Halemaumau Crater

Halemaokinaumaokinau crater is a pit crater located within the much larger summit caldera, of Kīlauea, Hawaii Volcanoes National Park. The roughly circular crater floor is convert|770|m|ft|-1 x convert|900|m|ft|-1 and is convert|83|m|ft|-1 below the floor of Kīlauea caldera. Halemaokinaumaokinau is home to Pele, Goddess of Hawaiian Volcanoes, according to the traditions of the native people.cite web | title = Introduction to Kilauea Volcano, Hawai`i | publisher = Hawaiian Volcano Observatory | date = 13 March 2007 | url = http://hvo.wr.usgs.gov/kilauea/ | accessdate = 2008-04-23 ] cite web | last = Knabel | first = Sarah | title =FIELD STOP 12: HALEMA'UMA'U CRATER | work = GEOGRAPHY CAPSTONE OCTOBER 23, 2005 | date = 2005-11-22 | url =http://www.uwec.edu/jolhm/Hawaii2005/Day3/HIwebsite/FS12.htm | accessdate = 2008-04-19 ]

Eruptive history

William Ellis, a missionary and amateur ethnographer and geologist, published the first description of Halemaokinaumaokinau as it appeared in 1823.William Ellis: "A Narrative of an 1823 Tour Through Hawaii: Journal of William Ellis" Mutual Publishing, ISBN 1566476054] Quotation|Astonishment and awe for some moments rendered us mute, and like statues, we stood fixed to the spot, with our eyes riveted on the abyss below. Immediately before us yawned an immense gulf, in the form of a crescent, about two miles (3 km) in length, from north-east to south-west, nearly a mile in width, and apparently convert|800|ft|m deep. The bottom was covered with lava, and the south-west and northern parts of it were one vast flood of burning matter, in a state of terrific ebullition, rolling to and fro its “fiery surge” and flaming billows.In 1866 Mark Twain, an American humorist, satirist, lecturer and writer hiked to the Caldera floor.Mark Twain: Roughing It/CHAPTER LXXV" Produced by David Widger| url = http://www.fullbooks.com/Roughing-It-Part-8-.html] Here's his account of the lake of molten lava, which he found there:Quotation|It was like gazing at the sun at noon-day, except that the glare was not quite so white. At unequal distances all around the shores of the lake were nearly white-hot chimneys or hollow drums of lava, four or five feet high, and up through them were bursting gorgeous sprays of lava-gouts and gem spangles, some white, some red and some golden--a ceaseless bombardment, and one that fascinated the eye with its unapproachable splendor. The mere distant jets, sparkling up through an intervening gossamer veil of vapor, seemed miles away; and the further the curving ranks of fiery fountains receded, the more fairy-like and beautiful they appeared.

The level of the lava lake varied over the decades and at times was only convert|30|m|ft|-1 below the crater rim. In 1924,cite web | title = The 1924 explosions of Kilauea | publisher = Hawaiian Volcano Observatory | date = May 1924 | url = http://hvo.wr.usgs.gov/kilauea/history/1924May18/| accessdate = 2008-04-25 ] explosive eruptions sent dust high into the atmosphere and doubled the diameter of the crater. Fractures allowed the lava lake to drain to the east until its surface was convert|366|m|ft|-1 below the caldera floor. Subsequent eruptions have mostly refilled the crater. Most of the current crater floor was formed in 1974. A 1982 eruption covered a small portion of the northeastern crater floor.cite web | title = Summary of Historical Eruptions, 1750 - Present | publisher = Hawaiian Volcano Observatory | date = 18 April 2005 | url = http://hvo.wr.usgs.gov/kilauea/history/historytable.html | accessdate = 2008-04-23 ]

2008 eruption episodes

Episodes in this calendar year are being listed in order of current activity for ease of reading and editing. As of September 072008, and according to the Hawaiian Volcano Observatory, the activity in the crater is in an active state.
* Other than the described events, no erupting or fountaining of lava has occurred in the crater, unlike the concurrent activity on the Eastern Rift Zone around Pu'u O'O.
* Night time viewing of the crater's webcam reveals an incandescent illumination of the venting gases, leading scientists to suggest in their daily reports that molten lava may reside at shallow depth within the new vent; cite news | title = Last 24 hours at Kilauea summit| date = April 18 2008 | url = http://volcano.wr.usgs.gov/kilaueastatus.php| accessdate = 2008-04-18 ] . An active lava lake was spotted in September.
* The crater overlook is closed and frequent closures of Crater Rim Drive are expected. Visitors may view the crater from the relatively safe locations of the Hawaiian Volcano Observatory and Volcano House.

