Some aspects of seismic hazard assessment when comparing different approaches     

Laura Peruzza  Dario Slejko 《Natural Hazards》1994,9(1-2):273-273

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Estimates of the γ-ray flux from Sagittarius A     

Laura Maraschi  Massimo Tarenghi  Aldo Treves 《Astrophysics and Space Science》1970,8(1):12-19

Analysis of the anisotropy of the -ray background observed by Clarket al. (1968) has lead to the suggestion that part of the anisotropy be due to a source at the Galactic Centre. The complex structure of radio and infrared emission of the region of Sgr A is considered. The -ray flux arising from Compton scattering and ₀ decay is calculated. For a value of the magnetic field H10^–4 Gauss, corresponding to equipartition, the -ray flux above 100 MeV at Earth from the Sgr A source is expected to lie between 10^–6 and 10^–5 gamma/cm² sec. Such a source should be detectable in the near future.  相似文献   

Book reviews     

Fakhry A. Assaad  Laura Stafford  Philip E. LaMoreaux 《Environmental Geology》2005,48(8):1149-1150

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Entrepreneurial Regionalist Planning in a Rescaled Spain: The Cases of Bilbao and València     

David L. Prytherch  Laura Huntoon 《GeoJournal》2005,62(1):41-50

European politics and planning have recently been characterized by a shift to economic entrepreneurialism at sub-national scales, and the planned redevelopment of the city-region in pursuit of global competitiveness, which scholars have interpreted in light of political-economic “rescaling” or regionalization and the emergence of a “new regionalism.” Analyzing rescaling largely in terms of shifting economic and institutional structures, however, many accounts underestimate the complexity and enduring power of so-called ‘old’ regionalist politics of culture and identity as backdrop to urban redevelopment planning. In this paper we address how the urban planning process mediates between the seemingly dichotomous tendencies of regionalized entrepreneurialism and cultural regionalism. Using case studies of two Spanish autonomous regions and their major urban centers – the Basque Country or Euskadi (Bilbao) and the Comunitat Valenciana (València) – we review the historical geography of planning in the European region in order to explore how cultural regionalism collides with economic rescaling and entrepreneurialism, in and through the planned landscape. We propose that such emerging and hybrid politics and planning be understood as a form of entrepreneurial regionalism, a culturally inflected form of economic competitiveness characteristic of but not unique to the Spanish region. This specific notion of entrepreneurial regionalism may illuminate how planners mediate global and local imperatives within political discourse and landscapes that materialize them, and allow us to better reconceptualize the relationship between economic globalization, state restructuring, and cultural politics in a new Europe of the Regions.  相似文献   

Pleistocene geomorphology and geochronology of eastern Grand Canyon: linkages of landscape components during climate changes     

Matt D. Anders  Joel L. Pederson  Tammy M. Rittenour  Warren D. Sharp  John C. Gosse  Karl E. Karlstrom  Laura J. Crossey  Ronald J. Goble  Lisa Stockli  Guang Yang 《Quaternary Science Reviews》2005,24(23-24):2428-2448

We report new mapping, soils, survey, and geochronologic (luminescence, U-series, and cosmogenic-nuclide) data from Pleistocene deposits in the arid setting of eastern Grand Canyon. The result is a stratigraphic framework of inset fill gravels and associated terraces that provide a record of the responses of hillslopes, tributary streams, and the Colorado River to the last 400 kyr of glacial–interglacial climate change. The best-preserved last 80 kyr of this record indicates a stratigraphic–chronologic disconnect between both deposition and incision along the Colorado River versus along the trunks of local tributaries. For example, the Colorado River finished aggrading and had already begun incising before the main pulse of aggradation in the trunks of local catchments during Marine Isotope Stage 3, and then tributary incision followed during the millennial-scale fluctuations of the last glacial epoch, potentially concurrent with mainstem aggradation. The mainstem record appears to broadly correlate with regional paleoclimate and upstream geomorphic records and thus may be responding to climatic–hydrologic changes in its mountain headwaters, with aggradation beginning during full-glacial times and continuing into subsequent interglacials. The contrasting lag time in responses of the dryland catchments within Grand Canyon may be largely a function of the weathering-limited nature of hillslope sediment supply.  相似文献   

A unified global height reference system as a basis for IGGOS   总被引：1，自引：0，他引：1  

Johannes Ihde  Laura Snchez 《Journal of Geodynamics》2005,40(4-5):400

The definition of a global height reference system is based on a mean sea surface, gravity field parameters, and a three-dimensional terrestrial reference frame (TRF). Tide gauge records, satellite altimetry, gravity measurements on Earth and from space, TRF coordinates, and spirit levelling have to be combined for the realization of the vertical reference frame. Observations and parameters have to be consistent with respect to the used standards, conventions and models. They have to provide globally unified reference surfaces (geoid or quasigeoid, respectively, and mean sea surface). The continental reference systems of Europe (EUREF, ECGN) and South America (SIRGAS) are considering these requirements in their strategies. They are presented here, and slightly different definitions and realizations for a globally unified height reference system are discussed.  相似文献   

The Runaway Weed: Costs and Failures of Phragmites australis Management in the USA     

Laura J. Martin  Bernd Blossey 《Estuaries and Coasts》2013,36(3):626-632

While public funding of invasive species management has increased substantially in the past decade, there have been few cross-institutional assessments of management programs. We assessed management of Phragmites australis, a problematic invader of coastal habitats, through a cross-institutional economic survey of 285 land managers from US public and private conservation organizations. We found that from 2005 to 2009, these organizations spent >$4.6 million per year on P. australis management, and that 94 % used herbicide to treat a total area of ～80,000 ha. Despite these high expenditures, few organizations accomplished their management objectives. There was no relationship between resources invested in management and management success, and those organizations that endorsed a particular objective were no more likely to achieve it. Our results question the efficacy of current P. australis management strategies and call for future monitoring of biological management outcomes.  相似文献   

Effects of land-cover and watershed protection futures on sustainable groundwater management in a heavily utilized aquifer in Hawai‘i (USA)     

Bremer  Leah L.  Elshall  Ahmed S.  Wada  Christopher A.  Brewington  Laura  Delevaux  Jade M.S.  El-Kadi  Aly I.  Voss  Clifford I.  Burnett  Kimberly M. 《Hydrogeology Journal》2021,29(5):1749-1765

Hydrogeology Journal - Groundwater sustainability initiatives, including sustainable yield and watershed policy protection policies, are growing globally in response to increasing demand for...  相似文献   

Correction to: Beat-the-wave evacuation mapping for tsunami hazards in Seaside,Oregon, USA     

Priest  George R.  Gabel  Laura L.  Wood  Nathan J.  Madin  Ian P.  Watzig  Rudie J. 《Natural Hazards》2018,92(3):1509-1522

Natural Hazards - Due to a procedural error in construction of Figs.&;nbsp;8 and 9, listed minimum speeds to beat the tsunami wave in areas of Seaside seaward of Neawanna Creek are too high. The...  相似文献   

Detection of a widespread mantle component of 3He in thermal springs of Lhasa Block and Tethyan Himalaya, eastern Tibet: evidence for roll-back of the Indian-Asian mantle suture south of the Yarlung suture zone, and asthenospheric upwelling beneath the Lhasa block     

Simon L. Klemperer  Ping Zhao  Danian Shi  Laura J. Crossey  Karl E. Karlstrom  Carmen L. Winn  Tianze Liu  Zhongyu Xiong  Xudong Guo  Deng Zeng  Shiqi Wang  Thomas H. Darrah  David R. Hilton  Lin Ding 《《地质学报》英文版》2018,92(Z1):56-57

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