An efficient artificial intelligence model for prediction of tropical storm surge   总被引：1，自引：0，他引：1  

M. Reza Hashemi  Malcolm L. Spaulding  Alex Shaw  Hamed Farhadi  Matt Lewis 《Natural Hazards》2016,80(1):471-486

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A New Approach for Conditioning Process-Based Geologic Models to Well Data     

David Wingate  Jonathan Kane  Matt Wolinsky  Zoltán Sylvester 《Mathematical Geosciences》2016,48(4):371-397

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Conductive heat flow and nonlinear geothermal gradients in marine sediments—observations from Ocean Drilling Program boreholes     

Christian Stranne  Matt O’Regan 《Geo-Marine Letters》2016,36(1):25-33

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Dating in the Craven Dales     

Peter Wilson  Tom C. Lord  Matt W. Telfer  Timothy T. Barrows  Peter J. Vincent 《Geology Today》2013,29(1):16-22

The Craven Dales of North Yorkshire contain some of the finest examples of limestone geology and landscape in the UK. The extensive limestone pavements with their clints, grikes and other water‐worn features, are a key attraction for both scientists and recreational visitors. Likewise the cave systems attract attention with their remarkable sediment accumulations, some of which are in excess of 500 000 years old and others contain the bones of mammals that are either extinct or no longer present in the British Isles. The glacial erratic boulders at Norber and the loessic sediments that, in places, mask the limestone have also provided stimulus for investigation. Summarized below are the findings of several recent studies that focussed on establishing the age of various features. Whilst the reports answer some long‐standing questions, they also demonstrate that there is still much that can be learned about this seemingly familiar territory.  相似文献   

The release of dissolved actinium to the ocean: A global comparison of different end-members   总被引：1，自引：1，他引：0  

Walter Geibert  Matt Charette  Guebuem Kim  Willard S. Moore  Joseph Street  Megan Young  Adina Paytan   《Marine Chemistry》2008,109(3-4):409

The measurement of short-lived ²²³Ra often involves a second measurement for supported activities, which represents ²²⁷Ac in the sample. Here we exploit this fact, presenting a set of 284 values on the oceanic distribution of ²²⁷Ac, which was collected when analyzing water samples for short-lived radium isotopes by the radium delayed coincidence counting system. The present work compiles ²²⁷Ac data from coastal regions all over the northern hemisphere, including values from ground water, from estuaries and lagoons, and from marine end-members. Deep-sea samples from a continental slope off Puerto Rico and from an active vent site near Hawaii complete the overview of ²²⁷Ac near its potential sources.The average ²²⁷Ac activities of nearshore marine end-members range from 0.4 dpm m^− 3 at the Gulf of Mexico to 3.0 dpm m^− 3 in the coastal waters of the Korean Strait. In analogy to ²²⁸Ra, we find the extension of adjacent shelf regions to play a substantial role for ²²⁷Ac activities, although less pronounced than for radium, due to its weaker shelf source. Based on previously published values, we calculate an open ocean ²²⁷Ac inventory of 1.35 * 10¹⁸ dpm ²²⁷Ac_ex in the ocean, which corresponds to 37 moles, or 8.4 kg. This implies a flux of 127 dpm m⁻² y^− 1 from the deep-sea floor. For the shelf regions, we obtain a global inventory of ²²⁷Ac of 4.5 * 10¹⁵ dpm, which cannot be converted directly into a flux value, as the regional loss term of ²²⁷Ac to the open ocean would have to be included.Ac has so far been considered to behave similarly to Ra in the marine environment, with the exception of a strong Ac source in the deep-sea due to ²³¹Pa_ex. Here, we present evidence of geochemical differences between Ac, which is retained in a warm vent system, and Ra, which is readily released [Moore, W.S., Ussler, W. and Paull, C.K., 2008-this issue. Short-lived radium isotopes in the Hawaiian margin: Evidence for large fluid fluxes through the Puna Ridge. Marine Chemistry]. Another potential mechanism of producing deviations in ²²⁷Ac/²²⁸Ra and daughter isotope ratios from the expected production value of lithogenic material is observed at reducing environments, where enrichment in uranium may occur. The presented data here may serve as a reference for including ²²⁷Ac in circulation models, and the overview provides values for some end-members that contribute to the global Ac distribution.  相似文献   

Science-based and stakeholder-driven marine protected area network planning: A successful case study from north central California     

Mary Gleason  Scott McCreary  Melissa Miller-Henson  John Ugoretz  Evan Fox  Matt Merrifield  Will McClintock  Paulo Serpa  Kathryn Hoffman 《Ocean & Coastal Management》2010,53(2):52-68

