July 17, 2008

A weekly feature provided by scientists at the Hawaiian Volcano Observatory.

Spectacular show underway at lava ocean entry

Lava explodes from Kilauea's lava ocean entry near Kalapana. The high ground on the lower right side of the image is a cone that has been built by the explosions. An excellent view of the activity can be had from the County viewing area, about 1 mile distant.

As dedicated Volcano Watchers know, the entry of lava into the ocean on Kilauea's south flank ceased in June 2007 after several years of near-constant activity, due to a change in the volcanic plumbing of the east rift zone. For months, surface lava was present only on the east rift zone, erupting from a vent just downrift of Pu`u `O`o. Finally, in March 2008, lava made its way from the east rift zone, through the remains of the Royal Gardens subdivision, across the coastal plain, and into the ocean. Kilauea had an active lava ocean entry again for the first time in almost 9 months.

The new entry point was not far from Kalapana, and in fact destroyed a segment of road and overran several home sites (fortunately, the RVs located on these sites were moved before being covered). About 10 abandoned structures in the Royal Gardens subdivision were also destroyed.

For the first several weeks of the new ocean entry, lava flowed into the sea across a broad (1/2 mile) region. More recently, activity has stabilized at the Waikupanaha entry point, and that's where (with due respect to Barnum and Bailey) the Greatest Show on Surf can now be seen.

For about the past week, the ocean entry has been the site of some spectacular explosions. Blobs of lava and ash are thrown 100-200 feet into the air every few seconds as ocean waves crash into an active lava tube. The explosions have built a small cone on the coastline, which sits about 30 feet above the surrounding terrain. The explosions are accompanied by a strong plume of steam and gas, with occasional small bursts of lightning.

In addition to the explosions, small funnel clouds commonly extend down from the plume to the water. The water itself is, in some places, unusually calm, owing to upwelling patches of warm (up to 200 degrees F!), lava-heated water coming in contact with colder surface water.

Hawai'i County maintains a short trail and viewing area about 1 mile upwind of the lava ocean entry. From that spot, visitors can get up close and personal with Pele's display. Even if you are equipped only with good vision, the explosions and lightning are large enough to be easily appreciated from well over 1 mile away. With a pair of binoculars or telephoto camera lens, Pele's display is even more impressive.

The county viewing area can be visited free of charge, and is open between 2:00 p.m. and 10:00 p.m. every day (the last cars are allowed in at 8:00 PM), unless weather or volcanic conditions cause the area to be closed. For more information, call 961-8093 or check out http://www.lavainfo.us.

Please remember that the lava ocean entry is extremely hazardous, and it is dangerous to approach the explosions closer than the designated trail and viewing area. Not only are more powerful explosions possible, which would affect a wider area, the region around the ocean entry is highly unstable and could collapse into the sea at any time. Several such collapses have removed acres of land in recent weeks; these collapses are likely to continue as long as the lava ocean entry is active.

From the County viewing area, the show is unforgettable, and we encourage you to see it in person. For those of you who can't make the trip, feel free to visit the recent photo section of the Hawaiian Volcano Observatory Web site (http://hvo.wr.usgs.gov/kilauea/update/images.html), which contains many pictures and video clips of the Greatest Show on Surf!

Activity update

Kīlauea Volcano Kilauea Volcano continues to be active. A vent in Halema`uma`u Crater is erupting elevated amounts of sulfur dioxide gas and very small amounts of ash. Resulting high concentrations of sulfur dioxide in downwind air have closed the south part of Kilauea caldera and produced occasional air quality alerts in more distant areas, such as Pahala and communities adjacent to Hawai`i Volcanoes National Park, during kona wind periods.

Pu`u `Ō`ō continues to produce sulfur dioxide at even higher rates than the vent in Halema`uma`u Crater. Trade winds tend to pool these emissions along the West Hawai`i coast. Kona winds blow these emissions into communities to the north, such as Mountain View, Volcano and Hilo. The lava effusion and spattering observed in Pu`u `Ō`ō last week have diminished significantly. This week only weak spattering was observed at two vents on the crater floor.

Lava continues to erupt from fissure D of the July 21, 2007, eruption and is supplying several breakouts along the 2007 Thanksgiving Eve Breakout (TEB) tube system on the pali within Royal Gardens. The breakouts on the TEB shields, which have been active the last several weeks and hosted a lava fountain, were completely inactive on Thursday, July 17.

Lava also continues to flow through what remains of Royal Gardens and across the coastal plain to the ocean in a well-established lava tube active now for several months. Much of last week's activity was characterized by large littoral explosions at the Waikupanaha ocean entry, with an impressively large plume. Lightning, caused by the buildup of static charge due to abundant ash particles, has been observed in the ocean entry plume this past week.

Be aware that lava deltas could collapse at any time, potentially generating large explosions. This may be especially true during times of rapidly changing lava supply conditions, as have been seen lately. Do not venture onto the lava deltas. Even the intervening beaches are susceptible to large waves generated during delta collapse; avoid these beaches. In addition, steam plumes rising from ocean entries are highly acidic and laced with glass particles. Check Civil Defense Web site (http://www.lavainfo.us) or call 961-8093 for viewing hours.

Mauna Loa is not erupting. Three earthquakes were located beneath the summit this past week. Continuing extension between locations spanning the summit indicates slow inflation of the volcano.

No earthquakes beneath Hawai`i Island were reported felt within the past week.

Visit our Web site (http://hvo.wr.usgs.gov) for daily Kīlauea eruption updates, a summary of volcanic events over the past year, and nearly real-time Hawai`i earthquake information. Kīlauea daily update summaries are also available by phone at (808) 967-8862. Questions can be emailed to askHVO@usgs.gov.