Seismic shallow

The commercial value of a clay deposit depends on market trends, competitive materials, transportation faciflties, new machinery and processes, and labor and fuel costs. Naturally exposed outcrops, geological area and stmcture maps, aerial photographs, hand and power auger drills, core drills, earth resistivity, and shallow seismic methods are used ia exploration for clays (32). Clays are mined primarily by open-pit operation, including hydraulic extraction however, underground mining is also practiced. 

When choosing an offshore drillsite, the primary considerations are the location of shipping lanes, foundation stability (for bottom-supported vessels), and the possible presence of shallow gas. Seismic surveys generally provide... 

It is common in many offshore areas to encounter a shallow gas hazard. Quite often, these hazards can be spotted on seismic, and a surface location is chosen to avoid the hazard. However, there is always a risk of encountering a shallow gas flow with insufficient casing in the well to allow a shut-in. In this instance a diverter system is called on as a safety measure. The ideal function of the diverter system is to allow the well to flow and subside by natural means. In many cases the diverter system simply provides enough time to evacuate the rig. 

When selecting a site for an injection well, it is crucial to understand the hydro-geological conditions to ensure any existing or potential fresh water supplies do not become contaminated. Potable aquifers are more likely to be found at shallower depths, while deep aquifers are more likely to be lower in quality and are less likely to be used as a water source (Mickley 2006). Siting injection wells away from areas known to by seismically active also helps to reduce the possibility of contaminating aquifers. The use of injection wells should also be avoided near recoverable resources like ores, coal, oil and gas (Mickley 2006). The selected receiving aquifer must be able to contain the volume of concentrate for the expected life of the plant (Chelme-Ayala et al. 2009). 

Improved magnetotelluric methods have detected deep conductors and shallow alteration zones in the search for deep unconformity-related deposits (Farqu-harson Craven 2008). Clay-rich, quartz-corroded quartz-arenite has relatively low resistivity, whereas quartz-rich silicified zones are characterized by high resistivity. Although expensive, 3D seismic has been used to image details of basement topology and more favourable areas for drilling. 

Under-ice direct shock pressure, air-induced under-ice shock pressure, and air-blast pressure from shallow under-ice bursts, contact bursts, and near-contact bursts were measured. The apparent crater and the true crater were measured, and the mechanics of the fracture were studied. The height to which the flyrock was thrown was measured using motion pictures, and the ground rise venting phenomena were studied also. Sixty-six seismic records were taken... 

Seismic PW" is designed for shallow-hole pattern shooting where high water resistance is not required. Its detonation velocity is low (See also Ref 63, p362)... 

There is considerable debate on the present condition of the Colli Albani volcano. As mentioned earlier, shallow seismicity has been repeatedly registered. Moreover, historical documents from Roman authors (e.g. Titus Livius, Pliny the Elder, etc.) report on phenomena, such as rain of stones, sudden explosions and fires, which can be ascribed to volcanic eruptions. Moreover, findings of pre-Roman pottery and other human artefacts beneath pyroclastic products are considered as an evidence of a volcanic activity which is much younger than the latest dated rock (see Voltaggio and Barbieri 1995 and references therein). Therefore, based on archaeological and historical records and on seismicity, the volcano is now considered in a quiescent state (Montone et al. 1995 Voltaggio and Barbieri 1995 and references therein). 

Dunn R. A., Toomey D. R., and Solomon S. C. (2000) Three-dimensional seismic structure and physical properties of the crust and shallow mantle beneath the East Pacific Rise at 9°30 N. J. Geophys. Res. Solid Earth 105, 23537-23555. 

Harvey, N., 1977. The identification of subsurface solution disconformities on the Great Barrier Reef, Australia, between 14°S and 17°S, using shallow seismic refraction techniques. Proceedings of the Third International Symposium on Coral Reefs, Vol. 2, pp. 45—51. 

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