Editorial: Tribute to Eugene S. Simpson     

Shlomo P. Neuman  Michael E. Campana 《Hydrogeology Journal》1998,6(1):1-2

  相似文献   

A glacial interpretation for the origin and formation of the Marinet Rock Glacier, Alpes Maritimes, France     

W. Brian Whalley  Cheryl F. Palmer 《Geografiska Annaler: Series A, Physical Geography》1998,80(3-4):221-236

  相似文献   

Comment on the "Nothing older than three years"     

Neuman SP 《Ground water》2005,43(3):294

  相似文献   

Cellular diagnostics and coral health: declining coral health in the Florida Keys     

Downs CA  Fauth JE  Robinson CE  Curry R  Lanzendorf B  Halas JC  Halas J  Woodley CM 《Marine pollution bulletin》2005,51(5-7):558-569

Coral reefs within the Florida Keys are disappearing at an alarming rate. Coral cover in the Florida Keys National Marine Sanctuary declined by 38% from 1996 to 2000. In 2000, populations of Montastraea annularis at four sites near Molasses Reef within the Florida Keys National Marine Sanctuary and one reef within Biscayne National Park were sampled on a quarterly basis. Anecdotal observations showed corals at Alina's Reef in Biscayne National Park appeared healthy in March, but experienced an acute loss of coral cover by August. Cellular Diagnostic analysis indicated that Alina's Reef corals were in distress: they had been afflicted with a severe oxidative damaging and protein-denaturing stress that affected both the corals and their symbiotic zooxanthellae. This condition was associated with a significant xenobiotic detoxification response in both species, reflecting probable chemical contaminant exposure. These results demonstrate that applying a Cellular Diagnostic approach can be effective in helping to identify stress and its underlying causes, providing diagnostic and prognostic biomarkers of coral health.  相似文献   

Characterizing aquatic sediment-oil aggregates using in situ instruments     

Sterling MC  Bonner JS  Ernest AN  Page CA  Autenrieth RL 《Marine pollution bulletin》2004,48(5-6):533-542

The effects of emulsified crude oil and salinity (15, 30 per thousand ) on the steady state aggregate volume distributions and fractal dimensions were determined for a range of mean velocity gradients, (G(m) =5-50 s(-1)). Aggregation was performed in a 40-L cylindrical tank with a 4-blade paddle mixer. Three-dimensional fractal dimensions (D3) and volume distributions were determined using a procedure integrating data from an electrozone and an in situ light scattering instrument. Two-dimensional fractal dimensions (D2) and derived volume distributions were determined using a recently developed submersible flow cytometer equipped with a digital camera and image analysis software. For latex beads or emulsified crude oil systems, the above listed instruments yielded consistent size distributions and fractal dimensions (D2=1.92 +/- 0.16, D3=2.94 +/- 0.12). Mean volume aggregate diameters determined using the FlowCAM were consistently larger that those determined using the LISST-100 or Coulter Multisizer due to aggregate orientations during measurements. With increasing G(m) values, all colloidal aggregates showed increasing D3 values due to reduced aggregate length. Because of the compactness of all the aggregates (D3 >2), D2 values remained constant at 2. Neither salinity nor sediment type significantly affected D2 values calculated for sediment-crude oil aggregates. However, clay-oil aggregates showed higher D3 values than clay aggregates. This suggests that colloidal oil and mixing shear are the more dominant factors influencing aggregate morphology in nearshore waters. Overall, the data suggests that the analysis methods provide consistent size distribution results. However, because of the shear and salinity of coastal waters, resulting aggregates are too compact to estimate their D3 values using image analysis alone.  相似文献   

Cytochrome P4501A1 induction in Kenai River sculpin (Cottus spp.) as a monitor of freshwater pollution effects     

Cheryl E. Paige  John M. Kennish 《Marine environmental research》1995,39(1-4)

Freshwater sculpin were taken from various locations in the Kenai River to determine their in-vivo response to pollution exposure. The specific activity of cytochrome P4501A1 was determined using fluorescence detection of the 7-ethoxyresorufin-O-dealkylase (EROD) reaction. The EROD specific activity was found to be independent of river miles but appeared to relate to specific sites of urban runoff. Glutathione-S-transferase (GST) activities were also measured but showed no significant difference between sites. Cytochrome P450 laboratory induction studies were carried out on individuals collected from a pristine site. Five groups of 10 fish were dosed from 10–150 mg β-Naphthoftavone (βNF)/kg body weight. The response was linear from 10–50 mg βNF/kg body weight. Sculpin appear to have excellent potential as a sensitive indicator of xenobiotic exposure in a freshwater benthic habitat.  相似文献   

