USGS HVO Press Release — Holoholo to Mauna Ulu

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Hike to Mauna Ulu on Saturday and learn what happened there from a scientist who witnessed it more than forty years ago.

In the pre-dawn hours of May 24, 1969, a 2.5 mile-long series of fissures opened on the upper east rift zone of Kīlauea volcano. Molten lava spattered from the fissures, announcing the start of a new eruption that continued for five years, completely filled two pit craters, and formed a new lava shield, Mauna Ulu (Growing Mountain).

Don Swanson, a geologist with the U.S. Geological Survey's Hawaiian Volcano Observatory, witnessed the first two years of Kīlauea's 1969-1974 east rift zone eruption. He will share the experiences he had during the Mauna Ulu eruption and talk about the volcanic landscape created by it in a 3-mile guided hike on Saturday, January 9, 2010.

The hike is free and open to the public, but park entrance fees apply. Hikers should wear sturdy shoes, bring drinking water and snacks, and be prepared for cool, rainy weather. The hike begins at 9:00 a.m. sharp at the Mauna Ulu parking lot on the Chain of Craters Road in Hawai‘i Volcanoes National Park. It will last about 3 hours.

This Mauna Ulu hike is one of many programs offered by HVO during Volcano Awareness Month (January 2010). For more information about this hike and other Volcano Awareness Month events, visit the HVO Web site at or call (808) 967-8844.

Daily updates about ongoing eruptions, recent images and videos of summit and East Rift Zone volcanic activity, maps, and data about recent earthquakes in Hawaii are posted on the HVO website at

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