bluuebunny/crossref_metadata_2025_split huggingface dataset:
A long‐term circulation and water mass monitoring program for the Arctic Ocean
Authors: Polyakov Igor , Walsh David , Dmitrenko Igor , Colony Roger , Hutchings Jennifer , Timokhov Leonid , Johnson Mark , Carmack Eddy 
Published: October 2006

Substantial changes have occurred in the Arctic over the last few decades. These changes are linked with the variability of external climate system in ways not yet fully understood. Unresolved issues concerning the driving processes and mechanisms behind these changes in the Arctic environment require further investigation.A major constraint on our ability to understand linkages between the Arctic Ocean and the global climate system is the scarcity of observational data. We have thus initiated efforts to establish a long‐term, mooring‐based observational system in the Eurasian and Canadian basins of the Arctic Ocean. A number of regional monitoring programs have elucidated local details of the circulation, but none has provided the large‐scale coverage proposed here (Figure l). The widely spaced array of moorings discussed here will emphasize the largest‐scale modes of variability over relevant time scales.
Amphibious seismic survey images plate interface at 1960 Chile Earthquake
Authors: Krawcyzk C. ,   The SPOC Team
Published: October 2006

The southern central Chilean margin at the site of the largest historically recorded earthquake in the Valdivia region, in 1960 (Mw = 9.5), is part of the 5000‐km‐long active subduction system whose geodynamic evolution is controversially debated and poorly understood. Covering the area between 36° and 40°S, the oceanic crust is segmented by prominent fracture zones. The offshore forearc and its onshore continuation show a complex image with segments of varying geophysical character, and several fault systems active during the past 24 m.y.In autumn 2001, the project SPOC was organized to study the Subduction Processes Off Chile, with a focus on the seismogenic coupling zone and the forearc. The acquired seismic data crossing the Chilean subduction system were gathered in a combined offshore‐onshore survey and provide new insights into the lithospheric structure and evolution of active margins with insignificant frontal accretion.
The MOBB experiment: A prototype permanent off‐shore ocean bottom broadband station
Authors: Romanowicz Barbara , Stakes Debra , Uhrhammer Robert , McGill Paul , Neuhauser Doug , Ramirez Tony , Dolenc David 
Published: October 2006

Technical accomplishments of the past 10 years in the design and deployment of sea floor broadband seismic systems are now making it possible to start addressing the issue of the limited coverage of the Earth that can be achieved through land‐based installations, at the regional or global scale. In particular, the September 2002 Ocean Mantle Dynamics (OMD) workshop in Snowbird, Utah [OMD Workshop Committee, 2003] proposed the development of two “leap‐frogging arrays” of about 30 broadband sea floor instruments to fill geophysically important target holes in ocean coverage for deployment periods of 1 to 2 years. The rationale for an off‐shore (“Webfoot”) component of the SArray/Earth‐scope “Bigfoot” array was also highlighted at this meeting, pointing out that the study of the North American continent should not stop at the ocean margin.The ocean floor environment is challenging for broadband seismology for several reasons. Broadband seismometers cannot be simply “dropped off” a ship with the expectation that they will produce useable data, particularly on the horizontal components. Several pilot experiments, [e.g., Montagner et al., 1994; OSN1, 1998; Suyehiro et al., 2002] have addressed the issue of optimal installation of ocean bottom stations, and in particular, have carried out comparisons between borehole, sea floor, and buried sea floor installations.
Atmospheric Pollution: History, Science and Regulation
Authors: Fraser Matt 
Published: October 2006

