• Nitrate inhibited U(VI) reduction in acetate-amended aquifer sediments collected from a uranium-contaminated site in New Mexico. (umass.edu)
  • Knowledge of sediment transport is most often used to determine whether erosion or deposition will occur, the magnitude of this erosion or deposition, and the time and distance over which it will occur. (wikipedia.org)
  • This river, like other braided streams , rapidly changes the positions of its channels through processes of erosion , sediment transport, and deposition . (wikipedia.org)
  • Glaciers can carry the largest sediment, and areas of glacial deposition often contain a large number of glacial erratics , many of which are several metres in diameter. (wikipedia.org)
  • The passage of Hurricane Wilma across Shark River estuary in 2005 allowed us to quantify sediment deposition and nutrient inputs in FCE mangrove forests associated with this storm event and to evaluate whether these pulsing events are sufficient to regulate nutrient biogeochemistry in mangrove forests of south Florida. (springer.com)
  • The Earth-sculpting processes of weathering, erosion, sediment transport and deposition occur everywhere on Earth's surface. (carleton.edu)
  • Off active major deposition centres, such as the Mississippi delta, slope sequences may accumulate through progradation, while the active slope front is continuously shedding sediments downslope by gravity processes. (britannica.com)
  • Study of geologic records of dust composition, sources and deposition rates is important for understanding the role of dust in the overall planetary radiation balance, fertilization of organisms in the world's oceans, nutrient additions to the terrestrial biosphere and soils, and for paleoclimatic reconstructions. (unl.edu)
  • Presentations at the workshop provided a guide to our present knowledge of the entire spectrum of processes and phenomena important to the generation, transport, and deposition of eolian terrigenous material that ultimately becomes part of the geologic record and the modeling techniques that used to represent these processes. (bookdepository.com)
  • The presenta- tions on the geologic record of eolian deposition documented our present understanding of the na~e and causes of climate change on time scales of the last glacial ages (tens of thousands of years) to time scales over which the arrangement of continents, mountains, and oceans has changed sub- stantially (tens of millions of years). (bookdepository.com)
  • Most of the tilting developed after deposition of Permian sediments. (ku.edu)
  • Aeolian processes , involving erosion, transportation, and deposition of sediment by the wind, occur in a variety of environments, including the coastal zone, cold and hot deserts, and agricultural fields. (nps.gov)
  • If this enormous thickness of sediments was deposited over 500 or more million years, as conventionally believed, then some boundaries between layers should show evidence of millions of years of slow erosion, when deposition was not occurring, just as erosion is occurring on some land surfaces today. (answersingenesis.org)
  • On the other hand, if this enormous thickness of sediments was all deposited in just over a year during the Genesis Flood, then the boundaries between the layers should show evidence of continuous rapid deposition, with only occasional rapid erosion or no erosion at all. (answersingenesis.org)
  • The primary sources of data are 'geohistorical': the fossils, geochemistry and sediments of the geologic record. (nsf.gov)
  • This vertical display of the various geologic eras, periods, and epochs supposedly illustrates the nature of the fossil record, with recent fossils on the top and older ones on the bottom. (icr.org)
  • There are fossils in the metamorphosed sediments of a type of blue-green algae called stromatolites. (idaho.gov)
  • Geologic units from the same time but different parts of the world often look different and contain different fossils, so the same time-span was historically given different names in different locales. (wikipedia.org)
  • At the start of the Flood all the fountains of the great deep were rent open sending repeated pulses of water toward the continents from every direction bringing sediments and marine fossils to the land. (icr.org)
  • This immobility makes it highly unlikely that these porphyrins could have moved from younger formations into the Nonesuch sediments, and the widely disseminated particulate organic matters and fossils in this Precambrian shale are certainly indigenous. (sciencemag.org)
  • What geologic conditions lead to the formation of fossils. (scienceviews.com)
  • This sediment is important to the soil budget and ecology of several islands. (wikipedia.org)
  • Total P inputs from storm-derived sediments were equivalent to twice the average surface soil nutrient P density (0.19 mg cm −3 ). (springer.com)
