description: This data set maps and describes the geology of the Cucamonga Peak 7.5' quadrangle, San Bernardino County, California. Created using Environmental Systems Research Institute's ARC/INFO software, the database consists of the following items: (1) a map coverage containing geologic contacts and units, (2) a coverage containing site-specific structural data, (3) a coverage containing geologic-unit label leaders and their associated attribute tables for geologic units (polygons), contacts (arcs), and site-specific data (points). In addition, the data set includes the following graphic and text products: (1) A PostScript graphic plot-file containing the geologic map, topography, cultural data, a Correlation of Map Units (CMU) diagram, a Description of Map Units (DMU), an index map, a regional geologic and structure map, and a key for point and line symbols; (2) PDF files of this Readme (including the metadata file as an appendix) and the graphic produced by the PostScript plot file. The Cucamonga Peak quadrangle includes part of the boundary between two major physiographic provinces of California, the Transverse Ranges Province to the north and the Peninsular Ranges Province to the south. The north part of the quadrangle is in the eastern San Gabriel Mountains, and the southern part includes an extensive Quaternary alluvial-fan complex flanking the upper Santa Ana River valley, the northernmost part of the Peninsular Ranges Province. Thrust faults of the active Cucamonga Fault zone along the the south margin of the San Gabriel Mountains are the rejuvenated eastern terminus of a major old fault zone that bounds the south side of the western and central Transverse Ranges (Morton and Matti, 1993). Rejuvenation of this old fault zone, including the Cucamonga Fault zone, is apparently in response to compression in the eastern San Gabriel Mountains resulting from initiation of right-lateral slip on the San Jacinto Fault zone in the Peninsular Ranges. Within the northern part of the quadrangle are several arcuate-in-plan faults that are part of an antiformal, schuppen-like fault complex of the eastern San Gabriel Mountains. Most of these arcuate faults are reactivated and deformed older faults that probably include the eastern part of the San Gabriel Fault. The structural grain within the San Gabriel Mountains, as defined by basement rocks, is generally east striking. Within the Cucamonga Peak quadrangle, these basement rocks include a Paleozoic schist and gneiss sequence which occurs as large, continuous and discontinuous bodies intruded by Cretaceous granitic rocks. Most of the granitic rocks are of tonalitic composition, and many are mylonitic. South of the granitic rocks is a comple assemblage of Proterozoic(?) metamorphic rocks, at least part of which is metasedimentary. This assemblage is intruded by Cretaceous tonalite on its north side, and by charnockitic rocks near the center of the mass. The charnockitic rocks are in contact with no other Cretaceous granitic rocks. Consequently, their relative position in the intrusive sequence is unknown. The Proterozoic(?) assemblage was metamorphosed to upper amphibolite and lower granulite grade, and subsequently to a lower metamorphic grade. It is also intensely deformed by mylonitization characterized by an east-striking, north-dipping foliation, and by a pronounced subhorizontal lineation that plunges shallowly east and west. The southern half of the quadrangle is dominated by extensive, symmetrical alluvial-fan complexes, particularly two emanating from Day and Deer Canyons. Other Quaternary units ranging from early Pleistocene to recent are mapped, and represent alluvial-fan, landslide, talus, and wash environments. The geologic map database contains original U.S. Geological Survey data generated by detailed field observation and by interpretation of aerial photographs. This digital Open-File map supercedes an older analog Open-File map of the quadrangle, and includes extensive new data on the Quaternary deposits, and revises some fault and bedrock distribution within the San Gabriel Mountains. The digital map was compiled on a base-stable cronoflex copy of the Cucamonga Peak 7.5' topographic base and then scribed. This scribe guide was used to make a 0.007 mil blackline clear-film, from which lines and point were hand digitized. Lines, points, and polygons were subsequently edited at the USGS using standard ARC/INFO commands. Digitizing and editing artifacts significant enough to display at a scale of 1:24,000 were corrected. Within the database, geologic contacts are represented as lines (arcs), geologic units as polygons, and site-specific data as points. Polygon, arc, and point attribute tables (.pat, .aat, and .pat, respectively) uniquely identify each geologic