HAWAIIAN VOLCANO OBSERVATORY DAILY UPDATE
Friday, July 29, 2011 8:23 AM HST (Friday, July 29, 2011 18:23 UTC
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 volcano's activity is supplying two lava lakes and a lava flow advancing southwest from Pu`u `O`o crater. In the east rift zone, Pu`u `O`o Crater seems to be bursting at its seams: sources within Pu`u `O`o crater fed a lava lake perched in the middle of the crater floor that continued to be uplifted by a shallow pressure source; lava activity from sources outside the perched lake but within Pu`u `O`o Crater partially filled small pits on the west side of Pu`u `O`o crater and spilled over a short distance southwest. At the summit, the lava lake level was fairly stable with persistent southeast-to-northwest circulation. Seismicity levels were low. Gas emissions remained elevated from summit and rift zone vents.
Past 24 hours at Kilauea summit: The lava lake level remained fairly stable. The circulation pattern remained toward the northwest spattering sink with a few other spattering spots making brief appearances around the edge.
The summit tiltmeter network recorded minor variations on a long-term trend of slowing inflation since July 22; a small but abrupt inflation step occurred about 11:30 am yesterday but did not coincide with any discernible change in the summit vent. The summit GPS network recorded steady long-term extension with a slight increase in rate after July 17. Seismic tremor levels were generally low. Thirteen earthquakes were strong enough to be located within Kilauea volcano - two beneath the area immediately west of the summit caldera, four within the upper east rift zone(including a preliminary magnitude-3.2 quake southeast of Pauahi Crater), six deep quakes within the lower southwest rift zone, and one north of the lower east rift zone.
The most recent (preliminary) sulfur dioxide emission rate measurement was 800 tonnes/day on July 27, 2011. Small amounts of ash-sized tephra, including fresh spatter bits, continued to be wafted within the plume and deposited on nearby surfaces.
Background: The summit lava lake is deep within a ~150 m (500 ft) diameter near-vertical cylindrical vent inset within the east wall and floor of Halema`uma`u Crater. The vent has been mostly active since opening with a small explosion on March 19, 2008.
Past 24 hours at the middle east rift zone vents: Uplift of the crater floor and perched lake continued but may have slowed. Lava in the Puka Nui and MLK pits (smaller craters to the west of the main Pu`u `O`o Crater), fed from sources along the southern edge of the crater floor, continued to spill out of both pits on the southwest side producing a tube-fed pahoehoe flow that has advanced about 700 m (2,300 ft) from the Puka Nui rim since Monday. Lava also continued to issue from sources along the base of the northeastern crater wall filling the trough between the wall and the perched lake but remained within the crater. Check our new webcams to view this activity.
The GPS network around Pu`u `O`o Cone recorded long-term extension since mid-April; more rapid extension was recorded across the crater since July 3 that was not recorded by nearby receivers outside the crater which is consistent with the action of a shallow pressure source beneath the crater floor that is clearly driving the multiple extrusion sources within the Crater. The tiltmeter on the north flank of Pu`u `O`o Cone recorded continued weak deflation. Seismic tremor levels were low. The most recent (preliminary) sulfur dioxide emission rate measurement was 900 tonnes/day on July 27, 2011, from all east rift zone sources.
Background: The eruption of Kilauea's middle east rift zone started with a fissure eruption on January 3, 1983, and has continued with few interruptions through Pu`u `O`o Crater or vents within a few kilometers to the east or west.
Viewing Summary: East rift vents and flow field - The only lava erupting from Kilauea volcano's east rift zone is within Pu`u `O`o Crater and on the southwest flank of Pu`u `O`o Cone within Hawai`i Volcanoes National Park. Access and viewing information can be found at http://www.nps.gov/havo/planyourvisit/lava2.htm. Access via Kahauale`a Natural Area Reserve is closed by the state of Hawai`i Department of Land and Natural Resources. Kilauea Crater - Hawai`i Volcanoes National Park access and viewing information can be found at http://www.nps.gov/havo/planyourvisit/lava2.htm.
Hazard Summary: East rift vents and flow field - near-vent areas could erupt or collapse without warning with spatter and/or ash being wafted within the gas plume; potentially-lethal concentrations of sulfur dioxide gas may be present within 1 km downwind of vent areas. Kilauea Crater - explosive events are capable of ejecting rocks and lava several hundred meters (yards) from the Halema`uma`u vent; ash and Pele's hair can be carried several kilometers downwind; potentially-lethal concentrations of sulfur dioxide can be present within 1 km downwind.
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
