Publications

Knowledge of basal stresses is essential for analyzing slope stability and modeling the dynamics and erosive potential of debris flows and avalanches. Here we derive and test new algebraic formulas for calculating the shear stress τ and normal stress σ at the base of variable‐thickness granular debris masses in states of static or dynamic equilibrium on slopes. The formulas include a lateral press

Mammoth Mountain, California, has exhibited unrest over the past ~30 years, characterized by seismicity over a broad range of depths, elevated 3He/4He ratios in fumarolic gas, and large-scale diffuse CO2 emissions. This activity has been attributed to magmatic intrusion, but minimal ground deformation and the presence of a shallow crustal gas reservoir beneath Mammoth Mountain pose a challenge for

Eruptions of Kīlauea Volcano, Hawaiʻi, USA, can be more powerful than previously recognized. The Kulanaokuaiki-3 (K-3) eruption, ca. 900 CE, consisted of two episodes that dispersed lithic wall-rock clasts (Episode 1) and dominantly scoria (Episode 2; VEI-3) across >65 km2 southeast of the summit. Dense 12 cm blocks of Episode 1 fell 8–10 km from the summit vent, and 2–4 cm lithic lapilli reached

A 2.5-km3 debris avalanche during the 1980 eruption of Mount St. Helens reset the fluvial landscape of upper North Fork Toutle River valley. Since then, a new drainage network has formed and evolved. Cross-section surveys repeated over nearly 40 years at 16 locations along a 20-km reach of river valley document channel evolution, geomorphic processes, and their impacts on sediment delivery. We ana

The deep mantle carbon content and flux are fundamental quantities in understanding global volatile cycles and distributions. Here, we present CO2 concentrations measured in 407 olivine-hosted melt inclusions from Hualalai, Kilauea, Koolau, Loihi, and Mauna Loa to constrain the Hawaiian mantle CO2 content and flux. Quantification of melt inclusion CO2 is complicated by the ubiquitous presence of v

Volcanic eruptions are among Earth’s most dramatic and powerful agents of change. Ash, mudflows, and lava flows can devastate communities near volcanoes and cause havoc in areas far downwind, downstream, and downslope. Even when a volcano is quiet, steep volcanic slopes can collapse to become landslides, and large rocks can be hurled by powerful steam blasts. Hazardous volcanic conditions might la

The master joints bounding the columns that make up the basal colonnade of large lava flows of the Columbia Plateau are, in places, flanked by sub-horizontal mini-columns that have grown normal to the master joints. The secondary mini-columns grow into the main columns and are clearly younger than them. They are small adjacent to the master joint, but merge together and thicken away from the fract

The chemical record contained within the nal increment of growth on crystals is utilized to reveal the dynamics and time- scales of magma assembly and storage before eruption of the cataclysmic 2800 km3 Youngest Toba Tu (YTT), Indonesia. In situ U–Th disequilibrium dates and trace element concentrations were obtained via secondary ionization mass spectrometry (SIMS) on unsectioned and unpolished

Our understanding of the tectonic development of the African continent and the interplay between its geological provinces is hindered by unevenly distributed seismic instrumentation. In order to better understand the continent, we used long-period ambient noise full waveform tomography on data collected from 186 broadband seismic stations throughout Africa and surrounding regions to better image t

To facilitate infrasound propagation studies, we present AVO-G2S, an open-source, Ground-to-Space model which provides temperature and wind specifications from the surface to an altitude of 225 km. This model provides a means of smoothly characterizing atmospheric conditions using multiple numerical weather prediction forecast and reanalysis products, along with upper-atmospheric empirical models

Microgravity time series at active volcanoes can provide an indication of mass change related to subsurface magmatic processes, but uncertainty is often introduced by hydrologic variations and other noise sources that cannot easily be isolated. We empirically assessed seasonality and noise by conducting four surveys over the course of May-October 2017 at Yellowstone caldera, Wyoming. Yellowstone

This database release contains all the information used to produce Geologic Investigations Series I-2614 (https://pubs.usgs.gov/imap/2614/). The main component of this digital release is a geodatabase prepared using ArcGIS, but Esri shapefiles are included as well.Kīlauea is an active shield volcano in the southeastern part of the Island of Hawai‘i. The middle East Rift Zone (MERZ) map includes ab