Hydrodynamical simulations of the decay of high-speed molecular turbulence – II. Divergence from isothermality     

Georgi Pavlovski  Michael D. Smith  Mordecai-Mark Mac Low 《Monthly notices of the Royal Astronomical Society》2006,368(2):943-958

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Rational approximations in the parabolic equation method for water waves   总被引：3，自引：0，他引：3  

James T. Kirby 《Coastal Engineering》1986,10(4)

Approximations based on minimax principles are developed in order to allow for large-angle propagation in the parabolic equation method. Numerical studies show that the minimax approximations do not cause any significant degradation of accuracy at small angles of incidence when compared with an existing model based on a (1,1) Padé approximant, and that they allow for much more successful treatment of large angles of incidence than is possible using the previously available methods.  相似文献   

An unsteady wave driver for narrowbanded waves: modeling nearshore circulation driven by wave groups     

Andrew B. Kennedy  James T. Kirby   《Coastal Engineering》2003,48(4):257-275

In this paper, we derive an unsteady refraction–diffraction model for narrowbanded water waves for use in computing coupled wave–current motion in the nearshore. The end result is a variable coefficient, nonlinear Schrödinger-type wave driver (describing the envelope of narrow-banded incident waves) coupled to forced nonlinear shallow water equations (describing steady or unsteady mean flows driven by the short-wave field). Comparisons with experimental data show that good accuracy can be obtained for cases of nonbreaking wave transformation. Numerical simulations show that the interaction of wave groups with longshore topographic nonuniformities generates strong edge wave resonances, providing a generating mechanism for low-order edge waves.  相似文献   

Late Holocene sea-level changes and isostasy in western Denmark     

W. Roland Gehrels  Katie Szkornik  Jason R. Kirby  William A. Marshall  Jørn B.T. Pedersen 《Quaternary Research》2006,66(2):288-302

Cores and exposed cliff sections in salt marshes around Ho Bugt, a tidal embayment in the northernmost part of the Danish Wadden Sea, were subjected to ¹⁴C dating and litho- and biostratigraphical analyses to reconstruct paleoenvironmental changes and to establish a late Holocene relative sea-level history. Four stages in the late Holocene development of Ho Bugt can be identified: (1) groundwater-table rise and growth of basal peat (from at least 2300 BC to AD 0); (2) salt-marsh formation (0 to AD 250); (3) a freshening phase (AD 250 to AD 1600?), culminating in the drying out of the marshes and producing a distinct black horizon followed by an aeolian phase with sand deposition; and (4) renewed salt-marsh deposition (AD 1600? to present). From 16 calibrated AMS radiocarbon ages on fossil plant fragments and 4 calibrated conventional radiocarbon ages on peat, we reconstructed a local relative sea-level history that shows a steady sea-level rise of 4 m since 4000 cal yr BP. Contrary to suggestions made in the literature, the relative sea-level record of Ho Bugt does not contain a late Holocene highstand. Relative sea-level changes at Ho Bugt are controlled by glacio-isostatic subsidence and can be duplicated by a glacial isostatic adjustment model in which no water is added to the world's oceans after ca. 5000 cal yr BP.  相似文献   

Rob Van der Voo—an appreciation     

Conall Mac Niocaill  Trond Torsvik  Ben van der Pluijm 《Tectonophysics》2003,362(1-4):xi-xii

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(Hetero)sexing Space: Gay Men and “Straight” Space in Adelaide,South Australia     

Stewart Kirby  Iain Hay 《The Professional geographer》1997,49(3):295-305

This paper examines gay men's perceptions and experiences of everyday places in Adelaide, South Australia. It illustrates the nature of social space as a heterosexual artifact. The paper also outlines ways in which gay men may contribute to the heterosexualization of space. Many gay men monitor the public and private roles they play for fear of the consequences of “discovery,” and through self-policing and restricted behaviors they may contribute to the spatial supremacy of heterosexuality. Acts of nondisclosure and the adoption of straight sexual facades constrain gay men's social and spatial lives.  相似文献   

