Magnetometers used in the Earth sciences are called geophysical surveys, a term that also embraces a wide range of other geophysical techniques including gravity, seismic refraction, seismic reflection, electromagnetics ( EM ), induced polarisation ( IP ), magneto-tellurics ( MT ), controlled source magneto-tellurics ( CSAMT ), sub-audio magnetics ( SAM ), mise-a-la-masse, resistivity, self Potential ( SP ) and Very Low Frequency ( VLF ).

Magnetometers are also used to detect archaeological sites, shipwrecks and other buried or submerged objects.

Magnetometers are used in directional drilling for oil or gas to detect the azimuth of the drilling tools near the drill.

Magnetometers such as the German Forster are used to locate ferrous ordnance.

Magnetometers are one of the primary tools used to locate world-class deposits of gold, silver, copper, iron, tin, platinum and diamonds.

Magnetometers may also use a variety of different sensor types.

Magnetometers can measure the magnetic fields of planets.

Magnetometers can also be classified as " AC " if they measure fields that vary relatively rapidly in time, and " DC " if they measure fields that vary only slowly ( quasi-static ) or are static.

Magnetometers measure minute differences in the magnetic field of the earth caused by ferrous concentrations ( and iron objects ) in the soil, thermo-remnant magnetism of fired clays, and differences in the magnetic susceptibility of disturbed soils.

Magnetometers can detect only magnetic ( ferrous ) metals, but can detect such metals at a much larger depth than a metal detector ; magnetometers are capable of detecting large objects, such as cars, at tens of meters, while a metal detector's range is rarely more than 2 meters.

Airborne Magnetometers detect the change in the earth's magnetic field using sensors attached to the aircraft in the form of a " stinger " or by towing a magnetometer on the end of a cable.

Magnetometers detect minute deviations in the Earth's magnetic field caused by iron artifacts, kilns, some types of stone structures, and even ditches and middens in archaeological geophysics.

Magnetometers can be divided into two basic types:

Magnetometers assist mineral explorers both directly ( i. e. gold mineralisation associated with magnetite, diamonds in kimberlite pipes ) and, more commonly, indirectly, such as by mapping geological structures conducive to mineralisation ( i. e. shear zones and alteration haloes around granites ).

Magnetometers can also locate zones ignited by lightning ) and map siderite ( an impurity in coal ).

Sometimes, geophysical methods are used to obtain data about sites.

In different geophysical regions of the world, other regional names are also used for the same or overlapping ages and other timeline subdivisions.

Historically they were used as gravimeters to measure the acceleration of gravity in geophysical surveys, and even as a standard of length.

A variety of electric methods are used in geophysical survey.

Electromagnetic methods that are used for geophysical survey include transient electromagnetics and magnetotellurics.

UAVs can be used to perform geophysical surveys, in particular geomagnetic surveys where the processed measurements of the differential Earth's magnetic field strength are used to calculate the nature of the underlying magnetic rock structure.

Underwater explosions are used for a variety of purposes including military activities, construction and oceanographic or geophysical research.

This forms the basis of magnetostratigraphy, a geophysical correlation technique that can be used to date both sedimentary and volcanic sequences as well as the seafloor magnetic anomalies.

A form of spatial aliasing can also occur in antenna arrays or microphone arrays used to estimate the direction of arrival of a wave signal, as in geophysical exploration by seismic waves.

VLF is also used in electromagnetic geophysical surveys.

A sound geological and geophysical understanding of the Foz do Amazonas Basin is already available and used by the energy companies.

It is commonly used in geophysical phenomena in the oceans and atmosphere, where it characterizes the importance of Coriolis accelerations arising from planetary rotation.

The Ekman number is a dimensionless number used in describing geophysical phenomena in the oceans and atmosphere.

Gravimeters are used for petroleum and mineral prospecting, seismology, geodesy, geophysical surveys and other geophysical research, and for metrology.

They are widely used in geodesy, for surveying networks and for geophysical purposes.

The supercomputer is used in human genome research, protein research, astrophysical simulations, weather forecasting, geological or geophysical modeling, and the design of new drugs.

Principles of soil mechanics are also used in related disciplines such as geophysical engineering, coastal engineering, agricultural engineering, hydrology and soil physics.

Although geophysical survey has been used in the past with intermittent success, good results are very likely when it is applied appropriately.

Surface geophysical methods may be used to locate geophysical anomalies associated with gold deposits.

The most commonly used acres today are the international acre and, in the United States, the survey acre.

In 1794, this fortress was used by the French astronomer Pierre François André Méchain for observations relating to a survey stretching to Dunkirk that provided the official basis of the measurement of a metre.

Worldwide, most survey offices used this printer before color inkjet plotters become popular.

Starting from 1880 the Hungarian census system was based on native language ( the language spoken at home in the early life of the person and at the time of the survey ), vulgar language ( the most frequently used language in the family ), and other spoken languages.

An international survey of psychiatrists in 66 countries comparing use of the ICD-10 and DSM-IV found the former was more often used for clinical diagnosis while the latter was more valued for research.

The 1967 survey, published by The Smithsonian is used as the most authoritative baseline for more recent research.

The term " Geiger counter " is commonly used to mean a hand-held survey type meter, however the Geiger principle is in wide use in installed " area gamma " alarms for personnel protection, and in process measurement and interlock applications.

A Geiger tube is still the sensing device, but the processing electronics will have a higher degree of sophistication and reliability than that used in a hand held survey meter.

Donald Knuth notes that Hans Peter Luhn of IBM appears to have been the first to use the concept, in a memo dated January 1953, and that Robert Morris used the term in a survey paper in CACM which elevated the term from technical jargon to formal terminology.

An international survey of psychiatrists in 66 countries comparing use of the ICD-10 and DSM-IV found that the former was more often used for clinical diagnosis while the latter was more valued for research.

St. Laurent was ranked # 4 on a survey of the first 20 prime ministers ( through Jean Chrétien ) of Canada done by Canadian historians, and used by J. L. Granatstein and Norman Hillmer in their book Prime Ministers: Ranking Canada's Leaders.

It was discovered while scientists from the Hawaii Institute of Geophysics and Planetology were completing a survey around Guam ; they used a sonar mapping system towed behind the research ship to conduct the survey.

This is the model used by " insider magazines " or industry-based publications distributed only to qualifying readers, often for free and determined by some form of survey.

Based on an annual survey from Norwegian households, it seeks to collect data that may be used for comparison between businesses, comparisons between various fields, and comparisons over time.

In 2002, the BBC used the headline " English and Welsh are races apart " to report a genetic survey of test subjects from market towns in England and Wales.

Techniques used during this investigation include bathymetry survey, sub-bottom survey, side-scan survey, and magnetic survey.

A survey may refer to many different types or techniques of observation, but in the context of survey sampling it most often involves a questionnaire used to measure the characteristics and / or attitudes of people.

* Snowball Samples: Often used when a target population is rare, members of the target population recruit other members of the population for the survey.

This term is commonly used in opinion polling and survey sampling.

Those used in the targeted search had a bandwidth of 1 hertz per channel, while those used in the sky survey had a bandwidth of 30 hertz per channel.