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At least 253 records · Page 14Linked to original sources
USGS2024

Will there be water? Climate change, housing needs, and future water demand in California

Climate change in California is expected to alter future water availability, impacting water supplies needed to support future housing growth and agriculture demand. In groundwater-dependent regions like California's Central Coast, new land-use related water demand and decreasing recharge is already stressing depleted groundwater basins. We developed a spatially explicit state-and-transition simulation model that integrates climate, land-use change, water demand, and groundwater gain-loss to examine the impact of future climate and land use change on groundwater balance and water demand in five counties along the Central Coast from 2010 to 2060. The model incorporated downscaled groundwater recharge projections based on a Warm/Wet and a Hot/Dry climate future from a spatially explicit hydrological process-based model. Two urbanization projections from a parcel-based, regional urban growth model representing 1) recent historical and 2) state-mandated housing growth projections were used as alternative spatial targets for future urban growth. Agricultural projections were based on recent historical trends from remote sensing data. Annual projected changes in groundwater balance were calculated as the difference between land-use related water demand, based on historical estimates, and climate-driven recharge plus agriculture return flows. Results indicate that future changes in climate-driven groundwater recharge, coupled with cumulative increases in agricultural water demand, result in overall declines in future groundwater balance, with a Hot/Dry future resulting in cumulative groundwater decline in all but Santa Cruz County. Cumulative declines by 2060 are especially prominent in San Luis Obispo (−2.9 to −5.1 Bm 3 ) and Monterey counties (−6.5 to −8.7 Bm 3 ), despite limited changes in agricultural water demand over the model period. These two counties show declining groundwater reserves in a Warm/Wet future as well, while San Benito and Santa Barbara County barely reach equilibrium. These results suggest future groundwater supplies may not be able to keep pace with regional demand and declining climate-driven recharge, resulting in a potential reduction in water security in the region. However, our county-scale projections showed new housing and associated water demand does not conflict with California's groundwater sustainability goals. Rather, future climate coupled with increasing agricultural groundwater demand may reduce water security in some counties, potentially limiting available groundwater supplies for new housing.

California↗
USGS2001

Geologic map and database of the Roseburg 30' x 60' quadrangle, Douglas and Coos Counties, Oregon

The Roseburg 30' x 60' Quadrangle covers the southeastern margin of the Oregon Coast Range and its tectonic boundary with Mesozoic terranes of the Klamath Mountains (see figures 1 and 2 in pamphlet, also shown on map sheet). The geologic framework of the Roseburg area was established by the pioneering work of Diller (1898), Wells and Peck, (1961) and Ewart Baldwin (1974) and his students (see figure 3 in pamphlet, also shown on map sheet). Baldwin and his students focussed on the history of the Eocene Tyee basin, where the sediments lap across the tectonic boundary with the Mesozoic terranes and record the accretion of the Coast Range basement to the continent. Others have examined the sedimentary fill of the Tyee basin in detail, recognizing the deep marine turbidite facies of the Tyee Formation (Snavely and others, 1964) and proposing several models for the Eocene evolution of the forearc basin (Heller and Ryberg, 1983; Chan and Dott, 1983; Heller and Dickinson, 1985; Molenaar, 1985; see Ryu and others, 1992 for a comprehensive summary). Along the eastern margin of the quadrangle, both the Tyee basin and the Klamath terranes are overlain by Eocene volcanic rocks of the Western Cascade arc (Walker and MacLeod, 1991). The thick Eocene sedimentary sequence of the Tyee basin has significant oil and gas potential (Armentrout and Suek, 1985; Gautier and others, 1993; Ryu and others, 1996). Although 13 deep test wells have been drilled in the Roseburg quadrangle (see figure 2 and table 1 in pamphlet, also shown on map sheet), exploration to date has been hampered by an incomplete understanding of the basin�s tectonic setting and evolution. In response, the Oregon Department of Geology and Mineral Industries (DOGAMI) initiated a five year assessment of the oil and gas potential of the Tyee basin. This map is a product of a cooperative effort by the U. S. Geological Survey, Oregon State University, and DOGAMI to systematically map the sedimentary facies and structure of the Tyee basin. New geologic mapping of twenty-eight 7.5' quadrangles is summarized on the map (see figure 3, also shown on map sheet), and the digital database contains geologic information suitable for both 1:100K and 1:24K scale analysis. DOGAMI has published a compilation and synthesis of previous mapping (Niem and Niem, 1990), a basin-wide sequence stratigraphic model and correlations (Ryu and others, 1992), and a report on the oil and gas potential (Ryu and others, 1996). Readers interested in the oil and gas potential of the Roseburg quadrangle should use the map in combination with Ryu and others (1996) to address specific stratigraphic units and structural plays. Stratigraphic terminology for the Tyee basin adopts the type sections, formation names, and framework of Ryu and others (1992, 1996), which were developed concurrently with the mapping and are recognized throughout the basin. For detailed discussion of nomenclature, type sections, lithology, thickness and distribution, age, contact relationships, and depositional environment of stratigraphic units, the reader is referred to Ryu and others (1992). In this report we focus on the spatial, temporal, and structural relationships between units revealed by geologic mapping. Map unit ages (see figure 4 in pamphlet, also shown on map sheeet) are adjusted slightly from Ryu and others (1992, 1996) to fit new coccolith age determinations (D. Bukry, cited in pamphlet), paleomagnetic polarity data (Simpson, 1977 and new data cited in pamphlet), and the time scale of Berggren and others (1995).

