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In the second half of the 20th century, the foundation of the U.S. Geological Survey's national map series was the handcrafted 7.5-minute topographic map. Times change, budgets get squeezed and currency expectations become ever more challenging. The USGS's Larry Moore, who oversees data production operations at two National Geospatial Technical Operations Centers, provides an introduction to the new US Topo quadrangle maps.
The U.S. Geological Survey's Larry Moore provides an update on the US Topo effort, the Survey’s general purpose, digital, quadrangle map series. He outlines the successes thus far and the obstacles still ahead in 2013.
The occurrence of numerous terraces on the mountain slopes over-looking the Dead Sea has been reported by several observers, but no accurate measurements of their elevations or definite correlation of the terraces on the opposite slopes of the depression, seem to have been attempted. In the central part of the Wady Arabah on the west flank of the promontory known as Samrat el Fedan, a terrace, or perhaps more properly a gravel bar, has been observed by Hull at an elevation of about 1300 feet above the Dead Sea. This is apparently a definite record of the surface level of the Dead Sea during a former period. On the sides of the Jordan valley the terraces range in height from a few feet to 750 feet above the river. The measurements reported show great variation due principally to an inclination of the surfaces of the terraces, towards the centre of the valley, but indicating also that they are not horizontal in the direction of drainage.
The following account of the geology of the Dead Sea basin A. has been compiled from the observations of others, and I am especially indebted in this connection to H. J. Johnson, Geologist of the United States Expedition to the Dead Sea, to Professor Louis Lartet, Geologist of the Due de Luynes' Expedition to the same region, and to Prof. Edward Hull, F.R.S., Director of the Geological Survey of Ireland, who visited Arabia Petraaa and Palestine in 1883–84, under the auspices of the Committee of the Palestine Exploration Fund. Besides these observers, who devoted their attention specially to the geology of the regions traversed during their several expeditions, the writer is under obligations to the Ordnance Survey of Palestine, and to many observant travellers, including Condor, Fraas, Tristram, Wilson, and others, for many interesting details and attractive descriptions concerning the regions to which it is desired to direct the reader's attention.
The Blue Ridge thrust sheet is one of the principal thrust masses of metamorphic rocks in the southern Appalachians. A broad zone of sheared and retrogressively metamorphosed rocks near the sole of the thrust sheet around the Grandfather Mountain window displays numerous small tight or isoclinal folds having axes subparallel to an intense penetrative cataclastic a lineation and axial planes parallel to foliation in the thrust sheet. These folds seem to have formed by tightening, flattening, and passive rotation of earlier more open folds originally formed perpendicular to the direction of transport. The style and orientation of these folds closely resemble those of analogous structures in thrust masses of crystalline rocks in the Caledonian orogenic belt in Scotland and Norway, suggesting that the structures of both regions may have similar origins.
Understanding the effects of hydrology on fish populations is essential to managing for native fish conservation. However, despite decades of research illustrating streamflow influences on fish habitat, reproduction and survival, biologists remain challenged when tasked with predicting how fish populations will respond to changes in flow regimes. This uncertainty stems from insufficient understanding of the context-dependent mechanisms underlying fish responses to, for example, periods of reduced flow or altered frequency of high-flow events. We aim to address this gap by drawing on previous research to hypothesize mechanisms by which low- and high-flows influence fish populations and communities, identifying challenges that stem from data limitations and ecological complexity, and outlining research directions that can advance an empirical basis for prediction. Focusing flow-ecology research on testing and refining mechanistic hypotheses can help narrow management uncertainties and better support species conservation in changing flow regimes.
Most processes controlling volcanic activity involve underground mass redistribution (e.g., magma accumulation or withdrawal). Because of its unique ability to provide direct information on subsurface mass/density changes over time, gravimetry has important advantages over other volcano-monitoring techniques. As an example, if pre-eruptive magma accumulation occurs in voids, surface uplift or seismicity may not occur because the stress transmitted to the surrounding rock is not enough to induce fracturing or deformation; nevertheless, the addition of new mass would be associated with a gravity increase that may be measurable at the surface [1].
