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USGS1974

Distribution and occurrence of rare earths in the thorium veins on Hall Mountain, Idaho

Rare earths, although equal to or more abundant than thorium in many thorium veins, are much less abundant than thorium in the veins on Hall Mountain, Idaho. Total rare-earth content of these veins ranges from 0.00111 to 0.197 percent in 12 samples from 10 veins; the thoria (ThO 2 ) content, from 0.011 to 5.84 percent. The rare-earth oxide to thoria ratios range from 0.0019 to 3.22. Only two samples contained more rare earths than thorium, and these two samples came from veins related to a fault near the base of a thick sill; the others came from veins near the top of the same sill. The relative amounts of the individual lanthanides are remarkably similar in the Hall Mountain veins, although cerium, gadolinium, or dysprosium are the most abundant in different samples. These veins differ in lanthanide distribution both from the Earth's crust and from the thorium veins of the Lemhi Pass district, Idaho and Montana, in that they contain chiefly yttrium-group rare earths. Most of the rare earths occur in thorite, whose atomic structure will accommodate wide-ranging proportions of the rare earths. Cenosite, one of the few minerals with a high content of the yttrium group of rare earths, was found in one vein.

Idaho↗

USGS1973

Value and validity of earth resources observations from space

Observations of the earth from space can provide overall repetitive views in various regions of the electromagnetic spectrum. Data from such surveys can be used as the basis for more detailed observations from aircraft and on the ground to guide resource exploration, development, and conservation activities. The value of earth resource observations from space has been demonstrated by the practical use of photographs from the Gemini and Apollo spaceflights and particularly by a series of multispectral photographs taken during the flight of Apollo 9. The analysis of those photographs has shown that the performance of the planned Earth Resources Technology Satellite will meet the needs of the resource and environmental community for small-scale repetitive images of the earth in the visible and solar infrared portions of the spectrum and has provided a limited base of material for earth scientists to work with in order to ready themselves for the ERTS data. The validity of earth resource observations from space can be derived by analogy from the successively closer observations of the moon, culminating in repeated physical sampling of the moon's surface. The method of inductive reasoning and analysis used for the moon is the opposite of the normal deductive analysis used on the earth. Adoption of the inductive methods and reasoning for earth observations will provide a framework of broad observations and conclusions leading to the identification of target areas for more detailed observation and will, in time, reduce the costs and time required for surveys dealing with resource and environmental problems.