Oregon↗
USGS1965

Quality of surface waters in the lower Columbia River Basin

This report, made during 1959-60, provides reconnaissance data on the quality of waters in the lower Columbia River basin ; information on present and future water problems in the basin; and data that can be employed both in water-use studies and in planning future industrial, municipal, and agricultural expansion within this area. The lower Columbia River basin consists of approximately 46,000 square miles downstream from the confluence of the Snake and Columbia Rivers The region can be divided into three geographic areas. The first is the heavily forested, sparsely populated mountain regions in which quality of water in general is related to geologic and climatological factors. The second is a semiarid plateau east of the Cascade Mountains; there differences in geology and precipitation, together with more intensive use of available water for irrigation, bring about marked differences in water quality. The third is the Willamette-Puget trough area in which are concentrated most of the industry and population and in which water quality is influenced by sewage and industrial waste disposal. The majority of the streams in the lower Columbia River basin are calcium magnesium bicarbonate waters. In general, the rivers rising in the. Coast Range and on the west slope of the Cascade Range contain less than 100 parts per million of dissolved solids, and hardness of the water is less than 50 parts per million. Headwater reaches of the streams on the east slope of the Cascade Range are similar to those on the west slope; but, downstream, irrigation return flows cause the dissolved-solids content and hardness to increase. Most of the waters, however, remain calcium magnesium bicarbonate in type. The highest observed dissolved-solids concentrations and also some changes in chemical composition occur in the streams draining the more arid parts of the area. In these parts, irrigation is chiefly responsible for increasing the dissolved-solids concentration and altering the chemical composition of the streams. The maximum dissolved-solids concentration and hardness of water observed in major irrigation areas were 507 and 262 parts per million, respectively, for the. Walla Walla River near Touchet, Wash. In terms of the U.S. Salinity Laboratory Staff classification (1954, p. 80), water in most streams in the basin has low salinity and sodium hazards and is suitable for irrigation. A salt-balance problem does exist in the Hermiston-Stanfield, Oreg., area of the Umatilla River basin, and because of poor drainage, improper irrigation practices could cause salt-balance problems in the Willamette River Valley, Oreg., in which irrigation is rapidly increasing. Pollution by sewage disposal has reached undesirable levels in the Walla Walla River, in the Willamette River from Eugene to Portland, Oreg., and in the Columbia River from Portland to Puget Island. In the lower reaches of the Willamette River, the pollution load from sewage and industrial-waste disposal at times depletes the dissolved oxygen in the water to concentrations below what is considered necessary for aquatic life. Water in most of the tributaries to the lower Columbia River is of excellent quality and after some treatment could be used for industrial and municipal supplies. The principal treatment required would be disinfection and turbidity removal.

Water Supply Paper↗
USGS1987

Number of oil-killed birds and fate of bird carcasses at crude oil pits in Texas

A survey was taken of bird losses in crude oil pits near the central Texas Gulf Coast and in northwestern Texas. At one pit near the Texas Coast, 297 bird carcasses (largely ducks) were counted. Duck losses from oil pollution in northwestern Texas occurred largely in playa basins of the Permian Basin south of the Panhandle. To determine the fate of birds that die in oil pits, 40 carcasses of nine bird species were placed in two crude oil pits near the central Texas Coast in October (19) 1981 and December (15) 1981 and April (6) 1982 and studied for 5 months. Rate of sinking and disappearance of carcasses were positively related to carcass size. In a comparison of three seasons, the time required for a carcass to disappear was longer in winter when oil temperatures were lowest and shorter in spring and fall when oil temperatures were highest.

Southwestern Naturalist↗
USGS2012

Preliminary assessment of channel stability and bed-material transport in the Rogue River basin, southwestern Oregon

