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At least 829 records · Page 46Linked to original sources

Minerals, lands, and geology for the common defence and general welfare, Volume 3, 1904-1939 : A history of geology in relation to the development of public-land, federal-science, and mapping policies and the development of mineral resources in the United States from the 25th to the 60th year of the U.S. Geological Survey

Mrs. Rabbitt's third volume covers the years 1904 to 1939, from the beginning of the conservation movement under Theodore Roosevelt to the beginning of World War II. From a national perspective, these were years of great development and change in the use of energy, trouble in the coal industry, and a great expansion in the oil industry. They were also years in which the public perceived for the first time that the Nation's mineral resources are not infinite, and the mineral industry realized its dependence on international trade. In these years, water became an increasingly valuable commodity, and the need for a national mapping program became abundantly evident. These were also the years when the Federal Government for the most part practiced stringent economy in funding science, but State and municipal agencies increasingly sought the services of the Survey's topographic and water specialists to aid in the solution of local problems. The balance maintained between fundamental and practical research during the first 25 years was more than once upset during the next 25 years, but the successful struggle to maintain a significant level of research laid the groundwork for the tremendous expansion in the Survey in the subsequent years.

Book↗

Science is the first step to siting nuclear waste repositories

As Shaw [2014] notes, U.S. research on shale as a repository host was halted before expending anything close to the effort devoted to studying crystalline rock, salt, and - most notably - tuff at Yucca Mountain. The new political reality regarding Yucca Mountain may allow reconsideration of the decision to abandon research on shale as a repository host.

Eos, Earth and Space Science News↗

The Mars Science Laboratory Curiosity rover Mastcam instruments: Preflight and in-flight calibration, validation, and data archiving

The NASA Curiosity rover Mast Camera (Mastcam) system is a pair of fixed-focal length, multispectral, color CCD imagers mounted ~2 m above the surface on the rover's remote sensing mast, along with associated electronics and an onboard calibration target. The left Mastcam (M-34) has a 34 mm focal length, an instantaneous field of view (IFOV) of 0.22 mrad, and a FOV of 20° × 15° over the full 1648 × 1200 pixel span of its Kodak KAI-2020 CCD. The right Mastcam (M-100) has a 100 mm focal length, an IFOV of 0.074 mrad, and a FOV of 6.8° × 5.1° using the same detector. The cameras are separated by 24.2 cm on the mast, allowing stereo images to be obtained at the resolution of the M-34 camera. Each camera has an eight-position filter wheel, enabling it to take Bayer pattern red, green, and blue (RGB) “true color” images, multispectral images in nine additional bands spanning ~400–1100 nm, and images of the Sun in two colors through neutral density-coated filters. An associated Digital Electronics Assembly provides command and data interfaces to the rover, 8 Gb of image storage per camera, 11 bit to 8 bit companding, JPEG compression, and acquisition of high-definition video. Here we describe the preflight and in-flight calibration of Mastcam images, the ways that they are being archived in the NASA Planetary Data System, and the ways that calibration refinements are being developed as the investigation progresses on Mars. We also provide some examples of data sets and analyses that help to validate the accuracy and precision of the calibration.

Earth and Space Science↗

Invasive species: Ocean ecosystem case studies for earth systems and environmental sciences

Marine species are increasingly transferred from areas where they are native to areas where they are not. Some nonnative species become invasive, causing undesirable impacts to environment, economy and/or human health. Nonnative marine species can be introduced through a variety of vectors, including shipping, trade, inland corridors (such as canals), and others. Effects of invasive marine species can be dramatic and irreversible. Case studies of four nonnative marine species are given (green crab, comb jelly, lionfish and Caulerpa algae).