There is no shortage of textbooks available for introductory courses on air pollution. However, finding a text that is ideally suited for a specific course can be nearly impossible, since the focus of the text never quite matches what you want to teach in the course. Atmospheric Pollution: History, Science and Regulation, by Mark Z. Jacobson, provides a novel perspective on air pollution by examining the historical developments of air pollution science and regulation prior to presenting information on the major air pollution issues of today.The first two chapters set the stage for studying the atmosphere from a historical context. In the first chapter, the basics of atmospheric gases and particles are defined, and the topic progresses to a historical accounting of the discoveries of the important atmospheric chemicals. The author discusses the experiments that determined the composition of the various trace gases present in the atmosphere, and how the misinterpretation of some experiments led to incorrect conclusions about the makeup of atmospheric trace gases. The second chapter focuses on the evolution of the Earth's atmosphere, beginning at the time of formation of the Sun and Earth, the evolution of a pre‐biotic atmosphere into an anoxic biotic atmosphere, and finally the evolution of oxygen through photosynthesis. This material provided new insight into how trace gases were first discovered and how the atmosphere evolved. While this might be fascinating to someone who has spent years studying the present‐day atmosphere, it may not necessarily be important in an introductory course.
Geophysical project in Ethiopia studies continental breakup
Authors: Maguire P. K. H. , Ebinger C. J. , Stuart G. W. , Mackenzie G. D. , Whaler K. A. , Kendall J.‐M. , Khan M. A. , Fowler C. M. R. , Klemperer S. L. , Keller G. R. , Harder S. , Furman T. , Mickus K. , Asfaw Laike , Ayele Atalay , Abebe Bekele 
Published: October 2006

As continental rift zones evolve to sea floor spreading, they do so through progressive episodes of lithospheric stretching, heating, and magmatism, yet the actual process of continental breakup is poorly understood. The East African Rift system in northeastern Ethiopia is central to our understanding of this process, as it lies at the transition between continental and oceanic rifting [Ebinger and Casey, 2001].We are exploring the kinematics and dynamics of continental breakup through the Ethiopia Afar Geoscientific Lithospheric Experiment (EAGLE), which aims to probe the crust and upper mantle structure between the Main Ethiopian (continental) and Afar (ocean spreading) rifts, a region providing an ideal laboratory to examine the process of breakup as it is occurring. EAGLE is a multidisciplinary study centered around the most advanced seismic project yet undertaken in Africa (Figure l). Our study follows the Kenya Rift International Seismic Project [e.g., KRISP Working Group, 1995],and capitalizes on the IRIS/PASSCAL broadband seismic array [Nyblade and Langston, 2002], providing a telescoping view of the East African Rift within this suspected plume province.
Seismic experiment searches for active magmatic source in deep lithosphere, central Europe
Authors: Babska Vladišlav , Plomerová Jaroslava ,   BOHEMA Working Group
Published: October 2006

The Bohemian Massif (BM) is the largest coherent surface exposure of basement rocks in central Europe. It is a geodynamically active part of the Hercynian orogenic belt representing a collage of magmatic arcs and micro‐continents caused by the collision of Laurasia (Laurentia‐Baltica) and Africa (Gondwana). The general northwest direction of accretion is typical of the northern part of the Hercynian belt. Irregularly‐shaped colliding blocks resulted in a very complicated structure of convergence, lithospheric subduction, and crustal shortening, followed by extensional processes and rifting.The western part of the Bohemian Massif is the well‐known health and resort landscape of Bohemia, Saxonia, and Bavaria, with Karlovy Vary (Karlsbad) as the flagship of the famous spa towns of the region (Figure 1). Allegedly, the Emperor Charles IV founded the spa in the years 1347–1349 at the site, which was already well known for its hot springs. For centuries, 12 springs in Karlovy Vary ranging in temperatures between 42°C and 72°C have been exploited, especially for the treatment of digestive system disorders and metabolic diseases.
Deep electromagnetic soundings conducted in Trans‐European Suture Zone
Authors: Semenov Vladimir Yu. , Jozwiak Waldemar , Pek Josef 
Published: October 2006

A consortium of nine geophysical institutions recently carried out a large‐scale geomagnetic experiment focused on revealing the deep electrical structure beneath central and eastern Europe around the Trans‐European Suture Zone (TESZ), the region's first‐order geological lineament. The TESZ is considered a broad zone of deformation that crosses all of Europe, from the British Isles in the northwest to the Black Sea area in the southeast, and it most likely continues in North America [Keller and Hatcher, 1999].The geomagnetic experiment was called Central Europe Mantle Geoelectrical Structure (CEMES). Initiated by Polish scientists, geophysicists from eight other countries joined the project during a NATO Advanced Research Workshop held in the spring of 2001 in Belsk, Poland. The experimental phase of the project was held from 2001 through 2002; and altogether, 12 geomagnetic observatories, the international codes of which are shown among others in Figure 1, took part in acquiring the data. They will serve the objective of inferring information on the mantle conductivity structures beneath the region of TESZ, as well as beneath surrounding units, specifically the western part of the East European Craton (EEC), Variscides, including the Bohemian Massif, the Carpathians, and the Pannonian Basin.
The role of greenhouse gases in orbital‐scale climatic changes
Authors: Ruddiman William F. 
Published: October 2006

