Publications

Debris flow runout poses a hazard to life and infrastructure. The expansion of human population into mountainous areas and onto alluvial fans increases the need to predict and mitigate debris flow runout hazards. Debris flows on unconfined alluvial fans can exhibit spontaneous self-channelization through levee formation that reduces lateral spreading and extends runout distances compared...

This article is the second of three projected IUPAC Technical Reports on reference materials for phase equilibrium studies. The goal of this project was to select reference systems with critically evaluated property values for the verification of instruments and techniques used in phase equilibrium studies of mixtures. This report proposes seven systems for solid–liquid equilibrium...

Mafic to intermediate shield volcanoes with multi-cubic-kilometer eruptive volumes are common in the Cascades Volcanic Arc, but little is known about their eruptive histories as either singular or sustained episodes, or the total time required for their construction. Paleomagnetic data were collected from the lava flows of Ash Creek Butte (17 sites) and Crater Mountain (14 sites) in...

The leucogranitic crystal-mush pluton beneath the iconic Long Valley Caldera, California, USA, released >820 km3 of crystal-poor Pleistocene rhyolite, which was hosted by numerous Mesozoic granitic plutons, only a few of which had been dated until now. Reported here are U-Pb zircon ages, determined by sensitive high-resolution ion microprobe−reverse geometry (SHRIMP-RG), for 11...

Loss of local biodiversity resulting from abrupt environmental change is a significant environmental problem throughout the world. Extinctions of plants are particularly important yet are often overlooked. Drawing from a case in Hawai‘i, a global hotspot for plant and other extinctions, we demonstrate an effort to better understand and determine priorities for the management of an...

The geologic map and description of map units presented here cover approximately 880 km2 of northeastern Umnak Island, Aleutian Islands, Alaska. This report focuses on Okmok Volcano and its eruptive products and updates the mid-20th-century geologic map of Byers (1959). Mapped deposits reflect the state of the volcano just prior to the 2008 eruption. Published information about other...

Olivine is commonly used as a ‘crystal clock’ to extract timescales relevant to pre-eruptive perturbations within mafic magmatic systems. Diffusion chronometry applications require accurate calibrations for the rates at which Fe-Mg or other commonly measured elements like Ni, Mn, and Ca diffuse through the crystal lattice. In the past, these rates have been mainly characterized using...

The composition of clinopyroxene and clinopyroxene-liquid (Cpx-Liq) pairs are frequently used to calculate crystallization/equilibration pressures in igneous systems. While canonical uncertainties are often assigned to calculated pressures based on fits to calibration or test datasets, the sources of these uncertainties (and thus ways to reduce them) have not been rigorously assessed. We...

No abstract available.

The 2015 VESPA voyage (Volcanic Evolution of South Pacific Arcs) was a seismic and rock dredging expedition to the Loyalty and Three Kings Ridges and South Fiji Basin. In this paper we present 33 40Ar/39Ar, 22 micropaleontological, and two U/Pb ages for igneous and sedimentary rocks from 33 dredge sites in this little-studied part of the southwest Pacific Ocean. Igneous rocks include...

A significant number of the world’s approximately 1,400 subaerial volcanoes with Holocene eruptions are unmonitored by ground-based sensors yet constitute a potential hazard to nearby residents and infrastructure, as well as air travel and global commerce. Data from an international constellation of more than 60 current satellite instruments provide a cost-effective means of tracking...

Veniaminof Volcano on the Alaska Peninsula of southwest Alaska is one of a small group of ice-clad volcanoes globally that erupts lava flows in the presence of glacier ice. Here, we describe the nature of lava-ice-snow interactions that have occurred during historical eruptions of the volcano since 1944. Lava flows with total volumes on the order of 0.006 km3 have been erupted in 1983...