This report summarizes a preliminary assessment of bed-material transport, vertical and lateral channel changes, and existing datasets for the Rogue River basin, which encompasses 13,390 square kilometers (km 2 ) along the southwestern Oregon coast. This study, conducted to inform permitting decisions regarding instream gravel mining, revealed that: The Rogue River in its lowermost 178.5 kilometers (km) alternates between confined and unconfined segments, and is predominately alluvial along its lowermost 44 km. The study area on the mainstem Rogue River can be divided into five reaches based on topography, hydrology, and tidal influence. The largely confined, active channel flows over bedrock and coarse bed material composed chiefly of boulders and cobbles in the Grants Pass (river kilometers [RKM] 178.5–152.8), Merlin (RKM 152.8–132.7), and Galice Reaches (RKM 132.7–43.9). Within these confined reaches, the channel contains few bars and has stable planforms except for locally wider segments such as the Brushy Chutes area in the Merlin Reach. Conversely, the active channel flows over predominately alluvial material and contains nearly continuous gravel bars in the Lobster Creek Reach (RKM 43.9–6.7). The channel in the Tidal Reach (RKM 6.7–0) is also alluvial, but tidally affected and unconfined until RKM 2. The Lobster Creek and Tidal Reaches contain some of the most extensive bar deposits within the Rogue River study area. For the 56.6-km-long segment of the Applegate River included in this study, the river was divided into two reaches based on topography. In the Upper Applegate River Reach (RKM 56.6–41.6), the confined, active channel flows over alluvium and bedrock and has few bars. In the Lower Applegate River Reach (RKM 41.6–0), the active channel alternates between confined and unconfined segments, flows predominantly over alluvium, shifts laterally in unconfined sections, and contains more numerous and larger bars. The 6.5-km segment of the lower Illinois River included in this study was treated as one reach. This stretch of the Illinois River is fully alluvial, with nearly continuous gravel bars flanking the channel. The width of the active channel is confined by the narrow topography of the valley. The primary human activities that have likely influenced channel condition, bed-material transport, and the extent and area of bars are (1) historical gold mining throughout the basin, (2) historical and ongoing gravel mining from instream sites in the Tidal Reach and floodplain sites such as those in the Lower Applegate River Reach, (3) hydropower and flow control structures, (4) forest management and fires throughout the basin, and (5) dredging. These anthropogenic activities likely have varying effects on channel condition and the transport and deposition of sediment throughout the study area and over time. Several vertical (aspect) aerial photographs (including the complete coverages of the study area taken in 1995, 2000, 2005, and 2009 and the partial coverages taken in 1967, 1968, 1969, and 1990) are available for assessing long-term changes in attributes such as channel condition, bar area, and vegetation cover. A Light Detection And Ranging (LiDAR) survey performed in 2007–2008 provides 1-m resolution topographic data for sections of the Grants Pass (RKM 178.5–167.6) and Lobster Creek (RKM 17.8–12 and 10–6.7) Reaches and the entire Tidal Reach. Previous studies provide information for specific locations, including (1) an estimated average annual bed-material load of 76,000 m 3 at the former Savage Rapids Dam site (RKM 173.1, Grants Pass Reach), (2) over 490 m of channel shifting from 1965 to 1991 in the Brushy Chutes area (RKM 142–141, Merlin Reach), (3) active sediment transport and channel processes in the Lobster Creek Reach, (4) lateral channel migration in the Tidal Reach, and (5) up to 1.8 m of bar aggradation from the town of Agness (RKM 45.1) to the Rogue River mouth following the flood in water year 1997. Review of the repeat surveys conducted at the instream gravel-mining sites on Elephant and Wedderburn Bars tentatively indicated that these bars (1) experience some bed-material deposition in most years and more substantial deposition following high flows such as those in water years 1997 and 2006, and (2) are dynamic and subject to local scour and deposition. Results from the specific gage analyses completed for five long-term USGS streamflow-gaging stations showed that only the Grants Pass station on the Rogue River (RKM 164.4, Grants Pass Reach) experienced substantial changes in the stage–discharge relationship across a range of flows from 1938 to 2009. Observed changes indicate channel incision at this site. The Rogue and Applegate Rivers are dynamic and subject to channel shifting, aggradation, and incision, as indicated by channel cross sections surveyed during 2000–2010 on the Rogue River and 1933–2010 on the Applegate River. The elevation of the riverbed changed substantially (defined here as more than a net 0.5 m of incision or aggradation) at three locations on the Rogue River (near RKM 164.5, 139.2, and 1.3) and two on the Applegate River (near RKM 42 and 13.5). Systematic delineation of bar features from vertical photographs taken in 1967–69, 2005, and 2009 indicated that most of the repeat mapping sites had a net loss in bar area over the analysis period, ranging from 22 percent at the Oak Flat site (Illinois River Reach) to 69 percent at the Thompson Creek site (Upper Applegate River Reach). Bar area remained stable at the Williams Creek site (Lower Applegate River Reach), but increased 11 percent at the Elephant Rock site (Tidal Reach). The declines in bar area were associated primarily with the establishment of vegetation on upper bar surfaces lacking obvious vegetation in the 1960s. Some of the apparent changes in bar area may also owe to some differences in streamflow and tide levels between the vertical photographs. On the mainstem Rogue River, the median diameter of surface particles varied from 21 mm at the Wedderburn Bar in the Tidal Reach to more than 100 millimeters (mm) at some of the coarsest bars in the Galice Reach. Low armoring ratios tentatively indicated that sediment supply likely exceeds transport capacity at Orchard (Lobster Creek Reach) and Wedderburn (Tidal Reach) Bars. Conversely, relatively higher armoring ratios indicated that transport capacity likely is in balance with sediment supply at Roberston Bridge Bar (Merlin Reach) and exceeds sediment supply at Rogue River City (Grants Pass Reach), Solitude Riffle (Galice Reach), and Hooks Gulch (Galice Reach) Bars. Limited particle data were collected in the study areas on the Applegate and Illinois Rivers. Particle size measurements and armoring ratios tentatively show that sediment supply likely exceeds transport capacity at Bakery Bar in the Lower Applegate Reach. Also, the bed material exiting the Applegate River is likely finer than the bed material in the Rogue River, whereas bed material exiting the Illinois River is likely coarser than the bed material in the Rogue River. Together, these observations and findings indicate that (1) the size, area, and overall position of bars in the Rogue River study area are determined largely by valley physiography, such that unconfined alluvial sections have large channel-flanking bars, whereas confined sections have fewer and smaller bars, (2) segments within the Grants Pass, Merlin, Tidal, Upper Applegate River, and Lower Applegate River Reaches are prone to vertical and/or lateral channel adjustments, and (3) the balance between transport capacity and sediment supply varies throughout the study area. High winter flows and the steep, confined character of much of the Rogue River within the study area result in a river corridor with a high capacity to transport bed material. In the Grants Pass and Galice Reaches, the extensive in-channel bedrock as well as the sparse number and coarse texture of bars indicate that these reaches are likely supply-limited, meaning that the river’s transport capacity exceeds the supply of bed material. In contrast, the Lobster Creek and Tidal Reaches and perhaps portions of the Merlin Reach receive bed-material inputs that more closely balance or even exceed the river’s transport capacity. The lowermost reaches on the Illinois and Applegate Rivers are fully alluvial segments that are likely transport limited, meaning sediment supply likely exceeds the river's transport capacity. However, the steeper Upper Applegate River Reach is likely supply-limited as indicated by the sparse number and area of bars mapped in this reach and the intermittent bedrock outcrops in the channel. The sediment loads derived from these large tributaries draining the Klamath Mountains are probably important contributions to the overall transport of bed material in the Rogue River basin. Compared to the slightly smaller Umpqua River basin (drainage area 12,103 km 2 ) to the north, the Rogue River (13,390 km 2 ) likely transports more bed material. Although this conclusion of greater bed-material transport in the Rogue River is tentative in the absence of either actual transport measurements or transport capacity calculations, empirical evidence, including the much greater area and frequency of bars along most of the Rogue River as well as the much shorter tidal reach on the Rogue River (6.7 km) compared to the Umpqua River (40 km) supports this inference. More detailed investigations of bed-material transport rates and channel morphology would support assessments of channel condition, longitudinal trends in particle size, the relation between sediment supply and transport capacity, and the potential causes of bar area loss (such as vegetation establishment and potential changes in peak flow patterns). The reaches most practical for such assessments and relevant to several management and ecological issues are (1) the lower Rogue River basin, including the Lobster Creek and Tidal Reaches of the Rogue River as well as the Illinois River Reach and (2) the Lower Applegate River Reach.

