An algorithm for the computer arrangement of reactions about invariant points

A computerised algorithm is used to arrange fluid-absent reactions about invariant points in P—T space for an end-member model of blueschist facies metamorphism at Port Macquarie, N.S.W., consisting of the nine phases quartz, albite, jadeite, lawsonite, zoisite, paragonite, glaucophane, pyrope and chlorite. Inspection of the print-out (a table of reaction take-off angles for each invariant point) indicates that this multisystem consists of two mutually exclusive sets of invariant points; lawsonite-absent, paragonite-absent and glaucophane-absent versus the other six. The algorithm is completely general for any two intensive variables and can treat solid solution minerals or degeneracy in reactions/invariant points.Terms ABS(X) Absolute value of X - A(J) Slope of reaction J in degrees - V(J) Denominator variable in the slope fraction for reaction J - R(K, J) Reaction coefficient of phase K in reaction J - S(K, J) Stability pointer for phase K in reaction J, in degrees - SGN (X) Library function: =–1 when X<0; =+1 when X0 - B(Q) Correct take-off angle for the Q-absent reaction in degrees     

Late Quaternary palaeohydrology of the Konya Basin, Turkey, based on isotope studies of modern hydrology and lacustrine carbonates

The Konya plain in south central Anatolia, Turkey, which is now largely dry, was occupied around the time of the Last Glacial Maximum by a fresh-oligosaline lake covering more than 4000 km². Sediment cores from three residual water bodies (Pinarbai, Akgöl and Süleymanhaci) within the larger Pleistocene lake basin, have been analysed using a multidisciplinary approach. The sediment sequences are dated as spanning the last 50 Ka years, although breaks in sedimentation mean that there is only partial chronological overlap between them. Carbon and oxygen isotope analyses on lacustrine carbonate from the three cores give contrasting isotope profiles which reflect the different ages and independent hydrological behaviour of different sub-basins through the late Quaternary. Distinguishing changes that are regional from local effects is aided by modern isotope hydrology studies and by comparing the carbonate ¹³C and ¹⁸O values to diatom and other analyses undertaken on the same cores.     

复杂断块储层非均质性研究——以辽河油田沈84—安12块Es3^3段为例

以岩心、岩石薄片、扫描电镜、物性、压汞曲线等资料为基础,对沈84—安12块Es33段储层非均性及其对开发的影响进行了研究。结果表明:该区储层在层间、平面及层内都表现出较强的非均质性,在微观上表现为孔隙间连通程度差、配位数较低、孔喉比高的特点。利用储层各项参数对其进行了综合评价和分类,该区主要以Ⅲ类储层为主;同时针对非均质性对注水开发效果的影响,提出分层系开采、注水井多级分注等措施,实施后含水上升速度得到控制;断块注水利用率得到明显的提高,改善了水驱开发效果,提高了断块采收率,增加了可采储量。     

Relating Microwave Modulation to Microbreaking Observed in Infrared Imagery

Microwave modulation by swell waves and its relation to microbreaking waves were investigated in an ocean experiment. Simultaneous collocated microwave and infrared (IR) measurements of wind waves and swell on the ocean were made. The normalized radar cross section sigma₀ and the skin temperature T _skin were both modulated by the swell, but with differing phases. In general, sigma₀ maxima occurred on the front face, whereas T _skin maxima occurred on the rear face of the swell. Infrared imagery has shown that swell-induced microbreaking occurred at or near the swell crest and that the resulting warm wakes occurred on the rear face of the wave. When tilt and range modulations are taken into account, the location of microbreaking also accounts for the maximum of sigma₀ occurring on the front face of the swell. Thus, microbreaking waves generated near the crest of low-amplitude swell can produce microwave and IR signatures with the observed phase. The relationship between microwave and IR signals was further emphasized by comparing microwave Doppler spectra with simultaneous IR and visible images of the sea surface from the same location. When small and microscale breaking waves were present, Doppler spectra exhibited characteristics that are similar to those from whitecaps, having peaks with large Doppler offsets and polarization ratios near unity. When no microbreakers were present, Doppler offsets and polarization ratios were much smaller in accordance with a composite surface scattering theory.     