datum.; abstract: This data set maps and describes the geology of the Cucamonga Peak 7.5' quadrangle, San Bernardino County, California. Created using Environmental Systems Research Institute's ARC/INFO software, the database consists of the following items: (1) a map coverage containing geologic contacts and units, (2) a coverage containing site-specific structural data, (3) a coverage containing geologic-unit label leaders and their associated attribute tables for geologic units (polygons), contacts (arcs), and site-specific data (points). In addition, the data set includes the following graphic and text products: (1) A PostScript graphic plot-file containing the geologic map, topography, cultural data, a Correlation of Map Units (CMU) diagram, a Description of Map Units (DMU), an index map, a regional geologic and structure map, and a key for point and line symbols; (2) PDF files of this Readme (including the metadata file as an appendix) and the graphic produced by the PostScript plot file. The Cucamonga Peak quadrangle includes part of the boundary between two major physiographic provinces of California, the Transverse Ranges Province to the north and the Peninsular Ranges Province to the south. The north part of the quadrangle is in the eastern San Gabriel Mountains, and the southern part includes an extensive Quaternary alluvial-fan complex flanking the upper Santa Ana River valley, the northernmost part of the Peninsular Ranges Province. Thrust faults of the active Cucamonga Fault zone along the the south margin of the San Gabriel Mountains are the rejuvenated eastern terminus of a major old fault zone that bounds the south side of the western and central Transverse Ranges (Morton and Matti, 1993). Rejuvenation of this old fault zone, including the Cucamonga Fault zone, is apparently in response to compression in the eastern San Gabriel Mountains resulting from initiation of right-lateral slip on the San Jacinto Fault zone in the Peninsular Ranges. Within the northern part of the quadrangle are several arcuate-in-plan faults that are part of an antiformal, schuppen-like fault complex of the eastern San Gabriel Mountains. Most of these arcuate faults are reactivated and deformed older faults that probably include the eastern part of the San Gabriel Fault. The structural grain within the San Gabriel Mountains, as defined by basement rocks, is generally east striking. Within the Cucamonga Peak quadrangle, these basement rocks include a Paleozoic schist and gneiss sequence which occurs as large, continuous and discontinuous bodies intruded by Cretaceous granitic rocks. Most of the granitic rocks are of tonalitic composition, and many are mylonitic. South of the granitic rocks is a comple assemblage of Proterozoic(?) metamorphic rocks, at least part of which is metasedimentary. This assemblage is intruded by Cretaceous tonalite on its north side, and by charnockitic rocks near the center of the mass. The charnockitic rocks are in contact with no other Cretaceous granitic rocks. Consequently, their relative position in the intrusive sequence is unknown. The Proterozoic(?) assemblage was metamorphosed to upper amphibolite and lower granulite grade, and subsequently to a lower metamorphic grade. It is also intensely deformed by mylonitization characterized by an east-striking, north-dipping foliation, and by a pronounced subhorizontal lineation that plunges shallowly east and west. The southern half of the quadrangle is dominated by extensive, symmetrical alluvial-fan complexes, particularly two emanating from Day and Deer Canyons. Other Quaternary units ranging from early Pleistocene to recent are mapped, and represent alluvial-fan, landslide, talus, and wash environments. The geologic map database contains original U.S. Geological Survey data generated by detailed field observation and by interpretation of aerial photographs. This digital Open-File map supercedes an older analog Open-File map of the quadrangle, and includes extensive new data on the Quaternary deposits, and revises some fault and bedrock distribution within the San Gabriel Mountains. The digital map was compiled on a base-stable cronoflex copy of the Cucamonga Peak 7.5' topographic base and then scribed. This scribe guide was used to make a 0.007 mil blackline clear-film, from which lines and point were hand digitized. Lines, points, and polygons were subsequently edited at the USGS using standard ARC/INFO commands. Digitizing and editing artifacts significant enough to display at a scale of 1:24,000 were corrected. Within the database, geologic contacts are represented as lines (arcs), geologic units as polygons, and site-specific data as points. Polygon, arc, and point attribute tables (.pat, .aat, and .pat, respectively) uniquely identify each geologic datum.