Hydrological Sciences Bulletin↗

USGS2003

Geothermal energy: clean power from the Earth's heat

Societies in the 21st century require enormous amounts of energy to drive the machines of commerce and to sustain the lifestyles that many people have come to expect. Today, most of this energy is derived from oil, natural gas, and coal, supplemented by nuclear power. Local exceptions exist, but oil is by far the most common source of energy worldwide. Oil resources, however, are nonrenewable and concentrated in only a few places around the globe, creating uncertainty in long-term supply for many nations. At the time of the Middle East oil embargo of the 1970s, about a third of the United States oil supply was imported, mostly from that region. An interruption in the flow of this import disrupted nearly every citizen’s daily life, as well as the Nation’s economy. In response, the Federal Government launched substantial programs to accelerate development of means to increasingly harness “alternative energies”—primarily biomass, geothermal, solar, and wind. The new emphasis on simultaneously pursuing development of several sources of energy recognized the timeless wisdom found in the proverb of “not putting all eggs in one basket.” This book helps explain the role that geothermal resources can play in helping promote such diversity and in satisfying our Nation’s vast energy needs as we enter a new millennium. For centuries, people have enjoyed the benefits of geothermal energy available at hot springs, but it is only through technological advances made during the 20th century that we can tap this energy source in the subsurface and use it in a variety of ways, including the generation of electricity. Geothermal resources are simply exploitable concentrations of the Earth’s natural heat (thermal energy). The Earth is a bountiful source of thermal energy, continuously producing heat at depth, primarily by the decay of naturally occurring radioactive isotopes—principally of uranium, thorium, and potassium—that occur in small amounts in all rocks. This heat then rises to and through the Earth’s surface, where it escapes into the atmosphere. The amount of heat that flows annually from the Earth into the atmosphere is enormous—equivalent to ten times the annual energy consumption of the United States and more than that needed to power all nations of the world, if it could be fully harnessed. Even if only 1 percent of the thermal energy contained within the uppermost 10 kilometers of our planet could be tapped, this amount would be 500 times that contained in all oil and gas resources of the world. How might we benefit from this vast amount of thermal energy beneath our feet? Where, by what means, and how much of the Earth’s natural heat can be usefully harnessed? These are especially important questions to contemplate, because global population is expected to soon exceed seven billion and many scientists believe that the world’s fossilfuel resources may be substantially depleted within this century. Faced with such prospects, both the public and private sectors are working toward more fully utilizing the Earth’s abundant thermal energy and other alternative energy resources. A skeptic might question the wisdom of devoting much national effort to geothermal energy development, especially because many experts think that geothermal heat can contribute at most about 10 percent to the Nation’s energy supply using current technologies. However, ongoing advances in exploration and heat-extraction technologies are improving our ability to use the resource and may substantially increase the geothermal contribution to the Nation’s energy supply. In an attempt to help national planners and average citizens alike understand the nature and energy potential of geothermal resources, this book (1) describes the distribution and nature of geothermal energy, (2) reviews the common types of geothermal systems that provide useful energy with current technology, (3) considers potential geothermal resources that might someday be tapped with developing technologies, and (4) summarizes the role of earth-science information in assessing and harnessing geothermal resources wherever they occur worldwide. The predecessor to this book (Tapping the Earth’s Natural Heat, U.S. Geological Survey Circular 1125, published in 1994) summarized the situation in the early 1990s. In an effort to support national energy planners, this new circular incorporates more recent advances in geothermal science and technology.

Circular↗

USGS2007

Precambrian Time - The Story of the Early Earth

The Precambrian is the least-understood part of Earth history, yet it is arguably the most important. Precambrian time spans almost nine-tenths of Earth history, from the formation of the Earth to the dawn of the Cambrian Period. It represents time so vast and long ago that it challenges all comprehension. The Precambrian is the time of big questions. How old is the Earth? How old are the oldest rocks and continents? What was the early Earth like? What was the early atmosphere like? When did life appear, and what did it look like? And, how do we know this? In recent years, remarkable progress has been made in understanding the early evolution of the Earth and life itself. Yet, the scientific story of the early Earth is still a work in progress, humankind's latest attempt to understand the planet. Like previous attempts, it too will change as we learn more about the Earth. Read on to discover what we know now, in the early 21st century.

Fact Sheet↗

USGS2018

The ongoing educational anomaly of earth science placement

The geosciences have traditionally been viewed with less “academic prestige” than other science curricula. Among the results of this perception are depressed K-16 enrollments, Earth Science assignments to lower-performing students, and relegation of these classes to sometimes under-qualified educators, all of which serve to confirm the widely-held misconceptions. An Earth Systems course developed at San José State University demonstrates the difficulty of a standard high school Earth science curriculum, while recognizing the deficiencies in pre-college Earth science education. Restructuring pre-college science curricula so that Earth Science is placed as a capstone course would greatly improve student understanding of the geosciences, while development of Earth systems courses that infuse real-world and hands-on learning at the college level is critical to bridging the information gap for those with no prior exposure to the Earth sciences. Well-crafted workshops for pre-service and inservice teachers of Earth Science can help to reverse the trends and unfortunate “status” in geoscience education.

Journal of Geoscience Education↗

USGS2011

Mineral resource of the month: rare earth elements

The article provides information on rare earth elements, which are group of 17 natural metallic elements. The rare earth elements are scandium, yttrium and lanthanides and classified into light rare earth elements (LREE) and heavy rate earth elements (HREE). The principal ores of the rare earth elements are identified. An overview of China's production of 97 percent of the rare earths in the world is provided. Commercial applications of rare earths are described.