Earth Systems and Environmental Sciences↗

USGS42 and USGS43: Human-hair stable hydrogen and oxygen isotopic reference materials and analytical methods for forensic science and implications for published measurement results

Because there are no internationally distributed stable hydrogen and oxygen isotopic reference materials of human hair, the U.S. Geological Survey (USGS) has prepared two such materials, USGS42 and USGS43. These reference materials span values commonly encountered in human hair stable isotope analysis and are isotopically homogeneous at sample sizes larger than 0.2 mg. USGS42 and USGS43 human-hair isotopic reference materials are intended for calibration of δ(2)H and δ(18)O measurements of unknown human hair by quantifying (1) drift with time, (2) mass-dependent isotopic fractionation, and (3) isotope-ratio-scale contraction. While they are intended for measurements of the stable isotopes of hydrogen and oxygen, they also are suitable for measurements of the stable isotopes of carbon, nitrogen, and sulfur in human and mammalian hair. Preliminary isotopic compositions of the non-exchangeable fractions of these materials are USGS42(Tibetan hair)δ(2)H(VSMOW-SLAP) = -78.5 ± 2.3‰ (n = 62) and δ(18)O(VSMOW-SLAP) = +8.56 ± 0.10‰ (n = 18) USGS42(Indian hair)δ(2)H(VSMOW-SLAP) = -50.3 ± 2.8‰ (n = 64) and δ(18)O(VSMOW-SLAP) = +14.11 ± 0.10‰ (n = 18). Using recommended analytical protocols presented herein for δ(2)H(VSMOW-SLAP) and δ(18)O(VSMOW-SLAP) measurements, the least squares fit regression of 11 human hair reference materials is δ(2)H(VSMOW-SLAP) = 6.085δ(2)O(VSMOW-SLAP) - 136.0‰ with an R-square value of 0.95. The δ(2)H difference between the calibrated results of human hair in this investigation and a commonly accepted human-hair relationship is a remarkable 34‰. It is critical that readers pay attention to the δ(2)H(VSMOW-SLAP) and δ(18)O(VSMOW-SLAP) of isotopic reference materials in publications, and they need to adjust the δ(2)H(VSMOW-SLAP) and δ(18)O(VSMOW-SLAP) measurement results of human hair in previous publications, as needed, to ensure all results on are on the same scales.

Forensic Science International↗

A revision in hydrogen isotopic composition of USGS42 and USGS43 human-hair stable isotopic reference materials for forensic science

The hydrogen isotopic composition ( δ 2 H VSMOW-SLAP ) of USGS42 and USGS43 human hair stable isotopic reference materials, normalized to the VSMOW (Vienna-Standard Mean Ocean Water)–SLAP (Standard Light Antarctic Precipitation) scale, was originally determined with a high temperature conversion technique using an elemental analyzer (TC/EA) with a glassy carbon tube and glassy carbon filling and analysis by isotope-ratio mass spectrometer (IRMS). However, the TC/EA IRMS method can produce inaccurate δ 2 H VSMOW-SLAP results when analyzing nitrogen-bearing organic substances owing to the formation of hydrogen cyanide (HCN), leading to non-quantitative conversion of a sample into molecular hydrogen (H 2 ) for IRMS analysis. A single-oven, chromium-filled, elemental analyzer (Cr-EA) coupled to an IRMS substantially improves the measurement quality and reliability of hydrogen isotopic analysis of hydrogen- and nitrogen-bearing organic material because hot chromium scavenges all reactive elements except hydrogen. USGS42 and USGS43 human hair isotopic reference materials have been analyzed with the Cr-EA IRMS method, and the δ 2 H VSMOW-SLAP values of their non-exchangeable hydrogen fractions have been revised: where mUr = 0.001 = ‰. On average, these revised δ 2 H VSMOW-SLAP values are 5.7 mUr more positive than those previously measured. It is critical that readers pay attention to the δ 2 H VSMOW-SLAP of isotopic reference materials in publications as they may need to adjust the δ 2 H VSMOW–SLAP measurement results of human hair in previous publications to ensure all results are on the same isotope-delta scale.

