Search Results

This chapter analyses the scope and limitations of the principle of national property over natural resources of the subsoil established by Art 27 of the Mexican Constitution. It discusses the difference between state and national property from a comparative perspective. In addition, it describes the evolution of the constitutional and legal framework regarding the role private investment has played in the public monopoly of oil exploration and exploitation. From this analysis, the chapter proposes the adoption of a new approach to make effective the principle of national sovereignty over oil resources without excluding the possibility of private investment participating in oil exploration and exploitation.

This chapter focuses on Nigerian author Ben Okri’s 1987 short story “What the Tapster Saw” as an illuminating example of petro-magic-realism, a literary mode that arose during the Nigerian oil boom. Petro-magic-realism uses tropes drawn from Yoruba narrative tradition to contend with the state violence and environmental degradation that defined oil exploration in the Niger Delta. In 1958, two years before Independence, Nigeria exported its first barrel of oil from Port Harcourt. That year also saw the publication in London of Chinua Achebe’s novel Things Fall Apart. The timing of Nigeria’s simultaneous entry into global print and petrocapitalisms on the eve of its independence may have been a historical coincidence, but the imbrication of oil and literature in national imagining and international circulation has continued for decades. From the vantage of the Niger Delta, it is evident that oil has fueled national imagining from the beginning, and that the contradictions within such a project are perhaps better read as an unimagining of national community.

Seven regions are described in terms of their pollution history, other synergistic human pressures, the current challenges and management approaches. Although the timing and detailed impacts vary, primarily for historical reasons, between regions all show similar patterns of change. Sea regions exposed to centuries of human activity (North Sea, Black Sea, Mediterranean Sea and Chesapeake Bay) are considered, as are those for which pollution is more recent (Canadian LOMAs and Coral Sea), and those expected to experience intense pressure in the near future (Arctic Ocean). Nutrients from agriculture and sewage from growing human populations are ubiquitous and not easily managed in marine systems. Controls on industrial discharges have succeeded in halting, sometimes reversing, degradation in some regions (Black Sea, Mediterranean, North Sea, Chesapeake Bay). However, shipping, coastal development and offshore infrastructure continue to apply pressure. While most regions are subject to international agreements and management regimes the effectiveness varies.

Characteristic analysis is well known in mineral resources appraisal and has proved useful for petroleum exploration. It also can be used to integrate geological data in sedimentary basin analysis and hydrocarbon assessment, considering geological relationships and uncertainties that result from lack of basic geological knowledge, A generalization of characteristic analysis, using fuzzy—set theory and fuzzy logic, may prove better for quantification of geologic analogues and also for description of reservoir and sedimentary facies. Characteristic analysis is a discrete multivariate procedure for combining and interpreting data; Botbol (1971) originally proposed its application to geology, geochemistry, and geophysics. It has been applied mainly in the search for poorly exposed or concealed mineral deposits by exploring joint occurrences or absences of mineralogical, lithological, and structural attributes (McCammon et al., 1981). It forms part of a systematic approach to resource appraisal and integration of generalized and specific geological knowledge (Chaves, 1988, 1989; Chaves and Lewis, 1989). The technique usually requires some form of discrete sampling to be applicable—generally a spatial discretization of maps into cells or regular grids (Melo, 1988). Characteristic analysis attempts to determine the joint occurrences of various attributes that are favorable for, related to, or indicative of the occurrence of the desired phenomenon or target. In geological applications, the target usually is an economic accumulation of energy or mineral resources. Applying characteristic analysis requires the following steps: 1) the studied area is sampled using a regular square or rectangular grid of cells; 2) in each cell the favorabilities of the variables are expressed in binary or ternary form; 3) a model is chosen that indicates the cells that include the target (Sinding—Larsen et al, 1979); and 4) a combined favorability map of the area is produced that points out possible new targets. The favorability of individual variables is expressed either in binary form— assigning a value of +1 to favorable and a value of 0 to unfavorable or unevaluated variables—or in ternary form if the two states represented by 0 are distinguishable—the value +1 again means favorable, the value—1 means unfavorable, and the value 0 means unevaluated.

This chapter explores how satellite remote sensing can be employed to monitor a wide range of anthropogenic pressures which affect species and ecosystems, in both terrestrial and marine systems. First, it reviews the literature on the use of satellite data to monitor deforestation and forest degradation. It then explores how these data can be used to monitor fragmentation, which is another form of habitat degradation that can represent an important threat to the preservation of biological diversity. This is followed by a review of the use of satellite remote sensing information to monitor urbanisation, night-time light pollution, oil exploration and exploitation, mineral extraction activities, oil spills and run-off, and illegal fishing. The chapter concludes by discussing opportunities for satellite remote sensing to monitor and predict the impact of climate change on biodiversity.

In the mid-1960s the British Government began issuing commercial licences for the exploration of the North Sea for gas and oil. Companies were required to share their geophysical findings with the Ministry of Power, and by 1967 officials in the Ministry were aware that they had a great deal of geological information they could neither analyse nor control. They were also aware that the first licenses would expire in 1970, at which time the Ministry would need to know the value of the licensed areas as another round of licensing began. The Institute of Geological Sciences (now the British Geological Survey) was therefore instructed to begin a rapid survey of the geology of the North Sea on behalf of the Ministry. This expansion of the Institute’s functions shaped it over the following decade, recast relations between ministries and scientific experts, and had long-term implications for the funding of ‘pure’ and ‘applied’ science in Britain.