We explored the conservation potential of tributaries in the upper Colorado River basin by modeling native fish species richness as a function of river discharge, temperature, barrier‐free length, and distance to nearest free‐flowing main‐stem section. We investigated a historic period prior to large‐scale water development and a contemporary period. In the historic period, species richness was log‐linearly correlated to variables capturing flow magnitude, particularly mean annual discharge. In the contemporary period, the log‐linear relationship between discharge and species richness was still evident but weaker. Tributaries with lower average temperature and separated from free‐flowing main‐stem sections often had fewer native species compared to tributaries with similar discharge but with warmer temperature and directly connected to free‐flowing main stems. Thus, tributaries containing only a small proportion of main‐stem discharge, especially those at lower elevations with warmer temperatures and connected to free‐flowing main stems, can support a relatively high species richness. Tributaries can help maintain viable populations by providing ecological processes disrupted on large regulated rivers, such as natural flow and temperature regimes, and may present unique conservation opportunities. Efforts to improve fish passage, secure environmental flows, and restore habitat in these tributaries could greatly contribute to conservation of native fish richness throughout the watershed.
The historical context of current environment conditions offers vital guidance to North American fisheries professionals as they strive to develop effective management plans and policies. This retrospective includes understanding the remarkable historic fisheries resource and causative reasons for establishing their public fisheries agencies and the American Fisheries Society (Society). Through a review of primary historical documents and literature for North America, this paper identifies: factors contributing to the of founding of the Society and public fish commissions; shows how selected resource issues evolved; and documents how and why selected fisheries and aquatic habitat policies changed in response to those issues. Overexploitation, landscape-scale habitat alterations, mining, and dams were the causative agents for emergence of fisheries agencies and the Society, and these environmental factors remain relevant today. Beginning in the 1960s, after 100 years of inaction, North Americans grew tired of degraded waters and fisheries and forced policy changes that have directly and indirectly affected the fisheries we manage today. The historical events and resulting corrective legislation are taken for granted by those unaware that our Society has actively participated in developing policies to address these environmental harms. Further, the Society continues to play a vital role in identifying key issues, providing conduits for information to cope with impairments, and advocating for policies to conserve intact habitats and improve degraded systems. The struggles documented in this paper offer crucial lessons as we continue to be challenged by legacy resource issues and face emerging environmental stressors such as climate change as well as regression in long-standing environmental protection policies.
Understanding and predicting recruitment, longstanding goals in fisheries science and ecology, are complicated by variation in the importance of environmental drivers coupled with the dynamic nature of individual ecosystems. Developing an understanding of recruitment from well-monitored stocks offers an opportunity to overcome these complexities. We used a systematic literature review, a survey, and a workshop attended by professionals with expertise in recruitment of Walleye Sander vitreus to identify common environmental drivers of Walleye recruitment and additional sources of variation (i.e., context dependencies) among populations. The importance of individual environmental drivers, as well as the direction of their influence, differed as a function of geographic region, lake surface area, and Walleye life stage. The literature suggested abiotic conditions (e.g., temperature) during the first year of life were influential in determining recruitment. Professional opinion noted the importance of biotic factors, with prey availability and predation risk having the most consistent relationships with recruitment. We synthesized this information to propose a conceptual model that illustrates the suite of characteristics that shape Walleye recruitment over large spatial and temporal scales. Our findings emphasize the importance of first-year growth and system-specific contextual factors, which can alter the relative importance of the environmental drivers of recruitment.
By merging our specialization silos, fisheries professionals can expand the options that are available to them to address difficult fisheries and aquatic conservation problems, which require an understanding of spatial patterns in geographically large systems. Our purpose is to start a profession-wide conversation about additional ways to think about and use spatial data. We use case studies to illustrate how identifying and merging multiple specialized approaches (e.g., fish tracking, fish surveys, geomorphology, social science, jurisdictional viewpoints) can create an ensemble that has advantages over the use of any single approach alone. Thus, our perspective is not about solving a specific technical problem with a new tool, but about the benefits of identifying gaps in data from one specialized approach, and filling those gaps with data from other specialized approaches. If multiple approaches are coordinated through a larger, problem-specific planning strategy, the result can be better outcomes for difficult problems through creative integration. We encourage others to add constructive ideas to the views initiated here.
