Publications

The 1959 eruption of Kīlauea Iki on the Island of Hawai’i is a principal example of powerful Hawaiian fountaining. Over 36 days (including repose periods), 16 fountaining episodes created a small cone, a downwind tephra blanket of approximately 0.003 km3 and a lava lake of about 0.04 km3 volume. During the explosive activity, the maximum fountain heights reached 600 m. Based on a dataset of more t

Strike-slip faults commonly include extensional and contractional bends and stepovers, whereas rotational stepovers are less common. The Volcanic Tableland, Black Mountain, and River Spring areas (California and Nevada, USA) (hereafter referred to as the VBR region) straddle the transition from the dominantly NW-striking dextral faults that define the northwestern part of the eastern California sh

The age and style of opening of the Havre Trough back-arc system is uncertain due to a lack of geochronologic constraints for the region. 40Ar/39Ar dating of 19 volcanic rocks from across the southern Havre Trough and Kermadec Arc was conducted in three laboratories to provide age constraints on the system. The results are integrated and interpreted as suggesting that this subduction system is you

Monogenetic volcanoes, distributed over large areas, contribute to the growth of monogenetic volcanic fields (MVFs) over thousands to millions of years of activity. It is now accepted that MVFs are also temporally clustered. To reduce uncertainties inherent to this episodic character, it is critical to combine multi-disciplinary studies to improve our knowledge of the temporal evolution of MVFs. T

During the 2018 Kilauea eruption the caldera ffloor dropped 500 meters in 62 nearly periodic events of up to 8 meters. Caldera collapse maintains pressure in the magma reservoir necessary to sustain high-rate eruptions. The 2018 collapses were accompanied by inflationary tilts and displacements, similar to observations at other basaltic calderas. Collapse is modeled in 2D by uniform slip dislocati

Shallow submarine volcanoes pose unique scientific and monitoring challenges. The interaction between water and magma can create violent explosions just below the surface, but the inaccessibility of submerged volcanoes means they are typically not instrumented. This both increases the risk to marine and aviation traffic and leaves the underlying eruption physics poorly understood. Here we use low-

In Southern Cascadia, precise Global Navigation Satellite System (GNSS) measurements spanning about 15 years reveal steady deformation due to locking on the Cascadia megathrust punctuated by transient deformation from large earthquakes and episodic tremor and slip events. Near the Mendocino Triple Junction, however, we recognize several abrupt GNSS velocity changes that reflect a different process

The dynamics of slow landslide motion can predispose oversteepened and extended slide regions to debris-flow initiation. For more than 20 years, our real-time monitoring, combined with repeat high-precision GPS surveys, of the Cleveland Corral landslide complex, California, USA, reveals that debris flows initiate from slow-moving kinematic elements of this complex. Different slide elements move in

Debris-flow experiments and models commonly use “hot-start” initial conditions in which downslope motion begins when a large force imbalance is abruptly imposed. By contrast, initiation of natural debris flows almost invariably results from small perturbations of static force balances that apply to debris masses poised in steep channels or on steep slopes. Models that neglect these static balanc

Using long-term data sets, the eruptive size, timing and style can typically be successfully forecast for dormant volcanoes using current monitoring data and knowledge of precursory eruptive patterns. The USAID-USGS Volcano Disaster Assistance Program (VDAP) utilizes seismic data over multiple eruption cycles and across volcano types to successfully forecast eruption size, style and onset times, a

We estimated 3D P-wave velocity (Vp), S-wave velocity (Vs), and Vp/Vs tomographic structures in and around the Sinabung Volcano area, Northern Sumatra, Indonesia during the intereruptive period between October 2010 and July 2013 using high-quality P- and S-wave phases from > 600 local volcano tectonic (VT) earthquakes and more than 5000 phase picks. We used the iteritive damped-least-squares metho

A small phreatic eruption of Sinabung Volcano, North Sumatra on August 28, 2010, at 18:30 local time marked the first eruption in the past ~1200 years. The eruption took place from two small vents in the south crater area. Explosions and ash emissions from these vents generated multiple ash plumes that reached altitudes of up to 5 km during early- to mid-September. By the end of September, only lo