Oregon↗
USGS2012

Preliminary assessment of channel stability and bed-material transport in the Coquille River basin, southwestern Oregon

This report summarizes a preliminary study of bed-material transport, vertical and lateral channel changes, and existing datasets for the Coquille River basin, which encompasses 2,745 km 2 (square kilometers) of the southwestern Oregon coast. This study, conducted to inform permitting decisions regarding instream gravel mining, revealed that: The 115.4-km-long study area on the South Fork and mainstem Coquille River can be divided into four reaches on the basis of topography and hydrology. In the fluvial (nontidal, or dominated by riverine processes) reaches on the South Fork Coquille River, the channel consists of bedrock and alluvium in the Powers Reach and mostly alluvium in the Broadbent Reach. In both fluvial reaches, the channel alternates between confined and unconfined segments and contains gravel bars. In the tidally affected Myrtle Point and Bandon Reaches, the channel consists of alluvial deposits and contains sparse gravel and sand bars as well as expansive mud flats and tidal marshes near the Coquille River mouth. The 15.4- and 14.6-km-long study areas on the Middle and North Forks of the Coquille River, respectively, were treated as distinct reaches. The channel beds consist of mixed bedrock and alluvium in the Bridge Reach on the Middle Fork Coquille River and alluvium in the Gravelford Reach on the North Fork Coquille River. Both of these reaches contain fewer bars than the Powers and Broadbent Reaches on the South Fork Coquille River and are predominately fluvial. Channel condition, bed-material transport, and the distribution and area of bars have likely been influenced by logging and splash damming, dredging and wood removal for navigation, historical and ongoing instream gravel mining, gold mining, fires, and mass movements. These anthropogenic and natural disturbances likely have varying effects on channel condition and sediment flux throughout the study area and over time. Available data include at least eight sets of aerial and orthophotographs that were taken of the study area from 1939 to 2011 that are available for assessing long-term changes in channel condition, bar area, and vegetation establishment patterns. Additionally, a high-resolution Light Detection And Ranging (LiDAR) survey conducted in 2008 for nearly the entire study area would be useful in future quantitative analyses of channel morphology and bed-material transport. Previous studies found (1) substantial bank erosion in the Broadbent Reach, resulting in banks with near vertical profiles and heights exceeding 7.6 m, (2) erosion of over 40,000 square meters of riparian land from 1939 to 1992, (3) incision along the South Fork Coquille River, and (4) potential for lateral channel migration at several locations along the mainstem and South Fork Coquille River. A review of deposited and mined bed-material estimates derived largely from repeat surveys at instream mining sites on the South Fork Coquille River indicates that bed material transported by the river tends to rebuild mined bar surfaces in most years. Reported annual deposition volumes for 1996–2009 indicate average transport of over 34,700 cubic meters per year (m 3 /yr) of bed material into the South Fork Coquille River study area. The spatial variation in the number and area of gravel bars is controlled by factors such as valley confinement, channel slope, basin geology, and tidal extent. The Powers and Broadbent Reaches of the South Fork Coquille River have the greatest abundance of gravel bars, likely owing to a substantial area of the South Fork Coquille River basin draining the gravel-producing Klamath Mountains geologic province. From 1939 to 2009, the fluvial reaches all had a net loss in bar area, ranging from 24 percent in the Powers Reach to 56 percent in the Bridge Reach. In the Powers and Broadbent Reaches, the declines in active bar area were associated primarily with vegetation establishment on bar surfaces and lateral bar erosion. The reductions in active bar area were attributed to vegetation establishment in the Bridge and Gravelford Reaches as well as some lateral bar erosion in the Bridge Reach. In contrast, the tidal Myrtle Point and Bandon Reaches had a net increase in bar area (28 and 29 percent, respectively) from 1939 to 2009. In the Myrtle Point Reach, these increases in bar area were primarily attributed to lateral channel migration that led to the deposition of bed material at newly formed bars. In the Bandon Reach, bar area increased primarily in the lower 5.4 km of the reach owing possibly to factors such as tide differences between the photographs and sediment deposition. Analyses of multiple channel cross sections along the South Fork Coquille River as well as historical stage-discharge data collected by the U.S. Geological Survey (USGS) at Powers, Oregon, indicate that the bed of the South Fork Coquille River has locally lowered, as much as 1.9 m from 1994 to 2008 for one site in the Broadbent Reach. Stage-discharge data indicate persistent incision at the Powers site since 1939 (with a net incision of about 0.3 m) that has been interrupted by episodic aggradation apparently corresponding with large floods. For the Bridge and Gravelford Reaches on the Middle and North Forks of the Coquille River, channel cross sections indicate a mix of aggradation and incision as well as bank erosion and deposition from 1992 to 2010 and 2000 to 2009, respectively. Cross sections in the tidal reaches indicate local incision of 0.4 m in at one site in the Myrtle Point Reach from 2004 to 2008 and 0.5 m at one site in in the Bandon Reach from 2000 to 2010. On the South Fork Coquille River, the median diameter of surface particles varied from 78.0 mm (millimeters) at China Flat Bar slightly upstream of the study area to 48.8 mm at Seals Bar in the Broadbent Reach. The armoring ratio (or ratio of the median grain sizes of the surface and subsurface layers) for Seals Bar was 3.5, indicating that the river’s transport capacity likely exceeds sediment supply at this site. Most fluvial reaches in the Coquille River study area are likely supply-limited, meaning that the river’s transport capacity exceeds the supply of bed-material, as indicated by the intermittent bedrock outcrops in the Powers and Bridge Reaches and the paucity of bars in the Bridge and Gravelford Reaches. The Broadbent Reach of the South Fork Coquille River may be presently and probably was historically transport-limited, meaning that bed-material transport is primarily a function of local transport capacity. However, the locally coarse bed texture, high armoring ratio measured at Seals Bar, and recent channel incision indicate that sediment supply has likely diminished relative to transport capacity in recent decades. Because of exceedingly low gradients, the tidal Myrtle Point and Bandon Reaches are transport limited. Bed material in these reaches is primarily sand and finer grain-size material, much of which is probably transported as suspended load from upstream reaches. The tidal reaches will be most susceptible to watershed conditions affecting the supply and transport of fine sediment. Compared to the nearby Chetco and Rogue Rivers and Hunter Creek on the southwestern Oregon coast, the Coquille River likely has lower overall transport of gravel bed material. While the conclusion of lower bed-material transport in the Coquille River is tentative in the absence of actual transport measurements or transport capacity calculations, empirical evidence including the much lower area and frequency of bars for most of the Coquille River study area and the head of tide reaching to RKM (river kilometer) 63.2 on the South Fork Coquille River supports this conclusion. More detailed investigations of bed-material transport rates and channel morphology would support assessments of lateral and vertical channel condition and longitudinal trends in bed material. Such assessments would be most practical for the Powers and Broadbent Reaches and relevant to several ongoing management and ecological issues pertaining to sand and gravel transport. The tidal Bandon and Myrtle Point Reaches may also be logical subjects for in-depth analyses of fine sediment deposition and transport (and associated channel and riparian conditions and processes) rather than coarse bed material.

