USGS2010
Viewing an erupting volcano is a memorable experience, one that has inspired fear, superstition, worship, curiosity, and fascination since before the dawn of civilization. In modern times, volcanic phenomena have attracted intense scientific interest because they provide the key to understanding processes that have created and shaped more than 80 percent of the Earth’s surface. The active Hawaiian volcanoes have received special attention worldwide because of their frequent spectacular eruptions, which often can be viewed and studied with relative ease and safety. In January 1987, the U.S. Geological Survey Hawaiian Volcano Observatory (HVO), then located on the caldera rim of Kīlauea, celebrated its 75th anniversary. To honor this anniversary, the U.S. Geological Survey (USGS) published Professional Paper 1350 , a comprehensive summary of the many studies on Hawaiian volcanism by USGS and other scientists through the mid-1980s. Drawing from the wealth of data contained in that volume, the USGS also published in 1987 the original edition of this general-interest booklet, focusing on selected aspects of the eruptive history, style, and products of two of the State of Hawaii’s active volcanoes—Kīlauea and Mauna Loa. A second edition of the booklet was published in 2010 to commemorate the Centennial of HVO (which occurred in January 2012), summarizing abundant new information gained since the January 1983 onset of Kīlauea’s middle East Rift Zone eruption at Pu‘u‘ō‘ō and the March 2008 beginning of Kīlauea’s summit lava-lake activity within Halema‘uma‘u. In this third edition, we include highlights from Kīlauea’s subsequent activity, including the 2018 eruption in the lower East Rift Zone—the largest and most destructive in at least 200 years—and associated summit-collapse events, the eruptions at Kīlauea’s summit since 2018, and the 2022 eruption of Mauna Loa, which occurred after 38 years of quiescence. It also considers new data leading to an improved history of Kīlauea’s explosive activity in the recent geologic past. This general-interest booklet is a companion to the one on Mount St. Helens volcano (southwestern Washington) first published in 1984, revised in 1990. Together, these publications illustrate the contrast between the two main types of volcanoes: shield volcanoes, such as those in the State of Hawaii, which generally are nonexplosive to weakly explosive; and composite volcanoes, such as Mount St. Helens in the Cascade Range, which generally erupt explosively.