Forensic Science International↗

The stability of sulfate and hydrated sulfate minerals near ambient conditions and their significance in environmental and planetary sciences

Sulfate and hydrated sulfate minerals are abundant and ubiquitous on the surface of the Earth and also on other planets and their satellites. The humidity-buffer technique has been applied to study the stability of some of these minerals at 0.1 MPa in terms of temperature-relative humidity space on the basis of hydration-dehydration reversal experiments. Updated phase relations in the binary system MgSO 4 -H 2 O are presented, as an example, to show how reliable thermodynamic data for these minerals could be obtained based on these experimental results and thermodynamic principles. This approach has been applied to sulfate and hydrated sulfate minerals of other metals, including Fe (both ferrous and ferric), Zn, Ni, Co, Cd, and Cu. Metal-sulfate salts play important roles in the cycling of metals and sulfate in terrestrial systems, and the number of phases extends well beyond the simple sulfate salts that have thus far been investigated experimentally. The oxidation of sulfide minerals, particularly pyrite, is a common process that initiates the formation of efflorescent metal-sulfate minerals. Also, the overall abundance of iron-bearing sulfate salts in nature reflects the fact that the weathering of pyrite or pyrrhotite is the ultimate source for many of these phases. Many aspects of their environmental significance are reviewed, particularly in acute effects to aquatic ecosystems related to the dissolution of sulfate salts during rain storms or snow-melt events. Hydrous Mg, Ca, and Fe sulfates were identified on Mars, with wide distribution and very large quantities at many locations, on the basis of spectroscopic observations from orbital remote sensing and surface explorations by rovers. However, many of these findings do not reveal the detailed information on the degree of hydration that is essential for rigorous interpretation of the hydrologic history of Mars. Laboratory experiments on stability fields, reactions pathways, and reaction rates of hydrous sulfates likely to be found on Mars enhance our understanding of the degrees of hydration of various sulfates that should currently exist on Mars at various seasons and locations and during various atmospheric pressure and obliquity periods. Two sets of systematic experiments were described; one on hydrous Mg sulfates and the other on hydrous Fe 3+ sulfates. Also, their implications to Mars sulfates mineralogy were discussed.

Journal of Asian Earth Sciences↗

Quaternary science reviews Pacific Basin tsunami hazards associated with mass flows in the Aleutian arc of Alaska

We analyze mass-flow tsunami generation for selected areas within the Aleutian arc of Alaska using results from numerical simulation of hypothetical but plausible mass-flow sources such as submarine landslides and volcanic debris avalanches. The Aleutian arc consists of a chain of volcanic mountains, volcanic islands, and submarine canyons, surrounded by a low-relief continental shelf above about 1000–2000 m water depth. Parts of the arc are fragmented into a series of fault-bounded blocks, tens to hundreds of kilometers in length, and separated from one another by distinctive fault-controlled canyons that are roughly normal to the arc axis. The canyons are natural regions for the accumulation and conveyance of sediment derived from glacial and volcanic processes. The volcanic islands in the region include a number of historically active volcanoes and some possess geological evidence for large-scale sector collapse into the sea. Large scale mass-flow deposits have not been mapped on the seafloor south of the Aleutian Islands, in part because most of the area has never been examined at the resolution required to identify such features, and in part because of the complex nature of erosional and depositional processes. Extensive submarine landslide deposits and debris flows are known on the north side of the arc and are common in similar settings elsewhere and thus they likely exist on the trench slope south of the Aleutian Islands. Because the Aleutian arc is surrounded by deep, open ocean, mass flows of unconsolidated debris that originate either as submarine landslides or as volcanic debris avalanches entering the sea may be potential tsunami sources. To test this hypothesis we present a series of numerical simulations of submarine mass-flow initiated tsunamis from eight different source areas. We consider four submarine mass flows originating in submarine canyons and four flows that evolve from submarine landslides on the trench slope. The flows have lengths that range from 40 to 80 km, maximum thicknesses of 400–800 m, and maximum widths of 10–40 km. We also evaluate tsunami generation by volcanic debris avalanches associated with flank collapse, at four locations (Makushin, Cleveland, Seguam and Yunaska SW volcanoes), which represent large to moderate sized events in this region. We calculate tsunami sources using the numerical model TOPICS and simulate wave propagation across the Pacific using a spherical Boussinesq model, which is a modified version of the public domain code FUNWAVE. Our numerical simulations indicate that geologically plausible mass flows originating in the North Pacific near the Aleutian Islands can indeed generate large local tsunamis as well as large transoceanic tsunamis. These waves may be several meters in elevation at distal locations, such as Japan, Hawaii, and along the North and South American coastlines where they would constitute significant hazards.

Alaska↗

Comment on "Donders, T.H. 2014. Middle Holocene humidity increase in Florida: climate or sea-level? Quaternary Science Reviews 103:170-174."