Oregon↗
USGS1970

Seismic refraction study of crustal structure in the western United States

A network of 64 seismic-refraction profiles recorded by the U.S. Geological Survey in California and Nevada and adjacent areas of Idaho, Wyoming, Utah, and Arizona from 1961 to 1963 was re-interpreted. From record sections compiled for all profiles, a basic travel-time diagram can be derived. In addition to the first arrivals on profiles in the Snake River Plain, the northern Basin and Range province, and the middle Rocky Mountains, two dominant phases can be correlated in secondary arrivals, whereas the profiles in other areas show only one dominant phase in later arrivals. Based on velocity-depth functions calculated for each profile after the method of Giese, the crustal structure of the western United States is presented on contour maps and on a fence diagram that is composed of 15 crustal cross sections. Crustal thickness reaches maxima under the Sierra Nevada (42 km), the Transverse Ranges of southern California (37 km), and in southwestern Nevada (36 km), whereas the crust is relatively thin under the Coast Ranges of California (24–26 km), under the Mojave Desert (28 km), and under parts of the central Basin and Range province in Nevada and Utah (29–30 km). The base of the crust dips generally from the Basin and Range province toward greater depths in the Colorado Plateau (43 km), the middle Rocky Mountains (45 km), and the Snake River Plain (44 km). The upper-mantle velocity is less than 8.0 kmps under the Great Basin of the Basin and Range province, the Sierra Nevada, and the Colorado Plateau, but it is equal to or greater than 8.0 kmps under the Coast Ranges of California, the Mojave Desert, and the middle Rocky Mountains. Velocity inversions within the upper crust are indicated under the southern Cascade Mountains and the middle Rocky Mountains, but not under the Sierra Nevada. The average velocity of the upper crust beneath the Basin and Range province is 6.1 to 6.2 kmps to a depth of 15 to 20 km. Only beneath the middle Rocky Mountains, the Snake River Plain, and the northern part of the Basin and Range province can a boundary zone between upper and lower crust be determined confidently.

Arizona, California, Idaho, Nevada, Utah, Wyoming↗
USGS2006

Chapter 7. The GIS project for the geologic assessment of undiscovered oil and gas in the Cotton Valley group and Travis Peak and Hosston formations, East Texas basin and Louisiana-Mississippi salt basins provinces

A geographic information system (GIS) focusing on the Upper Jurassic-Lower Cretaceous Cotton Valley Group and the Lower Cretaceous Travis Peak and Hosston Formations in the northern Gulf Coast region was developed as a visual-analysis tool for the U.S. Geological Survey's 2002 assessment of undiscovered, technically recoverable oil and natural gas resources in the East Texas Basin and Louisiana-Mississippi Salt Basins Provinces. The Central Energy Resources Team of the U.S. Geological Survey has also developed an Internet Map Service to deliver the GIS data to the public. This mapping tool utilizes information from a database about the oil and natural gas endowment of the United States-including physical locations of geologic and geographic data-and converts the data into visual layers. Portrayal and analysis of geologic features on an interactive map provide an excellent tool for understanding domestic oil and gas resources for strategic planning, formulating economic and energy policies, evaluating lands under the purview of the Federal Government, and developing sound environmental policies. Assessment results can be viewed and analyzed or downloaded from the internet web site, http://energy.cr.usgs.gov/oilgas/noga/ .

Alabama, Arkansas. Florida, Georgia, Louisiana, Mi↗
USGS1979

Resource report for proposed OCS lease sale no. 70, St. George Basin, shelf area, Alaska

St. George basin is a long (300 km), narrow (30-50 km) graben whose long axis strikes northwestward, parallel to the continental margin of the southern Bering Sea. Located near the Pribilof Islands, and beneath the virtually featureless Bering Sea shelf, the basin is filled with more than 10 km of sedimentary deposits. These sedimentary rocks are ruptured by normal faults associated with the sides of the graben; these ruptures commonly correlate with offsets in the basement surface. Offset along these faults increases with depth implying that they are growth-type structures. Basement rocks, that floor and flank St. George basin are part of an assemblage of Mesozoic eugeosynclinal rocks that extends from southern Alaska to eastern Siberia beneath the Bering Sea margin and outer shelf. A parallel belt of igneous rocks of late Mesozoic and earliest Tertiary age may also extend from western Alaska to northeastern Siberia beneath the inner Bering Sea shelf. The Bering Sea margin and adjacent shelf were apparently uplifted by the end of Mesozoic time, resulting in deep subaerial erosion• Following uplift, the outer Bering Sea shelf has undergone extensional rifting and regional subsidence. Differential subsidence has resulted in the formation of a series of basement ridges and basins whose axes parallel the Bering Sea margin. Some of these basins are very large to gigantic in size, e.g., St. George basin, and involve crustal subsidence exceeding 10 km. Such large scale crustal collapse suggests deep crustal or upper mantle processes, such as thermal metamorphism or stress-induced crustal migration. Nine wells drilled along the northern coast of the Alaska Peninsula, as well as several onshore Soviet wells in northeastern Siberia, relate directly to the submerged basins of the Bering Sea shelf. Although all of the wells on the Alaska Peninsula were abandoned as dry holes, shows of oil and gas were found. In addition, Soviet drilling resulted in the discovery of oil and gas shows in Oligocene and Miocene sandstone. Regional geologic and geophysical mapping suggests that there are suitable source beds, reservoir rocks, and traps within St. George basin. However, it is not known if hydrocarbons are present or if the possible reservoirs are of commercial size. A resource appraisal of St. George basin out to 200 meters water depth indicates that, at 5 percent probability, 6.4 billion barrels of oil and 18.6 trillion cubic feet of gas may be in the basin; at 95 percent probability 0.8 billion barrels of oil and 4.5 trillion cubic feet of gas may be in the basin. The statistical mean of the appraisal is 2.7 billion barrels of oil and 10.3 trillion cubic feet of gas. A large number of faults, evidence for recent movement along some of the faults, and high seismicity all indicate that faulting is a major environmental concern for the outer continental shelf region of the southern Bering Sea, especially in St. George basin. Most of the faults are potentially active and their movement is probably influenced by the local geology, including basement structures and sediment loading. Unstable sediment masses pose potential threats to resource development in the vicinity of the Pribilof Canyon. Volcanic activity along the Aleutian arc south of St. George basin may also pose an environmental hazard to petroleum development in the area. Another environmental hazard is the presence of shallow gas pockets, which could pose such problems during drilling as blowouts and liquefaction of bottom sediment.