Risk analysis of an oil or gas prospect requires a probability distribution with two components, a dry-hole probability plus a distribution of oil or gas volumes if there is a discovery. While these components should be estimated objectively, risk analysis as currently practiced is mostly guesswork. Geologists assign outcome probabilities without appropriate procedures or data for objective estimation. Valid estimates require frequency data on regional exploratory drilling-success ratios, frequency distributions of oil and gas field volumes, and systematic tabulations of geological variables on a prospect-by-prospect basis. Discriminant functions can be used to analyze relationships between geological variables and hydrocarbons, leading to outcome probabilities conditional on discriminant scores. These probabilities can be incorporated in risk-analysis tables to yield risk-weighted financial forecasts. Computers are required for all procedures. Prior to drilling a petroleum prospect, the likelihood of good outcomes must be weighed against the bad to obtain a risked financial estimate that combines all possibilities. Some oil operators simply contrast the value of discovery that is expected, versus the cost of a dry hole. A cashflow projection yields an estimate of the revenue that will be received if a discovery is made. This assumes an initial producing rate and an ultimate cumulative production for the operator's net revenue interest, and an oil price. When the stream of revenue is discounted and costs for the lease, the completed well, and operating expenses and taxes are subtracted, the net present value is obtained. If the hole is dry, its cost is readily estimated. Only two monetary estimates coupled with an intuitive guess about the likelihood of a producer versus a dry hole form the basis for a decision. A great deal of oil has been found by both independent operators and major oil companies using such simple decision systems. Oil companies generally use more advanced methods at present. Many require their geologists to supply probability estimates for a spectrum of outcomes for each individual prospect, ranging from the probability of a dry hole through the probability of a small discovery, a medium-sized discovery, and various magnitudes of large discoveries.

The 1962 revolution in Yemen has often been attributed to the machinations of Egyptian president Gamal Abdel Nasser. The events of September 1962 were in a manifestation of two decades of growing Yemeni nationalism fostered by an educated cadre of expatriates known as the Famous Forty. Prior to the outbreak of war in 1962, Yemen had been drawn into the growing Cold War conflict. The Soviet Union paid for the construction of the new Hodeidah port while courting an alliance with the “red prince” Muhammad al-Badr, in the hopes that Yemen would become a logistical base for their regional operations. Fearing Soviet penetration on the Arabian Peninsula, the United Statesundertook a series of unsuccessful oil explorations to maintain a nominal presence in a country that could scarcely be identified by American policy makers.

The reverse search starts from a set of desired properties and asks for substances that possess them. Theoretical knowledge and past experience should be relied upon to suggest where to look, since it is the fastest and least expensive approach. When theoretical knowledge and past experience have been exhausted, then random searches may be the only way to make progress, if the problem is sufficiently important and there is enough budget and patience. Table 7.1 compares some of the requirements and the pros and cons of the guided search and the random search The best strategy on how to spend resources of time and money most efficiently can be considered a problem in operations research, under the topic of “optimal resource allocation.” the best way to use the limited resources of money and time effectively may be a mixed strategy, with some guided and some random searches. Even a random search has to start somewhere. At the beginning, there should be a plan on what territories to cover and how to cover them. The plan can be deterministic, which is completely planned out in advance and executed accordingly. The plan can also be adaptive: after the arrival of each batch of results and preliminary evaluations, the plan would evolve to take advantage of the new information and understanding gained. Even a random search must begin at a starting point and stake out the most promising directions for initial explorations. In most cases, there is a lead compound that has some of the desired properties, but which is deficient in others, and serves as the starting point of the random search to find better compounds in this neighborhood. The historic cases in section 1.2 involve the modification of an existing product, such as vulcanizing raw rubber and adding an acetyl group to salicylic acid. One explores around the lead compound by using small amounts of additives, blending with other material, changing processing conditions and temperature, and changing structure by chemical reactions.

Reconstructions of past, climates and other applications of global models require specification of landforms arid geomorphic systems as boundary conditions. As general circulation models become more sophisticated and comprehensive and the range of applications for reconstructions grows, there will be an increasing demand for valid geomorphic boundary conditions throughout the Phanerozoic. Geomorphologists have not yet, developed the tools and expertise needed to produce reconstructions, so a major gap in understanding of global change now exists. A strategy to fill that gap is presented here. If geomorphology is the study of the form of the land, and if the form of the land can be described by a set of numbers (digital elevation models), then whither geomorphology? Do we become numericists, mathematicians, and statisticians? If geomorphology is the study of the processes shaping the land, and if the form is completely explained by a set of processes and an initial condition (i.e., landform at some earlier time), then two "knowns," current form and current processes, are essential. But if processes themselves change through time and there is an infinite set, of initial conditions, one set for each point in time, then the job becomes overwhelmingly complex. As the geomorphic community has become painfully aware of the difficulties of deep reconstructions, we have withdrawn into the Quaternary, a period during which many simplifying assumptions can be made which allow solution of geomorphic problems. Hence the Geological Society of America lumps "Quaternary Geology" and "Geomorphology" into one division. We have become so comfortable with the notion that, geomorphology and Quaternary geology are synonymous that we have lost sight of the goals of founders of the science such as William Morris Davis and John Wesley Powell who strove to unearth the landforms of the distant past. Of course there is plenty to keep us busy in the good ol’ Quaternary; but we shouldn't ignore the enormous challenges and opportunities that await those who would reconstruct landforms of earlier times.