Earthquake simulator testing of pounding between adjacent buildings

Two-storey-building frames have been designed and built in an effort to investigate the pounding phenomenon of adjacent buildings during earthquakes. Static tests have been first performed to determine the static characteristics and the support conditions of the test structures. Sinusoidal and random acceleration signal tests have been subsequently performed to determine the dynamic characteristics of the test structures. Two series of tests were carried out using the shaking table simulator. In the first case, the dynamic response has been recorded without pounding, while in the second case, the test structures have been placed with zero-gap separation and pounding was induced. Input energy time histories were correlated and compared with and without pounding. The experimental results were compared with analytical ones based on a formulation of the contact impact problem by the Lagrange multiplier method. Good agreement between the experimental and the analytical results was achieved.     

Detecting Changes in Ground Water Quality at Regulated Facilities

The Resource Conservation and Recovery Act (PL 94–580) and related federal and state legislation have mandated routine monitoring of ground water quality at regulated facilities. The objective of the required monitoring activities is detection of adverse changes in ground water quality caused by the facilities.
Both failure to detect pollution and an incorrect determination of pollution can be very expensive. It is crucial, therefore, that monitoring programs be designed and operated to provide statistically sound information. It is equally important that users of ground water quality data understand the nature and limitations of information from monitoring.
To address the preceding issues, the authors present a general approach to analyzing ground water quality data in light of the stated monitoring objective. The suggested approach accounts for "natural" variation in background water quality through pairing of observations. The limitations of quarterly sampling for detecting small changes in quality over a short time frame are discussed.     

Vertical distribution of plankton in the skagerrak in relation to doming of the seasonal thermocline

In the central Skagerrak between Norway and Denmark, the seasonal thermocline tends to be relatively shallow (10 to 15 m) probably due to geostrophic effects. An investigation of phytoplankton distribution in this region in late August 1981 showed the presence of an intense subsurface chlorophyll maximum (up to 30 γ 1⁻ Chl a) at a temperature of <6°C, dominated by coccolithophores and the dinoflagellate, Prorocentrum minimum. Data are presented on the vertical distribution of zooplankton in relation to these phytoplankton populations.     

A review of the premium-protection method and its possible application in detection of displacements

A statistical technique using the concepts of Premium-Protection for error detection is applied to deformation measurement. The most attractive aspect of the method is the expression of test values involved in terms of size of deformation (within the limits of a particular design) to be detected. As a demonstration observations from a dam settlement survey are analysed.     

Estimation of uranium endowment by subjective geological analysis—a comparison of methods and estimates for the San Juan Basin,New Mexico

This study investigates how estimates of uranium endowment made by a geologist using an appraisal system that is based upon a formalization of geoscience and decision rules compare with estimates made by informal and unconstrained intuitive processes. The motivation for this study derives from the premise that formalization of decisions would mitigate the heuristic biases and hedging that may result from the use of unconstrained intuitive processes. Estimates of the uranium endowment of the San Juan Basin of New Mexico by four methodologies are compared in this study. These methods, ranked from top to bottom by degree of decomposition (mitigating of heuristic bias)and control on hedging, are as follows Implicit 2 1.5 × 10⁶ s.t. of U₃O₈ Implicit 1 1.6 × 10⁶ s.t. of U₃O₈ NURE (1980) 2.4 × 10⁶ s.t. of U₃O₈ Appraisal system 3.9 × 10⁶ s.t. of U₃O₈ The magnitude of expected uranium endowment estimated by these methods, ranked from smallest to largest, is in this same order. With the exception of the NURE estimates, the magnitude of the variance (uncertainty)of uranium endowment, ranked from smallest to largest, also is in this same order. These results prompt the suggestion that the more decomposed and formalized the estimation procedure, the greater the expected value and the variance of uranium endowment. Equivalently, predicating U ₃ O ₈ endowment estimation strictly upon that part of the geologist's geoscience that is useful in making U ₃ O ₈ endowment estimates and upon his understanding of the region's history produced larger estimates than have previously been reported. However, this method of estimation also shows that uncertainty about the actual state of U ₃ O ₈ endowment is much greater than previously described.     