Modeling biodiversity benefits and external costs from a keystone predator reintroduction policy

In this paper, an economic model was constructed to determine the optimal wolf population and distribution across the Northern Rocky Mountains. Both ecological and economic concepts were incorporated in an implicitly spatial social welfare maximization problem. This interdisciplinary model relies on multiple data sources, including current wolf population and distribution information, opportunity cost to local landowners, and contingent valuation studies to determine willingness-to-pay for wolves. Economic models tend to externalize ecological concerns and ecological models often omit the complex human dimensions of conservation policy. Accordingly, this model can serve as a guide for integrating best practices from both fields. The model presented here is sufficiently general to apply to wolves in other ecosystems and to other highly interacting species such as beavers and bison. The Northern Rocky Mountain wolf was used as an example of how this economic model works, but this model can be applied far more broadly.     

Lava channel roofing,overflows, breaches and switching: insights from the 2008–2009 eruption of Mt. Etna

During long-lived basaltic eruptions, overflows from lava channels and breaching of channel levées are important processes in the development of extensive 'a'ā lava flow-fields. Short-lived breaches result in inundation of areas adjacent to the main channel. However, if a breach remains open, lava supply to the original flow front is significantly reduced, and flow-field widening is favoured over lengthening. The development of channel breaches and overflows can therefore exert strong control over the overall flow-field development, but the processes that determine their location and frequency are currently poorly understood. During the final month of the 2008–2009 eruption of Mt. Etna, Sicily, a remote time-lapse camera was deployed to monitor events in a proximal region of a small ephemeral lava flow. For over a period of ~10 h, the flow underwent changes in surface elevation and velocity, repeated overflows of varying vigour and the construction of a channel roof (a required prelude to lava tube formation). Quantitative interpretation of the image sequence was facilitated by a 3D model of the scene constructed using structure-from-motion computer vision techniques. As surface activity waned during the roofing process, overflow sites retreated up the flow towards the vent, and eventually, a new flow was initiated. Our observations and measurements indicate that flow surface stagnation and flow inflation propagated up-flow at an effective rate of ~6 m h⁻¹, and that these processes, rather than effusion rate variations, were ultimately responsible for the most vigorous overflow events. We discuss evidence for similar controls during levée breaching and channel switching events on much larger flows on Etna, such as during the 2001 eruption.     

Seagrass-Watch: Engaging Torres Strait Islanders in marine habitat monitoring

Involvement in scientifically structured habitat monitoring is a relatively new concept to the peoples of Torres Strait. The approach we used was to focus on awareness, and to build the capacity of groups to participate using Seagrass-Watch as the vehicle to provide education and training in monitoring marine ecosystems. The project successfully delivered quality scientifically rigorous baseline information on the seasonality of seagrasses in the Torres Strait—a first for this region.     

Predicting surf zone injuries along the Delaware coast using a Bayesian network

Natural Hazards - More than 2000 surf zone injury (SZI) events, including 196 spinal injuries and 6 fatalities, were recorded at the five most populated beaches along the 25 miles of...     

Tourism,forest conversion,and land transformations in the Angkor basin,Cambodia

The Angkor basin of Cambodia, the site of the great Angkor temple complex, has experienced explosive tourism growth since the 1993 onset of national political stability and renewed international investment, which in turn has driven increasing demand for water, wood, and biomass fuel, and rapid and extensive land-use and land-cover change. We use multi-temporal Landsat imagery (1989–2005) to describe the rate and extent of land-cover change throughout the Angkor basin. While 50% of the landscape remained in rice agriculture it is notable that a larger proportion of the area was deforested (23.4%) than experienced forest regrowth (4.9%). Most forest loss occurred between the Angkor temple complex and Phnom Kulen National Park, and was due in part to charcoal production to serve the tourist industry, and also conversion to permanent agriculture. The small area of forest increase was concentrated along the eastern boundary of the main Angkor complex. The interplay among global (tourism, climate), regional (national policies, large-river management), and local (construction and agriculture, energy and water sources to support the tourism industry) factors drives a distinctive but complex pattern of land-use and land-cover change.