Integrating Scales of Seagrass Monitoring to Meet Conservation Needs     

Hilary A. Neckles  Blaine S. Kopp  Bradley J. Peterson  Penelope S. Pooler 《Estuaries and Coasts》2012,35(1):23-46

We evaluated a hierarchical framework for seagrass monitoring in two estuaries in the northeastern USA: Little Pleasant Bay, Massachusetts, and Great South Bay/Moriches Bay, New York. This approach includes three tiers of monitoring that are integrated across spatial scales and sampling intensities. We identified monitoring attributes for determining attainment of conservation objectives to protect seagrass ecosystems from estuarine nutrient enrichment. Existing mapping programs provided large-scale information on seagrass distribution and bed sizes (tier 1 monitoring). We supplemented this with bay-wide, quadrat-based assessments of seagrass percent cover and canopy height at permanent sampling stations following a spatially distributed random design (tier 2 monitoring). Resampling simulations showed that four observations per station were sufficient to minimize bias in estimating mean percent cover on a bay-wide scale, and sample sizes of 55 stations in a 624-ha system and 198 stations in a 9,220-ha system were sufficient to detect absolute temporal increases in seagrass abundance from 25% to 49% cover and from 4% to 12% cover, respectively. We made high-resolution measurements of seagrass condition (percent cover, canopy height, total and reproductive shoot density, biomass, and seagrass depth limit) at a representative index site in each system (tier 3 monitoring). Tier 3 data helped explain system-wide changes. Our results suggest tiered monitoring as an efficient and feasible way to detect and predict changes in seagrass systems relative to multi-scale conservation objectives.  相似文献   

The impact of Greenland melt on local sea levels: a partially coupled analysis of dynamic and static equilibrium effects in idealized water-hosing experiments   总被引：2，自引：1，他引：1  

Robert E. Kopp  Jerry X. Mitrovica  Stephen M. Griffies  Jianjun Yin  Carling C. Hay  Ronald J. Stouffer 《Climatic change》2010,103(3-4):619-625

Local sea level can deviate from mean global sea level because of both dynamic sea level (DSL) effects, resulting from oceanic and atmospheric circulation and temperature and salinity distributions, and changes in the static equilibrium (SE) sea level configuration, produced by the gravitational, elastic, and rotational effects of mass redistribution. Both effects will contribute to future sea level change. To compare their magnitude, we simulated the effects of Greenland Ice Sheet (GIS) melt by conducting idealized North Atlantic “water-hosing” experiments in a climate model unidirectionally coupled to a SE sea level model. At current rates of GIS melt, we find that geographic SE patterns should be challenging but possible to detect above dynamic variability. At higher melt rates, we find that DSL trends are strongest in the western North Atlantic, while SE effects will dominate in most of the ocean when melt exceeds ~20 cm equivalent sea level.  相似文献   

Submarine landslides at the eastern Sunda margin: observations and tsunami impact assessment     

Brune  Sascha  Ladage  Stefan  Babeyko  Andrey Y.  Müller  Christian  Kopp  Heidrun  Sobolev  Stephan V. 《Natural Hazards》2010,54(2):547-562

Our analysis of new bathymetric data reveals six submarine landslides at the eastern Sunda margin between central Java and Sumba Island, Indonesia. Their volumes range between 1 km3 in the Java fore-arc basin up to 20 km3 at the trench off Sumba and Sumbawa. We estimate the potential hazard of each event by modeling the corresponding tsunami and its run-up on nearby coasts. Four slides are situated remarkably close to the epicenter of the 1977 tsunamigenic Sumba M _w  = 8.3 earthquake. However, comparison of documented tsunami run-up heights and arrival times with our modeling results neither allows us to confirm nor can we falsify the hypothesis that the earthquake triggered these submarine landslides.  相似文献   

Alpine deformations in Donbass: Periodicity,character of stresses,and their probable sources     

M. L. Kopp  V. A. Korchemagin  A. A. Kolesnichenko 《Geotectonics》2010,44(5):405-423

The periodicity, dynamics, and kinematics of the insufficiently studied Cenozoic (Alpine) movements in the Donets Fold Edifice and its framework are considered. The synthesis of the available data on the Donets Basin (Donbass) and the adjacent territories of the Russian and Scythian plates shows that the Early Alpine, or Laramian epoch of deformation in the Paleocene and the Late Alpine, or recent epoch of deformation in the early Miocene-Quaternary were divided by a tectonic pause in the Eocene and Oligocene. Judging from macrostructural pattern and results of mesotectonic observations, both epochs were characterized by meridional compression and latitudinal extension but substantially differed in the scope of deformation and the style of structure. The former developed to the west of the Donbass and resulted in compression of diapirs in the Dnieper-Donets Aulacogen, whereas the latter created the recent Donets-Azov Swell and brought about right-lateral strike-slip faulting along the North Donets and Persianovsky faults bounding the Donbass. The recent movements and related deformation in the eastern area, including the substantial role of right-lateral strike-slip faulting, more intense deformation in comparison with Laramian movements, and the mobilization of the basement not only in the Dnieper-Donets Aulacogen but also far beyond its limits allow us to connect these phenomena with coeval orogeny in the Greater Caucasus. The nature of the moderate Laramian movements confined to the axial zone of the aulacogen is more questionable; however, it can be explained in terms of within-plate reactivation of western and part of eastern Europe as a response to plate collision in the Alps, Dinarides, and Pontides in combination with coeval onset of spreading in the North Atlantic and Arctic, which created counter-pressure from the north. The eventual result of both processes was inversion and compression of some European aulacogens, including the Dnieper-Donets Aulacogen.  相似文献   

