Publications

Lava flows into the sea at Kīlauea Volcano, Hawaiʻi, and generates an airborne gas and aerosol plume. Water (H2O), hydrogen chloride (HCl), carbon dioxide (CO2), nitrogen dioxide (NO2) and sulphur dioxide (SO2) gases were quantified in the plume in 2004–2005, using Open Path Fourier Transform infra-red Spectroscopy. The molar abundances of these species and thermodynamic modelling are...

Seismic signals generated during the flow and degassing of low-viscosity magmas include long-period (LP) and very-long-period (VLP) events, whose sources are often attributed to dynamic fluid processes within the conduit. We present the results of laboratory experiments designed to investigate whether the passage of a gas slug through regions of changing conduit diameter could act as a...

We report the results of two soil CO2 efflux surveys by the closed chamber circulation method at the Puhimau thermal area in the upper East Rift Zone (ERZ) of Kilauea volcano, Hawaii. The surveys were undertaken in 1996 and 1998 to constrain how much CO2 might be reaching the ERZ after degassing beneath the summit caldera and whether the Puhimau thermal area might be a significant...

Young volcanic deposits in Kahoolawe Island, cutting up through the caldera-filling lava, colluvium and talus in the west wall of Kanapou Bay, had long been stratigraphically considered the rejuvenated-stage products. New K-Ar ages, combined with magnetic polarity data, show that young volcanism was at about 0.98-1.04 Ma and indicate no substantial quiescence between the filling of the...

Major-element and volatile (H2O, CO2, S) compositions of glasses from the submarine flanks of Kilauea Volcano record its growth from pre-shield into tholeiite shield-stage. Pillow lavas of mildly alkalic basalt at 2600–1900 mbsl on the upper slope of the south flank are an intermediate link between deeper alkalic volcaniclastics and the modern tholeiite shield. Lava clast glasses from...

Interferometric synthetic aperture radar (InSAR) imagery documents the consistent subsidence, during the interval 1992–1999, of a pyroclastic flow deposit (PFD) emplaced during the 1986 eruption of Augustine Volcano, Alaska. We construct finite element models (FEMs) that simulate thermoelastic contraction of the PFD to account for the observed subsidence. Three-dimensional problem...

We present a morphostructural analysis of the submarine portions of Haleakala Volcano and environs, based upon a 4-year program of geophysical surveys and submersible explorations of the underwater flanks of Hawaiian volcanoes that was conducted by numerous academic and governmental research organizations in Japan and the U.S. and funded primarily by the Japan Agency for Marine–Earth...

This paper quantifies atmospheric mercury (Hg) emissions from substrates and fumaroles associated with three hydrothermal systems: Lassen Volcanic Center, California (LVC); Yellowstone Caldera, Wyoming (YC); and Dixie Valley, Nevada (DV). Substrate Hg fluxes were measured using field chamber methods at thermal and nonthermal sites. The highest Hg fluxes (up to 541 ng m−2 h−1) were...

Rapid response to the onset of volcanic activity allows for the early assessment of hazard and risk [Tilling, 1989]. Data from remote volcanoes and volcanoes in countries with poor communication infrastructure can only be obtained via remote sensing [Harris et al., 2000]. By linking notifications of activity from ground-based and spacebased systems, these volcanoes can be monitored when...

Compositional heterogeneity (56–64 wt% SiO2 whole-rock) in samples of tephra and lava from the 1986 eruption of Augustine Volcano, Alaska, raises questions about the physical nature of magma storage and interaction beneath this young and frequently active volcano. To determine conditions of magma storage and evolutionary histories of compositionally distinct magmas, we investigate...

Seven new 40Ar/39Ar and 23 new radiocarbon ages of eruptive units, in support of new geologic mapping, improve the known chronology of Middle to Late Pleistocene and Holocene volcanic activity on the island of Terceira, Azores and define an east-to-west progression in stratovolcano growth. The argon ages indicate that Cinco Picos Volcano, the oldest on Terceira, completed its main...

On January 11, 2006 Augustine Volcano erupted after nearly 20 years of quiescence. Global Positioning System (GPS) instrumentation at Augustine, consisting of six continuously recording, telemetered receivers, measured clear precursory deformation consistent with a source of inflation or pressurization beneath the volcano's summit at a depth of around sea level. Deformation began in...