description: This dataset represents results from this study attributed to the NHDPlus catchments. Human impacts occurring throughout the Northeast United StatesDOI Northeast Climate Science Center, including urbanization, agriculture, and dams, have multiple effects on the region s streams which support economically valuable stream fishes. Changes in climate are expected to lead to additional impacts in stream habitats and fish assemblages in multiple ways, including changing stream water temperatures. To manage streams for current impacts and future changes, managers need region-wide information for decision-making and developing proactive management strategies. Our project met that need by integrating results of a current condition assessment of stream habitats based on fish response to human land use, water quality impairment, and fragmentation by dams with estimates of which stream habitats may change in the future. Results are available for all streams in the NE CSC region through a spatially-explicit, web-based viewer (FishTail). With this tool, managers can evaluate how streams of interest are currently impacted by land uses and assess if those habitats may change with climate. These results, available in a comparable way throughout the NE CSC, provide natural resource managers, decision-makers, and the public with a wealth of information to better protect and conserve stream fishes and their habitats. These data are integrated into a web-based decision support viewer (FishTail): 1) current condition of streams determined from disturbances limiting stream fishes, 2) future conditions resulting from changes in climate, and, 3) changes in water temperature for key locations resulting from climate changes for all streams of the NE CSC region. The report that documents these data is: Daniel, W., N. Sievert, D. Infante, J. Whittier, J. Stewart, C. Paukert, and K. Herreman. 2016. A decision support mapper for conserving stream fish habitats of the Northeast Climate Science Center region. Final Report to the US Geological Survey, Northeast Climate Science Center, Amherst, MA.; abstract: This dataset represents results from this study attributed to the NHDPlus catchments. Human impacts occurring throughout the Northeast United StatesDOI Northeast Climate Science Center, including urbanization, agriculture, and dams, have multiple effects on the region s streams which support economically valuable stream fishes. Changes in climate are expected to lead to additional impacts in stream habitats and fish assemblages in multiple ways, including changing stream water temperatures. To manage streams for current impacts and future changes, managers need region-wide information for decision-making and developing proactive management strategies. Our project met that need by integrating results of a current condition assessment of stream habitats based on fish response to human land use, water quality impairment, and fragmentation by dams with estimates of which stream habitats may change in the future. Results are available for all streams in the NE CSC region through a spatially-explicit, web-based viewer (FishTail). With this tool, managers can evaluate how streams of interest are currently impacted by land uses and assess if those habitats may change with climate. These results, available in a comparable way throughout the NE CSC, provide natural resource managers, decision-makers, and the public with a wealth of information to better protect and conserve stream fishes and their habitats. These data are integrated into a web-based decision support viewer (FishTail): 1) current condition of streams determined from disturbances limiting stream fishes, 2) future conditions resulting from changes in climate, and, 3) changes in water temperature for key locations resulting from climate changes for all streams of the NE CSC region. The report that documents these data is: Daniel, W., N. Sievert, D. Infante, J. Whittier, J. Stewart, C. Paukert, and K. Herreman. 2016. A decision support mapper for conserving stream fish habitats of the Northeast Climate Science Center region. Final Report to the US Geological Survey, Northeast Climate Science Center, Amherst, MA.