Fold interference patterns in the Late Palaeozoic Anti-Atlas belt of Morocco     

Caritg Séverine  Burkhard Martin  Ducommun Romain  Helg Urs  Kopp Lionel  Sue Christian 《地学学报》2004,16(1):27-37

We document two phases of folding within the central part of the Late Palaeozoic Anti‐Atlas chain of Morocco. A first generation of SW–NE folds involve a horizontal shortening of 10–20%, accommodated by polyharmonic buckle folding of contrasting wavelengths in Ordovician Jbel Bani quartzites and Devonian Jbel Rich carbonates. A second generation of folds with similar style and wavelengths in an E–W direction lead to complex interference patterns. Dome and basins are developed within the Jbel Rich and within Lower Cambrian dolomites. Both folding phases are related to thick‐skinned uplift of Precambrian basement in a Laramide style. In contrast to the typical Rocky Mountain foreland style, however, cover deformation in the Anti‐Atlas is mostly decoupled from the undying basement along thick incompetent horizons such as the Lower Cambrian Lie‐de‐Vin and Silurian shales.  相似文献   

The Solar Cycle 23?�C?24 Minimum. A Benchmark in Solar Variability and Effects in the Heliosphere     

O. White  G. Kopp  M. Snow  K. Tapping 《Solar physics》2011,274(1-2):159-162

Given the numerous ground-based and space-based experiments producing the database for the Cycle 23??C?24 Minimum epoch from September 2008 to May 2009, we have an extraordinary opportunity to understand its effects throughout the heliosphere. We use solar radiative output in this period to obtain minimum values for three measures of the Sun??s radiative output: the total solar irradiance, the Mg ii index, and the 10.7 cm solar radio flux. The derived values are included in the research summaries as a means to exchange ideas and data for this long minimum in solar activity.  相似文献   

Crustal structure of the central Sunda margin at the onset of oblique subduction   总被引：1，自引：0，他引：1  

Heidrun Kopp  Ernst R. Flueh  Dirk Klaeschen  Jörg Bialas  Christian Reichert 《Geophysical Journal International》2001,147(2):449-474

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Über eine intra-triadische Deckenbewegung auf Kreta     

Dr. Karl -Otto Kopp  Gerhard Wernado 《International Journal of Earth Sciences》1983,72(3):895-909

In the Phyllite Group of Crete a stratigraphic succession from Permian to Upper Triassic members is represented. In Carnian parts of this succession in eastern Crete a coherent sheet of Hercynian amphibolites and micaschists is included. It is 20 km long and up to 300 m thick. The Hercynian metamorphics are shown to have been thrusted upon the pre-Carnian part of the Phyllite Group before the Carnian sedimentation continued. A strong, andesitic volcanism was connected with this thrusting in time and space. Tectonic events like these are not known in the outer zones of the Hellenides until now.  相似文献   

Elemental concentrations and their distribution in two bituminous coals of different paleoenvironments     

L.A. Harris  H.E. Barrett  O.C. Kopp 《International Journal of Coal Geology》1981,1(3):175-193

The vertical distributions of major and minor elements in two high-volatile bituminous coals of Eastern Tennessee are compared. The coals studied are the Pewee, deposited in a fresh-water environment, and the Upper Grassy Spring, previously thought to be influenced by a late incursion of marine water.X-ray fluorescence analyses were performed on a continuous series of specimens obtained from full-face channel samples representing the entire thickness of each seam. Correlation coefficients (r) for all element pairs show high positive correlations for element pairs normally associated with clay minerals. Equally good correlations were observed for (Si, Ti) and (Al, Ti), suggesting that titanium is associated with clay minerals in both coals. Strontium and phosphorous showed a high positive r factor for both the Upper Grassy Spring and the Pewee.Major differences were found to exist in the concentrations and distributions of sulfur, iron, and arsenic in the Upper Grassy Spring and Pewee seams. The Upper Grassy Spring contains an order of magnitude more sulfur than the Pewee as well as several times as much iron and arsenic. The element concentrations and especially their distributions in the Upper Grassy Spring suggest an earlier time for the marine incursion than previously reported. In fact, there is evidence that this coal deposit may have been influenced by marine conditions from its inception.  相似文献   

A semi-analytical approach to time-dependent coronal expansion     

Roger A. Kopp 《Solar physics》1980,68(2):307-316

In this paper we point out the existence of a special class of solutions to the nonlinear hydrodynamic equations describing the time-dependent solar wind, namely that for which the velocity profile is time-invariant but the density at each point of the corona changes exponentially with time. Theoretical velocity curves are calculated for the case of isothermal expansion and compared with the Parker model for steady-state expansion. These solutions can be used to obtain quantitative estimates for the degree of departure from the latter of a real corona undergoing evolution on a finite time scale.On leave from Los Alamos Scientific Laboratory, Los Alamos, N.M., U.S.A.  相似文献