Donders (2014) has recently proposed that the climate of Florida became progressively wetter over the past 5000 years in response to a marked strengthening of the El Niño regime. This reconstruction is largely based on a re-analysis of pollen records from regions north of Lake Okeechobee ( Fig. 1 ) using a new set of pollen transfer functions. Donders concluded that a latitudinal gradient in precipitation prevailed across Florida since the mid Holocene, but the overall trend was toward progressively wetter conditions from 5000 cal BP to the present. Donders (2014) also proposed that this climatic trend extended across South Florida despite contrary paleo-records from the Everglades. In particular he singled out the Northeast Shark River Slough (NESRS) record of Glaser et al. (2013) as an atypical local signal of paleo-environmental change that was biased by a misinterpretation of the ecology of pine and Amaranthaceae (Amaranth family). In response to this direct critique of our paleo-environmental interpretation, we wish to point out that: Our interpretation of the NESRS sedimentary sequence (site 4, Fig. 1 A) was based on multiple lines of evidence that all indicate a shift from wetter to drier (i.e. less wet) conditions that occurred after 2800 cal BP. A similar climatic shift from wetter to less wet conditions was reported for this time interval from other sites in the Everglades ( Willard et al., 2006 and Willard and Bernhardt, 2011 ) and also from the Caribbean region to the east ( Hodell et al., 1991 , Hodell et al., 1995 and Higuera-Gundy et al., 1999 ). The NESRS site is located in an area where runoff collected from a 10,000 km 2 wetland prior to 1900 AD when most of the drainage from the Everglades was channeled to the sea through the narrow Shark River Slough. The sedimentary sequence at the NESRS site should therefore contain an integrated record of hydrological change across the pre-historical Everglades ( Glaser et al., 2012 ). In addition this essentially non-forested wetland is well suited to accumulate a representative sample of the regional pollen rain in its sediments (e.g. Jaccobson and Bradshaw, 1981 and Prentice, 1985 ).

Florida↗

Thiamine deficiency: a viable hypothesis for paralytic syndrome in Baltic birds. Commentary on Sonne et al., 2012. A review of the factors causing paralysis in wild birds: implications for the paralytic syndrome observed in the Baltic Sea. Science of the Total Environment 416:32-39

In a recent assessment of hypotheses presented by Balk et al. (2009) regarding the etiology of a paralytic disease inflicting bird populations in Northern Europe, Sonne et al. (2012) “call for a major coordinated effort on research…” to “… integrate clinical, physiological, ecological and demographic investigations at all levels to better dissect the causes, the effects on ecosystems and potential impact on affected populations.” Further, they offer, “This should be undertaken before thiamine deficiency can be considered to constitute a serious problem to e.g. the Baltic ecosystems.” While we agree that holistic approaches to environmental research and management are essential, our experience suggests that waiting for definitive results from long-term research and monitoring programs prior to “consideration” of thiamine deficiency as a major factor in the paralytic disease observed in wild bird populations would hinder the ability of natural resource managers to understand and mitigate declining trends in avian population abundance.

Science of the Total Environment↗

Mercury isotope fractionation by internal demethylation and biomineralization reactions in seabirds: Implications for environmental mercury science

A prerequisite for environmental and toxicological applications of mercury (Hg) stable isotopes in wildlife and humans is quantifying the isotopic fractionation of biological reactions. Here, we measured stable Hg isotope values of relevant tissues of giant petrels ( Macronectes spp.). Isotopic data were interpreted with published HR-XANES spectroscopic data that document a stepwise transformation of methylmercury (MeHg) to Hg-tetraselenolate (Hg(Sec) 4 ) and mercury selenide (HgSe) (Sec = selenocysteine). By mathematical inversion of isotopic and spectroscopic data, identical δ 202 Hg values for MeHg (2.69 ± 0.04‰), Hg(Sec) 4 (−1.37 ± 0.06‰), and HgSe (0.18 ± 0.02‰) were determined in 23 tissues of eight birds from the Kerguelen Islands and Adélie Land (Antarctica). Isotopic differences in δ 202 Hg between MeHg and Hg(Sec) 4 (−4.1 ± 0.1‰) reflect mass-dependent fractionation from a kinetic isotope effect due to the MeHg → Hg(Sec) 4 demethylation reaction. Surprisingly, Hg(Sec) 4 and HgSe differed isotopically in δ 202 Hg (+1.6 ± 0.1‰) and mass-independent anomalies (i.e., changes in Δ 199 Hg of ≤0.3‰), consistent with equilibrium isotope effects of mass-dependent and nuclear volume fractionation from Hg(Sec) 4 → HgSe biomineralization. The invariance of species-specific δ 202 Hg values across tissues and individual birds reflects the kinetic lability of Hg-ligand bonds and tissue-specific redistribution of MeHg and inorganic Hg, likely as Hg(Sec) 4 . These observations provide fundamental information necessary to improve the interpretation of stable Hg isotope data and provoke a revisitation of processes governing isotopic fractionation in biota and toxicological risk assessment in wildlife.

