Geophysical survey is the systematic collection of geophysical

Geophysics

Geophysics is the physics of the Earth and its environment in space; also the study of the Earth using quantitative physical methods. The term geophysics sometimes refers only to the geological applications: Earth's shape; its gravitational and magnetic fields; its internal structure and...

 data for spatial studies. Geophysical surveys may use a great variety of sensing instruments, and data may be collected from above or below the Earth's surface or from aerial or marine platforms. Geophysical surveys have many applications in Earth science

Earth science

Earth science is an all-embracing term for the sciences related to the planet Earth. It is arguably a special case in planetary science, the Earth being the only known life-bearing planet. There are both reductionist and holistic approaches to Earth sciences...

, archaeology

Archaeology

Archaeology, or archeology , is the study of human society, primarily through the recovery and analysis of the material culture and environmental data that they have left behind, which includes artifacts, architecture, biofacts and cultural landscapes...

, mineral and energy exploration

Exploration geophysics

Exploration geophysics is the applied branch of geophysics which uses surface methods to measure the physical properties of the subsurface Earth, in order to detect or infer the presence and position of ore minerals, hydrocarbons, geothermal reservoirs, groundwater reservoirs, and other geological...

, and engineering

Engineering

Engineering is the discipline, art, skill and profession of acquiring and applying scientific, mathematical, economic, social, and practical knowledge, in order to design and build structures, machines, devices, systems, materials and processes that safely realize improvements to the lives of...

. Geophysical surveys are used in industry as well as for academic research.

Types of geophysical survey

There are many methods and types of instrumentation used in geophysical surveys. Technologies used for geophysical surveys include:

1. Seismic methods
   Seismology
   Seismology is the scientific study of earthquakes and the propagation of elastic waves through the Earth or through other planet-like bodies. The field also includes studies of earthquake effects, such as tsunamis as well as diverse seismic sources such as volcanic, tectonic, oceanic,...
   
   , such as reflection seismology
   Reflection seismology
   Reflection seismology 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/Tovex, a specialized air gun or a...
   
   , seismic refraction
   Seismic refraction
   Seismic refraction is a geophysical principle governed by Snell's Law. Used in the fields of engineering geology, geotechnical engineering and exploration geophysics, seismic refraction traverses are performed using a seismograph and/or geophone, in an array and an energy source...
   
   , and seismic tomography
   Seismic tomography
   Seismic tomography is a methodology for estimating the Earth's properties. In the seismology community, seismic tomography is just a part of seismic imaging, and usually has a more specific purpose to estimate properties such as propagating velocities of compressional waves and shear waves . It...
   
   .
2. Seismoelectrical method
   Seismoelectrical Method
   The seismoelectrical method is based on the generation of electromagnetic fields in soils and rocks by seismic waves...
   
   
3. Geodesy
   Physical geodesy
   Physical geodesy is the study of the physical properties of the gravity field of the Earth, the geopotential, with a view to their application in geodesy.-Measurement procedure:...
   
    and gravity techniques
   Gravity anomaly
   A gravity anomaly is the difference between the observed acceleration of Earth's gravity and a value predicted from a model.-Geodesy and geophysics:...
   
   , including gravimetry
   Gravimetry
   Gravimetry is the measurement of the strength of a gravitational field. Gravimetry may be used when either the magnitude of gravitational field or the properties of matter responsible for its creation are of interest...
   
    and gravity gradiometry
   Gravity Gradiometry
   Gravity gradiometry is the study and measurement of variations in theacceleration due to gravity. The gravity gradient is the spatial rate of change of gravitational acceleration....
   
   .
4. Magnetic techniques
   Magnetism
   Magnetism is a property of materials that respond at an atomic or subatomic level to an applied magnetic field. Ferromagnetism is the strongest and most familiar type of magnetism. It is responsible for the behavior of permanent magnets, which produce their own persistent magnetic fields, as well...
   
   , including aeromagnetic survey
   Aeromagnetic survey
   An aeromagnetic survey is a common type of geophysical survey carried out using a magnetometer aboard or towed behind an aircraft. The principle is similar to a magnetic survey carried out with a hand-held magnetometer, but allows much larger areas of the Earth's surface to be covered quickly for...
   
   s and magnetometer
   Magnetometer
   A magnetometer is a measuring instrument used to measure the strength or direction of a magnetic field either produced in the laboratory or existing in nature...
   
   s.
5. Electrical techniques
   Electricity
   Electricity is a general term encompassing a variety of phenomena resulting from the presence and flow of electric charge. These include many easily recognizable phenomena, such as lightning, static electricity, and the flow of electrical current in an electrical wire...
   
   , including electrical resistivity tomography
   Electrical resistivity tomography
   Electrical resistivity tomography or electrical resistivity imaging is a geophysical technique for imaging sub-surface structures from electrical measurements made at the surface, or by electrodes in one or more boreholes. It is closely related to the medical imaging technique electrical...
   
   , induced polarization
   Induced polarization
   Induced polarization is a geophysical imaging technique used to identify subsurface materials, such as ore. The method is similar to electrical resistivity tomography, in that an electric current is induced into the subsurface through two electrodes, and voltage is monitored through two other...
   
    and spontaneous potential
   Spontaneous potential
   Spontaneous potential , also called self potential, is a naturally occurring electric potential difference in the Earth, measured by an electrode relative to a fixed reference electrode...
   
   .
6. Electromagnetic methods
   Electromagnetism
   Electromagnetism is one of the four fundamental interactions in nature. The other three are the strong interaction, the weak interaction and gravitation...
   
   , such as magnetotellurics
   Magnetotellurics
   Magnetotellurics is an electromagnetic geophysical method of imaging the earth's subsurface by measuring natural variations of electrical and magnetic fields at the Earth's surface. Investigation depth ranges from 300m below ground by recording higher frequencies down to 10,000m or deeper with...
   
   , ground penetrating radar and transient/time-domain electromagnetics.
7. Borehole geophysics, also called well logging
   Well logging
   Well logging, also known as borehole logging is the practice of making a detailed record of the geologic formations penetrated by a borehole. The log may be based either on visual inspection of samples brought to the surface or on physical measurements made by instruments lowered into the hole...
   
   .
8. Remote sensing techniques
   Remote sensing
   Remote sensing is the acquisition of information about an object or phenomenon, without making physical contact with the object. In modern usage, the term generally refers to the use of aerial sensor technologies to detect and classify objects on Earth by means of propagated signals Remote sensing...
   
   , including hyperspectral.