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Time-lapse movie of Halemaumau Overlook Vent
Activity updates are written by scientists at the U.S. Geological Survey’s Hawaiian Volcano Observatory.)
Activity Summary for past 24 hours: Back-to-back deflation-inflation (DI) events continued while the summit slowly inflated. Overnight, glow was visible within the Halema`uma`u gas plume and from sources within and on the upper east flank of Pu`u `O`o cone. Active surface flows advanced on the coastal plain southeast of Pu`u `O`o but were not yet entering the ocean. Seismic tremor levels were low; gas emissions were elevated.
Past 24 hours at Kilauea summit: DI inflation started at noon yesterday followed by another minor DI deflation just before 3 am this morning. The lava lake level rose and dropped a small amount with the tilt changes; the initial tilt rate suggests that, like the last three, this will probably be a smaller DI event that won’t produce noticeable east rift zone eruption changes. The most recent (preliminary) sulfur dioxide emission rate measurement was 1,000 tonnes/day on February 28, 2012; new measurements must await the return of moderate trade winds. Although not measured this morning, small amounts of ash-sized tephra were probably wafted within the gas plume and deposited on nearby, downwind surfaces.
Since mid-October 2011, the summit GPS network recorded continued weak extension indicating summit inflation. Seismic tremor levels were low with small variations that generally mimicking the tilt. Twelve earthquakes were strong enough to be located beneath Kilauea: One beneath the lower southwest rift zone, three within the upper east rift zone, and eight on south flank faults.
Background: The summit lava lake is deep within a ~160 m (520 ft) diameter cylindrical vent with nearly vertical sides inset within the east wall and floor of Halema`uma`u Crater. Its level fluctuates from about 70 m to more than 150 m (out of sight) below the floor of Halema`uma`u Crater. The vent has been mostly active since opening with a small explosive event on March 19, 2008. Most recently, the lava level of the lake has remained below an inner ledge (75 m or 250 ft below the floor of Halema`uma`u Crater) and responded to summit tilt changes with the lake receding during deflation and rising during inflation.
Past 24 hours at the middle east rift zone vents: Within Pu`u `O`o crater, strong glow could be seen from a small collapse pit on the northeast edge with weak glow from the spatter cone on the southeast edge of the floor; glow could also be seen from the uppermost tube system on the east flank of Pu`u `O`o cone. Seismic tremor levels near Pu`u `O`o increase slightly but were still low. The tiltmeter on the north flank of Pu`u `O`o cone recorded inflation at 1 pm yesterday and so far has not shown signs of expected minor deflation. GPS receivers on opposite sides of the cone continued to show neither extension nor contraction. The most recent (preliminary) sulfur dioxide emission rate measurement was 600 tonnes/day on February 17, 2012, from all east rift zone sources.
Lava flows were active on the pali and the coastal plain: the weaker east lobe was still creeping downhill at mid-pali while the more active west lobe had advanced about 400 m (440 yds) onto the coastal plain as of yesterday afternoon. The leading edge of the flows are more 9 km (5.5 mi) southeast of Pu`u `O`o and about 3 km (2 mi) from the coast. There were no active flows entering the ocean.
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