  • Allochthonous mineral inputs from Hurricane Wilma represent a significant source of sediment to soil vertical accretion rates and nutrient resources in mangroves of southwestern Everglades. (springer.com)
  • The measured volumes of sediment, watershed morphology, distributions of burn severity within each watershed, the time since the most recent fire, triggering storm rainfall conditions, and engineering soil properties were analyzed using multiple linear regressions to develop two models. (usgs.gov)
  • This book provides the most up-to-date information on synchrotron-based research applications in the field of soil, sediment and earth sciences. (elsevier.com)
  • Grains begin to move and sediment is entrained by the wind when fluid forces (lift, drag, moment) exceed the effects of the weight of the particle, and any cohesion between adjacent particles as a result of moisture, salts, or soil crusts. (nps.gov)
  • The UPV/EHU's Hydrology and Environment Research Group has located the stretches in the River Deba and its tributaries posing the greatest potential hazard owing to their high metal content, has identified the sources of pollution and has assessed the effect that a certain type of flood event has on the carrying away and distribution of sediments and associated metals. (phys.org)
  • The UPV/EHU's Hydrology-Environment Group has conducted research on the River Deba and its tributaries to assess the influence of anthropogenic inputs and the effect exerted by major flooding events on the distribution of the metals associated with the sediments. (phys.org)
  • Clear Creek Section in Marshall County showing thick glacial sediments. (illinois.edu)
  • On April 20, glacial geologists and mappers from geological surveys of the eight Great Lakes states, Kentucky, Ontario, and the U.S. Geological Survey (USGS) gathered at the Illinois State Geological Survey (ISGS) for their annual meeting of the Great Lakes Geologic Mapping Coalition. (illinois.edu)
  • that also present abundant geologic hazards. (carleton.edu)
  • Debris flows and sediment-laden floods in the Transverse Ranges of southern California pose severe hazards to nearby communities and infrastructure. (usgs.gov)
  • It's public, but whether it gets disseminated to the people who make land-use decisions and planning for geologic hazards doesn't necessarily happen," said Dan McShane, a geologist in Whatcom County, Wash. (pbs.org)
  • In addition, hydrologic modeling will predict the discharge and sediment flux from the watershed under different climate conditions. (carleton.edu)
  • This river is characterized by a flash flood regime discharging large amounts of water (more than 20 times the mean water discharge) and sediment in very short periods lasting from hours to few days. (usgs.gov)
  • The Hydraulics Characteristics section presents a survey of the hydraulic characteristics of the river, examining a number of variables that affect water discharge and sediment load. (ku.edu)
  • Aeolian or eolian (depending on the parsing of æ ) is the term for sediment transport by wind . (wikipedia.org)
  • Bedforms are generated by aeolian sediment transport in the terrestrial near-surface environment. (wikipedia.org)
  • Aeolian sediment transport is common on beaches and in the arid regions of the world, because it is in these environments that vegetation does not prevent the presence and motion of fields of sand. (wikipedia.org)
  • Sediment transport due to fluid motion occurs in rivers , oceans , lakes , seas , and other bodies of water due to currents and tides . (wikipedia.org)
  • Previously undocumented in North American rivers, concentrations of microplastic particles in the St. Lawrence are as high as has been observed in the world's most contaminated marine sediments. (phys.org)
  • They largely depend on other geologic agents, such as rivers and waves, to supply sediment for transport. (nps.gov)
  • The trapped sediments have low concentrations of anthropogenic metals. (biomedsearch.com)
  • 137)Cs activity concentrations were studied in the sediment profiles collected at five locations in the Middle and South Adriatic. (nih.gov)
  • The ability of accelerator mass spectrometry (AMS) to measure very small concentrations of the nuclides 10 Be, 14 C, 26 Al, 36 Cl, and 129 I has led to many innovative applications in geologic research. (semanticscholar.org)
  • The data can be used with geographic information systems (GIS) software to display geologic and oceanographic information. (usgs.gov)
  • About one-half of all continental slopes descend into deep-sea trenches or shallower depressions, and most of the remainder terminate in fans of marine sediment or in continental rises . (britannica.com)
  • Common features of these environments are a sparse or nonexistent vegetation cover, a supply of fine sediment (clay, silt, and sand), and strong winds. (nps.gov)
