Predicting tsunami arrivals: Estimates and policy implications     

Dao Hua Zhang  Tsz Leung Yip  Chiu-On Ng 《Marine Policy》2009

Tsunami is one of a few kinds of natural disasters that leave people some time for escape. This escape time, which is essentially the time for the giant wave to propagate from the epicentre to a coast, has to be estimated without delay upon the occurrence of the incident. With the advancement of water wave theories, much work has been done to model the propagation of tsunamis from deep oceans to shallow water. The authors argue that while much emphasis has been put on the expansion of the high-tech early warning system and the development of complicated tsunami models, a simple-to-use yet accurate predictive model is still wanting. This paper presents a handy linear wave model, which is capable of estimating the arrival time of a tsunami with very good accuracy, as has been verified by comparison with past incidents. With the availability of such a simple model, even local communities without access to a high-tech warning system can readily estimate the time left for emergency evacuation.  相似文献   

Mineralogy and petrogenesis of lunar magnesian granulitic meteorite Northwest Africa 5744          下载免费PDF全文

Jeremy J. Kent  Alan D. Brandon  Katherine H. Joy  Anne H. Peslier  Thomas J. Lapen  Anthony J. Irving  Daniel M. Coleff 《Meteoritics & planetary science》2017,52(9):1916-1940

Lunar meteorite Northwest Africa (NWA) 5744 is a granulitic breccia with an anorthositic troctolite composition that may represent a distinct crustal lithology not previously described. This meteorite is the namesake and first‐discovered stone of its pairing group. Bulk rock major element abundances show the greatest affinity to Mg‐suite rocks, yet trace element abundances are more consistent with those of ferroan anorthosites. The relatively low abundances of incompatible trace elements (including K, P, Th, U, and rare earth elements) in NWA 5744 could indicate derivation from a highlands crustal lithology or mixture of lithologies that are distinct from the Procellarum KREEP terrane on the lunar nearside. Impact‐related thermal and shock metamorphism of NWA 5744 was intense enough to recrystallize mafic minerals in the matrix, but not intense enough to chemically equilibrate the constituent minerals. Thus, we infer that NWA 5744 was likely metamorphosed near the lunar surface, either as a lithic component within an impact melt sheet or from impact‐induced shock.  相似文献   

Private rights,public benefits: Industry-driven seabed protection     

Jeremy Helson  Stefan Leslie  George Clement  Richard Wells  Ray Wood 《Marine Policy》2010

New Zealand has a large exclusive economic zone (EEZ) that contains a variety of marine habitats and commercially-important species. The commercial fishing industry operating within New Zealand's EEZ is of significant value to the economy and fisheries resources are managed through the extensive use of Individual Transferable Quotas (ITQs). One of the benefits of ITQs has been to better align some of the private incentives of quota owners with the public interest. These incentives contributed to an initiative proposed by the fishing industry to close large areas of New Zealand's EEZ to protect the seabed from trawling. These closed areas are termed benthic protection areas (BPAs) and protect the benthic biodiversity of about 1.1 million square kilometres of seabed—approximately 30% of New Zealand's EEZ. A significant proportion of New Zealand's known seamounts and active hydrothermal vents are protected by these closed areas. We describe and discuss the criteria used to select BPAs and some of the criticism of this marine protection initiative. We argue that the assignment of strong property rights in fishing resources was an important precondition to an industry initiative that has a significant public benefit. Where private and public interests are well aligned, government can adopt an enabling and facilitation role, ceding direct control of processes in order to get the results the align with the public interest.  相似文献   

Computer aided analysis of rock slope stability     

C. F. Leung  S. C. Kheok 《Rock Mechanics and Rock Engineering》1987,20(2):111-122

Summary A computer program is written in basic language on a micro-computer to carrying out kinematic analysis of rock slope stability. The program is capable of handling plane sliding, wedge sliding and toppling of rock slopes. Applications of the program are demonstrated by examples on opencast mine excavations and highway cuts. The computer output are presented in the form of tables and illustrations for ease of interpretation. As micro-computers are readily available in design offices nowadays, the present work provides an efficient means for engineers to analyse and design rock slope excavations.  相似文献   

Sticking up for ''amateur'' Huygens     

Jeremy Tatum 《Astronomy& Geophysics》2007,48(3):3.07-3.07

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Species sensitivity distributions: data and model choice   总被引：19，自引：0，他引：19  

Wheeler JR  Grist EP  Leung KM  Morritt D  Crane M 《Marine pollution bulletin》2002,45(1-12):192-202