Earth↗

USGS2023

Distribution of rare earth and other critical elements in lignites from the Eocene Jackson Group, Texas

Coal is increasingly evaluated as a source of rare earth elements (REEs) in the United States to address the overreliance on imported REEs. The objective of this study was to assess the distribution of REEs in lignites from selected mining areas in the Texas Gulf Coastal Plain region. Thirty-one archived lignite and rock samples previously collected by the U.S. Geological Survey were analyzed for their rare earth element and critical mineral content. These include samples from one core (5400 and 5500 lignite horizons) and two opencast lignite mines (Gibbons Creek 3500 and 4500 horizons, and San Miguel horizons A to D) in the Eocene Jackson Group of the Texas Gulf of Mexico Coastal Plain. Some lithologies in the Gibbons Creek 3500 and 4500 lignite-bearing sections have high total rare earth, yttrium (Y), and scandium (Sc) (REYSc) values, up to 7800 ppm (ash basis) REYSc. The lignite lithologies show an enrichment in rare earths, [samarium (Sm) through gadolinium (Gd)]. The basal Gibbons Creek 3500 lignite bench shows a heavy rare earth element enrichment pattern resembling that often seen in peats through high volatile A bituminous coals. The 5500 lignite sequence, overlying the latter lignite sections, shows a light rare earth enrichment. The San Miguel lignite benches have heavy rare earth enrichments with a negative europium (Eu) anomaly.

Texas↗

USGS2023

Rock-to-metal ratios of the rare earth elements

The relative quantities of ore mined and waste rock (i.e., overburden) removed to produce the rare earth elements—their rock-to-metal ratios—were calculated for 21 individual operations or regions covering nearly all mine production in 2018. The results indicate that the rock-to-metal ratios for the total rare earth elements ranged from a low of 1.6 × 10 1 to a high of 3.6 × 10 3 , with operations in Brazil and Russia having the lowest ratios and ion-adsorption clays operations in China and Myanmar having the highest. For comparison, the global average rock-to-metal ratio for the total rare earth elements (9.8 × 10 2 ) fell between that of cobalt (8.6 × 10 2 ) and tungsten (1.1 × 10 3 ). Driven by their relative abundance in the ore and unit prices that were used in the economic allocation of the environmental burdens, the global rock-to-metal ratio for individual rare earth elements was lowest for cerium (2.3 × 10 1 ) and lanthanum (7.7 × 10 1 ) and highest for dysprosium (1.7 × 10 4 ), terbium (3.7 × 10 4 ), and lutetium (6.4 × 10 4 ). Like the rock-to-metal ratios for the total rare earth elements, rock-to-metal ratios for individual rare earth elements varied by roughly two orders of magnitude among the various operations examined. An alternative perspective of only accounting for the overburden that is physically removed in ion-adsorption clays in-situ operations yielded global rock-to-metal ratios that were an order of magnitude lower or less for many of the rare earth elements.

Journal of Cleaner Production↗

USGS2000

A modern earth narrative: What will be the fate of the biosphere?

The modern Earth Narrative is the scientific description of the natural and human history of the Earth, and it is based on two fundamental concepts: Deep (or Geologic) Time and Biological Evolution. Changes in the Earth's biosphere and geosphere are discussed from the perspective of natural variability and impacts of the rapid increase in the human population. The failure of humans to comprehend and understand the Earth Narrative, especially the place of humans in it, presages dire consequences for the Earth's biosphere. The actions humans take, individually and collectively, during the 21st century will likely determine the fate of many millions of species, including our own. It is argued that we must quickly establish an Earth System-based conservation ethic that has the objective of complete preservation of the Earth's biotic inheritance. Published by Elsevier Science Ltd.

