3 Jan 2013 update from HVO
This is an excerpt of a report on the status of Kilauea volcanic activity (available at http://hvo.wr.usgs.gov/activity/kilaueastatus.php).
Activity Summary: The eruption is 30 years old today with only a modest slowdown in activity. Kilauea continued to erupt at two locations: At the summit, DI ('deflation-inflation') deflation and descent of the lava lake surface continued. At Pu`u `O`o crater, glow was visible from the usual sources. To the southeast of Pu`u `O`o, a lava flow was active on the coastal plain and was entering the ocean at several locations along the flow front. Seismic tremor levels were low and gas emissions were elevated.
Recent Observations at Kilauea summit: The summit tiltmeter network continued recording DI deflation totaling almost 5 microradians by this morning. The lava lake surface rose and fell (rise/fall events) during most of yesterday before resuming its descent early this morning. Because of the low lava level, veneer on the walls of the conduit started peeling off and falling into the lake with the first big chunk falling in around 6 am yesterday and several smaller pieces joining it in the lake during the day. The most recent (preliminary) sulfur dioxide emission rate measurement was 400 tonnes/day on January 2, 2013; the relatively low emissions measured yesterday were typical of the reduced emissions observed during rise/fall events. A very small amount of ash-sized tephra (mostly fresh spatter bits and Pele's hair) was carried out of the vent in the gas plume and deposited on nearby surfaces.
Background: The summit lava lake is deep within an ~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 has varied from about 25 m to more than 200 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. The surface level of the lava lake has remained below the inner ledge (~31 m or 100 ft below the floor of Halema`uma`u Crater on October 29, 2012) and has not risen above and flooded the ledge since October 28, 2012. The lake level responds to summit tilt changes with the lake receding during deflation and rising during inflation.
Recent Observations at the middle east rift zone vents: There was an apparent decrease in activity on the coastal plain. An approximately 1 km-wide (0.6 mi wide) lava flow remained active on the coastal plain with scattered surface activity extending from mid-coastal plain to the coast and straddling the easternmost boundary of Hawai`i Volcanoes National Park; activity levels appeared to decrease over the past 24 hours, possibly due to the ongoing DI deflation. Webcams recorded weak ocean entry plumes yesterday and this morning suggesting that lava was sporadically entering the ocean at multiple locations.
Background: The eruption in Kilauea's middle east rift zone started with a fissure eruption on January 3, 1983, and continued with few interruptions at Pu`u `O`o Cone, or temporarily from vents within a few kilometers to the east or west. A fissure eruption on the upper east flank of Pu`u `O`o Cone on Sept. 21, 2011, drained the lava lakes and fed a lava flow that advanced southeast through the abandoned Royal Gardens subdivision to the ocean within Hawai`i Volcanoes National Park in early December 2011. Since late December 2011, the flows have remained intermittently active on the pali and the coastal plain and finally re-entered the ocean starting on November 24, 2012. In general, activity waxes with inflation and wanes with deflation.
Eruption returns to Puu Oo crater after earlier floor collapse and new fissure eruption at Napau Crater (March 2011) |
|
The sequence of events are described here, condensced from the the HVO press release:
At 1:42 p.m. HST (5 Mar 2011), the USGS HVO monitoring network detected rapid deflation at Pu'u 'O'o and increased tremor along
Kilauea's middle east rift zone.
At 2:00 p.m., Kilauea's summit also began to deflate.
From 2:16 to 2:21 p.m., the floor of the Pu'u 'O'o crater began to
collapse, and within 10 minutes, incandescent ring fractures opened on
the crater floor a few tens of meters away from the crater wall. As
the floor continued to drop, lava appeared in the center of the crater
floor, the northeast spatter cone within Pu'u 'O'o collapsed, and an
obvious scarp developed on the west side of the crater floor, with
lava cascading over the scarp toward the center of the crater.
At 2:41 p.m., the scarp on the west side of the crater floor appeared
to disintegrate, exposing incandescent rubble. Five minutes later,
the collapse of a large block along the east crater wall produced a
dust plume.
Webcam images showed that the Pu'u 'O'o crater floor continued to drop
through 4:26 p.m. font>
|
explosive eruption rocks Halemaumau in 2008
HVO reported that a small explosion occurred at the Kilauea summit in the very early hours of March 19, 2008, making this the first explosion there since
1924. Lava was not erupted during the gas explosion, but lithic blocks
were scattered over a 75 acre region in an often visited part of Hawai'i Volcanoes National Park. A 20-30 m wide crater was formed in the explosion,
in the same area where intense sulfur dioxide gas venting has been occuring
lately, with incandescent (hot) rocks has been occuring over the past week
or so. The largest piece of material ejected in the explosion is believed
to measure about a cubic meter. The HVO webvsite has additional information, photos, and a newly installed Halemaumau webcam for your reading and viewing pleasure.
Earlier Updates: A detailed chronological summary of events during 'episode 55' (1997-2005) of the Pu`u `O`o eruption can be found on the episode 55 page.
PLEASE NOTE: HCV had been posting detailed eruption updates in the 1990s before web capability was established at HVO on the Big Island. HCV discontinued these detailed updates in late 1999 The latest updates can be now obtained from the Kilauea Update page of the USGS-HVO website
Visit our LISTING of Pu`u `O`o eruption episodes for a summary of previous activity and
links to previous eruption update pages (where available).
CREDITS and DISCLAIMER:
This synopsis was written by Ken Rubin using provided by the U.S.Geological Survey's Hawaii Volcano
Observatory (in the form of formal press releases, personal communications
and information from their HVO web site).
The US Geological Survey-Hawaiian Volcano Observatory is not directly responsible for
editorial changes or enhancements made by the HCV (the Hawaii Center for
Volcanology) web staff, nor does it claim responsiblity in any way for the
interpretive content of these pages.
This page created and maintained by Ken Rubin©, krubin@soest.hawaii.edu
Other credits for this web site.
Last page update on 3 Jan 2013
|
