Articles

The stress redistribution from an earthquake can produce localized measurable rotations of the principal stress axes if the absolute level of differential stress in the crust in on the order of the earthquake stress drop. Two simple analytic solutions have been developed to estimate the differential stress from an observed stress rotation. However, each has assumptions that may not be...

Leaf litter decomposition is a key ecosystem process in headwater streams, influenced by physical fragmentation, microbial degradation and feeding activity by stream biota. In some tropical streams, feeding by freshwater shrimps can exert strong top-down control on leaf litter decomposition, however, variation in shrimp macroconsumer effects across small spatial scales or among years is...

This technical commentary provides insights into a recent paper by a non-USGS group of authors who link hurricanes to mast seed production in long-leaf pine.

This paper considers resource-driven pattern formation in consumer-resource systems. Here, a planar pattern consists of many big patches, and a big patch can be regarded as combination of many patches on the plane. The consumer moves between patches asymmetrically, while the asymmetry is driven by the resource abundance. Based on experimental models with linearly-linked patches, we...

Streamflow is one of the most important variables in hydrology, but it is difficult to measure continuously. As a result, nearly all streamflow time series are estimated from rating curves that define a mathematical relationship between streamflow and some easy-to-measure proxy like water surface elevation (stage). Despite the existence of automated methods, most rating curves are still...

Sediment cores were collected from a mudflow lobe (80 m water depth) offshore of the Mississippi River’s Southwest Pass in 2017 to better understand the sedimentology near the lobe entraining the SS Virginia shipwreck (sunk by a German U-boat in 1942) and surrounding Mississippi River delta front. Core analyses included 210Pb/137Cs geochronology, granulometry, and X-radiography. Sediment

Despite the importance of sex-specific information for sturgeon conservation and management, sex identification has been a major challenge outside of mature adults on spawning grounds. Recent work identified a sex-specific locus (AllWSex2) that appears to be broadly conserved across many Acipenserids, but the assay was not validated for all species within the family. We tested the...

Ocean acidification (OA) driven by eutrophication, riverine discharge, and other threats from local population growth that affect the inorganic carbonate system is already affecting the eastern Gulf of Mexico. Long-term declines in pH of ~ -0.001 pH units yr-1 have been observed in many southwest Florida estuaries over the past few decades. Coastal and estuarine waters of southwest...

Close-kin mark–recapture (CKMR) is a method analogous to traditional mark–recapture but without requiring recapture of individuals. Instead, multilocus genotypes (genetic marks) are used to identify related individuals in one or more sampling occasions, which enables the opportunistic use of samples from harvested wildlife. To apply the method accurately, it is important to build...

No abstract available.

Lead isotope values for volcanogenic massive sulfide (VMS) deposits provide important insights into metal sources and the nature of pre-accretionary tectonostratigraphic terranes and underlying basements. Deposits of this type in New England formed in diverse tectonic settings including volcanic arcs and backarcs, a supra–subduction zone arc, a rifted forearc foreland basin, and a rifted

Large-scale disturbances, such as megafires, motivate restoration at equally large extents. Measuring the survival and growth of individual plants plays a key role in current efforts to monitor restoration success. However, the scale of modern restoration (e.g., >10,000 ha) challenges measurements of demographic rates with field data. In this study, we demonstrate how unoccupied aerial...