Categorized | Featured, Sci-Tech, Volcano

Volcano Watch: June 27th lava flow activity continues, so stay informed!

This figure compares the photo above with an equivalent view from a thermal camera on August 28, 2014. The plumes of smoke mark the farthest active lava on the surface (small, scattered lobes of pāhoehoe), which are also shown as small hotspots in the thermal image. The pad of lava that emerged from the ground crack earlier this week was inactive at the surface but still quite warm (high temperature patch in center of image). East of this pad of lava, steaming (just below the center of the photograph) has appeared over the past day, suggesting that lava is continuing to advance below the surface along a ground crack. Direct views into the crack were not possible due to thick vegetation, but close views of the steaming areas with the thermal camera reveal temperatures up to 190 C (370 F). These high temperature are further evidence of lava moving through the crack. Photos courtesy of USGS/HVO

This figure compares the photo above with an equivalent view from a thermal camera on August 28, 2014. The plumes of smoke mark the farthest active lava on the surface (small, scattered lobes of pāhoehoe), which are also shown as small hotspots in the thermal image. The pad of lava that emerged from the ground crack earlier this week was inactive at the surface but still quite warm (high temperature patch in center of image). East of this pad of lava, steaming (just below the center of the photograph) has appeared over the past day, suggesting that lava is continuing to advance below the surface along a ground crack. Direct views into the crack were not possible due to thick vegetation, but close views of the steaming areas with the thermal camera reveal temperatures up to 190 C (370 F). These high temperature are further evidence of lava moving through the crack. Photos courtesy of USGS/HVO

(Volcano Watch is a weekly article written by scientists at the U.S. Geological Survey’s Hawaiian Volcano Observatory.)

In response to the USGS Hawaiian Volcano Observatory’s (HVO’s) Aug. 22, 2014, news release (hvo.wr.usgs.gov/pressreleases/…) that Kīlauea’s June 27th lava flow could become a concern for communities downhill of the Pu‘u ‘Ō‘ō vent, the Hawaii County Civil Defense Agency (HCCDA) quickly organized a series of informational meetings.

To date, four meetings have been held at the Pāhoa Community Center to raise public awareness of the lava flow and to let potentially affected residents know how to stay informed about the flow’s progress. HCCDA also addressed the possible emergency-response measures that are being considered should the flow continue its northeastward advance.

During these meetings, HVO’s Scientist-in-Charge, Jim Kauahikaua, and HCCDA’s Director, Darryl Oliveira, provided brief presentations about the lava flow activity and emergency planning efforts, respectively, before answering dozens of questions from attendees. When and where the lava flow might reach specific communities, roads, and infrastructure were topmost among residents’ concerns, but are the most difficult questions to answer at this time.

While it’s true that lava flows travel downhill, their movement is more complex than might be expected. There are several critical factors that affect where lava actually flows and how quickly it advances.

For the June 27th lava flow, these include: (1) how much and how consistently lava is erupted from the Pu‘u ‘Ō‘ō vent; (2) whether or not lava breaks out of the tube and creates new surface flows (and tubes) that “steal” lava from the current flow front; and (3) the topography (shape and features) of the ground over which the lava is flowing, including slope steepness and direction, depressions, ground cracks, fault cliffs, craters, and cones.

During the past week, the most active part of the June 27th lava flow moved into extremely irregular topography with lots of cracks and depressions, which makes it futile—at this time—to forecast exactly which areas might be impacted.

The June 27th flow, named for when it began, is erupting from a vent located on the northeast flank of Pu‘u ‘Ō‘ō. The lava remained close to the vent for two weeks, but on July 10, the flow began to advance to the northeast, with an average speed of about 250 meters per day (820 ft/day), but as fast as about 500 meters per day (1,600 ft/day). These relatively rapid advance rates were likely due to two factors: a steady lava supply and confinement of the flow to a narrow low area between older lava flows.

This low area funneled the flow into a section of Kīlauea Volcano’s East Rift Zone that is marked by dozens of deep, discontinuous ground cracks and linear depressions that are hundreds to thousands of meters (yards) long. In mid-August, the lava flow disappeared into one of these cracks, creating uncertainty about if, when, and where it would reappear at the surface.

Over the following days, a line of rising steam along the crack suggested that lava was continuing to advance. On August 24, the flow resurfaced about 1.3 km (0.8 mile) farther down the rift zone, where, after forming a small pad of visible lava, the flow again cascaded into another crack and disappeared from view. As of August 29, a new line of steam progressing farther east along the crack indicated that lava continues to advance.

The irregular topography of the rift zone has kept the lava flow moving toward the northeast. But, as long as the lava continues to travel out of view within ground cracks, forecasting a precise flow path will remain difficult.

At the time of this writing (August 29), the June 27th lava flow did not pose an immediate threat to any residential area. However, HVO and HCCDA continue to closely track the flow with daily overflights of the area, which will continue as long as warranted.

We encourage you to stay informed about the flow. Daily eruption updates are posted on the HVO website (hvo.wr.usgs.gov) every morning, and maps and photographs of the flow are added after each HVO overflight.

HAWAII COUNTY MEDIA RELEASE

Hawai’i County Civil Defense and the Hawaiian Volcano Observatory will host additional community meetings on Tuesday, Sept. 2 and Thursday, Sept. 4 to update residents on the lava flow in the Wao Kele O Puna area.

The briefings will begin at 6:30 p.m. on Tuesday and Thursday in the Pahoa High School Cafeteria.


Multi-image movie of Pu’u ‘O’o Crater. (8/21-28/14)


Thermal image movie of Pu‘u ‘O‘o Crater (8/21-28/14)


Pu’u ‘O’o Crater East Flank. (8/21-28/14)


Pu’u ‘O’o Crater North Flank. (8/21-28/14)


Pu’u ‘O’o Crater South Flank. (8/21-28/14)

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