Summary of 40Ar/39Ar geochronology analytical results published in Fox, Jodi M., et al. "Construction of an intraplate island volcano: The volcanic history of Heard Island." Bulletin of Volcanology 83.5 (2021): 37.

Fourteen volcanic samples were selected for 40Ar/39Ar dating from collections housed at the University of Tasmania. Thirteen samples are from the 1986/1987 ANARE Wheller collection and one sample from the 2016 Cordell collection. These collections were the most accessible, include many specimens that have been collected insitu and have well documented sample locations. Sample KP-C78 is the only sample selected that was not collected insitu; it was collected from the Stephenson glacier moraine and is presumed to have been transported from the upper slopes of Big Ben. Due to the expected young age of the lavas less than 20 000 ka), sample selection within the collection was based on the freshness of the groundmass and the highest percentage of K2O measured in whole rock X-ray fluorescence spectrometry (XRF) analysis. Selected samples were predominantly from Laurens Peninsula and from the coastal, basaltic volcanic cones. Seven samples were analysed at the Western Australian Argon Isotope Facility (WAAIF), Curtin University, Australia. Seven samples were analysed at the Oregon State University Argon Geochronology Lab (OSUAGL), United States of America. Sample preparation was completed by the first author at Curtin University and by laboratory staff at Oregon State University.

40Ar/39Ar Methodology, West Australian Argon Isotope Facility, Curtin University, Australia
Weathered outer layers of the sample were removed and the rock crushed and sieved to 350-500 µm-size. The crushate was washed in water and fresh groundmass separated by careful hand picking under binocular microscope. The selected groundmass material were further leached in diluted HF for one minute and then thoroughly rinsed with distilled water in an ultrasonic cleaner.

Samples were loaded into five large wells of one 1.9 cm diameter and 0.3 cm depth aluminium disc. These wells were bracketed by small wells that included Fish Canyon sanidine (FCs) used as a neutron fluence monitor for which an age of 28.294 ± 0.036 Ma (1σ) was adopted (Renne et al., 2011). The discs were Cd-shielded (to minimize undesirable nuclear interference reactions) and irradiated for 20 minutes in the US Geological Survey nuclear reactor (Denver, USA) in central position. The mean J-values computed from standard grains within the small pits range from 0.00009337 ± 0.00000011 (0.12%) to 0.00009545 ± 0.00000019 (0.20%) determined as the average and standard deviation of J-values of the small wells for each irradiation disc. Mass discrimination was monitored using an automated air pipette and provided a mean values of 0.994047 ± 0.004 to 0.995193 ± 0.003 per dalton (atomic mass unit) relative to an air ratio of 298.56 ± 0.31 (Lee et al., 2006). The correction factors for interfering isotopes were (39Ar/37Ar)Ca = 7.30x10-4 (± 11%), (36Ar/37Ar)Ca = 2.82x10-4 (± 1%) and (40Ar/39Ar)K = 6.76x10-4 (± 32%).

The 40Ar/39Ar analyses were performed at the Western Australian Argon Isotope Facility at Curtin University. The samples (150 mg each) were step-heated using a continuous 100 W PhotonMachine© CO2 (IR, 10.4 µm) laser fired on the crystals during 60 seconds. Each of the FCs standard crystals was fused in a single step.

The gas was purified in an extra low-volume stainless steel extraction line of 240cc and using two SAES AP10 and one GP50 getter. Ar isotopes were measured in static mode using a low volume (600 cc) ARGUS VI mass spectrometer from Thermofisher© (Phillips and Matchan, 2013) set with a permanent resolution of ~200. Measurements were carried out in multi-collection mode using four faradays to measure mass 40 to 37 and a 0-background compact discrete dynode ion counter to measure mass 36. We measured the relative abundance of each mass simultaneously using 10 cycles of peak-hopping and 33 seconds of integration time for each mass. Detectors were calibrated to each other electronically and using air shot beam signals. The raw data were processed using the ArArCALC software (Koppers, 2002) and the ages have been calculated using the decay constants recommended by (Renne et al., 2011). Blanks were monitored every 3 to 4 steps and typical 40Ar blanks range from 1 x 10-16 to 2 x 10-16 mol. Ar isotopic data corrected for blank, mass discrimination and radioactive decay. Individual errors are given at the 1σ level.

