HAWAIIAN VOLCANO OBSERVATORY DAILY UPDATE

Thursday, March 11, 2010 8:11 AM HST (Thursday, March 11, 2010 18:11 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 Aviation Color Code: ORANGE
Current Volcano Alert Level: WATCH

Activity Summary for past 24 hours: The switch to DI inflation yesterday afternoon has not yet resulted in increased activity at the two eruption locations on Kilauea volcano. At the summit, lava was only visible to an infrared camera at low levels in a deep pit inset within the floor of Halema`uma`u Crater but it still produced weak glow that was visible from the Jaggar Museum. At the east rift zone vents, less lava flowed through tubes and fed fewer scattered surface flows on the pali and the coastal plain. Sulfur dioxide emission rates from both summit and east rift zone vents, however, remained elevated.

Past 24 hours at Kilauea summit: The summit tiltmeter network recorded the switch to DI inflation at about 4:15 pm; this DI inflation started gradually in contrast to the abrupt start of many DI inflation events. Seismic tremor remained at elevated levels dominated by episodic tremor bursts which decreased in amplitude and became quite steady by midnight. The number of RB2S2BL earthquakes was within background values. Six earthquakes beneath Hawai`i Island were strong enough to be located - three beneath the area west of the lower southwest rift zone and three on south flank faults.

The circulating and spattering lava surface was not directly visible via webcam last night but it was visible using an infrared camera and, when weather permitted, weak vent glow was visible from the Jaggar Museum Overlook last night all indicating lava was still within the deep pit inset within the floor of Halema`uma`u Crater.

The summit vent gas plume is moving to the southwest this morning. The most recent sulfur dioxide emission rate measurement was 900 tonnes/day on March 8, 2010, still elevated above the 2003-2007 average of 140 tonnes/day. Small amounts of mostly ash-sized tephra were lifted 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 600 tonnes/day on March 10, 2010, lower than the 2003-2007 average of 1,700 tonnes/day. No incandescence has been recorded within Pu`u `O`o Crater since February 27.

The tiltmeter on the north flank of Pu`u `O`o recorded insignificant changes in ground tilt and has not yet recorded the switch to DI inflation. Seismic tremor levels in the Pu`u `O`o - TEB vent portion of the east rift zone were slightly elevated and steady values. The number of RB2STBL earthquakes remained at background levels.

Lava from the TEB vent flowed through the upper portion of the tube system and probably fed scattered surface flows on the lower pali and the coastal plain. MODIS and GOES-WEST images contained few weak thermal anomalies suggesting diminished surface flow activity. Surface activity is expected to increase 12-24 hours after the onset of DI inflation at Pu`u `O`o.

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.

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. Source: Kilauea Volcano Observatory

Information courtesy of ...
U.S. Geological Survey Hawaiian Volcano Observatory (HVO).

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