Species sensitivity distributions (SSDs) are increasingly incorporated into ecological risk assessment procedures. Although these new techniques offer a more transparent approach to risk assessment they demand more and superior quality data. Issues of data quantity and quality are especially important for marine datasets that tend to be smaller (and have fewer standard test methods) when compared with freshwater data. An additional source of uncertainty when using SSDs is appropriate selection from the range of methods used in their construction. We show through examples the influence of data quantity, data quality, and choice of model. We then show how regulatory decisions may be affected by these factors.  相似文献   

中国当代土地利用对区域气候影响的数值模拟   总被引：20，自引：0，他引：20  

高学杰  张冬峰  陈仲新  Jeremy S.Pal  Filippo Giorgi 《中国科学D辑》2007,37(3):397-404

使用RegCM3区域气候模式，嵌套欧洲数值预报中心(ECMWF)ERA40再分析资料，分别进行了中国区域在实际植被和理想植被分布情况下各15年时间长度（1987-2001）的积分试验，以研究我国土地利用状况对气候的影响。通过两个试验结果的对比，研究了我国土地利用状况对气候的影响。分析主要集中于气温、降水等的变化上，并对结果进行了统计显著性检验。结果表明，当代土地利用/植被覆盖变化加强了中国地区冬、夏季的季风环流，同时改变了地表能量平衡状况，从而对各气候要素产生重要影响。冬季，植被改变引起长江以南降水减少、气温降低，长江以北降水增加。夏季，植被改变显著影响了南方地区的气候，使得这里降水增多，黄淮、江淮气温降低，华南气温上升；同时引起中国北方降水减少，气温在西北部分植被退化地区升高。植被变化对日最低、最高气温的影响更大。总体来说，土地利用引起了年平均降水在南方增加、北方减少，年平均气温在南方显著降低。  相似文献   

Sea level,climate change and coastal evolution in Morar,northwest Scotland     

Shennan  Ian  Tooley  Michael  Green  Frances  Innes  Jim  Kennington  Kevin  Lloyd  Jeremy  Rutherford  Mairead 《Geologie en Mijnbouw》1998,77(3-4):247-262

Analyses of geomorphologically contrasting sites in Morar, NW Scotland, describe the forcing mechanisms of coastal change. Isolation basins (i.e. basins behind rock sills and now isolated from the sea following isostatic uplift) accumulated continuous marine and freshwater sediments from c.12 to 2 ka BP. Raised dune, marsh and wetland sites register breaching, migration and stability of dunes from c. 9 to 2 ka BP. High-resolution methods designed to address issues of macroscale and microscale sea-level changes and patterns of storminess include 1-mm sampling for pollen, dinocyst and diatom analyses, infra-red photography, X-ray photography and thin-section analysis. The data enhance the record of relative sea-level change for the area. Major phases of landward migration of the coast occurred during the period of low sea-level rise in the mid-Holocene as the rate of rise decreased from c. 3 to < 1 mm/year. Relative sea-level change controls the broad pattern of coastal evolution at each site; local site-specific factors contribute to short-term process change. There is no record of extreme events such as tsunami. Within a system of dynamic metastable equilibrium, the Holocene records show that site-specific factors determine the exact timing of system breakdown, e.g. dune breaching, superimposed on regional sea-level rise. The global average sea-level rise of 3 to 6 mm/yr by AD 2050 predicted by IPCC would only partly be offset in the Morar area by isostatic uplift of about 1 mm/yr. A change from relative sea-level fall to sea-level rise, in areas where the regional rate of uplift no longer offsets global processes, is a critical factor in the management of coastal resources.  相似文献   

An example of enhanced tephra deposition driven by topographically induced atmospheric turbulence     

Sebastian F. L. Watt  Jennie S. Gilbert  Arnau Folch  Jeremy C. Phillips  Xiaoming M. Cai 《Bulletin of Volcanology》2015,77(5):1-14

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Jet Deflection by a Quasi-Steady-State Side Wind in the Laboratory     

David J. Ampleford  Andrea Ciardi  Sergey V. Lebedev  Simon N. Bland  Simon C. Bott  Jeremy P. Chittenden  Gareth N. Hall  Adam Frank  Eric Blackman 《Astrophysics and Space Science》2007,307(1-3):29-34

We present experimental data on the steady state deflection of a highly supersonic jet by a side-wind in the laboratory. The use of a long interaction region enables internal shocks to fully cross the jet, leading to the development of significantly more structure in the jet than in previous work with a similar setup (Lebedev et al., 2004). The ability to control the length of the interaction region in the laboratory allows the switch between a regime representing a clumpy jet or wind and a regime similar to a slowly varying mass loss rate. The results indicate that multiple internal oblique shocks develop in the jet and the possible formation of a second working surface as the jet attempts to tunnel through the ambient medium.  相似文献