Our criteria for the determination of plateau are as follows: plateaus must include at least 50% of 39Ar. The plateau should be distributed over a minimum of 3 consecutive steps agreeing at 95% confidence level (Baksi 2007) and satisfying a probability of fit (p) (Jourdan et al. 2009) of at least 0.05. The probability of fit is used in conjunction with the MSWD to assess if the clustering of data is consistent with measurement errors (Jourdan et al. 2007). Plateau ages are given at the 2σ level and are calculated using the mean of all the plateau steps, each weighted by the inverse variance of their individual analytical error Inverse isochrons include the maximum number of steps with a probability of fit ≥ 0.05. All sources of uncertainties are included in the calculation.

References
Baksi, A.K. 2007. A quantitative tool for detecting alteration in undisturbed rocks and mineral — I: water, chemical weathering and atmospheric argon. In: Foulger G.R. and Jurdy D.M. (eds) Plates, Plumes and Planetary Processes, Geological Society of America Special Paper, vol 430, 285-304.

Jourdan F, Renne P.R., and Reimold, W.U. 2009. An appraisal of the ages of terrestrial impact structures. Earth and Planetary Science Letters, vol 286, 1-13.

Koppers, A.A.P., 2002. ArArCALC-software for 40Ar/39Ar age calculations. Computers and Geosciences, vol 28, 605–619.

Lee, J.-Y., Marti, K., Severinghaus, J.P., Kawamura, K., Yoo, H.-S., Lee, J.B., Kim, J.S. 2006. A redetermination of the isotopic abundance of atmospheric Ar. Geochimica et Cosmochimica Acta, vol 70, p. 4507-4512.

Renne, P.R., Balco, G., Ludwig, K.R., Mundil, R., Min, K., 2011. Response to the comment by W.H. Schwarz et al. on "Joint determination of K-40 decay constants and Ar-40*/K-40 for the Fish Canyon sanidine standard, and improved accuracy for Ar-40/Ar-39 geochronology" by PR Renne et al. (2010). Geochimica et Cosmochimica Acta, vol 75, 5097-5100.

40Ar/39Ar Methodology, Oregon State University Argon Geochronology Lab, United States of America

ARGUS VI – Methodology 40Ar/39Ar Geochronology
Sample Preparation:
Both groundmass concentrations of basalts and one glass separate were prepared for this study. High-purity basalt groundmass concentrates ( greater than 99% purity); were obtained using standard separation techniques. All groundmass and glass separates were rigorously put through a series of acid leaching procedures. Each sample was treated with 1N and 6N HCl, 1N and 3N HNO3. Glass separates were treated in a dilute bath of HF (~5%) for approximately 5-10 minutes. Final mineral separates were hand picked under a binocular microscope to a purity of greater than 99% with particular attention to excluding grains with abundant inclusions, adhering material, carbonate, or alteration. All groundmass concentrates range in size between 60-100 mesh (250-150 µm). Visible phenocrysts were removed using a magnetic separator and detailed hand picking. Both glass and groundmass concentrates were washed in triple distilled water (3X) to dissolve any remaining fine particles and possible acid.

Brief Methods:
Between 40 and 20 mg of high purity groundmass and glass were hand picked using a binocular microscope. They were then encapsulated in aluminium and loaded with a standard of known age (FCT-NM-Fish Canyon Tuff sanidine standard produced from the New Mexico Geochronology Research Laboratory in Socorro, New Mexico) and vacuum sealed in quartz vials. The samples geometries (sample heights) were determined using a vernier caliper. After irradiation, the samples were separated from the flux monitors. Prior to analysing the basalt samples, the flux monitors (FCT-NM sanidines) were analysed in order to create a J-curve for the age calculation.