Application of GIS Processing Techniques for Producing Mineral Prospectivity Maps—A Case Study: Mesothermal Au in the Swayze Greenstone Belt,Ontario, Canada

A Geographic Information System (GIS) is used to prepare and process digital geoscience data in a variety of ways for producing gold prospectivity maps of the Swayze greenstone belt, Ontario, Canada. Data used to produce these maps include geologic, geochemical, geophysical, and remotely sensed (Landsat). A number of modeling methods are used and are grouped into data-driven (weights of evidence, logistic regression) and knowledge-driven (index and Boolean overlay) methods. The weights of evidence (WofE) technique compares the spatial association of known gold prospects with various indicators (evidence maps) of gold mineralization, to derive a set of weights used to produce the final gold prospectivity map. Logistic regression derives statistical information from evidence maps over each known gold prospect and the coefficients derived from regression analysis are used to weight each evidence map. The gold prospectivity map produced from the index overlay process uses a weighting scheme that is derived from input by the geologist, whereas the Boolean method uses equally weighted binary evidence maps.The resultant gold prospectivity maps are somewhat different in this study as the data comprising the evidence maps were processed purposely differently for each modeling method. Several areas of high gold potential, some of which are coincident with known gold prospects, are evident on the gold prospectivity maps produced using all modeling methods. The majority of these occur in mafic rocks within high strain zones, which is typical of many Archean greenstone belts.     

Partitioning of heavy metals on soil samples from column tests

In this study, column tests were used to determine the retention capability of three types of estuarine alluvia collected adjacent to landfill sites in South Wales. Selective sequential extraction (SSE) was used to study the retention mechanisms of heavy metals in the soil columns obtained from leaching experiments. Acid digestion was later used to check the validity of the SSE results. Breakthrough curves show good retention of heavy metal ions (Pb, Cu, and Zn) by all soils, where almost 99% of heavy metals were retained with the C_e/C_o values in the order of 10⁻³. The retention strength of these soils was observed to be constant up to five pore volumes (PV). This corresponds with the pH of the effluents and pore water of soil slices, which also show good buffering capacity against very acidic leachate up to 5PV. The heavy metal extraction profiles from SSE show very similar trends with the retention profiles from the leaching experiments, where heavy metals were retained mainly at the top part where the leachate entered the column. SSE indicates qualitatively that heavy metals precipitated with carbonates and amorphous materials (oxides/hydroxides) are higher than heavy metal retention via exchangeable mechanisms. The mass balance calculation gives range of deviation of 1–16% of the total soil extraction. The distribution of the heavy metals with various soil constituents are ranked in the following order: Carbonates>Amorphous oxides hydroxides>Organic matter>Exchangeable phases.     

Environmental management in Antarctica Instruments and institutions

Instruments and institutions for environmental management in Antarctica have evolved from beginnings in the Antarctic Treaty, with subsequent introduction of the Convention for the Conservation of Antarctic Seals, the Convention on the Conservation of Antarctic Marine Living Resources, and recommendations made at Treaty meetings. The Protocol on Environmental Protection to the Antarctic Treaty will improve existing provisions for environmental management in Antarctica. When it enters into force the Protocol will apply to all activities in the Treaty area: it provides rules for environmental impact assessment, conservation of fauna and flora, disposal of wastes, prevention of marine pollution and specially protected and managed areas. The Protocol's Committee for Environmental Protection will facilitate discussion and advice on environmental management. Management of information is a vital part of ensuring measures are effective. The Protocol should be ratified quickly to improve the basis for environmental protection, but the test will be whether and how it is implemented in practice.     

Estimation of exploration potential of a metallogenic unit by parametric modeling of the distribution of mineral occurrences when exploration is incomplete. Case study: Walker Lake quadrangle of Nevada and California

Analysis of the distribution of ore-bodies in space can be useful generally in the estimation of mineral resources or the management of exploration. This study is directed to analysis of the undiscovered potential of well known areas of mining district size, referred to as metallogenic units (MUs). The analysis employs an effort-adjusted and truncated probability model for number of occurrences within a subdivision (quadrat) of a MU and Monte Carlo sampling to generate an approximation to the probability distribution for number of occurrences and number of mines within an MU when it is totally explored. Exploration potential for Monitor, Bodie, Aurora, and Camp Douglas MUs (Walker Lake quadrangle of Nevada and California) are estimated to be 9, 4, 7, and 4 mines, respectively.