The anatomy of a disaster, an overview of Hurricane Katrina and New Orleans     

Lewis E. Link 《Ocean Engineering》2010,37(1):4-12

Hurricane Katrina created the one of the worst natural disaster in the history of the United States, resulting in over 1600 fatalities and $30B in direct economic losses in southern Louisiana. The Louisiana and Mississippi coastlines experienced the highest surge level recorded in North America and Katrina-generated waves in the Gulf of Mexico that equaled the highest previously measured by NOAA buoys. What happened in New Orleans epitomizes the risk of living below sea level in a coastal city, depending on structures that were the result of considerable compromise and piecemeal funding and construction. The Interagency Performance Evaluation Task Force was established to examine the performance of the New Orleans and southeast Louisiana hurricane protection system and provide real-time input to the repairs and rebuilding of the system. In addition to this atypical just-in-time forensic analysis, the task force examined the risk of living in New Orleans prior to and following the repairs to the hurricane protection system. Much of the forensic analysis depended on modeling and simulation of hurricane surge and waves. With virtually all measurement instruments swept away by Katrina, only models and high-water marks were available to recreate the conditions that the structures experienced during the storm. Because of the complexities of the region and the processes involved, simulation of hurricane surge and waves required many fresh ideas and new approaches and these topics, along with new concepts for future planning and design, are the focus of this special issue. Yet, the need to influence the repair and rebuilding of the damaged structures prior to the next hurricane season (roughly 9 months) dictated using existing computational tools that were ready to go. The same modeling and simulation approach was put to work to define the surge and wave hazard New Orleans faces for the future. To put this important body of work in context, this paper provides a broad overview of the entire scope of work of the task force and summarizes its principal findings.  相似文献   

中国海滑蛤属Liocyma(双壳纲:帘蛤科)一新种     

张爱君  徐凤山  冷宇 《海洋与湖沼》2010,41(5):796-798

滑蛤属至今已发现的种都分布于北半球,这些种类都是冷水种。新种Liocyma chinensis是一个温水种,采自渤海莱州湾,这是滑蛤属在亚洲大陆最南的分布界线。新种的发现,增加了黄、渤海动物区系中的冷水性因素。  相似文献   

Reservoir potential of Late Cretaceous terrestrial to shallow marine sandstones,Taranaki Basin,New Zealand   总被引：2，自引：0，他引：2  

K.E. Higgs  M.J. Arnot  G.H. Browne  E.M. Kennedy 《Marine and Petroleum Geology》2010

Late Cretaceous coals and coaly source rocks are the main source of hydrocarbons in the Taranaki Basin, yet to date there have not been any hydrocarbon discoveries within Cretaceous strata, and sandstone distribution and reservoir quality for this interval have been poorly understood. The Late Cretaceous sediments were deposited in several sub-basins across Taranaki, with their distribution largely determined by sediment supply, subsidence, and sea level change. In this study, we describe potential reservoir facies in well penetrations of Cretaceous strata in Taranaki, as well as from outcrop in northwest Nelson, on the southern edge of the basin.  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   

High‐ to ultrahigh‐temperature metamorphism in the lower crust: An example resulting from Hikurangi Plateau collision and slab rollback in New Zealand          下载免费PDF全文

Jean‐Baptiste Jacob  James M. Scott  Rose E. Turnbull  Matthew S. Tarling  Matthew W. Sagar 《Journal of Metamorphic Geology》2017,35(8):831-853

Lower crustal xenoliths erupted from an intraplate diatreme reveal that a portion of the New Zealand Gondwana margin experienced high‐temperature (HT) to ultrahigh‐temperature (UHT) granulite facies metamorphism just after flat slab subduction ceased at c. 110–105 Ma. P–T calculations for garnet–orthopyroxene‐bearing felsic granulite xenoliths indicate equilibration at ~815 to 910°C and 0.7 to 0.8 GPa, with garnet‐bearing mafic granulite xenoliths yielding at least 900°C. Supporting evidence for the attainment of HT and UHT conditions in felsic granulite comes from re‐integration of exsolution in feldspar (~900–950°C at 0.8 GPa), Ti‐in‐zircon thermometry on Y‐depleted overgrowths on detrital zircon grains (932°C ± 24°C at aTiO₂ = 0.8 ± 0.2), and correlation of observed assemblages and mineral compositions with thermodynamic modelling results (≥850°C at 0.7 to 0.8 GPa). The thin zircon overgrowths, which were mainly targeted by drilling through the cores of grains, yield a U–Pb pooled age of 91.7 ± 2.0 Ma. The cause of Late Cretaceous HT‐UHT metamorphism on the Zealandia Gondwana margin is attributed to collision and partial subduction of the buoyant oceanic Hikurangi Plateau in the Early Cretaceous. The halt of subduction caused the fore‐running shallowly dipping slab to rollback towards the trench position and permitted the upper mantle to rapidly increase the geothermal gradient through the base of the extending (former) accretionary prism. This sequence of events provides a mechanism for achieving regional HT–UHT conditions in the lower crust with little or no sign of this event at the surface.  相似文献   