The 40Ar/39Ar ages were obtained by incremental heating using the ARGUS-VI mass spectrometer. 4 groundmass splits and one glass sample were irradiated for 6 hours at 1 Megawatt power (Irradiation 16-OSU-05) in the TRIGA (CLICIT-position) nuclear reactor at Oregon State University, along with the FCT sanidine (28.201 ± 0.023 Ma, 1σ) flux monitor (Kuiper et al. 2008). Individual J-values for each sample were calculated by parabolic extrapolation of the measured flux gradient against irradiation height and typically give 0.2-0.3% uncertainties (1σ).

The term “plateau” refers to two or more contiguous temperature steps with apparent dates that are indistinguishable at the 95% confidence interval and represent 50% of the total 39ArK released (Fleck et al., 1977). Isochron analysis (York, 1969) of all samples was used to assess if non-atmospheric argon components were trapped in any samples, and in some cases, confirm the Plateau ages for each sample. A total gas age (Total Fusion Age), analogous to conventional K-Ar age, is calculated for each sample by weight averaging all ages of all gas fractions for the sample.

The 40Ar/39Ar incremental heating age determinations were performed on a multi-collector ARGUS-VI mass spectrometer at Oregon State University that has 5 Faraday collectors (all fitted with 1012 Ohm resistors) and 1 ion-counting CuBe electron multiplier (located in a position next to the lowest mass Faraday collector). This allows us to measure simultaneously all argon

This dataset represents results from this study attributed to the Hydrologic Unit Code (HUC) 12 watershed boundaries. Human impacts occurring throughout the Northeast United StatesDOI Northeast Climate Science Center, including urbanization, agriculture, and dams, have multiple effects on the region’s streams which support economically valuable stream fishes. Changes in climate are expected to lead to additional impacts in stream habitats and fish assemblages in multiple ways, including changing stream water temperatures. To manage streams for current impacts and future changes, managers need region-wide information for decision-making and developing proactive management strategies. Our project met that need by integrating results of a current condition assessment of stream habitats based on fish response to human land use, water quality impairment, and fragmentation by dams with estimates of which stream habitats may change in the future. Results are available for all streams in the NE CSC region through a spatially-explicit, web-based viewer (FishTail). With this tool, managers can evaluate how streams of interest are currently impacted by land uses and assess if those habitats may change with climate. These results, available in a comparable way throughout the NE CSC, provide natural resource managers, decision-makers, and the public with a wealth of information to better protect and conserve stream fishes and their habitats. These data are integrated into a web-based decision support viewer (FishTail): 1) current condition of streams determined from disturbances limiting stream fishes, 2) future conditions resulting from changes in climate, and, 3) changes in water temperature for key locations resulting from climate changes for all streams of the NE CSC region. The report that documents these data is: Daniel, W., N. Sievert, D. Infante, J. Whittier, J. Stewart, C. Paukert, and K. Herreman. 2016. A decision support mapper for conserving stream fish habitats of the Northeast Climate Science Center region. Final Report to the US Geological Survey, Northeast Climate Science Center, Amherst, MA.

Along-strike geological segmentation in the Andean chain has been recognized at various scales and is usually attributed to changes in plate motion vectors, as well as the upper-plate expression of differing subducted slab age, strength and composition. We present new multi-phase 40Ar/39Ar, apatite fission-track and zircon and apatite (U–Th)/He data from a north–south-oriented traverse between 35 and 38°S along the Principal Andean Cordillera of Chile that reveal (1) rapid cooling at 18 and 15 Ma, which can be attributed to both thermal relaxation following magmatic intrusion and regional-scale exhumation, and (2) along-strike differences in the extent of exhumation since 7.5 Ma that may be a consequence of the subduction of the Juan Fernandez Ridge above the flat-slab segment at 32°, since 10 Ma. A comparison of the response of the South American Plate to the collision of the Carnegie, Nazca and Juan Fernandez ridges suggests that slab flattening is not the dominant driving force that exhumes the upper plate in these settings. Rather, the extent of exhumation is controlled by pre-existing structural weaknesses, the time duration of the dynamically supported topography, and climate.

