[en] Magnetotelluric (MT) method plays an important role in geothermal exploration. For MT data interpretation, 2D modelling is still performed in a routine basis since 3D MT modelling is computationally intensive and needs sigificant computational resources. In 2D modelling, information on geoelectric strike direction is a requirement. In this study, analysis of geoelectric strike was performed on MT data from a geothermal prospect using phase tensor and tipper strike. The results from phase tensor analysis and verified by tipper strike show that the geoelectric strike of the study area is about N300°E that agrees well with the regional structure of the study area. The MT tensor data were rotated to the dominant geoelectric strike and 2D inversion modelling was performed. The subsurface resistivity model reveals the geothermal system of the study area. (paper)

[en] The age old mining technology is costly, cumbersome, menacing, unsustainable, environment burdening and down with foreign dependence. It generates a large quantity of a series of long time polluting solid wastes, radioactivity, and mine infertile along with the imposition of Geological and gravitational imbalances responsible for natural calamities. The closed Gold mines of Kolar Karnataka and Uranium mines of Jaduguda Singhbhoom shear zone Orissa India are becoming a very big challenge to environment and economy bitterly shattering health hazards and productivity losses. Foreign propagation to this effect is big defamation on GOI and its science and technology machinery. MRFR-STIMULATED EXPERIMENTATION when tried on the rocks of these mines clearly depicts the transportation of chemoionic transport even in solid phase. This type beam transport artificially attained in accelerators. The reason being these rocks to be really a fluid phase condensed as apparent solid structure due to geodynamical exchanges in earth crust formation. The electrode networking on these rocks under magneto-radiofrequency + radioactivity excitation promotes the nucleoionic deposition on electrodes to be isolated safe environment friendly way without crushing smelting and chemical bathing rock torturing in current mining. This is quite congruous to solid state electroplating under optimization of geological systems. The name NT-NANO is justified since MRFR perturbation imposes electrical conductivity variation on these rocks. The Nuclear Tracks on these rocks undergo their porosity fluctuations resulting in the generation of a series of concentric nano layers surrounding the nuclear tracks through which the vital ionic transport is facilitated for desired electronic exploration (JSEPHSON JUNCTION) as well as inward ionic transport may facilitate mineral farming. (author)

[en] This paper estimates hydrothermal exploration costs and the effects that using slim holes could have on those costs using a computer code developed for the US-DOE. The primary goal of exploration is to generate decision driving information about particular geothermal reservoirs. Compared to today's exploration strategies, the main effect of using slim holes would be to reduce the cost of exploration by about 40 percent. Slim hole exploration does not reduce the overall cost of electricity by much; however, the cost burden is shifted later in the project when outside financing is more likely. The reduced costs of slim holes may also encourage developers to drill more holes that better characterize the reservoir, thus reducing long term reservoir risk. The cost of power could then be cut as much as six percent and project financial risks related to reservoir uncertainties could be reduced by up to one quarter. In order to realize these improvements, the amount of reservoir information recovered from small diameter bore holes needs to be significantly increased

[en] Petrology is used in the various stages of exploration, development and exploitation of a geothermal area, often in conjunction with other fields of study. It is an effective operations tool for predicting syn- and post-drilling conditions in a well, for field and well maintenance, and to a small extent for monitoring fluids passing through the pipelines and steam turbines. Petrological data and interpretations are important in assessing an exploration area, and in formulating and developing strategy of a geothermal field. (auth.). 11 figs

[en] Geothermal surface exploration entails a multi-geoscientific process, which is aimed to define the geometry and characteristics of the geothermal reservoir prior to drilling. Lately, micro-seismic event monitoring is becoming a standard procedure in inferring the structure of the potential geothermal reservoir. However, a good coverage of seismic station and abundant seismic events must be fulfilled in order to map the subsurface structure. Taking advantage of the well-designed seismic station deployed at the “ARD” geothermal field prior to its first drilling, a study of micro-earthquake tomography for 3D reservoir structure is performed in this field. A seismic network of 26 stations was set up for more than eight months from August 2011 within 20 km radius from the centre of the expected reservoir. There were 637 micro-seismic events had been detected and located, which is a very high number of seismicity for a region that is not yet under geothermal development. The purpose of this study is to construct a 3D seismic velocity structure using double-difference tomography and to infer fluid properties, i.e. steam and brine, from the ratio of the P- and S-wave velocity. Double-difference tomography is used to its ability to reduce uncertainties of the model associated with picking and velocity structure. A zone with low P and S velocity anomaly as well as a low ratio of Vp/Vs, which is interpreted as the steam dominated reservoir, is observed. Below this reservoir, there is a high P and S velocity anomaly and a high ratio of Vp/Vs which may be correlate to the non-permeable rock. (paper)