A decade ago, the Spectral Analysis, Mapping and Prediction Project (SPECMAP) analyzed the relationship between changes in Earth's orbit produced by variations in obliquity precession, and eccentricity and all available long‐term responses observed within the climate system [Imbrie et al., 1992, 1993]. In the intervening decade, improvements to the gas time scale for the Vostok ice core from Antarctica have provided age constraints on greenhouse gas changes that are comparable to those for climatic responses based on marine δ18O signals; these prompted a new investigation of the orbital‐scale climatic changes.Milutin Milankovitch proposed that variations in northern hemisphere summer radiation at the 22,000‐yr precession cycle and 41,000‐yr obliquity cycle drive northern ice sheets by summer ablation control of ice mass balance, and he inferred that ice sheet responses should lag 5000 years behind summer radiation forcing. In confirmation of Milankovitch's hypothesis, Hays et al. [1976] found that coherent changes in δ18O lag several thousand years behind the forcing at those two orbital cycles. Imbrie et al. [1984] determined that δ18O lags of 5000 years behind precession and 8000 years behind obliquity simultaneously satisfied a 17,000‐yr time constant of ice response (Figure 1a). These studies also detected a dominant δ18O response at 100,000 years that Milankovitch had not anticipated because direct solar forcing at that period is negligible. Because the 100,000‐yr δ18O signal is phased with orbital eccentricity, Hays et al. [1976] called it a “paced” response but left its origin unresolved.
U.S. stream flow measurement and data dissemination improve
Authors: Hirsch Robert M. , Costa John E. 
Published: October 2006

Stream flow information is essential for many important uses across a broad range of scales, including global water balances, engineering design, flood forecasting, reservoir operations, navigation, water supply, recreation, and environmental management. Growing populations and competing priorities for water, including preservation and restoration of aquatic habitat, are spurring demand for more accurate, timely, and accessible water data. To be most useful, stream flow information must be collected in a standardized manner, with a known accuracy and for a long and continuous time period.The U.S. Geological Survey (USGS) operates over 7000 stream gauges nationwide, which constitute over 90% of the nation's stream gauges that provide daily stream flow records, and that are accessible to the public. Most stream flow records are not based on direct measurement of river discharge, but are derived from continuous measurements of river elevations or stage. These stage data, recorded to 3‐mm accuracy are then converted into discharge by use of a stage/discharge relation (rating) that is unique for each stream gauging location. Because stream beds and banks are not static, neither is the stage discharge rating. Much of the effort and cost associated with stream gauging lies in establishing and updating this relation. Ten years ago, USGS personnel would visit stream gauging stations 8 to 10 times a year to make direct measurements of river depth, width, and velocity using mechanical instruments: a sounding rod or cable, a tagline, and a current meter. From these data, flow rates were computed.The range of measured flow and concurrent river stages were then used to build the rating curve for each site and to track changes to the rating curve.
Central Arctic: Battleground of natural and man‐made climate forcing
Authors: Kukla George 
Published: October 2006

Alarming observations have been reported on recent climate changes in the Arctic. Sea ice is thinning and shrinking, and its area was the lowest since 1979 when systematic microwave satellite observations began. Will the summertime ice completely disappear due to man‐made greenhouse gases as predicted by climate models?Twenty‐three experts from the United States and abroad gathered in January to address this question. Additional scientists participated in the discussion sessions or contributed by mail.
Soliciting participation in climate model analyses leading to IPCC fourth assessment report
Authors: Meehl Gerald , Covey CurtCurt , Latif MojibMojib 
Published: October 2006

