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Renewable Energy Sources and Small Hydro Power Scenario in Mountainous Regions of Himalayas
Published in Krishan Arora, Suman Lata Tripathi, Sanjeevikumar Padmanaban, Smart Electrical Grid System, 2023
Umesh C. Rathore, Sanjeev Singh, Pradeep Singh Thakur, Krishan Arora
There are very few locations in the entire Himalayan regions where one can find the geothermal source of energy, which is generally available inside the earth’ core. This energy can be made available at the surface of earth either naturally in the form of hot springs or by drilling deep to bring the hot source in the form of steam or molten lava to earth surface, which can further be transformed to be used either directly or indirectly.
Heating Value and Combustion of Fuel
Published in Neil Petchers, Combined Heating, Cooling & Power Handbook: Technologies & Applications, 2020
Geothermal energy is heat (thermal) derived from the earth (geo). It is the thermal energy contained in the rock and fluid (that fills the fractures and pores within the rock) in the earth’s crust. In most areas, this heat reaches the surface in a very diffuse state. However, due to a variety of geological processes, some areas, including substantial portions of the Western United States, are underlain by relatively shallow geothermal resources. Below the crust of the earth, the top layer of the mantle is hot, liquid rock called magma. The crust of the earth floats on this liquid magma mantle. When magma breaks through the surface of the earth in a volcano, it is called lava.
Magmatism and Magmatic Rocks
Published in Aurèle Parriaux, Geology, 2018
The principal morphologies of eruption on land are summarized in figure 6.33. Their variability depends on the proportion of pyroclastic deposits and the fluidity of the lava. Depending on the fluidity of the lava, the morphology ranges from basaltic shields to domes (extrusion of very viscous lava, predominantly solid eruptions) including lava cones (with almost 45° slopes). Some volcanoes are mixed types, formed by the alternation of flows and pyroclastic layers: these are stratovolcanoes (examples are Etna and Vesuvius). The crater at the top is a flared volcanic chimney. In some particularly violent eruptions, the magma chamber partially empties, causing the circular collapse of the cone. This large depression is called a caldera. Sometimes a lake fills in the caldera (Fig. 6.34). Calderas vary widely in size; for example, the La Garita caldera in Colorado is 85 km long and 40 km wide.
Matangkaka manganese deposit, Ambitle Island, Feni Island Group, Papua New Guinea: a Quaternary epithermal stratabound manganese oxide deposit
Published in Australian Journal of Earth Sciences, 2022
Widespread tephra deposits in the Nanum Valley (Danmagal Tephra Member, new member), derived from Holocene (14C date 2300 a ± 100 a) eruptions of Ambitle Crater, make mapping of volcanic sequences difficult. However, valuable subsurface information from more than 80 drillholes has been important in understanding volcanic stratigraphy. Abbreviations are used to identify units in Table 1 and figures. Units are named for their dominant lithology, including block and ash deposits, epiclastic deposits, mafic–intermediate lava, lacustrine deposits, lahar deposits, tephra and trachyte lava, and are designated labels B, E, L, La, Lh, Te and Tr, respectively. Vent or cone facies are designated as subscript V or C, respectively, and Ambitle Volcano and Ambitle Crater eruptive centres are designated as subscript 1 or 2, respectively. The units described by Lindley (2015) and additional units noted during recent fieldwork in the Matangkaka Creek area are described in order of decreasing age. Grid references are to AGD66, Zone 56.
Planning to adapt: identifying key decision drivers in disaster response planning
Published in Civil Engineering and Environmental Systems, 2021
Charlotte O. Brown, Josh L. Hayes, Mark W. Milke
There are additional volcanic hazards that can occur during an eruption that are typically more destructive than volcanic ash (e.g. lahar, pyroclastic density currents, lava, volcanic ballistics). These hazards are likely to damage the built environment (e.g. building collapse, bridge failure) (Wilson et al. 2014; Jenkins et al. 2015), meaning the clean-up problem becomes much more involved than collecting and managing ash. Fires can also be induced by hot volcanic deposits or lava, as was observed in Heimaey, Iceland during the 1973 Heimaey eruption (Williams and Moore 1983) and more recently in Hawaii as a result of the 2018 eruption of Kīlauea (U.S. Department of the Interior Strategic Sciences Group 2019). Therefore, the presence of these hazards indicates that the waste stream will be highly mixed and will require a considerably different response than for volcanic ash alone. This raises additional considerations such as whether waste should be recycled or whether it is safe for the public to handle wastes. Therefore, where these hazards are likely to occur, indicators such as those described in the previous section would further enhance the ability to plan for these extreme volcanic events.
Spatial assessment and appraisal of groundwater suitability for drinking consumption in Andasa watershed using water quality index (WQI) and GIS techniques: Blue Nile Basin, Northwestern Ethiopia
Published in Cogent Engineering, 2020
Getnet Taye Bawoke, Zelalem Leyew Anteneh
The Ethiopian flood basalts stratigraphy has been described by many researchers as Ashengie, Aiba, Alaj and Tarmaber Formations (BECOM, 1998; Chernet, 1985, 1993; Mohr, 1971, 1983) in the former times. Currently, lower basalt (Tv1), middle basalt (Tv2), upper basalt (Tv3) and uppermost basalt (Tv4) units have been coined with extensive studies (Asrat, 2017; Hailemariam et al., 2012; Haro et al., 2010).In the study area, there are six lithological units: TV1, TV2, TV3, Quaternary flow basalts, scoria cones and Quaternary deposits (Figure 2). TV1 is composed of porphyritic with pyroxene, plagioclase and olivine with phenocrysts. In the Andasa watershed, TV2 behaved with phyric basalts of pyroxene-plagioclase, plagioclase, and occasional olivine-pyroxene-plagioclase, and olivine commonly forming gentle slope geomorphology (Asrat, 2017). The thickness of TV3 is up to 650 m in the area exhibiting pyroclastic nature towards the top and confined by columnar basaltic units (Asrat, 2017). Quaternary flow basalts are comprising olivine phyric, pyroxene-plagioclase phyric, zeolite-rich strongly vesiculated basalts; basalt lava flows separated by basaltic agglomerate and basaltic breccia. Scoria cones are vesicular to scoriaceous olivine, pyroxene-plagioclase phyric basaltic cones; commonly horizontally stratified scoria falls. The remaining unit, quaternary deposit, is situated mostly in depression portions, incised-bottom valleys, foot of hills, marshy as well as flood plains of the study area (Asrat, 2017; Beshawered et al., 2010).