Cambrian palaeomagnetic data confirm a Natal Embayment location for the Ellsworth–Whitmore Mountains, Antarctica, in Gondwana reconstructions     

Darren E. Randall  Conall Mac Niocaill 《Geophysical Journal International》2004,157(1):105-116

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El Ventorrillo,a paleostructure of Popocatépetl volcano: insights from geochronology and geochemistry     

G. Sosa-Ceballos  J. L. Macías  F. García-Tenorio  P. Layer  P. Schaaf  G. Solís-Pichardo  J. L. Arce 《Bulletin of Volcanology》2015,77(10):1-20

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Linear discriminant analysis to describe the relationship between rainfall and landslides in Bogotá, Colombia   总被引：1，自引：0，他引：1  

Alfonso Mariano Ramos-Cañón  Luis Felipe Prada-Sarmiento  Mario Germán Trujillo-Vela  Juan Pablo Macías  Ana Carolina Santos-R 《Landslides》2016,13(4):671-681

Bogotá is located in the central Andean region of Colombia, which is frequently affected by landslide processes. These processes are mostly triggered during the rainy season in the city. This fact remarks the importance of determining what rain-derived parameters (e.g. intensity, antecedent rain, daily rain) are better related with the occurrence of landslides. For this purpose, the linear discriminant analysis (LDA), a technique derived from multivariate statistics, was used. The application of this type of analysis led to obtain simple mathematical functions that represent the probability of occurrence of landslides in Bogotá. The functions also allow to identify the most relevant variables derived from records of rainfall linked to the generation of landslides. A proof of concept using the proposed methodology was done using historic rainfall data from a 9-km² area of homogenous climatology and geomorphology in the south part of Bogotá. Landslides needed to be grouped for the LDA. Each one of these grouping categories represents landslides that occurred in similar geomorphologic conditions. Another set of events with no landslides was generated synthetically. Results of the proof of concept show that rainfall parameters such as normalized rainfall intensity I _MAP, normalized daily rainfall R _MAP and rainy-days normal RDN have the best statistical correlation with the landslides observed in the zone of analysis.  相似文献   

A well‐established Early–Middle Pleistocene marine sequence on south‐east Zakynthos island,western Greece: Magneto‐biostratigraphic constraints and palaeoclimatic implications     

Maria D. Papanikolaou  Maria V. Triantaphyllou  Ellen S. Platzman  Philip L. Gibbard  Conall Mac Niocaill  Martin J. Head 《第四纪科学杂志》2011,26(5):523-540

The chronostratigraphy of a long, onshore Early–Middle Pleistocene marine sedimentary sequence on the south‐east part of Zakynthos island, Greece, is presented. Correlation of the succession with the isotope record of Ocean Drilling Program Site 963 reveals the combined influence of tectonics and eustacy in this area. The sequence is divided into three formations by two main unconformities that apparently relate to sea‐level lowstands associated with two major northern hemisphere glaciations, those of marine isotope stages (MIS) 22 and 12. The Zakynthos sequence in many ways is comparable with the Italian Valle di Manche section. Magnetostratigraphic and rock magnetic analyses, supported by biostratigraphy, document the position of the Matuyama/Brunhes Chron boundary (0.77 Ma), the top and base of the Jaramillo Subchron (0.99–1.07 Ma), the Cobb Mountain Subchron (1.173–1.185 Ma) and the top of the Olduvai Subchron (1.78 Ma). The underlying strata are constrained exclusively by detailed nannofossil biostratigraphy extending at least to the lowermost Pleistocene at around 2.54 Ma and therefore certainly incorporating the base of the Olduvai Subchron (1.95 Ma) and possibly the Gauss/Matuyama Chron boundary (2.58 Ma). In addition, a remarkable increase in sedimentation rate (from 3.2 and 28 cm ka^?1 to 167 cm ka^?1) and hence resolution above the Matuyama/Brunhes boundary (Middle Pleistocene) reveals one short‐lived magnetic excursion, possibly 17a (0.66 Ma), within the normal polarity Brunhes Chron. Copyright © 2011 John Wiley & Sons, Ltd.  相似文献