Friday, April 4, 2008 08:10 HST (Friday, April 4, 2008 18:10 UTC)
Reprinted from the US Geological Survey Webpage, here.
KILAUEA VOLCANO (CAVW#1302-01-)
19.42°N 155.29°W, Summit Elevation 4091 ft (1247 m)
Volcano Alert Level: WATCH
Aviation Color Code: ORANGE
This report, in addition to maps, photos, and webcam images (available using the menu bar above), was prepared by the Hawaiian Volcano Observatory (HVO):
Activity Summary for last 24 hours: Kilauea Volcano is active at two locations. At the summit, the Halema`uma`u vent continued erupting ash. Sulfur dioxide emission rates and seismic tremor levels continued elevated to several times background levels. At the coast, lava continued to flow through lava tubes into the ocean at the Waikupanaha and Ki ocean entries.
Hazard Summary: Hazardous conditions exist in the summit area and the area between the rift zone (Pu`u `O`o to Kupaianaha) downslope to the ocean between Kalapana and Kapa`ahu. There is also great beauty to be seen and experienced at safe distances. HVO, Hawai`i Volcanoes National Park, and Hawai`i County Civil Defense strive to make safe viewing possible.
1. Summit: The current increase in sulfur dioxide emission rates at the summit means that SO2 concentrations in the air are likely to be at hazardous levels for areas downwind of emission sources in Halema`uma`u crater. The National Park Service has closed Crater Rim Drive through the south caldera area until further notice (http://www.nps.gov/havo/closed_areas.htm). Most people are sensitive to sulfur dioxide at these levels. Children and individuals with asthma, chronic obstructive pulmonary disease (COPD), or other breathing problems especially should avoid downwind areas. During tradewind conditions (brisk winds from the northeast), concentrations will be highest and most hazardous in the south caldera. During weak or southerly winds, concentrations may be high and hazardous throughout the summit area of Hawai`i Volcanoes National Park and nearby communities. Stay informed about SO2 concentrations in continuously monitored areas at Jaggar Museum and Kilauea Visitor Center (http://www.nature.nps.gov/air/webcams/parks/havoso2alert/havoalert.cfm).
The gas plume also includes fine rock dust downwind of the source. During the past few days, several people have reported a fine grit on their car windshields while driving under or in the ash plume along highway 11 and as far away as South Point. Information on the effects of ash are available at http://www.ivhhn.org/ and http://volcanoes.usgs.gov/ash/.
The possibility of future small explosions or eruption of lava from Halema`uma`u Crater cannot be ruled out.
2. Pu`u `O`o/July 21/TEB flow field: Vent areas and lava channels are hazardous and conditions can change rapidly. Sulfur dioxide emissions from Pu`u `O`o are high and result in hazardous concentrations downwind. Access to the 7/21 eruption site in the Kahauale`a Natural Area Reserve is closed (see http://www.state.hi.us/dlnr/chair/pio/HtmlNR/07-N076.htm). Wao Kele o Puna is also closed.
There continues to be a threat from lava flows to anyone within Royal Gardens subdivision and the coastal plain. As long as lava flows are active south of fissure D, the subdivision is within likely paths of future flows. The rootless shields, which are now less than two miles from the subdivision, can collapse and release lava flows that advance that distance within a few days. Tube- or channel-fed lava flows established within the subdivision and on the coastal plain remain a threat due to tube ruptures which can produce new lava flows. Lava flows advancing through vegetation are hazardous and can produce fire and methane explosions that propel chunks of lava and rock several feet into the air. Hawai`i County Civil Defense has been notified and is taking appropriate measures (www.lavainfo.us).
Lava entering the ocean poses two additional hazards - potential collapse and laze. Lava entering the ocean builds a delta over its own rubble that is extremely unstable. That delta can collapse without warning and expose very hot surfaces to waves which can explode and throw rock debris up to one-quarter mile inland. For these reason, spectators should avoid the delta and the area one-quarter mile inland. The interaction between seawater and lava produces a steam plume laced with acids and fine particles of volcanic glass or \'laze\' that is unhealthy if inhaled and can produce skin or eye irritation if contacted. Hawai`i County continues to open a public viewing area between 2 and 10 pm with the last car allowed in at 8 pm. For details, see www.lavainfo.us or call 961-8093.
TEB lava flows at the coast as of yesterday evening (from combined HVO and NPS eruption crew reports): Lava continued to flow into the ocean at 3 points - east and west Waikupanaha and Ki ocean entries. West Waikupanaha entry was most vigorous with the Ki entry increasing in vigor in the evening. A sluggish surface flow was active on the 1990 delta below the old sea cliff. Yesterday's overflight documented three tube breakouts on the coastal plain within one mile of the coast, but none had entered unburned kipuka areas. There was no other surface activity on the coastal plain.
Last 24 hours in the area of the east rift zone that includes Pu`u `O`o and the TEB vent: Incandescence was seen from a small skylight adjacent to the TEB vent and from top of a nearby rootless shield. Early this morning, a small breakout occurred within the rootless shield complex. The lava tube system seems to be stable and transports lava efficiently to the ocean entries.
Diffuse incandescence was observed overnight in Pu`u `O`o crater by webcam as has become common over the last several nights. It was not possible to distinguish any tilt signal besides the daily oscillations and rain effects. GPS receivers on opposite sides of the crater recorded no extension or contraction above error since March 27. Seismic tremor levels were at low values. The SO2 emission rate was about 1,530 tonnes/day when last measured on April 1.
Last 24 hours at Kilauea summit: Eruption of ash continued with a white plume most of the day and into this morning. We are increasingly confident that the white plume is producing less ash but that the ash includes an increasing amount of volcanic glass. The base of the plume again glowed dimly and incandescent fragments were sporadically ejected overnight but most fell back into the vent. Seismic tremor levels continued to be elevated to several times background values. The summit tiltmeter network recorded typical daily oscillations with possible weak deflation of a source beneath the south caldera. Two small earthquakes were located beneath Halema`uma`u Crater, one beneath the southwest rift zone, one beneath the east rift zone, and 4 on south flank faults.
The sulfur dioxide (SO2) emission rate from the summit continued to be elevated and was about 480 tonnes/day on April 2, compared to a background rate of between 150-200 tonnes/day. Wednesday's emission rate measurement was the lowest since Feb. 13, 2008. Weakened trade winds yesterday permitted SO2 concentrations to peak at 0.4 ppm at Jaggar Museum just after noon but remain below 0.2 ppm through evening.
Maps, photos, webcam views, and other information about Kilauea Volcano are available at http://volcano.wr.usgs.gov/kilaueastatus.php. A daily update summary is available by phone at (808) 967-8862.
A map with details of earthquakes located within the past two weeks can be found at http://tux.wr.usgs.gov/
A definition of alert levels can be found at http://volcanoes.usgs.gov/2006/warnschemes.html
For more information on visiting the Island of Hawaii and exploring the lava flows of Kilauea Volcano, go to www.tourguidehawaii.com.
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