  • The sediment consisted of mostly clay and silts, along with sands, and calcium carbonate. (idaho.gov)
  • Carefully add another layer (or geologic stratum) of clay to your sample. (scienceviews.com)
  • This data layer is a point coverage of sediment samples collected by the U.S. Geological Survey Woods Hole Science Center's field operations. (usgs.gov)
  • The data were created by aggregating available sediment point data collected from the United States Geological Survey's (USGS) usSEABED, version 1.0, U.S. Geological Survey Data Series 118 (Reid 2005), the Massachusetts Water Resources Authority, the Massachusetts Division of Marine Fisheries, and the United States Environmental Protection Agency. (noaa.gov)
  • Coastal sediment transport results in the formation of characteristic coastal landforms such as beaches , barrier islands , and capes. (wikipedia.org)
  • Member 1 of the Chapel Island Formation includes uppermost Precambrian sediments. (purdue.edu)
  • Additionally, excess pore pressure may build up at this depth due to continued formation of free gas in conjunction with a low permeability of the hydrated sediments above. (rediris.es)
  • Over the past 20 years, synchrotron-based research applications have provided important insight into the geochemical cycling of ions and the chemical and crystallographic properties of minerals in soils and sediments. (elsevier.com)
  • The model assumes that the sediment type at the land surface is representative of the entire sediment thickness. (mn.us)
  • Based on simulations, large volumes of sediment eroded from the hillslopes were redeposited within the channel network throughout the storm, leading to the initiation of numerous debris flows as a result of the mass failure of sediment dams that built up within the channel. (usgs.gov)
  • Debris-retention basins protect communities and infrastructure from the impacts of debris flows and sediment-laden floods and also provide critical data for volumes of sediment deposited at watershed outlets. (usgs.gov)
  • In this study, we supplement existing data for the volumes of sediment deposited at watershed outlets with newly acquired data to develop new empirical models for predicting volumes of sediment produced by watersheds located in the Transverse Ranges of southern California. (usgs.gov)
  • A "long-term model" was developed for predicting volumes of sediment deposited by both debris flows and floods at various times since the most recent fire from a database of volumes of sediment deposited by a combination of debris flows and sediment-laden floods with no time limit since the most recent fire (n = 344). (usgs.gov)
  • A subset of this database was used to develop an "emergency assessment model" for predicting volumes of sediment deposited by debris flows within two years of a fire (n = 92). (usgs.gov)
  • Prior to developing the models, 32 volumes of sediment, and related parameters for watershed morphology, burn severity and rainfall conditions were retained to independently validate the long-term model. (usgs.gov)
  • Ten of these volumes of sediment were deposited by debris flows within two years of a fire and were used to validate the emergency assessment model. (usgs.gov)
  • The models were validated by comparing predicted and measured volumes of sediment. (usgs.gov)
  • These validations were also performed for previously developed models and identify that the models developed here best predict volumes of sediment for burned watersheds in comparison to previously developed models. (usgs.gov)
  • Davis, E.E., and Fisher, A.T., 1994, On the nature and consequences of hydrothermal circulation in the Middle Valley sedimented rift: Inferences from geophysical observations, ODP Leg 139. (tamu.edu)
  • On the other hand, its relative age is its age in comparison with other geologic phenomena, particularly the stratigraphic record of rock layers. (encyclopedia.com)
  • These studies will allow engineers to design sediment retention structures of appropriate size and residence time. (carleton.edu)
  • The expression geologic time refers to the vast span from Earth 's beginnings to the present, about 4.6 billion years. (encyclopedia.com)
  • Instead of thinking in terms of years, centuries, or even millennia, the most basic unit is a million years, and even that is rather small when compared with the four eons into which geologic time is divided. (encyclopedia.com)
  • Geologic time is divided according to two scales. (encyclopedia.com)
  • The more well-known of these is the geologic scale, which divides time into named groupings according to six basic units: eon, era, period, epoch, age, and chron. (encyclopedia.com)
  • IMPORTANCE Sediments sequester organic matter over geologic time scales and impact global climate regulation. (nih.gov)
