is not obscured by the vent walls. On this day, the lava lake surface was 25 m (82 ft) below the vent rim. USGS photo.

Closer to the vent at Pu‘u ‘Ō‘ō, molten lava moves downslope beneath a newly solidified lava surface through a system of lava tubes. It then streams over Pulama pali, a lava-mantled fault scarp, where, at times, the lava produces impressive ʻaʻā channels on the steep slopes. On the more gentle gradients of the coastal plain, the flow advances as slower-moving pāhoehoe lava lobes and sheets.

The lava flow front remains active, but has made little forward progress toward the ocean in the past two weeks. As of July 20, the flow front remained about 720 m (0.4 mi) from the emergency road and 850 m (0.5 mi) from the ocean. A few hundred meters (yards) upslope of the flow front, breakouts of pāhoehoe lava continue to widen the flow margins.

Visitors hoping to view the flow should consult access and critical safety information before attempting the long hike. Lava-viewing information is available from both Hawai‘i Volcanoes National Park and Hawai‘i County.

At this point, we cannot say with certainty if or when lava might reach the ocean. If it does, a different set of hazards—from steam explosions to collapsing lava deltas—will impact lava-viewing opportunities. Staying informed will help you stay safe.

To keep up with recent Kīlauea activity, you can sign up for daily updates via email and text message through the free USGS Volcano Notification Service. You can also visit the USGS Hawaiian Volcano Observatory website for daily updates, recent photos, maps, and other resources.

Other volcano and earthquake updates

Mauna Loa is not erupting. The volcano is, however, restless, with rates of deformation and seismicity remaining above long-term background levels. During the past week, small earthquakes occurred beneath the west and north flanks of Mauna Loa, mostly in the 5–11 km (3–7 mile) depth range.

Earthquakes are also occurring in the south caldera and upper Southwest Rift Zone of Mauna Loa at depths less than 5 km (3 miles). Global Positioning System measurements show deformation related to inflation of a magma reservoir beneath the summit and upper Southwest Rift Zone, with inflation occurring mainly in the southwestern part of the magma storage complex.

One earthquake was reported felt on the Island of Hawaiʻi in the past week.

On July 15, 2016, at 11:11 p.m., HST, a magnitude-2.5 earthquake occurred 7.1 km (4.4 miles) southeast of Pāhoa at a depth of 3.0 km (1.9 miles).

Volcano Watch is a weekly article and activity update written by U.S. Geological Survey Hawaiian Volcano Observatory scientists and affiliates.

Call for summary updates at (808) 967-8862 (Kīlauea) or (808) 967-8866 (Mauna Loa); email questions to [email protected].