Sulfur dioxide emission rates from Kīlauea Volcano, Hawai‘i, an update: 1998-2001

Introduction Sulfur dioxide (SO₂) emission rates from Kilauea Volcano were first measured by Stoiber and Malone (1975) and have been measured on a regular basis since 1979 (Greenland and others, 1985; Casadevall and others, 1987; Elias and others, 1998; Sutton and others, 2001). A compilation of SO₂ emission-rate and wind-vector data from 1979 through 1997 is available as Open-File Report 98-462 (Elias and others, 1998) and on the web at http://hvo.wr.usgs.gov/products/OF98462/. The purpose of this report is to update the existing database through 2001. Kilauea releases SO₂ gas predominantly from its summit caldera and east rift zone (ERZ) (fig. 1), as described in previous reports (Elias and others, 1998; Sutton and others, 2001). These two distinct sources are quantified independently. The summit and east rift zone emission rates reported here were derived using vehicle-based Correlation Spectrometry (COSPEC) measurements as described in Elias and others (1998). In 1998 and 1999, these measurements were augmented with airborne and tripod-based surveys.