Publications

Modeling martian surface properties fusing high resolution, spatially enabled, remotely sensed data and derived thermophysical modeling is an essential tool for surface property characterization studies. In this work, we describe the development of a thermal inertia modeling tool that integrates the KRC thermal model and a nine-dimensional parameter interpolation with inputs draw from...

The most common building typologies in Nepal are reinforced concrete (RC) frame buildings with masonry infill walls, unreinforced masonry (URM) bearing wall buildings, and wood frame buildings (Figure 5-1). The RC frames with masonry infills are commonly constructed in urban and semi-urban areas. Most of these buildings are three to five stories high, and most privately owned buildings...

The U.S. Geological Survey (USGS) has produced a one‐year (2016) probabilistic seismic‐hazard assessment for the central and eastern United States (CEUS) that includes contributions from both induced and natural earthquakes that are constructed with probabilistic methods using alternative data and inputs. This hazard assessment builds on our 2016 final model (Petersen et al., 2016) by...

A history of martian surface changes is documented by a sequence of global mosaics made up of Mars Global Surveyor Mars Orbiter Camera daily color images from 1999 to 2006, together with a single mosaic from the Mars Reconnaissance Orbiter Mars Color Imager in 2009. These observations show that changes in the global albedo patterns of Mars take place by a combination of dust storms and...

We performed a damage survey of buildings and carried out microtremor observations in the source region of the 2015 Gorkha earthquake. Our survey area spans the Kathmandu valley and areas to the east and north of the valley. Damage of buildings in the Kathmandu valley was localized, and the percentage of the totally collapsed buildings was less than 5 %. East of the Kathmandu valley...

“Blast zones” (BZs) around new martian craters comprise various albedo features caused by the initial impact, including diffuse halos, extended linear and arcuate rays, secondary craters, ejecta patterns, and dust avalanches. We examined these features for changes in repeat images separated by up to four Mars years. Here we present the first comprehensive survey of the qualitative and...

We make and analyze structural damage observations from within the Kathmandu valley following the 2015 M7.8 Gorkha, Nepal earthquake to derive macroseismic intensities at several locations including some located near ground motion recording sites. The macroseismic intensity estimates supplement the limited strong ground motion data in order to characterize the damage statistics. This...

Results from a highly idealized, 2-D computational model indicate that dynamic normal-stress rarefactions might cause friction reduction in long-runout landslides, but the physical relevance of the idealized dynamics has not been confirmed by experimental tests. More importantly, the model results provide no evidence that refutes alternative hypotheses about friction reduction mechanisms...

Some landslides move slowly or intermittently downslope, but others liquefy during the early stages of motion, leading to runaway acceleration and high-speed runout across low-relief terrain. Mechanisms responsible for this disparate behaviour are represented in a two-phase, depth-integrated, landslide dynamics model that melds principles from soil mechanics, granular mechanics and fluid...

Report on the Eastern Section Seismological Society of America Meeting.

This study provides the first systematic comparison of orbital facies maps with detailed ground-based geology observations from the Mars Science Laboratory (MSL) Curiosity rover to examine the validity of geologic interpretations derived from orbital image data. Orbital facies maps were constructed for the Darwin, Cooperstown, and Kimberley waypoints visited by the Curiosity rover using...

Physical processes controlling repeated openings and closures of a barrier island breach between a bay and the open ocean are studied using aerial photographs and atmospheric and hydrodynamic observations. The breach site is located on Pea Island along the Outer Banks, separating Pamlico Sound from the Atlantic Ocean. Wind direction was a major control on the pressure gradients between...