Reports

The spatial distribution of vents in a distributed volcanic field may provide clues about the geometry of the volcanic field’s plumbing system. Distributed volcanism is characterized by magma feeders that are independent of one another, scattered over wide areas, and active for relatively short times (typically less than one hundred years). On the other hand, focused volcanism results in...

There is increasing interest in extracting critical minerals (CM), including rare earth elements (REE), from coals in the United States to address the overreliance on imported REE. The Gulf Coast and the Fort Union regions are the two major lignite-bearing regions within the United States. Recent REE and CM studies of the lignite in these regions have indicated that the coals may be a...

Changing environmental conditions are increasing the frequency and severity of extreme weather and environmental hazards, including heat waves, wildfires, drought, reduced water quality, and degraded air quality from ozone (O3) and fine particulate matter pollution (AghaKouchak et al., 2020; Bolinger et al., 2024; Colorado Health Institute, 2023a; Fann et al., 2015; IPCC, 2023a; Nagamoto...

The giant gartersnake (Thamnophis gigas) is a semi-aquatic species of snake endemic to marshes and sloughs in the Central Valley of California. Because the Central Valley has lost a substantial amount of wetland habitat, giant gartersnake populations are typically found in aquatic habitats associated with rice (Oryza sativa) agriculture. Therefore, changes to the amount and location of...

Detailed and accurate historical data are crucial to characterizing landscape change, whether it is caused by natural phenomena or of anthropogenic origin. Aerial imagery has been periodically collected by government and nongovernment agencies, for a broad range of purposes, since the early 20th century. The acquisition of aerial images involves using standardized equipment with large...

The U.S. Geological Survey, in cooperation with the Gulf Coast Ecosystem Restoration Council, has used MODFLOW 6 to develop a groundwater-flow model to simulate groundwater and surface-water interactions in the Mobile Bay, Alabama, area. The model results indicated that, on average, groundwater discharge near the coastline is equal to 2.5 percent of the surface water that flows into the...

This study provides a comprehensive assessment of decadal changes in the quality of groundwater used for public drinking-water supply at 444 monitoring sites across California during 2004–23. We assessed decadal step trends in groundwater quality for 145 water-quality constituents and geochemical indicators statewide and across geographic and land-use based network groups. We evaluated...

Using a geology-based assessment methodology, the U.S. Geological Survey estimated undiscovered, technically recoverable mean resources of 2.4 billion barrels of shale oil and 65.4 trillion cubic feet of shale gas in the Berkine, Illizi, Hamra, Murzuq, and Erdis Kufra Basins of northern Africa.

Using a geology-based assessment methodology, the U.S. Geological Survey estimated undiscovered, technically recoverable mean resources of 114.1 trillion cubic feet of tight gas in the Berkine, Illizi, and Hamra Basins of northern Africa.  

This is the third volume in the U.S. Geological Survey (USGS) series of reports on stratigraphy entitled “Stratigraphic Notes,” which consists of short papers that highlight stratigraphic studies, changes in stratigraphic nomenclature, and explanations of stratigraphic names and concepts used on published geologic maps. “Stratigraphic Notes” is a long-term (multiyear), multivolume...