Linkages between the Florida Keys National Marine Sanctuary and the South Florida Ecosystem Restoration Initiative     

Brian D. Keller  Billy D. Causey 《Ocean & Coastal Management》2005,48(11-12):869

The Florida Keys National Marine Sanctuary is a large, multiple-use marine protected area, including a network of fully protected marine zones, which was designated in 1990 to protect the coral reef ecosystem surrounding the Florida Keys. The South Florida Ecosystem Restoration (SFER) Initiative was formed in 1993 to restore more natural flows to the ecosystem, restore and enhance the natural system, and transform the built environment. These two large-scale efforts at ecosystem-based management are tightly linked, albeit asymmetrically because of the importance of restored flows of pure fresh water across the Everglades and into the coastal ecosystem. The growing population of South Florida, combined with increasing development, agriculture, and other human activities, imperils the entire South Florida ecosystem, from the headwaters of Lake Okeechobee to the Florida Reef Tract. This paper presents the evolution and characteristics of the Florida Keys National Marine Sanctuary and the SFER Initiative, which have both been tasked with addressing complex issues regarding ecosystem-based management. Key linkages between these programs involve connectivity, both physical and human, through circulation patterns and exchange processes in South Florida coastal waters and through the complex bureaucracy that has grown to manage human uses of natural resources.  相似文献   

Complex chemical zoning in eclogite facies garnet reaction rims: the role of grain boundary diffusion     

J. Prenzel  R. Abart  L. Keller 《Mineralogy and Petrology》2009,95(3-4):303-313

In metapelites of the Saualpe complex (Eastern Alps) continuous 10 µm to 20 µm wide garnet reaction rims formed along biotite-plagioclase and biotite-perthite interfaces. The pre-existing mineral assemblages are remnants of low pressure high temperature metamorphism of Permian age. The garnet reaction rims grew during the Cretaceous eclogite facies overprint. Reaction rim growth involved transfer of Fe and Mg components from the garnet-biotite interface to the garnet-feldspar interface and transfer of the Ca component in the opposite direction. The garnets show complex, asymmetrical chemical zoning, which reflects the relative contributions of short circuit diffusion along grain boundaries within the polycrystalline garnet reaction rims and volume diffusion through the grain interiors on bulk mass transfer. It is demonstrated by numerical modelling that the spacing of the grain boundaries, i.e. the grain size of the garnet in the reaction rim is a first order control on its internal chemical zoning.  相似文献   

Development of a generic concept to analyze the accessibility of emergency facilities in critical road infrastructure for disaster scenarios: exemplary application for the 2017 wildfires in Chile and Portugal     

Guth  Johanna  Wursthorn  Sven  Braun  Andreas Ch.  Keller  Sina 《Natural Hazards》2019,97(3):979-999

Natural Hazards - Natural hazards such as earthquakes, floods, or wildfires pose a serious threat to road infrastructure. Especially in emergency situations, the society depends on the road...  相似文献   

New initiatives for synoptic observations     

C. U. Keller 《Journal of Astrophysics and Astronomy》2000,21(3-4):127-134

Several new synoptic facilities for long-term studies of the Sun will become operational within the next few years. This paper summarizes information on some of these projects, in particular GONG+, ISOON, GOES/SXI, and SOLIS. SOLIS, the Synoptic Optical Long-Term Investigations of the Sun, is currently being built by the National Solar Observatory and will become operational in 2001. It consists of a 50-cm vector spectromagnetograph, a 14-cm full-disk patrol, and an 8-mm sun-as-a-star spectrometer.  相似文献   

A comparison of stable platform and strapdown airborne gravity   总被引：3，自引：1，他引：2  

C. L. Glennie  K. P. Schwarz  A. M. Bruton  R. Forsberg  A. V. Olesen  K. Keller 《Journal of Geodesy》2000,74(5):383-389

To date, operational airborne gravity results have been obtained using either a damped two-axis stable platform gravimeter system such as the LaCoste and Romberg (LCR) S-model marine gravimeter or a strapdown inertial navigation system (INS), showing comparable accuracies. In June 1998 three flight tests were undertaken which tested an LCR gravimeter and a strapdown INS gravity system side by side. To the authors' knowledge, this was the first time such a comparison flight was undertaken. The flights occurred in Disko Bay, off the west coast of Greenland. Several of the flight lines were partly flown along existing shipborne gravity profiles to allow for an independent source of comparison of the results. The results and analysis of these flight tests are presented. The measurement method and error models for both the stable platform and strapdown INS gravity systems are presented and contrasted. An intercomparison of gravity estimates from both systems is given, along with a comparison of the individual estimates with existing shipborne gravity profiles. The results of the flight tests show that the gravity estimates from the two systems agree at the 2–3 mGal level, after the removal of a linear bias. This is near the combined noise level of the two systems. It appears that a combination of both systems would provide an ideal airborne gravity survey system, combining the excellent bias stability of the LCR gravimeter with the higher dynamic range and increased spatial resolution of the strapdown INS. Received: 3 June 1999 / Accepted: 30 November 1999  相似文献   