  • It follows that placement of the surface in geologic time is only approximate, that is, partly pre-Tertiary, or late Cretaceous, and partly post-Cretaceous, or early Tertiary. (ku.edu)
  • As one example shows, if all of geologic time were compressed into a single year, the first Homo sapiens would have appeared on the scene at about 8:00 p.m. on December 31. (encyclopedia.com)
  • In another example, geologic time is compared to the distance from Los Angeles to New York City. (encyclopedia.com)
  • Needless to say, the scope of geologic time compared with the units with which we are accustomed to measuring our lives (or even the history of our civilization) is more than a little intimidating. (encyclopedia.com)
  • Probably every textbook in use in America which in any way deals with evolutionary subjects includes a presentation of the 'Geologic Column,' or the 'Geologic Time Scale' as it is sometimes called. (icr.org)
  • Geologists theorize that liquid water has existed on earth from very early in geologic time. (uoregon.edu)
  • The geologic time scale ( GTS ) is a system of chronological dating that relates geological strata ( stratigraphy ) to time. (wikipedia.org)
  • The table of geologic time spans, presented here, agree with the nomenclature , dates and standard color codes set forth by the International Commission on Stratigraphy (ICS). (wikipedia.org)
  • The following four timelines show the geologic time scale. (wikipedia.org)
  • How does that relate to GEOLOGIC TIME. (scienceviews.com)
  • Today, I offer some background information on the geologic time scale and why it is so hard to figure out how old rocks are. (plos.org)
  • geologic time is based on the succession of rock layers. (plos.org)
  • More recently, we've used other methods to associate actual dates with different rock layers, thus linking geologic time (a relative method) with absolute time (= numbers of years old). (plos.org)
  • This merger of geologic time and absolute time is the geologic time scale. (plos.org)
  • Don't have a geologic time scale handy? (plos.org)
  • Geologic time is hard to sort out. (plos.org)
  • An outline of the theory of hydromechanics and rheological models for geologic deformation is included to place various analytical approaches in proper context and to provide an introduction to this broad topic for nonspecialists. (springer.com)
  • However, rigorous application of full coupling is often difficult because (1) the rheological behavior of geologic media is complex and poorly understood and (2) the architecture, mechanical properties and boundary conditions, and deformation history of most geologic systems are not well known. (springer.com)
  • The topics in shallow surface geophysics include field geophysical surveys of glaciotectonic deformation of Long Island sediments using ground penetrating radar, electrical resistivity, seismic reflection and refraction as well as borehole geophysics. (stonybrook.edu)
  • This redistribution of the topography implies extensive deformation of soft, freshly deposited sediments. (icr.org)
  • More generally, results provide a quantitative framework for assessing the potential of runoff-generated debris flows based on sediment supply and hydrologic conditions. (usgs.gov)
  • Emphasis is on the structure of turbulent shear flows and the forces exerted by fluid motions on bed of loosed sediment. (nottingham.ac.uk)
  • By lowering the peak flood discharge, reservoirs lower the volume of sediment moved during a given flood. (ku.edu)
  • A global geography of basinwide trapping of suspended sediment flux by the large reservoirs was analyzed (Vorosmarty et al. (nasa.gov)
  • Conversely, in some areas of the CPRAS excess recharge from surface-water irrigation over the past century has resulted in additional ground water in both the sediments and basalts that is potentially available for use. (usgs.gov)
  • The drilling process involves collecting and logging geologic samples from the floor of deep ocean basins through rotary coring and hydraulic piston coring. (nsf.gov)
  • Does The Geologic Column Prove Evolution? (icr.org)
  • In addition, when you look at the geologic column in the textbook you will notice that is mainly a statement of vertebrate evolution, it has very little to say about the other fossil types. (icr.org)
  • Every effort has been made to ensure the interpretation shown conforms to sound geologic and cartographic principles. (mn.us)
  • Emphasis is placed on understanding geologic principles and methods as applied to environmental science, Earth resources, and public policy. (jhu.edu)
  • We compiled and evaluated new geologic mapping and subsurface information and used it to refine the regional framework. (usgs.gov)
  • Through the Coalition's mapping efforts, stakeholders in the region, including municipalities, federal, state, and county agencies, and private landowners, are provided with unbiased, scientifically defensible geologic information on the shallow subsurface on which to base their policy decisions. (illinois.edu)