Readers and visitors are encouraged to refer to the United States Geological Survey's Hawaiian Volcano Observatory website as they publish frequent eruption summaries, press releases, maps, and other data, as well as provides both real- and near real-time hazard data and panoramic Internet web camera views of events.cite web | title = USGS Hawaiian Volcano Observatory (HVO) | publisher = Hawaiian Volcano Observatory | date = 24 March 2008 | url = http://hvo.wr.usgs.gov/ | accessdate = 2008-04-22 ] cite web | title = Live Panorama of Halema`uma`u, Kilauea Volcano, Hawai`i | publisher = Hawaiian Volcano Observatory | date = 30 July 2008 | url = http://hvo.wr.usgs.gov/cam/index.htm | accessdate = 2008-07-30 ]

eptember eruption episode

Hawaii Volcano Observatory news release and images dated September 5, 2008 confirm the first recorded images of a lava lake 130 feet below the lip of the vent. The HVO has alluded to the presence of lava within the vent, including the sporadic ejecting of lava materials from the vent due to explosive episodes, but this gave officials the first opportunity to visually confirm that active lava is present. The report also notes that the lava cannot be seen from observation points around the crater as of yet.cite news | title = Sloshing lava lake viewed within Halema'uma'u vent| publisher = Hawaii Volcano Observatory (HVO), USGS| date = September 05 2008| url = http://hvo.wr.usgs.gov/pressreleases/pr09_05_08.html
accessdate = 2008-09-06 ]

Since the vent's first appearance, 5.5 months ago, there have been six siginificant explosive events (the latest being September 2, 2008); changing the vent to its present shape of 65 meters or 215 feet across.

May-August

Activity within the crater and vent continued to present scientists with work as the vent continued to eject ash and gases. It wasn't until August 1, 2008 that the crater was rocked with the 4th Explosive event and later on August 27, 2008 its 5th event.

April eruption episode

This episode began with an explosion on the night of April 9 2008 that widened the hole by an additional 5–10 metres (15–30 feet), ejected debris over some convert|60|m|ft|-1 and further damaged the overlook as well as scientific monitoring instruments.cite news | title = Halema‘uma‘u Vent Explodes a Second Time| publisher = Hawaii Volcano Observatory (HVO), USGS| date = April 10 2008| url = http://hvo.wr.usgs.gov/pressreleases/pr04_10_08.html
accessdate = 2008-04-22 ]

In response to the second episode, scientists and local government officials on April 9, 2008 ordered hundreds of people to evacuate from Hawaii Volcanoes National Park and nearby villages because the sulfur dioxide concentration levels had reached a critical level and a hazardous vog plume extended downwind from the crater. The evacuation lasted two days.cite news | last =Dayton | first =Kevin | title =Volcano park evacuated; Blanket of toxic vog drifts over Big Isle but most residents stay put | work =The Honolulu Advertiser| publisher =Gannett Corporation | date = April 9 2008 | url =http://www.honoluluadvertiser.com/apps/pbcs.dll/article?AID=/20080409/NEWS01/804090433 | accessdate = 2008-04-18 ]

On April 16, 2008 the crater was rocked with its third significant explosive event, sending ash and debris throughout the area.

March eruption episode

Crater activity began to increase when between March 10 and March 14, 2008 gas began to vent from the east wall fumarole directly below the Crater Overlook;cite news | HVO News Release 03-14-08 HVO, USGS | title =New gas vent in Halema‘uma‘u crater doubles sulfur dioxide emission rates | work =Hawaii Volcano Observatory (HVO)| publisher =HVO, USGS| date =March 14, 2008| url =http://hvo.wr.usgs.gov/pressreleases/pr03_14_08.html ] however the gas event was only a prelude when in the wee hours (02:58 am HST) of March 19, 2008 HVO personnel thought they were experiencing seismic events, but sunrise revealed a 20–30 metre (65–100 foot) diameter hole blown in the side where the vent once was; scattering debris and [http://volcanoes.usgs.gov/Products/Pglossary/spatter.html| spatter] across convert|0.30|km2|acre and damaging the Crater Overlook. Pieces as large as convert|20|mm|in|0 were found on Crater Rim Drive while convert|0.3|m|ft|0 blocks hit the crater overlook area.cite news | HVO News Release 03-19-08 HVO, USGS | title =Explosive eruption in Halema`uma`u Crater, Kilauea Volcano, is first since 1924| work =Hawaii Volcano Observatory (HVO)| publisher =HVO, USGS| date =March 19, 2008| url =http://hvo.wr.usgs.gov/pressreleases/pr03_19_08.html ] This was the first explosive eruption of Halemaokinaumaokinau Crater since 1924, and the first lava eruption from the crater since 1982.cite news | last =Dondoneau| first = Dave| coauthors =| title =1st explosive eruption since 1924 reported at Kilauea| work =The Honolulu Advertiser| publisher =Gannett Corporation| date =March 19 2008| url=http://www.honoluluadvertiser.com/apps/pbcs.dll/article?AID=/20080319/BREAKING01/80319046/-1/BREAKING01| accessdate = 2008-04-18 ]

Sulfur dioxide gas emissions increased rapidly at the beginning of the episode. On March 13, HVO recorded a rate of 2,000 tons/day, the highest rate since measurements began in 1979. A concentration of over 40 ppm on Crater Rim Drive was measured, prompting alerts and other public safety measures. Halemaokinaumaokinau crater continued to intermittently emit high levels of volcanic gases, ash, spatter, Pele's Tears,and Pele's Hair until the second episode.cite news | title = Halema`uma`u gas plume becomes ash-laden| publisher = Hawaii Volcano Observatory (HVO), USGS| date = March 24 2008| url = http://hvo.wr.usgs.gov/pressreleases/pr03_24_08.html
accessdate = 2008-04-22 ]

References