Looking for a way to get involved in the IPCC Fourth Assessment Report (AR4)?Here's an opportunity to do so. You can sign up now to analyze some aspect of the 20th century or future climate simulations being performed by about 14 modeling groups around the world. These analyses will begin when the model simulations currently running are completed and the model data is collected and archived in September of this year.
The western U.S. drought: How bad is it?
Authors: Piechota Thomas , Timilsena Janak , Tootle Glenn , Hidalgo Hugo 
Published: October 2006

Historical stream flow records and the forecast for 2004 make the current (1999–2004) drought in the southwestern United States the worst one in the past 80 years for portions of the Upper Colorado River Basin (UCRB).For the Colorado River (near Cisco, Utah), the cumulative stream flow deficit (departure from long‐term mean) for the current drought is almost 11 km8, or approximately 2 years of average stream flow Although the current drought is the most significant, based on historical stream flow records, is it the worst ever?
Is the climate of the Bering Sea warming and affecting the ecosystem?
Authors: Overland James E. , Stabeno Phyllis J. 
Published: October 2006

Observations from the Bering Sea are good indicators of decadal shifts in climate, as the Bering is a transition region between the cold, dry Arctic air mass to the north, and the moist, relatively warm maritime air mass to the south. The Bering Sea is also a transition region between Arctic and sub‐Arctic ecosystems; this boundary can be loosely identified with the extent of winter sea‐ice cover.Like a similar transition zone in the eastern North Atlantic [Beaugrand et al., 2002], the Bering Sea is experiencing a northward biogeographical shift in response to changing temperature and atmospheric forcing. If this shift continues over the next decade, it will have major impacts on commercial and subsistence harvests as Arctic species are displaced by sub‐Arctic species. The stakes are enormous, as this rich and diverse ecosystem currently provides 47% of the U.S. fishery production by weight, and is home to 80% of the U.S. sea bird population, 95% of northern fur seals, and major populations of Steller sea lions, walrus, and whales.
Thermogenic gas hydrates in the northern Cascadia margin
Authors: Chapman Ross , Pohlman John , Coffin Rick , Chanton Jeff , Lapham Laura 
Published: October 2006

Gas hydrates are ice‐like solids that form in rigid cage structures under specific conditions of pressure, temperature, and gas and water concentration. Marine gas hydrates are stable in pore spaces of sediments in water depths greater than ∼300 m beneath the slopes of active and passive continental margins [Kvenvolden, 1988]. The lower limit of hydrate occurrence in marine sediments is determined by the geothermal gradient, so that the zone of hydrate stability is generally contained within the first few hundred meters of sediment. Continental hydrates occur in polar permafrost regions in the Arctic and Siberia. Most of the hydrates that have been discovered contain methane derived from microbial processes.Other hydrocarbons can also form hydrates, but in different structures of the surrounding water cages. Structure I, the most prevalent form, contains mostly (>99%) microbial methane, a small amount of ethane, and traces of C2+ hydrocarbons [Sassen et al, 2001]. Structure II and structure H hydrates contain significant quantities of thermogenic methane and larger, more complex hydrocarbons formed at high temperatures from fossil organic matter (i.e.,kerogen) or oil [Sassen and MacDonald, 1994].The gas origin is inferred from measurements of the carbon‐13 isotopic ratio (δ13); microbial methane is depleted in 13C (δ13 <−60‰) relative to thermogenic methane (δ13 from −20‰ to −50‰).
New insights into the origin and evolution of the Hikurangi oceanic plateau
Authors: Hoernle Kaj , Hauff Folkmar , Werner Reinhard , Mortimer Nicholas 
Published: October 2006

Oceanic plateaus and continental flood basalts, collectively referred to as large igneous provinces (LIPs), represent the most voluminous volcanic events on Earth. In contrast to continental LIPs, relatively little is known about the surface and internal structure, range in age and chemical composition, origin, and evolution of oceanic plateaus, which occur throughout the worlds oceans [e.g., Mahoney and Coffin, 1997].One of the major goals of the R/V Sonne SO168 ZEALANDIA expedition (depart Wellington, 3 December 2002, return Christchurch, 15 January 2003) was to investigate the Hikurangi oceanic plateau off the east coast of New Zealand.
New integrated data management system for Ridge2000 and MARGINS research
Authors: Carbotte S. M. , Arko R. , Chayes D. N. , Haxby W. , Lehnert K. , O'Hara S. , Ryan W. B. F. , Weissel R. A. , Shipley T. , Gahagan L. , Johnson K. , Shank T. 
Published: October 2006