Technology in Society↗

USGS2020

Modified GIC estimation using 3-D Earth conductivity

Geomagnetically induced currents (GICs) are quasi-direct current (DC) electric currents that flow in technological conductors during geomagnetic storms. Extreme GICs are hazardous to man-made infrastructure. GICs enter and exit the technological systems, such as the electric power grid, at grounding points, and their magnitudes depend on the currents that flow underground. They are, therefore, a function of the Earth's electrical conductivity, represented at ground level as Earth impedances, as well as the resistance parameters of the power network. Traditional GIC estimation practices are based on Earth impedances obtained from laterally homogeneous or piecewise layered-Earth models. We refer to these methods, collectively, as the 1-D approximation. However, GIC hazard mitigation can be improved with more accurate GIC modeling that takes the spatially heterogeneous Earth's conductivity into account. Here, we propose a modified approximation for GIC estimation that is very similar to the 1-D approximation but is instead derived from empirical 3-D Earth impedances. Our formulation sets up the computation of static, frequency-dependent power line telluric response functions, which, once computed, may be considered part of the power grid system model. These response functions may then be used for historical scenario analysis of GIC hazards and for simplified real-time, albeit approximate, GIC estimation in a power grid. This modest modification to the simpler local field formulation approach avoids real-time integration of geoelectric fields along power lines while taking the realistic 3-D Earth into account in a rigorous manner. Once implemented, the method provides a power grid operator with the benefits of convenience and computational speed for a first look real-time operational GIC hazard assessment. We estimate that the proposed modified 3-D GIC modeling approach produces GIC values that are well within 50% of those obtained with the full-scale power line integration of spatially variable geoelectric fields, for storms comparable in scale to the 2003 Halloween storm, all geological structures, and power lines located in the contiguous United States and other low- to middle-latitude regions.

Space Weather↗

USGS2010

Response of the water level in a well to Earth tides and atmospheric loading under unconfined conditions

The response of the water level in a well to Earth tides and atmospheric loading under unconfined conditions can be explained if the water level is controlled by the aquifer response averaged over the saturated depth of the well. Because vertical averaging tends to diminish the influence of the water table, the response is qualitatively similar to the response of a well under partially confined conditions. When the influence of well bore storage can be ignored, the response to Earth tides is strongly governed by a dimensionless aquifer frequency Q ′ u . The response to atmospheric loading is strongly governed by two dimensionless vertical fluid flow parameters: a dimensionless unsaturated zone frequency, R , and a dimensionless aquifer frequency Q u . The differences between Q ′ u and Q u are generally small for aquifers which are highly sensitive to Earth tides. When Q ′ u and Q u are large, the response of the well to Earth tides and atmospheric loading approaches the static response of the aquifer under confined conditions. At small values of Q ′ u and Q u , well response to Earth tides and atmospheric loading is strongly influenced by water table drainage. When R is large relative to Q u , the response to atmospheric loading is strongly influenced by attenuation and phase shift of the pneumatic pressure signal in the unsaturated zone. The presence of partial penetration retards phase advance in well response to Earth tides and atmospheric loading. When the theoretical response of a phreatic well to Earth tides and atmospheric loading is fit to the well response inferred from cross-spectral estimation, it is possible to obtain estimates of the pneumatic diffusivity of the unsaturated zone and the vertical hydraulic conductivity of the aquifer.

Water Resources Research↗

USGS2021

Hyperspectral narrowband data propel gigantic leap in the earth remote sensing

Hyperspectral narrowbands (HNBs) capture data as nearly continuous “spectral signatures” rather than a “few spectral data points” along the electromagnetic spectrum as with multispectral broadbands (MBBs). Almost all of satellite remote sensing of the Earth in the twentieth century was conducted using MBB data from sensors such as the Landsat-series, Advanced Very High-Resolution Radiometer (AVHRR), SPOT (Système Pour l’Observation de la Terre), and the Indian Remote Sensing (IRS) satellites. These systems typically provide 4 to 9 broad spectral wavebands spread from 400 to 2500 nm, often with one or two additional bands in the thermal range. Significant advances in the study of the Earth have been made based on these data [Thenkabail et al., 2018a,b,c,d; Thenkabail et al., 2015a,b,c]. Possibilities of great advances that can be made using HNB data over MBB data are well established based on studies conducted using hyperspectral sensors such as the hand-held spectroradiometers, the Airborne Visible/Infrared Imaging Spectrometer (AVIRIS), and spaceborne Earth Observing -1 (EO-1) Hyperion [Thenkabail 2018a,b,c,d]. The twenty-first century is already seeing the dawn of hyperspectral imaging data from sensors such as the German Aerospace Center’s (DLR’s) DESIS (DLR Earth Sensing Imaging Spectrometer) onboard the MUSES (Multi-User System for Earth Sensing) platform on the International Space Station (ISS), the polar-orbiting Italian Space Agency’s (ASI) PRISMA (PRecursore IperSpettrale della Missione Applicativa), and many other upcoming sensors such as the NASA Surface Biology and Geology (SBG) [Thenkabail et al., 2018a,b,c,d]. These satellites acquire data in hundreds of narrow spectral bands of 1 to 10 nm width, typically between 400 to 2500 nm; also future planned missions will be extending HNBs to the thermal (9,000 to 14,000 nm) electromagnetic spectrum. This expansion creates a quantum leap in new data, new information, and myriad possible new applications in the study of the Earth in addition to great advances in existing applications. Given the above, the objective of this article is to provide insights on the gigantic leap in our understanding, modeling, mapping, and monitoring of the Earth that can be made using HNB relative to MBB by focusing on agricultural and vegetation applications. We will address this in four aspects: 1. Comparison between HNB and MBB data; 2. Spectral libraries of agricultural crops; 3. HNB data analysis in general; and 4. HNB analysis using machine learning (ML) and cloud computing.

