Publications

Geoscience Australia has recently released its 2018 National Seismic Hazard Assessment (NSHA18). Results from the NSHA18 indicate significantly lower seismic hazard across almost all Australian localities at the 1/500 annual exceedance probability level relative to the factors adopted for the current Australian Standard AS1170.4–2007 (R2018). These new hazard estimates, coupled with...

High‐resolution lidar reveals newly recognized evidence of strong shaking in the New Madrid seismic zone in the central United States. We mapped concentrations of sackungen (ridgetop spreading features) on bluffs along the eastern Mississippi River valley in northwestern Tennessee that likely form or are reactivated during large earthquakes. These sackungen are concentrated on the...

The Albuquerque Seismological Laboratory (ASL) has preserved a collection of photographs of seismographic equipment, stations, and drawings used by the United States Coast and Geodetic Survey (USC&GS) in the early-to-mid-twentieth century. The photographs were transferred to ASL from the US Department of Commerce building in Washington DC after ASL became established as a USC&GS facility...

Here, we introduce the first openly available comprehensive database of magnetotelluric (MT) and related electromagnetic data that we developed and matured over the past decade, explain how to access the data, and describe the challenges that had to be overcome to make MT data sharing possible. The database is a helpful tool for MT scientists, and is widely used by the international...

Maps are presented of extreme‐value geoelectric field amplitude and horizontal polarization for the Northeast United States. These maps are derived from geoelectric time series calculated for sites across the Northeast by frequency‐domain multiplication (time‐domain convolution) of 172 magnetotelluric impedance tensors, acquired during a survey, with decades‐long, 1‐min resolution time...

A time series of three closely-spaced data sets are used to track the early expansion of the invasive Japanese benthic foraminifera Trochammina hadai in the southern portion of San Francisco Bay known as South Bay. The species initially appeared in 1983, comprising only 1.5% of the assemblage in one of four samples that were dominated by the native species Ammonia tepida and...

The agglutinated foraminifera Trochammina hadai Uchio (1962), a dominant species in Japan, first appeared as an invasive species in San Francisco Bay, US, in 1983. Trochammina hadai's first appearance in the Brazilian coastal waters of Flamengo Inlet, Ubatuba, Sao Paulo State, is recorded nearly three decades later, in two of thirty-four sediment samples collected in the western portion...

Overview The Digital Shoreline Analysis System (DSAS) is a freely available software application that works within the Esri Geographic Information System (ArcGIS) software. DSAS computes rate-of-change statistics for a time series of shoreline vector data. DSAS version 5.0 (v5.0) was released in December 2018 and has been tested for compatibility with ArcGIS versions 10.4 and 10.5. It is...

Currently, an aftershock sequence is ongoing in Alaska after the magnitude 7.0 Anchorage earthquake of November 30, 2018. Using two scenarios, determined with observations as of December 14, 2018, this report estimates that it will take between 2.5 years and 3 decades before the rate of aftershocks decays to the rate of earthquakes that were occurring in this area before the magnitude 7...

Tensiometer-equipped data acquisition systems measure and record positive and negative soil-water pressures. These data contribute to studies in hillslope hydrology, including analyses of rainfall runoff, near-surface hydrologic response, and slope stability. However, the unique ability of a tensiometer to rapidly and accurately measure pre- and post-saturation subsurface pressures...

Wastewater disposal is generally accepted to be the primary cause of the increased seismicity rate in Oklahoma within the past decade, but no statewide analysis has investigated the contribution of hydraulic fracturing (HF) to the observed seismicity or the seismic hazard. Utilizing an enhanced seismicity catalog generated with multi‐station template matching from 2010‐2016 and all...

On 14 February 2017, two small (equivalent MD 0.8 and 1.0) seismic events occurred in proximity to the Oroville Dam in the Sierra Nevada foothills, California. To examine possible causal relationships between these events and reservoir operations, including the spillway failure starting prior to these events, we applied a new optimized template matching approach to seismic data between...