Slug additions are often the most accurate method for determining discharge when traditional current meter or acoustic measurements are unreliable because of high turbulence, rocky streambed, shallow or sheet flow, or the stream is physically inaccessible (e.g., under ice or canyon walls) or unsafe to wade (Zellweger et al., 1989, Kilpatrick and Cobb 1984, Ferranti 2015). The slug addition method for determining discharge requires an injection of a known amount of a single salt and high-frequency downstream measurement of solute concentration to capture the response curve (Kilpatrick and Cobb 1984). A new slug method was developed to determine stream discharge utilizing specific conductance and ionic molal conductivities to quantify the downstream salt concentration. The new method adopts an approach that accurately calculates the specific conductance of natural waters (McCleskey, et al., 2012). The main advantage of the new method is high-frequency measurements of specific conductance are easily obtained and the method does not require collection or analyses of discrete samples, allowing for more rapid and less expensive measurements. Data from twenty-nine slug additions are presented. The data were used to evaluate the performance of the new discharge method by comparing with discharge estimates obtained by other means (Manning et al. 2022; McCleskey et al., 2021; U.S. Geological Survey, 2022). File information: SlugAdditions.csv is a tab separated file containing details of each slug addition including stream _location, date and time, type and mass of salt added, and discharge determined by an alternative method are presented. SlugAdditions_SC.csv is a tab separated file containing high-frequency specific conductance data collected from twenty-nine slug addition tests. FourmileWQ.csv is a tab separated file containing water quality data from eight different slug addition tests in Fourmile Creek, CO. Specific conductance was calculated and compared to field measurements to demonstrate the validity of the approach. Discharge.xlsx is an Excel spreadsheet that calculates discharge using high-frequency specific conductance data collected downstream from a slug addition. SaltMass.xlsx is an Excel spreadsheet that calculates the salt mass used in the slug addition. References Cited Ferranti, F., 2015. Validation Of Salt Dilution Method For Discharge Measurements In The Upper Valley Of Aniene River (Central Italy). Recent Advances in Environment, Ecosystems and Development. Kilpatrick, F.A. and Cobb, E.D., 1984. Measurement of discharge using tracers. U. S. Geological Survey Open-File Report 84-136. McCleskey, R.B., Nordstrom, D.K., Ryan, J.N. and Ball, J.W., 2012. A new method of calculating electrical conductivity with applications to natural waters. Geochimica et Cosmochimica Acta, 77(0): 369-382. McCleskey, R.B., Antweiler, R.C., Andrews, E.D., Roth, D.A. and Runkel, R.L., 2021. Streamflow and water chemistry in the Tenaya Lake Basin, Yosemite National Park, California. U.S. Geological Survey data release, https://doi.org/10.5066/P9X3WI80. U.S. Geological Survey, 2022. USGS water data for the Nation: U.S. Geological Survey National Water Information System database. accessed July 28, 2022, at https://doi.org/10.5066/F7P55KJN. Zellweger, G.W., Avanzino, R.J. and Bencala, K.E., 1989. Comparison of tracer-dilution and current-meter discharge measurements in a small gravel-bed stream, Little Lost Man Creek, California. U.S. Geological Survey Water-Resources Investigations Report 89-4150.

