• Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

As-Physics Investigation, Geo-Physics. the two main principles I will cover are, GPR- or Ground Penetrating Radar and EM- or ElectroMagnetic induction.

Extracts from this document...


Ryan George- 6166         Paul Britton         613 words

Geophysics – Ryan George

-Introduction to geophysics

Geophysics is a huge topic to cover, so in this case study I will only cover topics relating to radar, electromagnetic and other wave principles, such as the Doppler Effect or ultrasound. But the two main principles I will cover are, GPR- or Ground Penetrating Radar and EM- or ElectroMagnetic induction. Both of the methods stated above are used for various different detection, but mainly looking at ground defaults, checking mine shafts and looking for oil deposits. I will also be looking at other applications of GPR and EM, looking at the possible risks and benefits, as well as looking at the impact on the social and environmental factors.

-GPR (Ground Penetrating Radar)

Radar is a very simple protocolto grasp, a signal (usually radio waves) is produced by the radar transmitters and sent in the direction needing to be scanned, then the wave will reflect off the object wanting to be

...read more.


An image showing the Equipment used to collect the data for a EM scan [5]

The transmitter coil generates an electromagnetic flied at a specific frequency. The primary field then causes electrical currents to flow in conductive material at and in the subsurface. This flow of currents, called eddy currents, and then generates another magnetic field, or the secondary field, which is then detected by the secondary or receiver coil. The magnitude of the signal on the second coil depends on the type and disruption of the material in the sub surface. [6][7] Once this process is over the computer can generate an image looking like this:

An image showing the computer generated image of a EM scan [7]

-Social and environmental impacts

Using radar for looking underground at mines, or pipes doesn’t have a significant impact of the environment or social aspects, because the signal used is very weak. But one factor to think about is that to look underground without

...read more.


[4] - http://www.geophysical.com/whatisgpr.htm - image of GPR in use and the computer generated image (accessed 09/03/2010)

[5] - http://www.geophysical.com/whatisem.htm - image about EM induction equipment (accessed 09/03/2010)

[6] - http://www.geophysical.com/whatisem.htm - information about EM induction (accessed 09/03/2010)

 [8] - http://www.geophysical.com/whatisem.htm - image of them EM induction scan (accessed 09/03/2010)


[7] – Donald, Joseph. Retired university Physics lecture. (23/03/12) – explained how EM induction works.


Eddy currents- are electric currents induced in conductors when a conductor is exposed to a changing magnetic field.

EM- is the production of an electric current across a conductor moving through a magnetic field. It underlies the operation of generators, transformers, induction motors, and electric motors

GPR- is a geophysical method that uses radar pulses to image the subsurface. This non-destructive method uses electromagnetic radiation in the microwave band (UHF/VHF frequencies) of the radio spectrum, and detects the reflected signals from subsurface structures.

Radar- is an object-detection system which uses radio waves to determine the range, altitude, direction, or speed of objects. It can be used to detect aircraft, ships, spacecraft, guided missiles, motor vehicles, weather formations, and terrain.

Page  of

...read more.

This student written piece of work is one of many that can be found in our AS and A Level Electrical & Thermal Physics section.

Found what you're looking for?

  • Start learning 29% faster today
  • 150,000+ documents available
  • Just £6.99 a month

Not the one? Search for your essay title...
  • Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

See related essaysSee related essays

Related AS and A Level Electrical & Thermal Physics essays

  1. Peer reviewed

    Measurement of the resistivity of Nichrome

    5 star(s)

    The reason for that might be the diameters I measured for Wire B is more uniform than those for Wire A. Wire A is not as uniform as Wire B Conclusion In this coursework, I measured the resistivity of Nichrome which I found is 1.13�10-6?�m�4.5% and 1.14�10-6?�m�2.6%.

  2. Objective: To use a search coil and a CRO to investigate the magnetic ...

    As the induced e.m.f. ? = -NA dB/dt, the current flowing in the straight wire increases with the magnetic field produced by the current-carrying straight wire. From the V- graph in step 8 (Graph A.2), the distance from the straight wire is inversely proportional to the induced e.m.f. (V).

  1. The aim of my investigation is to determine the specific heat capacity of aluminium.

    From looking at my result tables I can estimate the time delay from which the heat from the heating filament reaches the thermometer. I can do this by finding the time taken for the maximum temperature to be reached, once the heating filament was switched off.

  2. Measuring The Resistivity Of A Pencil Lead.

    resistivity : The cross-sectional error : The diameter = 2.05mm = 0.00205m Using the formula The main sources of error will be * In the voltmeter with a percentage error of ?3% * In the ammeter with a percentage error of ?0.5% * In calculating the resistance with a percentage

  1. Characteristics of Ohmic and Non Ohmic Conductors.

    They are tetravalent. These are called valence electrons. The structure that is formed is a tetrahedral structure. This forms a crystalline structure. There are two types of semiconductors. One type is the intrinsic semiconductors and the extrinsic semiconductors. Intrinsic semiconductors are elements and compounds that are semiconductors.

  2. Characteristics of Ohmic and non-Ohmic Conductors.

    Resistance ??Length Area Resistance = P x length Area P = Resistance x Area Length Nichrome Resistance = 5.98 ohms Length = 80 cm = 0.8 m Diameter = 0.45 mm = 0.45 x 10-3 = 4.5 x 10-4 Radius = (4.5 x 10-4)

  1. I am going to investigate what the resistivity is of a pencil lead. ...

    I will use exactly the same equipment throughout the experiment as different wires have different diameters and length while the meters may all vary slightly. The temperature of the pencil lead will affect the resistance. It is especially important that this remains the same as materials that are ohmic resistors,

  2. Investigating the factors affecting the size of current flowing through a length of resistivity ...

    DEFICIENCIES WITH THE DATA COLLECTION Although I designed the experiments to be as accurate and fair as possible, there were obviously deficiencies in the data collection methods. Even the results published by UNILAB came up with different calculated values for the resistivity of the putty!

  • Over 160,000 pieces
    of student written work
  • Annotated by
    experienced teachers
  • Ideas and feedback to
    improve your own work