Photogrammetric Engineering and Remote Sensing.↗

USGS1991

Earth Science Information Center

An ESIC? An Earth Science Information Center. Don't spell it. Say it. ESIC. It rhymes with seasick. You can find information in an information center, of course, and you'll find earth science information in an ESIC. That means information about the land that is the Earth, the land that is below the Earth, and in some instances, the space surrounding the Earth. The U.S. Geological Survey (USGS) operates a network of Earth Science Information Centers that sell earth science products and data. There are more than 75 ESIC's. Some are operated by the USGS, but most are in other State or Federal agencies. Each ESIC responds to requests for information received by telephone, letter, or personal visit. Your personal visit.

Report↗

USGS1993

International strategic minerals inventory summary report; rare-earth oxides

Bastnaesite, monazite, and xenotime are currently the most important rare-earth minerals. Bastnaesite occurs as a primary mineral in carbonatites. Monazite and xenotime also can be found in primary deposits but are recovered principally from heavy-mineral placers that are mined for titanium or tin. Each of these minerals has a different composition of the 15 rare-earth elements. World resources of economically exploitable rare-earth oxides (REO) are estimated at 93.4 million metric tons in place, composed of 93 percent in primary deposits and 7 percent in placers. The average mineral composition is 83 percent bastnaesite, 13 percent monazite, and 4 percent of 10 other minerals. Annual global production is about 67,000 metric tons of which 41 percent is from placers and 59 percent is from primary deposits; mining methods consist of open pits (94 percent) and dredging (6 percent). This output could be doubled if the operations that do not currently recover rare earths would do so. Resources are more than sufficient to meet the demand for the predictable future. About 52 percent of the world's REO resources are located in China. Ranking of other countries is as follows: Namibia (22 percent), the United States (15 percent), Australia (6 percent), and India (3 percent); the remainder is in several other countries. Conversely, 38 percent of the production is in China, 33 percent in the United States, 12 percent in Australia, and 5 percent each in Malaysia and India. Several other countries, including Brazil, Canada, South Africa, Sri Lanka, and Thailand, make up the remainder. Markets for rare earths are mainly in the metallurgical, magnet, ceramic, electronic, chemical, and optical industries. Rare earths improve the physical and rolling properties of iron and steel and add corrosion resistance and strength to structural members at high temperatures. Samarium and neodymium are used in lightweight, powerful magnets for electric motors. Cerium and yttrium increase the density and heat resistance of sintered ceramics. Yttrium and gadolinium contribute to the efficiency of electronic switches and sensors. Cerium improves the effectiveness of catalysts in the petroleum and automotive industries. Cerium oxides speed glass melting and are used to polish glass by chemical, rather than mechanical, means. Cerium, europium, terbium, and yttrium, as phosphoric compounds, promote the vivid colors of television screens. Consumption of rare earths is expected to grow by about 2.6 percent per year.

