Investigations of the internal geomagnetic field by means of a global model of the Earth's crust

A global model of the Earth's crust has been constructed of two-layer blocks of 2° x 2° dimension, with thickness and susceptibility selected from a ten-step classification of the various crustal types. Considering induced magnetization only, the magnetic effect of each block has been approximated by a single dipole in the middle of the block, directed parallel to the field for a given main field model (32,400 dipoles altogether). The magnetic field of this global model of the crust has been calculated for an altitude of 450 km, appropriate for a comparison with anomaly fields from satellite surveys. From field values at 1° x 1° grid points, model anomaly charts for the X, Y, Z-components and for the total intensity can be plotted. The underlying crustal parameters have been prepared for modification towards adjusting the model field to the final Magsat anomaly field. The aim is to construct a truly realistic model of the whole Earth's crust. Based on a global distribution of the Z-component of the model field a spherical harmonic analysis has been made by a direct integral method, up to degree and order 35. The energy density spectrum of the magnetic field, apart from the lowest degree terms, resembles a "white" spectrum in which the level nearly meets that obtained for the crustal part of an actual field model (from n = 15 to 29), except for a factor of less than 3. A supplemental evaluation of the core part of the observed spectrum indicates a source depth of some 100 km below the surface of the Earth's core, supported by a similar result for the secular variation of the core field.           ARK: https://n2t.net/ark:/88439/y060920 Permalink: https://geophysicsjournal.com/article/166 &nbsp

Knowledge in process? Exploring barriers between epidemiological research and local health policy development

The Redes de Trueque (RT) thrived during the economic crisis of 2001 – 2002 in Argentina and still stand out as one of the largest Complementary Currency System in the world. These local exchange networks reach a large scale during times of severe economic distress, but as large non-state initiatives, they pose a governance problem. Four types of governance systems were structured within the Argentine RT, of varying degrees of sustainability: a) loosely regulated market systems, b) hierarchies, c) associational regional networks, and d) local communities. Based on a four dimensional analytical framework, this paper discusses the rules of governance and sustainability of the governance systems in the RT. It found that some became more sustainable than others in terms of achieving combinations of scale and organisational modes

Cheat Electricity? The Political Economy of Green Electricity Delivery on the Dutch Market for Households and Small Business

The European Commission’s renewable energy directive introduced a market-based Guarantees of Origin (GO)-trade system that gives consumers the choice of buying “real” green energy. This has been successful, as the market share of Dutch households that buy green energy grew to 64% in 2015. However, societal organizations are dissatisfied with the green energy offered, categorizing it as “cheat” electricity. This article aims to solve this riddle of a successful product created under the GO-trade system but also heavily criticized. Research reveals a lively marketplace with buyers eager to buy green energy and energy producers offering a wide range of labels. Marketplace mechanisms are strongly influenced by political choices, and financial support for energy suppliers makes green energy a credible option. Societal groups, however, argue that the information provided is incomplete and misleading, that buying green energy does not impact positively on greenhouse gas reduction, and that better information and structural reform are required. The GO-trade system is strongly influenced by member states’ national energy politics. Societal organizations have helped to optimize the implementation of the GO-trade system in the Netherlands, but they are not expected to be able to support the creation of a level playing field in which an optimal GO-trade system will flourish

Environmental baseline study for geothermal development in Puna, Hawaii

With illustrations.The Hawaii Geothermal Project, a coordinated research effort of the University of Hawaii funded by the County and State of Hawaii, as well as ERDA, was initiated in mid-1973 in order to identify and help develop geothermal energy on the Big Island of Hawaii. To develop a geothermal resource, a number of stages preliminary to production are required: exploration and selection of a site for drilling; exploratory drilling; testing to determine critical characteristics of the well or wells; and -- optionally -- operating a model plant to test output potential. By the spring of 1974 Phase I of the Project had been completed, when a site for an exploratory well was located and permission for drilling was obtained from the private corporation owning the site. After the competitive bidding process was completed, a drilling contract was awarded in November, 1975 and actual drilling began in December of last year. The drilling was completed late in April, 1976, when a depth of approximately 6,400 feet had been penetrated -- approximately 6,000 feet below sea level. A slotted liner for the bottom portion of the well was installed in June, 1976. The well flashed spontaneously on 3 July and was blown to rid it of drilling debris on 22 July 1976, after which testing of its physical properties was begun. From the beginning of the Hawaii Geothermal Project, it has been recognized that the successive steps of geothermal development starting with drilling must be carefully scrutinized to ascertain in a timely way if there would be any adverse effects on the environment and local ecosystems, and, should they occur, that it was necessary to identify and recommend measures to minimize such impacts. For this reason, in the summer of 1975, once the drill site had been selected and long before the drilling began, baseline data were collected on critical aspects of environmental conditions as they existed before any significant disturbance by the Project. These included ground water supply, air, soil and the flora, as well as the archaeology of the area surrounding the drill site. In February, 1976 the area was studied to see if it provided a habitat for birds which are endemic, or otherwise of special interest. Generally, the area examined for environmental impact lies within a circle having a radius of approximately a half mile from the center of the four-acre drill site. However, the testing of ground water included sampling wells and a spring more than a mile from the site. Additional tests of the water and air were conducted at the site in June, 1976, after the drilling was completed but before the well was blown to free it of debris accumulated during drilling. The results of that testing, along with results obtained before the drilling began, are summarized in this assessment statement. The results of the pre-drilling studies were such as to enable the University of Hawaii, under the regulations of the Hawaii Environmental Quality Commission, to issue a negative declaration concerning the exploratory hole -- i.e. that the drilling of the well seemed to pose no significant threat to the environment in the vicinity of the well site in Puna, Hawaii. It is hoped and intended that the environmental data established by this study will serve as baselines from which to measure changes which may be associated with geothermal development, not only in the area immediately neighboring the present drill site, but, with appropriate adjustments, for development which may occur elsewhere in the Puna District. How transferable the baselines may be to other areas, say other districts of the Island of Hawaii or to other islands within this archipelago, is a question which must be examined in context as further geothermal exploration is undertaken.U.S. Energy Research & Development AdministrationState of HawaiiCounty of Hawai