New Emmissions Risk Guidelines Next Week!
Kilauea Daily Update issued Mar 20, 2008 06:49 HST Volcanic-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: Lava continued to flow into the ocean at the Waikupanaha and Ki ocean entries. The east margin of the flow field continued to advance slowly eastward into the adjacent kipuka and was about 150 m (500 ft) east of the County viewing area yesterday morning. No new explosions have occurred at Kilauea summit. Sulfur dioxide emission rates and seismic tremor levels continued elevated to several times background levels at Kilauea summit.
Hazard Summary: Hazardous conditions exist in four areas on Kilauea volcano - potentially harmful sulfur dioxide concentrations and possible small explosions at the summit, potentially harmful sulfur dioxide concentrations and unstable conditions around the Pu`u `O`o/July 21/TEB vent area, lava flow threat to the Royal Gardens subdivision and the coastal plain to the southeast, and hazardous conditions associated with lava entering the ocean.
1. 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: southwest rift zone, south caldera pullouts, and the Halema`uma`u overlook parking lot - The National Park Service has closed this section of Crater Rim Drive. 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.
Sulfur dioxide levels have been on the rise at Kilauea since December. "There's enough sulfur dioxide being put out at the Kilauea summit right now to fill 150 Goodyear blimps a day". "It is a concern." (http:// www.nature.nps.gov/air/webcams/parks/havoso2alert/havoalert.cfm).
There is a possibility of small explosions from Halema`uma`u Crater.
2. 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.
3. 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 flow 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).
4. 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 prepare for safe public viewing hopefully this weekend. For details, see www.lavainfo.us.
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 the Waikupanaha and Ki ocean entries; evening visitors could see nearly a dozen entry points on the Waikupanaha delta but only incandescence in steam from the Ki entry. The eastern margin of active lava flows was still about 150 m (500 ft) west of the County viewing area yesterday morning and creeping eastward and over the old sea cliff onto the 1990 lava delta. Flows edging through the kipuka continued to produce local fires.
Last 24 hours of the TEB vent area: There was no incandescence from the TEB, rootless shields, or the Kalalua flow visible in the webcam overnight. Seismic tremor levels were at low levels.
Last 24 hours at Pu`u `O`o: Diffuse incandescence was observed by webcam overnight in the crater. The tiltmeter again recorded weak deflation from a source to the souteast. GPS receivers on opposite sides of the crater continued to record contraction at a rate averaging 2 cm/month over the past 3 months. Seismic tremor levels were at low values. The SO2 emission rate was about 2,050 tonnes/day on March 19.
Last 24 hours at Kilauea summit: Seismic tremor levels have been elevated above their already-elevated levels since the explosion at 2:58 HST March 19. The tremor levels abruptly decreased beginning at 2:30 am only at the seismometer nearest the Halema`uma`u gas vent. At about the same time, incandescence diminished from the the gas vent as viewed in the new webcam. The summit tiltmeter network recorded continued weak deflation. Only one small earthquake was located beneath Kilauea caldera and two were located on south flank faults.
Sulfur dioxide (SO2) emission rates from the summit area have been elevated at several times background values since early January and have more than doubled since March 12. The most recent emission rate measurement was about 1,600 tonnes/day on Mar. 19, compared to a background rate of between 150-200 tonnes/day.
Sulfur dioxide concentrations were again below detection limits at Jaggar museum and Kilauea Visitors Center. Trade (northeasterly) winds kept gas emissions in the south caldera where SO2 concentrations were up to 40 ppm in areas downwind of Halema`uma`u crater along Crater Rim Drive (mostly between Halema`uma`u parking lot and the southwest rift zone pullout during trade winds) and up to 140 ppm near the Halema`uma`u overlook close to the new vent.
Definitions of terms used in the update:
ppm: parts-per-million; 10,000 ppm = 1%.
mauka, makai: Hawaiian terms for the direction toward the mountains and toward the ocean, respectively.
incandescence: the production of visible light from a hot surface. The color of the light is related to the temperature of the surface. Some surfaces can display dull red incandescence at temperatures as low as 430 degrees Centigrade (806 degrees Fahrenheit). By contrast, molten lava displays bright orange to orange-yellow light from surfaces that are hotter than 900 degrees C (1,650 degrees F).
TEB: The most recent phase of activity started with a breakout from the perched channel/pond system on November 21, 2007 or Thanksgiving eve. TEB stands for Thanksgiving Eve Breakout.
kipuka: a Hawaiian word which describes an area of vegetation that is completely surrounded by active or inactive lava flows.
NPS eruption crew: a hardy band of experienced individuals who interpret active lava flow viewing for visitors while keeping them at a safe distance. The National Park Service (NPS) eruption crews normally work within the Hawai`i Volcanoes National Park but have been supporting the Hawai`i County lava viewing effort since it opened on Saturday, March 8, 2008.
rootless shields: Shield vents are normally built directly over a lava-supplying fissure, as is the case for the TEB shield. Rootless shield vents are not built directly over a lava-supplying fissure and are, instead, fed horizontally from a fissure via a lava tube. Rootless shields have been built over Kilauea lava tubes in the last few years.
perched ponds or channels: A lava pond or channel becomes perched above the surrounding terrain when repeated overflows build up their edges. The perching continues as long as the overflows continue. The channel developed by the July 21, 2007 eruption perched itself more than 100 feet above the pre-eruption ground surface.
gas emission rates: usually in metric tonnes (= 1,000 kilograms)/day if measured at HVO, a gas emission rate is the rate at which gas is released by a volcanic vent. Typical background SO2 emission rates for Kilauea are 150-200 tonnes/day from sources in Halema`uma`u crater and 1,500-3,000 tonnes/day from Pu`u `O`o vent. Once the gas is released into the air, the hazard it poses to living things is directly related to its concentration. Higher concentrations are found downwind of sources so changes in wind direction and speed can bring gases at hazardous concentrations into different areas.
LP earthquakes: Most volcanic earthquakes that occur in Hawai`i are short-period (SP) in nature, meaning that the shaking starts abruptly and contains relatively high frequency components; these quakes are usually associated with subsurface rock failure (breakage). Long-period (LP) earthquakes have lower frequency energy and emergent beginnings, meaning that their signals start with small amplitude and become stronger. LP earthquakes are usually associated with subsurface fluid movement.
DI tilt event: DI is an abbreviation for 'deflation-inflation' and describes a volcanic event of uncertain significance. DI events are recorded by tiltmeters at Kilauea summit as an abrupt deflation of up to a few microradians in magnitude lasting several hours to 2-3 days followed by an abrupt inflation of approximately equal magnitude. The tilt events are usually accompanied by an increase in summit tremor during the deflation phase. A careful analysis of these events suggests that they may be related to changes in magma supply to a storage reservoir at less than 1 km depth, just east of Halema`uma`u crater. Usually, though not always, these changes propagate through the magma conduit from the summit to the eruption site, as many of the DI events at Kilauea summit are also recorded at a tiltmeter at Pu`u `O`o, delayed by 1-2 hours. DI events often correlate with pulses and/or pauses in the eruption at the Pu`u `O`o/July 21/TEB vents.
Maps, photos, webcam views, and other information about Kilauea Volcano are available at http://volcano.wr.usgs.gov/hvostatus.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
Kilauea Information Release issued Mar 19, 2008 14:29 HST Volcanic-Alert Level WATCH - Aviation Color Code ORANGE