HAWAIIAN VOLCANO OBSERVATORY DAILY UPDATE
Tuesday, March 30, 2010 7:51 AM HST (Tuesday, March 30, 2010 17:51 UTC)
This report on the status of Kilauea volcanic activity, in addition to maps, photos, and webcam images (available using the menu bar above), was prepared by the USGS Hawaiian Volcano Observatory (HVO). Hawai`i Volcanoes National Park status can be found at http://www.nps.gov/havo/ or 985-6000. Hawai`i County Viewing Area status can be found at 961-8093. All times are Hawai`i Standard Time.
KILAUEA VOLCANO (CAVW #1302-01-)
19°25'16" N 155°17'13" W, Summit Elevation 4091 ft (1247 m)
Current Volcano Alert Level: WATCH
Current Aviation Color Code: ORANGE
Activity Summary for past 24 hours: Kilauea volcanic activity continued at two locations. At the summit, a circulating and spattering lava surface was visible in a deep pit inset within the floor of Halema`uma`u Crater and produced glow that was visible from the Jaggar Museum. At the east rift zone vents, lava flowed through tubes and fed slowly advancing surface flows above the pali. Sulfur dioxide emission rates from both summit and east rift zone vents remained elevated.
Past 24 hours at Kilauea summit: The circulating and spattering lava surface mostly stayed at middle levels in the deep pit inset within the floor of Halema`uma`u Crater and rose before falling back to middle levels several times; glow was easily visible from the Jaggar Museum Overlook.
The summit tiltmeter network recorded no significant change. Seismic tremor levels remained elevated with a brief drops while lava levels rose. The number of RB2S2BL earthquakes remained within background values. Four earthquakes beneath Kilauea Volcano were strong enough to be located - one beneath Halema`uma`u and three on south flank faults.
The summit vent gas plume is moving low to the southwest this morning. The most recent sulfur dioxide emission rate measurement was 800 tonnes/day on March 26, 2010, still elevated above the 2003-2007 average of 140 tonnes/day. Small amounts of mostly ash-sized tephra were carried out of the deep pit in ascending gases and deposited on nearby surfaces.
Past 24 hours at the middle east rift zone vents and flow field: Magma degases through Pu`u `O`o crater before erupting from the TEB vent located 2 km to the east. The most recent sulfur dioxide emission rate measurement was 300 tonnes/day on March 29, 2010, much lower than the 2003-2007 average of 1,700 tonnes/day. No incandescence was recorded within Pu`u `O`o Crater overnight.
The tiltmeter on the north flank of Pu`u `O`o recorded no significant change. Seismic tremor levels near the Pu`u `O`o and TEB vents remained low and steady. The number of RB2S2BL earthquakes remained within background levels.
Lava flowed through tubes and fed minor surface flows advancing to the east above the pali. HVO geologists reported that the flows had advanced about 700 m (2,300 ft) to the east since Thursday and are now visible from Kalapana. GOES-WEST images included steady thermal anomalies suggesting continuing surface flow activity through dawn.
Maps, photos, webcam views, and other information about Kilauea Volcano are available at http://volcanoes.usgs.gov/hvo/activity/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/activity/alertsystem/index.php
Definitions of Terms Used:
Halema`uma`u Overlook vent: has been difficult to describe concisely. The vent is actually a pit, or crater, in the floor of the larger Halema`uma`u Crater in the floor of the even larger Kilauea caldera or crater - a crater within a crater within a crater. It is easiest to describe as a pit inset within the floor of a crater within a caldera. The pit is about 140 m (460 ft) in diameter at the Halema`uma`u Crater floor, is about 50 m in diameter at the pit floor, and is about 200 m (660 ft) deep. As of November, 2009, a lava pond surface has been visible in a hole in the floor of this pit.
glow: light from an unseen source; indirect light.
incandescence: the production of visible light from a hot surface. The term also refers to the light emitted from a hot surface. The color of the light is related to surface temperature. 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).
CD: Hawai`i County Civil Defense
RB2S2BL earthquakes: earthquakes that were recorded but were too small to be located. These quakes have magnitudes less than 1.7 and may only be recorded by one or two seismometers. Recording at a minimum of 4 seismometer sites is required to locate an earthquake.
tonne: metric unit equal to 1,000 kilograms, 2,204.6 lbs, or 1.1 English tons.
tephra: all material deposited by fallout from an eruption-related plume, regardless of size.
ash: tephra less than 2 mm (5/64 inches) in size.
TEB: Thanksgiving Eve Breakout, the designation used for lava flows that started with a breakout on November 21, 2007.
microradian: a measure of angle equivalent to 0.000057 degrees.
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 lava pulses and/or pauses in the eruption at the Pu`u `O`o/July 21/TEB vents.
More definitions with photos can be found at http://volcano.wr.usgs.gov/about/pglossary/index.php .
The Hawaiian Volcano Observatory is one of five volcano observatories within the U.S. Geological Survey and is responsible for monitoring volcanoes and earthquakes in Hawai`i.