HAWAIIAN VOLCANO OBSERVATORY DAILY UPDATE

Saturday, March 20, 2010 6:49 AM HST (Saturday, March 20, 2010 16:49 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: DI inflation and Kilauea volcanic activity continued at two locations. At the summit, lava mostly stayed at middle levels 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 scattered 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 remained at mid-levels (not the highest nor the lowest) in the deep pit inset within the floor of Halema`uma`u Crater and produced increasingly strong glow that was visible from the Jaggar Museum Overlook last night; at 1 am this morning, the lava surface rose several meters before dropping back to mid-levels at 2 am.

The summit tiltmeter network recorded continued DI inflation. Seismic tremor remained elevated and steady with a brief drop in amplitude corresponding to the equally brief rise of the lava surface this morning. The number of RB2S2BL earthquakes was within background values. Three earthquakes beneath Hawai`i Island were strong enough to be located - one deep quake beneath the lower southwest rift zone and two on south flank faults.

The summit vent gas plume is moving to the southwest. The most recent sulfur dioxide emission rate measurement was 500 tonnes/day on March 19, 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; this morning's collection consisted almost entirely of spatter.

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 400 tonnes/day on March 12, 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 continued DI inflation. Seismic tremor levels near the Pu`u `O`o and TEB vents increased at 4:20 am this morning. The number of RB2S2BL earthquakes remained at background levels.

Lava flowed through tubes and fed surface flows above the pali. HVO geologists yesterday again confirmed a few scattered active surface lobes on the east side of the TEB flow field well above the pali. GOES-WEST images through dawn showed strong thermal anomalies consistent with continuing surface flow activity.

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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