The initiation of dedicated databases for the U.S. National Science Foundation (NSF)‐supported Ridge2000 and MARGINS programs provides the opportunity to develop a data management system capable of handling the primary data types of marine geoscience research.Ridge2000 and MARGINS are broad initiatives focused on fundamental problems of crustal creation, evolution, and destruction along the world's tectonic plate boundaries. These programs involve the collection of a wide range of geophysical data types, as well as rock, fluid, and biological samples, and time series data.
Multidisciplinary impact of the deep mantle phase transition in perovskite structure
Authors: Lay Thorne , Heinz Dion , Ishii Miaki , Shim Sang‐Heon , Tsuchiya Jun , Tsuchiya Taku , Wentzcovich Renata , Yuen David 
Published: October 2006

A phase transition in (Mg, Fe) SiO3 (magnesium silicate‐perovskite) for pressure‐temperature conditions near the base of Earth's mantle, first reported in May 2004, is stimulating strong multidisciplinary excitement and interactions. Experimentally and theoretically determined characteristics of this phase transition indicate that it may hold the key to understanding enigmatic seismological structures in the D” region of the lowermost mantle, with important implications for heat transport, thermal instabilities, and chemical properties of the lower mantle.All minerals undergo phase transitions with increasing depth into the Earth, reorganizing their crystal structures into denser‐packed forms stable over a finite range of pressures and temperatures. The changes in material properties across such transitions often give rise to detectable contrasts in seismic velocities and density.
Mount St. Helens reawakens
Authors: Dzurisin Daniel , Vallance James W. , Gerlach Terrance M. , Moran Seth C. , Malone Stephen D. 
Published: October 2006

Following 18 years of relative quiescence, Mount St. Helens volcano (MSH) became restless and began erupting again during September–December 2004.On 23 September, the U.S. Geological Survey's (USGS) David A. Johnston Cascades Volcano Observatory (CVO) and the Pacific Northwest Seismograph Network (PNSN) at the University of Washington detected the onset of a shallow earthquake swarm beneath the 1980–1986 lava dome. The Mount St. Helens Emergency Response Plan defines three alert levels that differ from normal background activity: Level 1, Notice of Volcanic Unrest (unusual activity detected); Level 2, Volcano Advisory (eruption likely but not imminent); and Level 3, Volcano Alert (eruption imminent or in progress).
Community InSAR Workshop calls for robust program and dedicated satellite mission
Authors: Donnellan Andrea , Glasscoe Margaret , Zebker Howard 
Published: October 2006

A recent workshop to guide U.S. efforts in interferometric synthetic aperture radar (InSAR) was supported by an overwhelming community response. Workshop participants called for a robust InSAR program that includes improved access to InSAR data and a dedicated U.S.‐led InSAR mission.Held last fall, the workshop brought together researchers in the fields of crustal deformation, cryospheric studies, hydrology land cover, oceanography, and planetary sciences with specialists in information technology and education and outreach. The workshop's purpose was to inform the community of the state of the art in satellite radar, to describe mission opportunities, and to receive community recommendations for needed InSAR measurements of Earth and planetary processes. Over 350 people registered their interest in the workshop, and 220 participants from 116 institutions and a variety of disciplines attended.
Integrating climate‐hydrology forecasts and multi‐objective reservoir management for northern California
Authors: Georgakakos K. P. , Graham N. E. , Carpenter T. M. , Yao H. 
Published: October 2006

The Integrated Forecast and Reservoir Management (INFORM) Project was conceived to demonstrate increased water‐use efficiency in Northern California water resources operations through (1) the innovative application of climate, hydrologic, and decision science, and (2) reciprocal technology transfer activities between the INFORM scientists and the staff of federal and state agencies with an operational forecast and management mandate in Northern California.Toward achieving this goal, INFORM objectives include implementing a prototype integrated forecast‐management system for primary Northern California reservoirs, for individual reservoirs as well as system‐wise. Project objectives also include demonstrating the utility of climate and hydrologic forecasts through near‐real‐time tests of the integrated system with actual data and management input.