Volcano Watch — Kīlauea Volcano has been erupting for a long, long time

The eruption began on January 3, 1983, when a series of fissures roared to life on Kīlauea's east rift zone. As the eruption progressed, it eventually focused on a single vent, forming the cinder-and-spatter cone now called Pu‘u ‘Ō‘ō during three years of episodic high lava fountains.
Since then, lava erupted from the east rift zone has covered about 47 square miles of the volcano's south flank, and continues to flow to the ocean today.

In March 2008, another vent opened at the summit of Kīlauea. Located in Halema‘uma‘u Crater, this vent continues to emit elevated levels of sulfur dioxide and erupt small amounts of volcanic ash.

Whether you measure the activity in years (27) or days (10,000), Kīlauea has now been erupting for a long time. Even so, this event is far from the longest-known eruption on the volcano. In the 19th century, vents at the summit of Kīlauea were continuously active for almost 100 years, and in the 1400s, a vent just east of Kīlauea Iki is believed to have erupted for about 60 years.

More remarkable than its extended duration is the fact that we are now witnessing the first sustained eruption of two vents on the same volcano at the same time Through each change in the eruption, HVO scientists have monitored Kīlauea's every twist and turn. But what is HVO and who are these scientists?

"HVO," which stands for "Hawaiian Volcano Observatory," was founded in 1912 by Thomas A. Jaggar. During its almost 100-year-long history, HVO has been managed by several different organizations, but in 1947, the U.S. Geological Survey (USGS) became its permanent administrator. HVO is now one of five volcano observatories in the United States operated by the USGS.

As part of the USGS Volcano Hazards Program, HVO's mission is to monitor, conduct research on, and assess hazards from volcanic eruptions and earthquakes on Hawaiian volcanoes. This mission is accomplished with a staff that has grown from one geologist (Jaggar) in 1912 to a team of almost 30 people today.

Just as it would require more than a hammer to build a house, more than one scientific tool is required to adequately monitor a volcano. Thus, HVO's staff includes specialists in a variety of fields-geology, seismology, gas geochemistry, geodesy (deformation), and geophysics-each of whom uses various monitoring tools and techniques. The HVO team also includes staff with expertise in computer technology, library and photo archives, electronics, administration, and public information, as well as a talented group of short- and long-term volunteers.

A common misconception about HVO is that it is part of the National Park Service (NPS). This is understandable, since HVO is located in Hawai‘i Volcanoes National Park-our office buildings are adjacent to the NPS-managed Thomas A. Jaggar Museum, named for HVO's founder-and because HVO was managed by NPS from 1935 to 1947.

Although now administered by separate organizations, HVO works closely with Hawai‘i Volcanoes National Park, forming a collaborative relationship that is fostered and appreciated by both the USGS and NPS. HVO also collaborates with State and County agencies, such as Hawai‘i County Civil Defense.

During a volcanic eruption or after an earthquake, HVO scientists provide scientific data-for example, geologic mapping and hazards assessments-needed to ensure the safety of island residents and visitors. Emergency Managers, land owners, or land managers can then use our information to choose the best way to mitigate hazards.

Kīlauea's current eruption has now reached 10,000 days-and could continue for years or decades to come. Whatever the future holds, HVO scientists will continue to carefully monitor the eruption - as well as other volcanoes in Hawai‘i - and to maintain strong lines of communication with National Park and public safety officials.

HVO will also continue to keep island residents and visitors informed about Kīlauea and other Hawaiian volcanoes through eruption updates, photographs, videos, and Webcam images posted on the HVO Web site; Volcano Awareness Month events; and in weekly Volcano Watch articles written by HVO scientists.

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Volcano Activity Update

Over the past week, breakouts along the new Quarry flow were scattered from the top of the Pulama pali to the coast, where the Ki ocean entry remains active. As of this writing (Thursday, May 20), small breakouts are active along the east margin of the flow a few hundred meters (yards) north of the end of the road. These flows are sluggish, but may reach the road in the coming days to weeks.

At Kīlauea's summit, a circulating lava pond deep in the collapse pit within the floor of Halema‘uma‘u Crater was visible via Webcam throughout the past week. The lava surface remained relatively steady, with only a few fluctuations in its depth below the rim of the vent. Volcanic gas emissions remain elevated, resulting in high concentrations of sulfur dioxide downwind.

Four earthquakes beneath Hawai‘i Island were reported felt during the past week. A magnitude-2.8 earthquake occurred at 7:42 p.m. on Thursday, May 13, 2010, H.s.t., and was located 7 km (4 miles) southeast of ‘Opihikao, at a depth of 10 km (6 miles). A magnitude-2.9 earthquake occurred at 10:40 a.m. on Saturday, May 15, and was located 17 km (11 miles) northwest of Nā‘ālehu, at a depth of 2 km (1 mile). A magnitude-3.5 earthquake occurred at 10:19 p.m. on Monday, May 17, and was located 10 km (6 miles) northwest of Ka‘ena Point at a depth of 10 km (6 miles). A magnitude-2.0 earthquake occurred at 8:06 a.m. on Tuesday, May 18, and was located 1 km (1 mile) northwest of Pahala at a depth of 37 km (23 miles).