[en] In geothermal exploration, magnetotelluric method (MT) has the capability to resolve conductive body which then can be interpreted as cap rock. A reliable representation of the Earth’s resistivity dimensionality can be achieved by incorporating the direction of geoelectrical strike and geological condition in the geothermal area. In this study, the magnetotelluric method was applied in Tangkuban Parahu volcanic area to reveal the subsurface structure of the area. Due to the uncertainty of MT modelling result, dimensionality analysis (polar diagram) is performed to find out MT data characteristic prior to MT inversion modelling. After that, lineament is mapped based on elevation map to estimate geological strike. Both methods are validated by geological condition in Tangkuban Parahu. The result of polar diagram analysis shows that the direction of geoelectrical strike is dominated NE-SW in mostly frequency and the result of lineament shows similar direction with polar diagram analysis as plotted in rose diagram yields about N45°E. (paper)

[en] Geothermal energy is a topic much discussed for its merits in terms of energy and environment. One application option may be the utilization of thermal waters of 40-100 C temperature for heating rooms and domestic/industrial water in Northeastern Germany. The use of the geothermal energy potential of thermal waters, however, depends from the existence of appropriate geological conditions like horizon, reservoir, temperature and chemistry. The experience gained in East Germany, indicates that any decision to be taken for the utilization of geothermal energy needs to be based on an in-depth analysis of the geological conditions down to 2,000 m and below by means of deep drilling and mining exploration. (BWI)

[en] The field geothermal Volcano Azufral is located to 60 km of Pasto City. It discharges waters chlorine-bicarbonates, diluted and of neuter pH. The riolitics of low k20, andesites, dacites as well as lava flows, hydro volcanic deposits due to events volcanic past and the influence of calcium like main component in the layer stamp are the main ones characteristic geologic of the volcanic area of Azufral. The layer stamp heats waters of the underground and it reacts until producing bicarbonates waters, more common type in the region. Glasses of sulfur toward the crater of the volcano are presented close to a sour lagoon. Thermal activity has been detected toward the southwest of the volcano with an area of covering of 1.47 there are, approximately. Changes in the last 14 years were determined by comparison of last chemical analysis with those obtained by INEA in 1996

[en] This paper reports on the Geothermal Training Program of the United Nations University which has been operated in Iceland since 1979. A six months course is operated annually for professionals from the developing countries. Specialized training is offered in geological exploration, borehole geology, geophysical exploration, borehole geophysics, reservoir engineering, chemistry of thermal fluids, geothermal utilization, and drilling technology. During 1979-1989, 82 scientists and engineers from 17 countries completed the course, and 11 trainees from 7 countries are expected to complete in October 1990 and receive the UNU Certificate. About 70% of those trained during 1979-1989 are actively working in geothermal in their home countries, and about 20% are working in related fields. Participants normally receive scholarships which are financed by the Government of Iceland and the United Nations University, and in some cases by the UNDP

[en] We have analyzed hyperspectral Airborne Visible-Infrared Imaging System (AVIRIS) imagery taken in September of 1992 in Long Valley Caldera, CA, a geothermally active region expressed surficially by hot springs and fumaroles. Geological and vegetation mapping are attempted through spectral classification of imagery. Particular hot spring areas in the caldera are targeted for analysis. The data is analyzed for unique geobotanical patterns in the vicinity of hot springs as well as gross identification of dominant plant and mineral species. Spectra used for the classifications come from a vegetation spectral library created for plant species found to be associated with geothermal processes. This library takes into account the seasonality of vegetation by including spectra for species on a monthly basis. Geological spectra are taken from JPL and USGS mineral libraries. Preliminary classifications of hot spring areas indicate some success in mineral identification and less successful vegetation species identification. The small spatial extent of individual plants demands either sub-pixel analysis or increased spatial resolution of imagery. Future work will also include preliminary analysis of a hyperspectral thermal imagery dataset and a multitemporal air photo dataset. The combination of these remotely sensed datasets for Long Valley will yield a valuable product for geothermal exploration efforts in other regions