Alaska↗
USGS2005

Ground-water hydrology of the Willamette basin, Oregon

The Willamette Basin encompasses a drainage of 12,000 square miles and is home to approximately 70 percent of Oregon's population. Agriculture and population are concentrated in the lowland, a broad, relatively flat area between the Coast and Cascade Ranges. Annual rainfall is high, with about 80 percent of precipitation falling from October through March and less than 5 percent falling in July and August, the peak growing season. Population growth and an increase in cultivation of crops needing irrigation have produced a growing seasonal demand for water. Because many streams are administratively closed to new appropriations in summer, ground water is the most likely source for meeting future water demand. This report describes the current understanding of the regional ground-water flow system, and addresses the effects of ground-water development. This study defines seven regional hydrogeologic units in the Willamette Basin. The highly permeable High Cascade unit consists of young volcanic material found at the surface along the crest of the Cascade Range. Four sedimentary hydrogeologic units fill the lowland between the Cascade and Coast Ranges. Young, highly permeable coarse-grained sediments of the upper sedimentary unit have a limited extent in the floodplains of the major streams and in part of the Portland Basin. Extending over much of the lowland where the upper sedimentary unit does not occur, silts and clays of the Willamette silt unit act as a confining unit. The middle sedimentary unit, consisting of permeable coarse-grained material, occurs beneath the Willamette silt and upper sedimentary units and at the surface as terraces in the lowland. Beneath these units is the lower sedimentary unit, which consists of predominantly fine-grained sediments. In the northern part of the basin, lavas of the Columbia River basalt unit occur at the surface in uplands and beneath the basin-fill sedimentary units. The Columbia River basalt unit contains multiple productive water-bearing zones. A basement confining unit of older marine and volcanic rocks of low permeability underlies the basin and occurs at land surface in the Coast Range and western part of the Cascade Range. Most recharge in the basin is from infiltration of precipitation, and the spatial distribution of recharge mimics the distribution of precipitation, which increases with elevation. Basinwide annual mean recharge is estimated to be 22 inches. Rain and snowmelt easily recharge into the permeable High Cascade unit and discharge within the High Cascade area. Most recharge in the Coast Range and western part of the Cascade Range follows short flowpaths through the upper part of the low permeability material and discharges to streams within the mountains. Consequently, recharge in the Coast and Ranges is not available as lateral ground-water flow into the lowland, where most ground-water use occurs. Within the lowland, annual mean recharge is 16 inches and most recharge occurs from November to April, when rainfall is large and evapotranspiration is small. From May to October recharge is negligible because precipitation is small and evapotranspiration is large. Discharge of ground water is mainly to streams. Ground-water discharge is a relatively large component of flow in streams that drain the High Cascade unit and parts of the Portland Basin where permeable units are at the surface. In streams that do not head in the High Cascade area, streamflow is generally dominated by runoff of precipitation. Ground-water in the permeable units in the lowland discharges to the major streams where there is a good hydraulic connection between aquifers and streams. Ground-water discharge to smaller streams, which flow on the less permeable Willamette silt unit, is small and mostly from the Willamette silt unit. Most ground-water withdrawals occur within the lowland. Irrigation is the largest use of ground water, accounting for 240,000 acre feet of withdrawals, or 81 p

Scientific Investigations Report↗
USGS2003

A thick lens of fresh groundwater in the southern Lihue Basin, Kauai, Hawaii, USA

A thick lens of fresh groundwater exists in a large region of low permeability in the southern Lihue Basin, Kauai, Hawaii, USA. The conventional conceptual model for groundwater occurrence in Hawaii and other shield-volcano islands does not account for such a thick freshwater lens. In the conventional conceptual model, the lava-flow accumulations of which most shield volcanoes are built form large regions of relatively high permeability and thin freshwater lenses. In the southern Lihue Basin, basin-filling lavas and sediments form a large region of low regional hydraulic conductivity, which, in the moist climate of the basin, is saturated nearly to the land surface and water tables are hundreds of meters above sea level within a few kilometers from the coast. Such high water levels in shield-volcano islands were previously thought to exist only under perched or dike-impounded conditions, but in the southern Lihue Basin, high water levels exist in an apparently dike-free, fully saturated aquifer. A new conceptual model of groundwater occurrence in shield-volcano islands is needed to explain conditions in the southern Lihue Basin.