Environmental Science and Technology↗

Setting the stage for a global science of atmospheric rivers

Atmospheric rivers are important mechanisms for transporting water vapor through the atmosphere outside the tropics. These long, narrow, transient corridors occur at low altitudes just ahead of the cold front in midlatitude cyclone systems. These rivers in the sky stitch together the components of the extratropical water cycle by providing large-scale horizontal water vapor transport.

Eos, Earth and Space Science News↗

Paleoclimatology and paleoceanography perspectives on integrated, coordinated, open, networked (ICON) science

This article is composed of three independent commentaries about the state of Integrated, Coordinated, Open, Networked (ICON) principles (Goldman et al., 2021, https://doi.org/10.1002/essoar.10508554.1 ) in the AGU section paleoclimatology and paleoceanography (P&P), and a discussion on the opportunities and challenges of adopting them. Each commentary focuses on a different topic: (Section 2) Global collaboration, technology transfer and application, reproducibility, and data sharing and infrastructure; (Section 3) Local knowledge, global gain: improving interactions within the scientific community and with locals, indigenous communities, stakeholders, and the public; (Section 4) Field, experimental, remote sensing, and real-time data research and application. P&P projects can better include ICON principles by directly incorporating them into research proposals. A promising way to overcome the challenges of interdisciplinarity and integration is to foster networking, which will advance our research discipline through the application of ICON.

Earth and Space Science↗

Near-surface geophysics perspectives on Integrated, Coordinated, Open, Networked (ICON) Science

Pointing to the Integrated, Coordinated, Open, Networked Findability, Accessibility, Interoperability, and Reusability (ICON-FAIR) principles, we have determined several opportunities for implementation within the realm of near-surface geophysics (NSG), representing a broad range of data acquisition and processing technologies. Our work explores the multifaceted community-driven nature of NSG and, by applying ICON-FAIR principles, we identify three key strategic objectives: (i) the development of an approach to integrating NSG into other geoscience data collection projects, (ii) the creation of coordinated and open standardized NSG data, and (iii) the networking of post-secondary institutions to foster an equipment sharing consortium. The precedence within the geoscientific community demonstrates that there are significant opportunities for advancing interdisciplinary applications of NSG through the implementation of structural change within the ICON-FAIR framework.

Earth and Space Science↗

Opinion: Endogenizing culture in sustainability science research and policy

Integrating the analysis of natural and social systems to achieve sustainability has been an international scientific goal for years ( 1 , 2 ). However, full integration has proven challenging, especially in regard to the role of culture ( 3 ), which is often missing from the complex sustainability equation. To enact policies and practices that can achieve sustainability, researchers and policymakers must do a better job of accounting for culture, difficult though this task may be. The concept of culture is complex, with hundreds of definitions that for years have generated disagreement among social scientists ( 4 ). Understood at the most basic level, culture constitutes shared values, beliefs, and norms through which people “see,” interpret, or give meaning to ideas, actions, and environments. Culture is often used synonymously with “worldviews” or “cosmologies” ( 5 , 6 ) to explain the patterned ways of assigning meanings and interpretations among individuals within groups. Used in this way, culture has been found to have only limited empirical support as an explanation of human risk perception ( 7 , 8 ) and environmentalism ( 9 ).

Proceedings of the National Academy of Sciences of↗