  • Recognition of these interruptions in the record is extremely important in helping to understand the geologic history of the area. (ku.edu)
  • The present land surface in Kansas is an important key to understanding the geologic history of the area (Jewett and Merriam, 1959). (ku.edu)
  • Thanks to a certain 1993 blockbuster, most people know the name of at least one period in geologic history. (encyclopedia.com)
  • This complex impact crater has a diverse geologic history, as indicated by various features on the crater rim and floor. (esa.int)
  • The crater's shallow interior has been infilled by sediments over its history. (esa.int)
  • Insure that you concisely cover the major sediment types recovered and what they tell us about the geologic history. (usna.edu)
  • This project studies sediment from the ocean floor to understand Antarctica's geologic history. (nasa.gov)
  • Sediment transport is the movement of solid particles ( sediment ), typically due to a combination of gravity acting on the sediment, and/or the movement of the fluid in which the sediment is entrained. (wikipedia.org)
  • Sediment transport due only to gravity can occur on sloping surfaces in general, including hillslopes , scarps , cliffs , and the continental shelf -continental slope boundary. (wikipedia.org)
  • Ripples and dunes form as a natural self-organizing response to sediment transport. (wikipedia.org)
  • Coastal sediment transport results in these evenly spaced ripples along the shore. (wikipedia.org)
  • Coastal sediment transport takes place in near-shore environments due to the motions of waves and currents. (wikipedia.org)
  • Another factor taken into consideration in this study was the mobilising of large quantities of sediments during the building of transport infrastructure, because it renders the effluent susceptible to being carried away by heavy rainfall. (phys.org)
  • The coupled ocean-atmosphere-wave-sediment transport (COAWST) model is used to hindcast Hurricane Ivan (2004), an extremely intense tropical cyclone (TC) translating through the Gulf of Mexico. (usgs.gov)
  • Transport of fine sediment by wind may cause dust storms, events in which visibility is reduced to less than 1 km by blowing dust. (nps.gov)
  • Modes of sediment transport by the wind (after Pyle, 1987). (nps.gov)
  • For any wind shear velocity, there is a potential rate of sand transport or transport capacity, which is only reached when the availability of sediment is unrestricted (e.g., most loose sand surfaces). (nps.gov)
  • This kinetic energy is used to perform all sorts of work: from the transport of sediments to turning electric generators in hydroelectric plants. (uoregon.edu)
  • Tom Horning, a geologist from Seaside who regularly pokes around the north coast, said Silver Point is primarily mudstone, but with sediments of interbedded turbidte making up those layers. (beachconnection.net)
  • With fluid dynamics as background, the course deals with sediment movement as bed load and suspended load, and with the geometry, kinematics, and dynamics of ripple and dune bed forms. (nottingham.ac.uk)
  • Finding plants, animals, and even early humans buried in the geologic strata gives us clues to what our planet Earth was like in the past. (scienceviews.com)
  • Geologic, Hydrothermal, and Biologic Studies at Escanaba Trough, Gorda Ridge, Offshore Northern California: U.S.G.S. Bull. (tamu.edu)
  • Sediment fill of Escanaba Trough. (tamu.edu)
  • Sediments build up until the mass becomes unstable and sloughs off to the lower slope and the continental rise. (britannica.com)
  • 1976. A semi-automated method for the determination of inorganic, organic and total phosphate in sediments. (springer.com)
  • The collecting of fine sediment along the riverbed as well as the subsequent analysis of it in the laboratory have revealed that the main anthropogenic source of organic matter and metals is untreated or partially treated industrial and municipal effluent. (phys.org)
  • This is reflected in the high organic load found in the sediments of the Ego stream, which until 2014 was receiving the untreated sewage of the municipality of Ermua. (phys.org)
  • Yet the diversion of the organic effluent of the municipality of Oñati to the Epele treatment plant in 2012 has had a beneficial effect on sediment quality as its organic load has been considerably reduced and, as a result, so have the metals associated with these organic complexes. (phys.org)
  • Globally, marine sediments are a vast repository of organic matter, which is degraded through various microbial pathways, including polymer hydrolysis and monomer fermentation. (nih.gov)
  • New analysis of previously published metatranscriptomes demonstrated that many of these genes were transcribed in two organic-rich Holocene sediments. (nih.gov)