description: Human impacts occurring throughout the Northeast United StatesDOI Northeast Climate Science Center, including urbanization, agriculture, and dams, have multiple effects on the region s streams which support economically valuable stream fishes. Changes in climate are expected to lead to additional impacts in stream habitats and fish assemblages in multiple ways, including changing stream water temperatures. To manage streams for current impacts and future changes, managers need region-wide information for decision-making and developing proactive management strategies. Our project met that need by integrating results of a current condition assessment of stream habitats based on fish response to human land use, water quality impairment, and fragmentation by dams with estimates of which stream habitats may change in the future. Results are available for all streams in the NE CSC region through a spatially-explicit, web-based viewer (FishTail). With this tool, managers can evaluate how streams of interest are currently impacted by land uses and assess if those habitats may change with climate. These results, available in a comparable way throughout the NE CSC, provide natural resource managers, decision-makers, and the public with a wealth of information to better protect and conserve stream fishes and their habitats. These data are integrated into a web-based decision support viewer (FishTail): 1) current condition of streams determined from disturbances limiting stream fishes, 2) future conditions resulting from changes in climate, and, 3) changes in water temperature for key locations resulting from climate changes for all streams of the NE CSC region. The report that documents these data is: Daniel, W., N. Sievert, D. Infante, J. Whittier, J. Stewart, C. Paukert, and K. Herreman. 2016. A decision support mapper for conserving stream fish habitats of the Northeast Climate Science Center region. Final Report to the US Geological Survey, Northeast Climate Science Center, Amherst, MA.; abstract: Human impacts occurring throughout the Northeast United StatesDOI Northeast Climate Science Center, including urbanization, agriculture, and dams, have multiple effects on the region s streams which support economically valuable stream fishes. Changes in climate are expected to lead to additional impacts in stream habitats and fish assemblages in multiple ways, including changing stream water temperatures. To manage streams for current impacts and future changes, managers need region-wide information for decision-making and developing proactive management strategies. Our project met that need by integrating results of a current condition assessment of stream habitats based on fish response to human land use, water quality impairment, and fragmentation by dams with estimates of which stream habitats may change in the future. Results are available for all streams in the NE CSC region through a spatially-explicit, web-based viewer (FishTail). With this tool, managers can evaluate how streams of interest are currently impacted by land uses and assess if those habitats may change with climate. These results, available in a comparable way throughout the NE CSC, provide natural resource managers, decision-makers, and the public with a wealth of information to better protect and conserve stream fishes and their habitats. These data are integrated into a web-based decision support viewer (FishTail): 1) current condition of streams determined from disturbances limiting stream fishes, 2) future conditions resulting from changes in climate, and, 3) changes in water temperature for key locations resulting from climate changes for all streams of the NE CSC region. The report that documents these data is: Daniel, W., N. Sievert, D. Infante, J. Whittier, J. Stewart, C. Paukert, and K. Herreman. 2016. A decision support mapper for conserving stream fish habitats of the Northeast Climate Science Center region. Final Report to the US Geological Survey, Northeast Climate Science Center, Amherst, MA.

About 62,000 dead or dying common murres (Uria aalge), the trophically dominant fish-eating seabird of the North Pacific, washed ashore between summer 2015 and spring 2016 on beaches from California to Alaska. Most birds were severely emaciated and, so far, no evidence for anything other than starvation was found to explain this mass mortality. Three-quarters of murres were found in the Gulf of Alaska and the remainder along the West Coast. Total mortality was estimated at 0.54 to 1.2 million birds. About two-thirds of murres killed were adults, a substantial blow to breeding populations. Additionally, 22 complete reproductive failures were observed at multiple colonies region-wide during (2015) and after (2016-2017) the mass mortality event. Die-offs and breeding failures occur sporadically in murres, but the magnitude, duration and spatial extent of this die-off, associated with multi-colony and multi-year reproductive failures, is unprecedented and astonishing. These events co-occurred with the most powerful marine heatwave on record that persisted through 2014-2016 and created an enormous volume of ocean water (the “Blob”) from California to Alaska with temperatures that exceeded average by 2-3 standard deviations. Other studies indicate that this prolonged heatwave reduced primary production and restructured zooplankton communities in favor of lower-calorie species, while it simultaneously increased metabolically driven food demands of ectothermic forage fish. In response, forage fish quality and quantity diminished. Similarly, large ectothermic groundfish increased their demand for forage fish, resulting in greater top-predator demands for diminished forage fish resources. We hypothesize that these bottom-up and top-down forces created an “ectothermic vise” on forage species leading to their system-wide scarcity and resulting in mass mortality of murres and many other fish, bird and mammal species in the region during 2014-2017. This was the largest climate-induced perturbation of North Pacific pelagic food webs since the 1976 regime shift.