All Publications

Aeromagnetic and gravity surveys of the Skaergaard intrusion in East Greenland were carried out in July–August 1971 as part of a grant to the University of Oregon Center for Volcanology to refine the models of crystallization and differentiation of the intrusion, specifically to test whether the intrusion is underlain by dense rocks of a reservoir 20 kilometers (km) thick (referred to as...

Rivers are home to a wide variety of biota, including fishes, amphibians, reptiles, birds, freshwater mussels, aquatic insects, and microscopic organisms that fill unique niches to support broader ecosystem functions. While the general public may be aware of recreationally relevant biological life (e.g., fishes and insects to model flyfishing flies from), they may not be aware of more...

Conventional dietary assessments are challenging in hematophagous species, particularly in sea lamprey (Petromyzon marinus). However, recent technological developments and molecular approaches have provided an attractive alternative through the use of DNA metabarcoding. While DNA metabarcoding has been used for dietary analyses in numerous species, including lampreys, applications of...

Improvements in logging practices since the mid-20th century are widely presumed to have reduced suspended sediment loads in streams across the Pacific Northwest. However, there have been few opportunities to directly assess this, particularly in larger rivers. We compare modern (2019–22) and historical (1960s) suspended sediment monitoring in three large, actively managed watersheds in...

Using a geology-based assessment methodology, the U.S. Geological Survey estimated undiscovered, technically recoverable mean conventional resources of 14.6 billion barrels of oil and 83.7 trillion cubic feet of gas in Mexico, Belize, and Guatemala.

Within the Mid-Atlantic United States, widespread landscape disturbance during European colonization resulted in erosion and subsequent storage of legacy sediments within river valleys and floodplains, altering their form, function, and flora. Previous studies of precolonial river corridors have influenced river restoration designs and targets throughout the region, but the...

The increased demand for clean energy technology and a significant reliance on foreign supply chains have given impetus to understanding critical mineral systems and locating potential resources within the United States. At least thirteen critical mineral-bearing systems have been identified throughout the U.S. southern Midcontinent (Hofstra and Kreiner, 2020) but much of the region’s...

The aquarium trade is a global industry responsible for the movement of live plants and animals, but it also serves as a major pathway for the introduction and spread of aquatic invasive species. Invasive species contribute to biodiversity loss, disrupt ecosystems, and can have widespread economic and societal impacts. A significant but poorly understood invasion risk in the plant...

Wildlife conservation planning increasingly requires collaboration and integration of research from discrete studies spanning large geographic areas. Tracking datasets are essential for analyzing animal movements and species distributions in relation to environmental conditions and combining them can enable powerful analyses to further aid planning efforts. However, combining datasets...

Aquatic invasive species (AIS) create costly, detrimental effects when established. Recognition of this in the United States reached a threshold in 1990 with the federal passage of the Nonindigenous Aquatic Nuisance Prevention and Control Act. This act created six regional panels, the national Aquatic Nuisance Species Task Force, and incentivized state-level AIS planning. The management...

Predicting where runoff-generated debris flows might occur during rainfall on steep, recently burned terrain is challenging. Studies of mass-movement processes in unburned areas indicate that event locations are well-predicted by rainfall anomaly, R*, in which peak observed rainfall is normalized by local rainfall climatology. Here, we use remote and field methods to map debris flows...

Society is fundamentally dependent upon commodities that are used in end-use products for the aerospace, defense, energy, telecommunication, and transportation sectors, resulting in centuries of mining to supply these commodities and materials. Waste from these mining operations can remain on the landscape indefinitely, but there is a lack of national understanding of the distribution...