Circular↗

USGS2010

Earth as art three

For most of us, deserts, mountains, river valleys, coastlines even dry lakebeds are relatively familiar features of the Earth's terrestrial environment. For earth scientists, they are the focus of considerable scientific research. Viewed from a unique and unconventional perspective, Earth's geographic attributes can also be a surprising source of awe-inspiring art. That unique perspective is space. The artists for the Earth as Art Three exhibit are the Landsat 5 and Landsat 7 satellites, which orbit approximately 705 kilometers (438 miles) above the Earth's surface. While studying the images these satellites beam down daily, researchers are often struck by the sheer beauty of the scenes. Such images inspire the imagination and go beyond scientific value to remind us how stunning, intricate, and simply amazing our planet's features can be. Instead of paint, the medium for these works of art is light. But Landsat satellite sensors don't see light as human eyes do; instead, they see radiant energy reflected from Earth's surface in certain wavelengths, or bands, of red, green, blue, and infrared light. When these different bands are combined into a single image, remarkable patterns, colors, and shapes emerge. The Earth as Art Three exhibit provides fresh and inspiring glimpses of different parts of our planet's complex surface. The images in this collection were chosen solely based on their aesthetic appeal. Many of the images have been manipulated to enhance color variations or details. They are not intended for scientific interpretation only for your viewing pleasure. Enjoy!

General Information Product↗

USGS2011

Rare earth elements: end use and recyclability

Rare earth elements are used in mature markets (such as catalysts, glassmaking, lighting, and metallurgy), which account for 59 percent of the total worldwide consumption of rare earth elements, and in newer, high-growth markets (such as battery alloys, ceramics, and permanent magnets), which account for 41 percent of the total worldwide consumption of rare earth elements. In mature market segments, lanthanum and cerium constitute about 80 percent of rare earth elements used, and in new market segments, dysprosium, neodymium, and praseodymium account for about 85 percent of rare earth elements used. Regardless of the end use, rare earth elements are not recycled in large quantities, but could be if recycling became mandated or very high prices of rare earth elements made recycling feasible.

Scientific Investigations Report↗

USGS2023

National preparedness strategy & action plan for potentially hazardous near-Earth objects and planetary defense

Near-Earth Objects (NEOs) are asteroids and comets that orbit the Sun, but have orbits that can bring them into Earth’s neighborhood—within 30 million miles of Earth’s orbit. Planetary defense is “applied planetary science” to address the NEO impact risks on Earth. This National Preparedness Strategy and Action Plan for Near-Earth Objects and Planetary Defense (2023 Planetary Defense Strategy) updates the United States’ first comprehensive Near-Earth Object Preparedness Strategy and Action Plan, released in 2018. The 2023 Planetary Defense Strategy builds on existing efforts by Federal Departments and Agencies to address the hazard of near-Earth object impacts, includes evaluation of where progress has been made since 2018, and focuses future work on planetary defense across the U.S. government. The 2023 Planetary Defense Strategy maintains and updates the core five goals of the 2018 Strategy and Action Plan, while adding a sixth goal to improve governance and interagency coordination on planetary defense issues across Federal Departments and Agencies for the decade ahead. The 2023 Planetary Defense Strategy focuses on six goals: • Goal 1: Enhance NEO detection, tracking, and characterization capabilities. • Goal 2: Improve NEO modeling, prediction, and information integration. • Goal 3: Develop technologies for NEO deflection and disruption missions. • Goal 4: Increase international cooperation on NEO preparation. • Goal 5: Strengthen and routinely exercise NEO impact emergency procedures and action protocols. • Goal 6: Improve U.S. governance of planetary defense through new interagency collaboration.

Report↗

USGS2016

Earth as art 4

Landsat 8 is the latest addition to the long-running series of Earth-observing satellites in the Landsat program that began in 1972. The images featured in this fourth installment of the Earth As Art collection were all acquired by Landsat 8. They show our planet’s diverse landscapes with remarkable clarity. Landsat satellites see the Earth as no human can. Not only do they acquire images from the vantage point of space, but their sensors record infrared as well as visible wavelengths of light. The resulting images often reveal “hidden” details of the Earth’s land surface, making them invaluable for scientific research. As with previous Earth As Art exhibits, these Landsat images were selected solely for their aesthetic appeal. Many of the images have been manipulated to enhance color variations or details. They are not intended for scientific interpretation—only for your viewing pleasure. What do you see in these unique glimpses of the Earth’s continents, islands, and coastlines?

General Information Product↗