Publications

We use combined teleseismic and strong motion data sets to investigate finite-fault slip models for a double of earthquakes that occurred on August 11, 2012, in northwestern Iran near the cities of Ahar and Varzaghan. The data include teleseismic P-waveforms retrieved from broadband seismic stations located between 30°–94° from the earthquakes and local strong motion data recorded by the...

Incorporating the influence of soil layering and local variability into the parameterizations of physics-based numerical models for distributed landslide susceptibility assessments remains a challenge. Typical applications employ substantial simplifications including homogeneous soil units and soil-hydraulic properties assigned based only on average textural classifications; the...

Near historic battlegrounds of the American Civil War, southeast of Fredericksburg, Virginia, on a secluded grassy glade surrounded by forest, a specially designed observatory records the Earth’s changing magnetic field. This facility, the Fredericksburg Magnetic Observatory, is 1 of 14 observatories the U.S. Geological Survey Geomagnetism Program operates at various locations across the...

The Intermountain West region of the United States extends from the eastern margin of the Sierra Nevada and Cascade Mountains in the west to the Rocky Mountains in the east. The region is characterized by dextral shear along the eastern margin of the Sierra Nevada and nearly east-west extension in the Basin and Range. This region experienced four significant earthquake sequences in the...

The CIG Developers Workshop resulted in a number of recommendations that we think will help expand the CIG developer community, make software more accessible to new users, and increase developer productivity through use of common infrastructure and best practices for software development. This includes building a broad user base with sufficient support through documentation, tutorials...

If you’ve ever seen tall antennas rising from everyday residences in your community and wondered what they are for, it could be that those homes belong to ham radio enthusiasts who enjoy communicating with each other over the airwaves. In addition to having fun with their radios and finding camaraderie, many ham radio operators are also prepared to help neighbors and authorities...

Electromagnetic geophysical methods image the electrical conductivity of the subsurface. Electrical conductivity is an intrinsic material property that is sensitive to temperature, composition, porosity, volatile and/or melt content, and other physical properties relevant to the solid Earth. Therefore, imaging the electrical structure of the crust and mantle yields valuable information...

Southern California has a long history of damaging debris flows after wildfire. Despite recurrent loss, forecasts of the frequency and magnitude of postfire debris flows are not available for the region like they are for earthquakes. Instead, debris flow hazards are typically assessed in a reactive manner after wildfires. Such assessments are crucial for evaluating debris flow risk by...

A new methodology that uses recent advances in unsaturated soil mechanics and hydrology was developed and tested. The approach consists of using soil suction and moisture content field information in the prediction of the likelihood of landslide movement. The testing ground was an active landslide on I-70 west of the Eisenhower/Johnson Memorial Tunnels. A joint effort between Colorado...

The extreme heat from wildfire alters soil properties and incinerates vegetation, leading to changes in infiltration capacity, ground cover, soil erodibility, and rainfall interception. These changes promote elevated rates of runoff and sediment transport that increase the likelihood of runoff-generated debris flows. Debris flows are most common in the year immediately following wildfire...

No abstract available.

The 2018 US Geological Survey National Seismic Hazard Model (NSHM) incorporates new data and updated science to improve the underlying earthquake and ground motion forecasts for the conterminous United States. The NSHM considers many new data and component input models: (1) new earthquakes between 2013 and 2017 and updated earthquake magnitudes for some earlier earthquakes; (2) two...