Deconvolution with wavelets and vaguelettes   总被引：2，自引：0，他引：2  

A. Gilbert  W. Keller 《Journal of Geodesy》2000,74(3-4):306-320

The use of wavelets for the solution of convolution equations is studied as a possible alternative to the well-established Fast Fourier Transform (FFT) technique. Two possible solution strategies are investigated: (1) The use of wavelets for the representation of both the given data and the unknown solution. This leads to an algorithm with good de-noising and data-compression properties. In terms of computational efficiency this algorithm is inferior to FFT. (2) The use of wavelets for the representation of the unknown solution and of so-called vaguelettes for the representations of the given data. This leads to an algorithm which is even faster than FFT. Received: 14 October 1998 / Accepted: 30 November 1999  相似文献   

Airborne gravity tests in the Italian area to improve the geoid model of Italy     

R. Barzaghi  A. Borghi  K. Keller  R. Forsberg  I. Giori  I. Loretti  A.V. Olesen  L. Stenseng 《Geophysical Prospecting》2009,57(4):625-632

  相似文献   

Visualization of spatial patterns and temporal trends for aerial surveillance of illegal oil discharges in western Canadian marine waters   总被引：1，自引：0，他引：1  

Serra-Sogas N  O'Hara PD  Canessa R  Keller P  Pelot R 《Marine pollution bulletin》2008,56(5):825-833

This paper examines the use of exploratory spatial analysis for identifying hotspots of shipping-based oil pollution in the Pacific Region of Canada’s Exclusive Economic Zone. It makes use of data collected from fiscal years 1997/1998 to 2005/2006 by the National Aerial Surveillance Program, the primary tool for monitoring and enforcing the provisions imposed by MARPOL 73/78. First, we present oil spill data as points in a “dot map” relative to coastlines, harbors and the aerial surveillance distribution. Then, we explore the intensity of oil spill events using the Quadrat Count method, and the Kernel Density Estimation methods with both fixed and adaptive bandwidths. We found that oil spill hotspots where more clearly defined using Kernel Density Estimation with an adaptive bandwidth, probably because of the “clustered” distribution of oil spill occurrences. Finally, we discuss the importance of standardizing oil spill data by controlling for surveillance effort to provide a better understanding of the distribution of illegal oil spills, and how these results can ultimately benefit a monitoring program.  相似文献   

Rapid vertical sampling in stably stratified turbulent shear flows     

K. H. Keller  C. W. Van Atta 《Dynamics of Atmospheres and Oceans》2000,31(1-4)

A new method for obtaining instantaneous vertical profiles of two components of velocity and temperature in thermally stratified turbulent shear flows is presented. In this report, the design and construction of the traversing system will be discussed and results to date will be presented. The method is based on rapid vertical sampling whereby probe sensors are moved vertically at a high speed such that the measurement is approximately instantaneous. The system is designed to collect many measurements for the calculation of statistics such as vertical wave number spectra, mean square vertical gradients, and Thorpe scales. Results are presented for vertical profiles of temperature and compared to vertical profiles measured by single-point Eulerian time averages. The quality of the vertical profiles is found to be good over many profiles. Some comparisons are made between vertical measurements and standard single-point Eulerian measurements for three cases of stably stratified turbulent shear flow in which the initial microscale Reynolds number, Re_λ≈30. In case 1, the mean conditions are characterized by a gradient Richardson number, Ri_g=0.015, for which the flow is “unstable”, meaning the spatially evolving turbulent kinetic energy (E_k) grows. In case 2, Ri_g=0.095, for which the evolving turbulent kinetic energy is almost constant. In case 3, the flow is highly stable, where Ri_g=0.25 and E_k decays with spatial evolution. The measurements indicate anisotropy in the small scales for all cases. In particular, it is found that the ratio grows initially to a maximum and then decays with further evolution. Maximum Thorpe displacements are measured and compared to single-point measures of the vertical scales. It is found that vertical length scales derived from single-point measurements, such as the Ozmidov scale, L_O=(ε/N³)^1/2 and the overturn scale, L_t=θ′/(dT/dz), do not represent well the wide range of overturning scales which are actually present in the turbulence.  相似文献   

Water Resource Implications of ¹⁸O and ²H Distributions in a Basalt Aquifer System     

Kathryn R. Larson  C. Kent Keller  Peter B. Larson  Richelle M. Allen-King 《Ground water》2000,38(6):947-953

  相似文献