Hydrogeology Journal↗
USGS2022

The Pondosa fault zone: A distributed dextral-normal-oblique fault system in northeastern California, USA

The tectonic domains of Basin and Range extension, Cascadia subduction zone contraction, and Walker Lane dextral transtension converge in the Mushroom Rock region of northeastern California, USA. We combined analysis of high-resolution topographic data, bedrock mapping, 40 Ar/ 39 Ar geochronology, low-temperature thermochronology, and existing geologic and fault mapping to characterize an extensive dextral-normal-oblique fault system called the Pondosa fault zone. This fault zone extends north-northwest from the Pit River east of Soldier Mountain, California, into moderately high-relief volcanic topography as far north as the Bartle (California) townsite with normal and dextral offset apparent in geomorphology and fault exposures. New and existing 40 Ar/ 39 Ar and radiocarbon dating of offset lava flows provides ages of 12.4 ka to 9.6 Ma for late Cenozoic stratigraphic units. Scarp morphology and geomorphic expression indicate that the fault system was active in the late Pleistocene. The Pondosa fault zone may represent a dextral-oblique accommodation zone between north-south–oriented Basin and Range extensional fault systems and/or part of the Sierra Nevada–Oregon Coast block microplate boundary.

California↗
USGS2003

African dust carries microbes across the ocean: are they affecting human and ecosystem health?

Atmospheric transport of dust from northwest Africa to the western Atlantic Ocean region may be responsible for a number of environmental hazards, including the demise of Caribbean corals; red tides; amphibian diseases; increased occurrence of asthma in humans; and oxygen depletion (eutrophication) in estuaries. Studies of satellite images suggest that hundreds of millions of tons of dust are trans-ported annually at relatively low altitudes across the Atlantic Ocean to the Caribbean Sea and southeastern United States. The dust emanates from the expanding Sahara/Sahel desert region in Africa and carries a wide variety of bacteria and fungi. The U.S. Geological Survey, in collaboration with the NASA/Goddard Spaceflight Center, is conducting a study to identify microbes--bacteria, fungi, viruses--transported across the Atlantic in African soil dust. Each year, millions of tons of desert dust blow off the west African coast and ride the trade winds across the ocean, affecting the entire Caribbean basin, as well as the southeastern United States. Of the dust reaching the U.S., Florida receives about 50 percent, while the rest may range as far north as Maine or as far west as Colorado. The dust storms can be tracked by satellite and take about one week to cross the Atlantic.

Open-File Report↗
USGS2011

Isostatic gravity map of the Point Sur 30' x 60' quadrangle and adjacent areas, California

This isostatic residual gravity map is part of a regional effort to investigate the tectonics and water resources of the central Coast Range. This map serves as a basis for modeling the shape of basins and for determining the location and geometry of faults in the area. Local spatial variations in the Earth's gravity field (after removing variations caused by instrument drift, earth-tides, latitude, elevation, terrain, and deep crustal structure), as expressed by the isostatic anomaly, reflect the distribution of densities in the mid- to upper crust, which in turn can be related to rock type. Steep gradients in the isostatic gravity field often indicate lithologic or structural boundaries. Gravity highs reflect the Mesozoic granitic and Franciscan Complex basement rocks that comprise both the northwest-trending Santa Lucia and Gabilan Ranges, whereas gravity lows in Salinas Valley and the offshore basins reflect the thick accumulations of low-density alluvial and marine sediment. Gravity lows also occur where there are thick deposits of low-density Monterey Formation in the hills southeast of Arroyo Seco (>2 km, Marion, 1986). Within the map area, isostatic residual gravity values range from approximately -60 mGal offshore in the northern part of the Sur basin to approximately 22 mGal in the Santa Lucia Range.

California↗
USGS2022

Genetics reveal long-distance virus transmission links in Pacific salmon

In the coastal region of Washington State, a major pathogen emergence event occurred between 2007 and 2011 in which steelhead trout ( Oncorhynchus mykiss ) experienced a high incidence of infection and disease outbreaks due to the rhabdovirus infectious hematopoietic necrosis virus (IHNV). Genetic typing showed that the introduced viruses were in the steelhead-specific MD subgroup of IHNV and indicated the most likely source was a virus from the nearby Columbia River Basin. In the current study, full-length viral glycoprotein (G) gene sequences were determined for 55 IHNV isolates from both coastal and Columbia fish populations to identify specific source populations and infer mechanisms of transmission to coastal steelhead. We identified three transmission links based on exact fullG genotype matches between Columbia and coastal fish. In all cases, the likely source population was infected juvenile fish, and sink populations were adult fish returning to coastal rivers to spawn. The time intervals between detection in source and sink populations varied from 6 months to nearly 4 years, suggesting different transmission pathways. Surprisingly, distances between source and sink populations varied between 140 and 1000 km. These results confirm repeated introductions of virus from Columbia River Basin fish as the cause of emergence of MD virus on the Washington coast from 2007 to 2011. View Full-Text

Washington↗
USGS2021

Implementation plan for the southern Pacific Border and Sierra-Cascade Mountains provinces