Subduction and back-arc activity at the Hikurangi convergent Margin,New Zealand     

Euan G. C. Smith  Tim Stern  Martin Reyners 《Pure and Applied Geophysics》1989,129(1-2):203-231

The Hikurangi Margin is a region of oblique subduction with northwest-dipping intermediate depth seismicity extending southwest from the Kermadec system to about 42°S. The current episode of subduction is at least 16–20 Ma old. The plate convergence rate varies along the margin from about 60 mm/a at the south end of the Kermadec Trench to about 45 mm/a at 42°S. The age of the Pacific lithosphere adjacent to the Hikurangi Trench is not known.The margin divides at about latitude 39°S into two quite dissimilar parts. The northern part has experienced andesitic volcanism for about 18 Ma, and back-arc extension in the last 4 Ma that has produced a back-arc basin onshore with high heaflow, thin crust and low upper-mantle seismic velocities. The extension appears to have arisen from a seawards migration of the Hikurangi Trench north of 39°S. Here the plate interface is thought to be currently uncoupled, as geodetic data indicate extension of the fore-arc basin, and historic earthquakes have not exceededM _s=7.South of 39°S there is no volcanism and a back-arc basin has been produced by downward flexure of the lithosphere due to strong coupling with the subducting plate. Heatflow in the basin is normal. Evidence for strong coupling comes from historic earthquakes of up to aboutM _s=8 and high rates of uplift on the southeast coast of the North Island.The reason for this division of the margin is not known but may be related to an inferred increase, from northeast to southwest, in the buoyancy of the Pacific lithosphere.  相似文献   

Large-scale deformation associated with ridge subduction   总被引：1，自引：0，他引：1  

Eric L. Geist  Michael A. Fisher  David W. Scholl 《Geophysical Journal International》1993,115(2):344-366

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Last interglacial sea levels on the south coast of New South Wales     

R.W. Young  E.A. Bryant  D.M. Price 《The Australian geographer》1993,24(2):72-75

Remnants of the Last Interglacial shoreline occur at Middle Lagoon on the far south coast of New South Wales. Relict beach sediments can be traced to a height of at least +4.8 m and are indicative of a former mean sea level of about +3 m. Thermoluminescence (TL) ages of 126 ± 13 ka and 114 ± 15 ka were determined for beach and aeolian facies respectively. Sands in the lower part of an exposure on the adjacent Gillards Beach gave TL ages of 108 ± 13 ka, but sands in the upper part of that exposure gave an age of 19.9 ± 3.5 ka. This chronological evidence of a stratigraphic unconformity in what was initially taken as pedogenic differentiation at Gillards Beach is supported by contrasting electron traps and colour centres in crystal lattices of quartz grains in these two samples. No tectonic displacement is apparent. This site provides the first evidence of the Last Interglacial sea level for 1000 km along the coast between Gippsland and Newcastle.  相似文献   

Interpretation of210Pb profiles and verification of the CRS dating model in PIRLA project lake sediment cores     

Michael W. Binford  Jeffrey S. Kahl  Stephen A. Norton 《Journal of Paleolimnology》1993,9(3):275-296

This paper reports results and analysis of²¹⁰Pb-activity measurements in 51 lake-sediment cores from 32 lakes in the four PIRLA (Paleoecological Investigations of Recent Lake Acidification) project regions (Adirondack Mountains [New York], Northern New England, Northern Florida, and the Northern Great Lakes States). General application of the Constant Rate of Supply (Constant Flux) model for²¹⁰Pb dating is valid for lakes in the PIRLA study, although application of the model is equivocal in a few lakes.²¹⁰Pb inventories and profiles are replicable among closely spaced cores within a lake. Specific²¹⁰Pb activity in surface sediments is negatively correlated with bulk sediment accumulation rate in seepage lakes, but not in drainage lakes. Drainage lakes with lower pH have lower unsupported²¹⁰Pb inventories in sediments, but the relationship does not occur in seepage lakes.²¹⁰Pb profiles in only seven of the cores, all from either the Adirondacks or the northern Great Lakes states, exhibit exponential decay curves. Deviations from an exponential profile include a flattening of the profile in the top few cm or excursions of one or a few measurements away from an exponential curve.²¹⁰Pb dates typically agree with other chronostratigraphic markers, most of which are subject to greater uncertainty. Several hypotheses, including sediment mixing, hydrologic regime, sediment focusing, and acidification, are proposed to explain variation of²¹⁰Pb distribution among lakes and regions. Hydrologic factors exert control on unsupported²¹⁰Pb inventories in PIRLA lakes, and there is a strong focusing effect in drainage lakes but a weak focusing effect in seepage lakes.This is the third of a series of papers to be published by this journal following the 20^th anniversary of the first application of²¹⁰Pb dating of lake sediments. Dr P. G. Appleby is guest editing this series.  相似文献   

第20届国际大地测量学与地球物理学联合会维也纳大会地震地质类成果交流简介     

陈家超 《华南地震》1991,11(4):90-96

根据作者参加大会收集到的资料和考察体会，介绍了在会上交流的地震地质类成果，对某些前缘研究领域的新进展作了重点介绍。  相似文献