December 24, 2009
A weekly feature provided by scientists at the Hawaiian Volcano Observatory.
Kīlauea glows as lava keeps churning at the summit
Clear weather and an active lava column in the Halema`uma`u Overlook vent this week is brightening the nighttime glow at the summit of Kilauea just in time for the holiday season. The glow is especially notable from the Jaggar Museum viewing area in Hawaii Volcanoes National Park, located only 1.9 km (1.2 mile) from the vent.
Activity in the summit vent is following a pattern observed many times in 2009. Early this past week, lava in the vent went through a series of impressive filling and draining cycles that lit up the base of the gas plume with incandescent glow. One filling and draining cycle took about 5 minutes to complete.
At the low stand, lava was contained within an elongate opening in the bottom of the vent about 200 m (660 ft.) below the floor of Halema`uma`u Crater. The lava formed a nearly continuous roiling fountain in the shape of a small dome. At the beginning of the filling phase lava started to spatter and slosh outside of the opening, and eventually rose above it to form a much larger lava pond and dome fountain.
At this high stand of lava, small plates of cooled crust would form around the edges of the pond. As the lava flowed back into the opening during the drainback phase of the cycle, the cooled crust pieces moved toward the center of the opening and disappeared down into the vent. The draining created a chaotic area of spattering at the center of the pond.
Similar to earlier episodes, the draining phase happened faster than the filling phase. During both filling and draining the sounds of lava sloshing and spattering were quite loud, and, when the draining was finished, there was a quiet period lasting tens of seconds. During this quiet period the vent went fairly dark compared to the very bright levels during active filling and draining.
This activity was captured on video by scientists making routine observations and measurements early this past week from directly above the Overlook vent, and can be viewed on the Web site of the Hawaiian Volcano Observatory. For images and video of Kilauea's activity, visit the following Web page: http://hvo.wr.usgs.gov/multimedia/images.html
The nighttime glow from the Overlook Vent varies considerably from hour to hour and week to week as the height of the lava column changes and the size of the opening above the column is altered by the accumulation of cooled lava and spatter and collapse of the material into the churning lava. Thus, at the time of this writing (Wednesday evening), the glow was a little subdued compared to earlier in the week, but beautiful at sunset nonetheless! Be sure to bring warm clothes if you plan to visit the Jaggar Museum at night!
Kīlauea Activity Update
Lava continues to erupt from the TEB vent on Kīlauea's east rift zone and flow through tubes to the ocean at the Waikupanaha location west of Kalapana. Small surface flows have been sporadically active on the coastal plain for the last several weeks.
Glow above the vent at Kīlauea's summit has been visible at night from the Jaggar Museum. Incandescent openings, sometimes yielding bursts of spatter, were visible on the floor of the vent cavity throughout the week, as recorded by the Webcam perched on the rim of Halema`uma`u Crater. Volcanic gas emissions remain elevated, resulting in high concentrations of sulfur dioxide downwind.
Two earthquakes beneath Hawai`i Island were reported felt during the past week. A magnitude-2.7 earthquake occurred at 6:05 p.m. on Friday, December 18, 2009, H.s.t., and was located offshore 27 km (17 miles) west of Waikoloa Village at a depth of 36 km (22 miles). A magnitude-3.0 earthquake occurred at 7:21 p.m. on Tuesday, December 22, and was located 17 km (10 miles) north of Pahala at a depth of 10 km (6 miles).
Visit our Web site (http://hvo.wr.usgs.gov) for detailed Kīlauea and Mauna Loa activity updates, recent volcano photos, recent earthquakes, and more; call (808) 967-8862 for a Kīlauea activity summary; email questions to askHVO@usgs.gov.
Updated: December 31, 2009 (pnf)