Search results
Results from the WOW.Com Content Network
There are many methods and types of instruments used in geophysical surveys. Technologies used for geophysical surveys include: [1] Seismic methods, such as reflection seismology, seismic refraction, and seismic tomography. This type of survey is carried out to discover the detailed structure of the rock formations beneath the surface of the Earth.
Reflection seismology (or seismic reflection) is a method of exploration geophysics that uses the principles of seismology to estimate the properties of the Earth's subsurface from reflected seismic waves. The method requires a controlled seismic source of energy, such as dynamite or Tovex blast, a specialized air gun or a seismic
Exploration geophysics is an applied branch of geophysics and economic geology, which uses physical methods at the surface of the Earth, such as seismic, gravitational, magnetic, electrical and electromagnetic, to measure the physical properties of the subsurface, along with the anomalies in those properties.
The method utilizes equipment typically employed in seismic refraction surveys. This equipment consists of a seismograph, geophones placed in an array, and a seismic source. An array consists of 6 to 48+ geophones placed at some interval along the ground surface to measure the propagating waves and are connected to a seismograph that records ...
Seismic refraction is exploited in engineering geology, geotechnical engineering and exploration geophysics. Seismic refraction traverses (seismic lines) are performed using an array of seismographs or geophones and an energy source. The methods depend on the fact that seismic waves have differing velocities in different types of soil or rock.
In geophysics, vertical seismic profile (VSP) is a technique of seismic measurements used for correlation with surface seismic data. The defining characteristic of a VSP (of which there are many types) is that either the energy source, or the detectors (or sometimes both) are in a borehole .
Geophysical methods are used in geotechnical investigations to evaluate a site's behavior in a seismic event. By measuring a soil's shear wave velocity, the dynamic response of that soil can be estimated. [15] There are a number of methods used to determine a site's shear wave velocity: Crosshole method
The electroseismic method is very susceptible to electrical cultural noise, and has also the same noise sources as reflection seismic method, which include ground roll, multiples and random noise. Seismoelectrical method also has a very low signal-to-noise ratio, because the attenuation of electromagnetic waves inside the earth is 1/r^3, thus ...