Introduction The National Cooperative Geologic Mapping Program (NCGMP) is publishing a strategic plan titled Renewing the National Cooperative Geologic Mapping Program as the Nation’s Authoritative Source for Modern Geologic Knowledge (Brock and others, in press). The plan provides a vision, mission, and goals for the program during the years 2020–2030, which are: Vision .—Create an integrated, three-dimensional, digital geologic map of the United States. Mission .—Characterize, interpret, and disseminate a national geologic framework model of the Earth through geologic mapping. Goal .—Focus on geologic mapping as a core function of the U.S. Geological Survey (USGS) within the long-term vision of adequately mapping the Nation’s geologic framework in three dimensions. In order to achieve the goals outlined in the strategic plan, the NCGMP has developed an implementation plan. This plan will guide the annual review of projects carried out by USGS staff (FEDMAP) described in the plan and the development of the annual FEDMAP prospectus that will ensure the effective application of the NCGMP strategy. This publication describes the implementation plan of the NCGMP strategy for the southern Pacific Border and Sierra-Cascade Mountains provinces, as defined by Fenneman (1917, 1928, and 1946). This implementation plan focuses on the geology of California and a sliver of Nevada surrounding Lake Tahoe. The southern Pacific Border and Sierra-Cascade Mountains provinces encompass the varied landscapes of the high Sierra Nevada, the Central Valley, and Coast Ranges in northern and central California and the Peninsular Ranges, Continental Borderland, Los Angeles Basin-San Gabriel-San Bernardino valleys, western and central Transverse Ranges, and northernmost Salton Trough in southern California. Societal demands create a need for earth-science data in each of these landscapes. The broader San Francisco Bay area, Central Valley, Los Angeles-San Gabriel-San Bernardino lowlands, and the coastal lowlands that border the Peninsular Ranges are densely populated (about 30 million people) areas at high risk of natural hazards. The mountains of the Sierra Nevada, Peninsular Ranges, and Transverse Ranges, and the coast all provide numerous recreational opportunities that attract visitors from around the world, whereas previously these ranges attracted people to mine their resources. The agricultural capacity of the Central Valley is a critical resource for the Nation that is increasingly water limited. The southern. Pacific Border and Sierra-Cascade Mountains provinces, at the edge of the North American continent, were profoundly influenced by subduction zone tectonics during the Mesozoic and early Cenozoic (ongoing in northernmost California) and subsequently by the inception, development, and present activity of the San Andreas transform margin system. Although the geology of this region is the poster child of fundamental conceptual models of subduction zone complexes, forearc basins, ophiolite obductions, magmatic arcs, and suspect terranes, as well as hosting one of Earth’s most notorious continental transform faults—the San Andreas Fault—important questions that have important societal consequences remain to be answered. Most of California’s population reside in these provinces and live within 30 miles of an active fault (according to www.earthquakeauthority.com ) yet new faults continue to be discovered, highlighting the importance of deformation off the main San Andreas Fault. Bedrock, surficial, and three-dimensional (3D) geologic maps depicting stratigraphic structure and depth to crystalline basement rocks provide critical context and information for understanding fault rupture, distributed deformation, fault connectivity, and history in addition to providing crucial data that enable forecasting of shaking amplitude and length from hypothetical earthquake scenarios. The tectonic evolution of California produced not only stunning mountains, with associated hazards from landslides and active volcanoes, but also fertile valleys that make California the top agricultural producer in the country in terms of cash receipts (according to www.ers.usda.gov/faqs ). These valleys lie atop large basins that not only store groundwater but, in many cases, host oil and gas fields, contributing to the fourth highest hydrocarbon production by State in the country in 2016 (according to https://www.aei.org/carpe-diem/animated-chart-of-us-oil-production-by-state-1981-2017 ). Water is a key resource increasingly stressed by growing agricultural, industrial, and residential needs. Warmer and drier conditions have led to an increased reliance on extracting groundwater resources, whose availability and quality are dictated at the first order by the 3D spatial distribution of bedrock and Quaternary surficial deposits. Thus, assessment of this critical resource is inextricably tied to knowledge of the surficial and subsurface geologic structure and material types.

California, Nevada↗
USGS2014

Modeling the effects of source and path heterogeneity on ground motions of great earthquakes on the Cascadia Subduction Zone Using 3D simulations

We ran finite‐difference earthquake simulations for great subduction zone earthquakes in Cascadia to model the effects of source and path heterogeneity for the purpose of improving strong‐motion predictions. We developed a rupture model for large subduction zone earthquakes based on a k −2 slip spectrum and scale‐dependent rise times by representing the slip distribution as the sum of normal modes of a vibrating membrane. Finite source and path effects were important in determining the distribution of strong motions through the locations of the hypocenter, subevents, and crustal structures like sedimentary basins. Some regions in Cascadia appear to be at greater risk than others during an event due to the geometry of the Cascadia fault zone relative to the coast and populated regions. The southern Oregon coast appears to have increased risk because it is closer to the locked zone of the Cascadia fault than other coastal areas and is also in the path of directivity amplification from any rupture propagating north to south in that part of the subduction zone, and the basins in the Puget Sound area are efficiently amplified by both north and south propagating ruptures off the coast of western Washington. We find that the median spectral accelerations at 5 s period from the simulations are similar to that of the Zhao et al. (2006) ground‐motion prediction equation, although our simulations predict higher amplitudes near the region of greatest slip and in the sedimentary basins, such as the Seattle basin.

Bulletin of the Seismological Society of America↗
USGS1986

USGS research on energy resources, 1986; program and abstracts

The extended abstracts in this volume are summaries of the papers presented orally and as posters in the second V. E. McKelvey Forum on Mineral and Energy Resources, entitled "USGS Research on Energy Resources-1986." The Forum has been established to improve communication between the USGS and the earth science community by presenting the results of current USGS research on nonrenewable resources in a timely fashion and by providing an opportunity for individuals from other organizations to meet informally with USGS scientists and managers. It is our hope that the McKelvey Forum will help to make USGS programs more responsive to the needs of the earth science community, particularly the mining and petroleum industries, and Win foster closer cooperation between organizations and individuals. The Forum was named after former Director Vincent E. McKelvey in recognition of his lifelong contributions to research, development, and administration in mineral and energy resources, as a scientist, as Chief Geologist, and as Director of the U.S. Geological Survey. The Forum will be an annual event, and its subject matter will alternate between mineral and energy resources. We expect that the format will change somewhat from year to year as various approaches are tried, but its primary purpose will remain the same: to encourage direct communication between USGS scientists and the representatives of other earth-science related organizations. Energy programs of the USGS include oil and gas, coal, geothermal, uranium-thorium, and oil shale; work in these programs spans the national domain, including surveys of the offshore Exclusive Economic Zone. The topics selected for presentation at this McKelvey Forum represent an overview of the scientific breadth of USGS research on energy resources. They include aspects of petroleum occurrence in Eastern United States rift basins, the origin of magnetic anomalies over oil fields, accreted terranes and energy-resource implications, coal quality, geothermal energy sources, integrated geology and chemistry in uranium-deposit studies, and interpretations of sea-floor geology seen in reconnaissance-scale sidescan-sonar mosaics of the Gulf of Mexico and west coast Exclusive Economic Zone. Data are presented that are being used in building models of geothermal energy settings, basin histories, and the occurrence of energy resources. In addition to the technical sessions presenting the results of USGS research, each congressionally mandated USGS Mineral Resource Program has a display outlining plans and progress. We are all excited about this continuing opportunity to disseminate and discuss our research with our colleagues in industry and academia, and we welcome your suggestions on improving this series of Forums.

Circular↗