Reservoirs in the Mississippi River basin are facing three momentous threats. The first two, aging and climate change, are relatively slow moving and their signal can be hard to discern given their stretched temporal scales. The third, species invasions, is faster paced and discernable within shorter temporal scales and restricted spatial scales. Aging and climate directly affect reservoir environments and indirectly affect their biotic communities. Climate change is expected to interact with aging to speed up and, in some instances, slow down aging. Conversely, invasions primarily imperil biotic communities but can also impact environmental elements. This triple jeopardy is expected to transform reservoir environs and their biotic assemblages in various, often uncertain, ways. I take a broad view of these threats within the Mississippi River basin. A basin-scale perspective, in contrast to a single reservoir or regional scale, may enhance awareness of reservoirs at a larger level and produce understanding less evident at local levels, hence possibly offering a wider range of choices for confronting threats. My aim is to (1) provide a synopsis of the assemblage of reservoirs and their attributes over the Mississippi River basin, (2) describe the issues related to aging, climate change, and invasions, and (3) consider a conservation framework for confronting these pressures. Given the overlapping temporal, spatial, and ecological effects of these threats, it is essential to address their effects simultaneously.
The turquoise group has the general formula: A (sub 0-1) B 6 (PO 4 ) (sub 4-x) (PO 3 OH) x (OH) 8 .4H 2 O, where x = 0-2, and consists of six members: planerite, turquoise, faustite, aheylite, chalcosiderite and an unnamed Fe (super 2+) -Fe (super 3+) analogue. The existence of "coeruleolactite" is doubtful. Planerite is revalidated as a species and is characterized by a dominant A-site vacancy. Aheylite is established as a new member of the group, and is characterized by having Fe (super 2+) dominant in the A-site. Chemical analyses of 15 pure samples of microcrystalline planerite, turquoise, and aheylite show that a maximum of two of the (PO 4 ) groups are protonated (PO 3 OH) in planerite. Complete solid solution exists between planerite and turquoise. Other members of the group show variable A-site vacancy as well. Most samples of "turquoise" are cation-deficient or are planerite. Direct determination of water indicates that there are 4 molecules of water. Planerite, ideally []Al 6 (PO 4 ) 2 (PO 3 OH) 2 (OH) 8 .4H 2 O, is white, pale blue or pale green, and occurs as mamillary, botryoidal crusts as much as several mm thick; may also be massive; microcrystalline, crystals typically 2-4 micrometres, luster chalky to earthy, H. 5, somewhat brittle, no cleavage observed, splintery fracture, D m 2.68(2), D c 2.71, not magnetic, not fluorescent, mean RI about 1.60. a 7.505(2), b 9.723(3), c 7.814(2) Aa, alpha 111.43 degrees , beta 115.56 degrees , Gamma 68.69 degrees , V 464.2(1) Aa 3 , Z = 1. Aheylite, ideally Fe (super 2+) Al 6 (PO 4 ) 4 (OH) 8 .4H 2 O, is pale blue or green, and occurs as isolated and aggregate clumps of hemispherical or spherical, radiating to interlocked masses of crystals that average 3 micrometres in maximum dimension; porcelaneous-subvitreous luster, moderate to brittle tenacity, no cleavage observed, hackly to splintery fracture, not magnetic, not fluorescent, biax. (+), mean RI is about 1.63, D m 2.84(2), D c 2.90. a 7.400(1), b 9.896(1), c 7.627(1) Aa, alpha 110.87 degrees , beta 115.00 degrees , gamma 69.96 degrees , V 460.62(9) Aa 3 , Z = 1.