The generation and preservation of multiple hurricane beds in the northern Gulf of Mexico   总被引：1，自引：0，他引：1  

Timothy R. Keen  Samuel J. Bentley  W. Chad Vaughan  Cheryl Ann Blain 《Marine Geology》2004,210(1-4):79-105

Cores collected from Mississippi Sound and the inner shelf of the northeast Gulf of Mexico have been examined using ²¹⁰Pb and ¹³⁷Cs geochronology, X-radiography, granulometry, and a multi-sensor core logger. The results indicate that widespread event layers were probably produced by an unnamed hurricane in 1947 and by Hurricane Camille in 1969. Physical and biological post-depositional processes have reworked the event layers, producing regional discontinuities and localized truncation, and resulting in an imperfect and biased record of sedimentary processes during the storms. The oceanographic and sedimentological processes that produced these event beds have been simulated using a suite of numerical models: (1) a parametric cyclone wind model; (2) the SWAN third-generation wave model; (3) the ADCIRC 2D finite-element hydrodynamic model; (4) the Princeton Ocean Model; (5) a coupled wave–current bottom boundary layer-sedimentation model; and (6) a model for bed preservation potential as a function of burial rate and bioturbation rate. Simulated cores from the Mississippi Sound region are consistent with the observed stratigraphy and geochronology on both the landward and seaward sides of the barrier islands.  相似文献   

Nature’s laboratory should be included in the fight against Ebola     

Cheryl Lans 《GeoJournal》2016,81(1):1-3

  相似文献   

Mangrove Range Expansion Rapidly Increases Coastal Wetland Carbon Storage     

Cheryl?L.?DoughtyEmail author  J.?Adam?Langley  Wayne?S.?Walker  Ilka?C.?Feller  Ronald?Schaub  Samantha?K.?Chapman 《Estuaries and Coasts》2016,39(2):385-396

The climate change-induced expansion of mangroves into salt marshes could significantly alter the carbon (C) storage capacity of coastal wetlands, which have the highest average C storage per land area among unmanaged terrestrial ecosystems. Mangrove range expansion is occurring globally, but little is known about how these rapid climate-driven shifts may alter ecosystem C storage. Here, we quantify current C stocks in ecotonal wetlands across gradients of marsh- to mangrove-dominance, and use unique chronological maps of vegetation cover to estimate C stock changes from 2003 to 2010 in a 567-km² wildlife refuge in the mangrove-salt marsh ecotone. We report that over the 7-yr. period, total wetland C stocks increased 22 % due to mangrove encroachment into salt marshes. Newly established mangrove stands stored twice as much C on a per area basis as salt marsh primarily due to differences in aboveground biomass, and mangrove cover increased by 69 % during this short time interval. Wetland C storage within the wildlife refuge increased at a rate of 2.7 Mg C ha^?1 yr.^?1, more than doubling the naturally high coastal wetland C sequestration rates. Mangrove expansion could account for a globally significant increase of terrestrial C storage, which may exert a considerable negative feedback on warming.  相似文献   

Numerical investigation of apparent multifractality of samples from processes subordinated to truncated fBm     

Alberto Guadagnini  Shlomo P. Neuman  Monica Riva 《水文研究》2012,26(19):2894-2908

We investigate numerically apparent multi‐fractal behavior of samples from synthetically generated processes subordinated to truncated fractional Brownian motion (tfBm) on finite domains. We are motivated by the recognition that many earth and environmental (including hydrological) variables appear to be self‐affine (monofractal) or multifractal with Gaussian or heavy‐tailed distributions. The literature considers self‐affine and multifractal types of scaling to be fundamentally different, the first arising from additive and the second from multiplicative random fields or processes. It has been demonstrated theoretically by one of us that square or absolute increments of samples from Gaussian/Lévy processes subordinated to tfBm exhibit apparent/spurious multifractality at intermediate ranges of separation lags, with breakdown in power‐law scaling at small and large lags as is commonly exhibited by real data. A preliminary numerical demonstration of apparent multifractality by the same author was limited to Gaussian fields having nearest neighbor autocorrelations and led to rather noisy results. Here, we adopt a new generation scheme that allows us to investigate apparent multifractal behaviors of samples taken from a broad range of processes including Gaussian with and without symmetric Lévy and log‐normal (as well as potentially other) subordinators. Our results shed new light on the nature of apparent multifractality, which has wide implications vis‐a‐vis the scaling of many hydrological as well as other earth and environmental variables. Copyright © 2011 John Wiley & Sons, Ltd.  相似文献