• 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...

Introduction

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.

Middle

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.

Conclusion

[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)

Interviews

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

Glossary

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)

    -1 Minimum value of uncertainty of gradient (Min) = (Blue line gradient/Best fit line gradient) -1 Uncertainty calculation The data in the table below is in 3 decimal place Graph A (Wire A) Graph B (Wire B) Max +1.9% +1.0% Min -1.9% -1.0% So the gradient for Graph A (Wire A)

  2. Peer reviewed

    Investgating resistivity - Planning and Implementing

    4 star(s)

    However, Ohm's Law also states that for V=IR to be true, the external conditions must be the same. As a wires current increases, so does its temperature. If the temperature increases greatly, this will cause the resistance to increase, because as a metal's temperature increases, the electrons and positive ions

  1. 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).

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

    and it therefore takes less time for the heat to reach the desired location. Conduction can also occur in the liquid as long as there is a temperature difference. When two particles collide and one has more energy than the other does the particle with greater energy transfers some of

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

    I will try to make it as accurate as possible by using an electric ammeter and a voltmeter where the intervals are 0.1V. Preliminary Experiment I will be carrying out a preliminary experiment so that I know exactly what I am doing and can eliminate any problems that I may come across.

  2. Characteristics of Ohmic and Non Ohmic Conductors.

    magnitude of current remains unchanged when the current or the voltage is reversed. The magnitude changes as displayed from the above graphs. The current is proportional to the voltage. The current is not proportional to the voltage. Temperature affects current and resistance.

  1. Measuring The Resistivity Of A Pencil Lead.

    Analysis & Conclusion See graph. Using the formula and the graph produced by my results I can calculate two gradients. One for the higher possible value and one for the lower possible values. The highest gradient is: = 0.64 ?/m The lowest gradient is: = 0.57 ?/m Evaluation Calculations Therefore

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

    This value is very close to the value of 2 which I predicted and within the limits of experimental error can be considered to be 2. Since doubling the length of the putty doubles the inverse of the current, it follows that doubling the length of putty will halve the

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