The planning process for California's Marine Life Protection Act in north central California represents a case study in the design of a regional component of a statewide network of marine protected areas (MPAs) for improved ecosystem protection. We describe enabling factors, such as a legislative mandate, political will, and adequate capacity and funding that fostered a successful planning process. We identify strategic principles that guided the design of a transparent public planning process that delivered regional MPA network proposals, which both met science guidelines and achieved a high level of support among stakeholders. We also describe key decision support elements (spatial data, planning tools, and scientific evaluation) that were essential for designing, evaluating, and refining alternative MPA network proposals and for informing decision-makers.  相似文献   

Levelling co-located GNSS and tide gauge stations using GNSS reflectometry     

Alvaro Santamaría-Gómez  Christopher Watson  Médéric Gravelle  Matt King  Guy Wöppelmann 《Journal of Geodesy》2015,89(3):241-258

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Monument-antenna effects on GPS coordinate time series with application to vertical rates in Antarctica     

Matt?A.?KingEmail author  Michael?Bevis  Terry?Wilson  Bjorn?Johns  Frederick?Blume 《Journal of Geodesy》2012,86(1):53-63

We examine the electromagnetic coupling of a GPS antenna–monument pair in terms of its simulated affect on long GPS coordinate time series. We focus on the Earth and Polar Observing System (POLENET) monument design widely deployed in Antarctica and Greenland in projects interested particularly in vertical velocities. We base our tests on an absolute robot calibration that included the top ~0.15 m of the monument and use simulations to assess its effect on site coordinate time series at eight representative POLENET sites in Antarctica over the period 2000.0–2011.0. We show that the neglect of this calibration would introduce mean coordinate bias, and most importantly for velocity estimation, coordinate noise which is highly sensitive to observation geometry and hence site location and observation period. Considering only sub-periods longer than 2.5 years, we show vertical site velocities may be biased by up to ±0.4 mm/year, and biases up to 0.2 mm/year may persist for observation spans of 8 years. Changing between uniform and elevation-dependent observation weighting alters the time series but does not remove the velocity biases, nor does ambiguity fixing. The effect on the horizontal coordinates is negligible. The ambiguities fixed series spectra show noise between flicker and random walk with near-white noise at the highest frequencies, with mean spectral indices (frequencies <20 cycles per year) of approximately −1.3 (uniform weighting) and −1.4 (elevation-dependent weighting). While the results are likely highly monument specific, they highlight the importance of accounting for monument effects when analysing vertical coordinate time series and velocities for the highest precision and accuracy geophysical studies.  相似文献   

The settler's plot: how stories take place in New Zealand – By Alex Calder     

Matt Henry 《New Zealand geographer》2012,68(1):71-72

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A relativistically smeared spectrum in the neutron star X-ray binary 4U 1705−44: looking at the inner accretion disc with X-ray spectroscopy     

T. Di Salvo  A. D'Aí  R. Iaria  L. Burderi  M. Dov&#;iak  V. Karas  G. Matt  A. Papitto  S. Piraino  A. Riggio  N. R. Robba  A. Santangelo 《Monthly notices of the Royal Astronomical Society》2009,398(4):2022-2027

Iron emission lines at 6.4–6.97 keV, identified with fluorescent Kα transitions, are among the strongest discrete features in the X-ray band. These are therefore one of the most powerful probes to infer the properties of the plasma in the innermost part of the accretion disc around a compact object. In this paper, we present a recent XMM–Newton observation of the X-ray burster 4U 1705−44, where we clearly detect a relativistically smeared iron line at about 6.7 keV, testifying with high statistical significance that the line profile is distorted by high-velocity motion in the accretion disc. As expected from disc reflection models, we also find a significant absorption edge at about 8.3 keV; this feature appears to be smeared, and is compatible with being produced in the same region where the iron line is produced. From the line profile, we derive the physical parameters of the inner accretion disc with large precision. The line is identified with the Kα transition of highly ionized iron, Fe  xxv , the inner disc radius is   R _in= 14 ± 2  R _g  (where R _g is the Gravitational radius,   GM / c ²  ), the emissivity dependence from the disc radius is   r ^{−2.27±0.08}  , the inclination angle with respect to the line of sight is   i = 39°± 1°  . Finally, the XMM–Newton spectrum shows evidences of other low-energy emission lines, which again appear broad and their profiles are compatible with being produced in the same region where the iron line is produced.  相似文献