Photo and Video Chronology - Kīlauea - November 3, 1997

[Eruption updates are posted approximately every two weeks. More frequent updates will accompany drastic changes in activity or increased threat to residential areas.]

For readers familiar with events of the past few months, recent changes include these:

• The vent inside Pu`u `O`o discharges lava almost constantly. The lava flows eastward about 200 m and disappears through a hole in the crater floor, 60 m below the east crater rim.
• At night, a spectacular orange glow emanates from Pu`u `O`o. The glow comes from incandescent lava that streams across the crater. We've received reports of the glow from as far away as Papaikou, a town on Hawai`i's Hamakua (northeastern) coast, 45 km north of the volcano.
• Lava from the south shield travels in tubes to the coast, an in-tube distance of about 10 km. Travel time for a particle of melt is probably about 3 hours from vent to ocean. Eruption rate is generally 500,000-600,000 cubic meters per day. Lava occasionally escapes from the tube to form new surface flows, but no breakouts have occurred in the past two weeks.
• Ocean entries remain situated at Waha`ula and East Kamokuna, which are the distal ends of the tube system.
• Sulfur dioxide gas emission from vents in the Pu`u `O`o area remains high, about 5,000 tons per day.
• For Big Island residents and tourists, symposia on Vog and Laze (volcanic fog and lava haze) will be held on November 8 (Hilo) and November 22 (Kona). Details are listed at the end of this report.

The 55th episode of Kilauea's 14.5-year-long east rift zone eruption continues. This episode, which began February 24, 1997, was characterized in its early months by shifting vent locations on the west and southwest flanks of Pu`u `O`o cone and by rapid enlargement of the episode 50-55 lava shield. The flow field expanded slowly until, in July, lava reached the sea. The supply of lava to these flows became restricted to tubes, and surface flow activity diminished greatly.

During the last thirteen weeks, eruptive activity has been concentrated at two main vents: a vent on the Pu`u `O`o crater floor and the "south shield," a lava shield about 300 m south of the Pu`u `O`o cone. The most obvious of these has been the "crater vent," which began as a spatter cone on the Pu`u `O`o crater floor. In September, however, the spatter cone subsided into its own throat, leaving a pit. The pit is about 40 m in diameter, and from this cauldron, lava froths and sloshes. This vent is the source of glow seen in the night sky from many vantage points on the east slope of Kilauea volcano.

Lava issuing from the crater vent flows eastward a short distance into Pu`u `O`o crater and drains through holes in the crater floor. Overflows occur when the subvolcanic drainage becomes clogged, which last occurred on October 18-19. The overflowing lava never travels far but has been visible throughout much of east Hawaii.

The other main vent is the south shield, source of the flows entering the ocean at the Waha`ula and Kamokuna sites near the eastern boundary of Hawai`i Volcanoes National Park. The flows are encased within lava tubes for most of their length and are visible only through skylights in the roof of the tube.

The tubes discharge their lava at the shoreline. The hot lava, about 1,150 degrees Celsius when it reaches the ocean, generates thick plumes of steam upon contact with seawater. The new lava builds benches beyond the former seacliffs. Small explosions periodically disrupt the rapidly chilling lava and throw it onto the bench, constructing low nearshore (littoral) cones. These small explosions pose a minor threat for visitors. A far greater threat exists, however; these benches can collapse into the sea without warning, triggering large steam explosions that hurl dense rock and molten spatter tens of meters inland. No one should venture onto the benches, no matter how stable the new land may appear.

Eruption-viewing opportunities change constantly, so those readers planning a visit to the volcano should contact Hawai`i Volcanoes National Park for the most current eruption information (808-985-6000).

Big Island residents and tourists who wish to learn more about vog and its effects on health, agriculture, equipment, and air quality are invited to attend one of two Vog and Laze Symposia, to be presented by the Center for the Study of Active Volcanoes. The first symposium will be held November 8 at the University of Hawai`i at Hilo Campus Center, Room 306-307; the second will be held in Kona on November 22 at the Kona Surf Hotel in the Kamehameha Ballroom.

Both symposia begin at 9 a.m., with presentations by scientists and medical professionals who will discuss the composition of vog and laze and its impact on the community. An informal discussion and resource booths will also be featured. These admission-free symposia are sponsored by a grant from the Federal Emergency Management Agency. For additional information call (808)-974-7631 (Hilo, Hawai`i).