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Halema uma u crater is a pit crater located within the much larger summit caldera, of Kīlaueamarker, Hawaii Volcanoes National Parkmarker. The roughly circular crater floor is x and is below the floor of Kīlauea caldera, located at coordinates . Halema uma u is home to Pele, Goddess of Hawaiian Volcanoes, according to the traditions of Hawaiian mythology.

Early history

Early eruptions were only recorded by oral history. One large one in 1790 killed several people, and left footprints in hardened ashmarker of some ancient Hawaiians killed by pyroclastic flows.

William Ellis, an English missionary and amateur ethnographer and geologist, published the first description of Halema uma u as it appeared in 1823.

In 1866 Mark Twain, an American humorist, satirist, lecturer and writer hiked to the Caldera floor.He wrote the following account of the lake of molten lava which he found there:

Another missionary, Titus Coan, observed and wrote about eruptions in the 19th century.Geologist Thomas Jaggar opened an observatory in 1912, and the area became Hawaii Volcanoes National Parkmarker in 1916.

The level of the lava lake varied over the decades and at times was only below the crater rim. In 1924, unusual 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 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.

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 7, 2008, and according to the Hawaiian Volcano Observatorymarker, 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 Ō ōmarker.
  • 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;. 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 Housemarker.


Readers and visitors are encouraged to refer to the United States Geological Survey's Hawaiian Volcano Observatorymarker 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.

September 2008 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.

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

May-August 2008

May 5, 2008 aerial image into Halema'uma'u gas vent, revealing dull orange glow from incandescent activity.
Reports still reflect lava present at some depth but not evident as of this date.
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 2008 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 and further damaged the overlook as well as scientific monitoring instruments.


In response to the second episode, scientists and local government officials on April 9, 2008 ordered hundreds of people to evacuate from the 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.

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

March 2008 eruption episode

Before and after comparison of the new gas vent.
The crater overlook is circled for reference.
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; 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 spatter across and damaging the Crater Overlook. Pieces as large as were found on Crater Rim Drive while blocks hit the crater overlook area. This was the first explosive eruption of Halema uma u Crater since 1924, and the first lava eruption from the crater since 1982.

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. Halema uma u crater continued to intermittently emit high levels of volcanic gases, ash, spatter, Pele's Tears,and Pele's Hair until the second episode.



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