1.   Geophysics involves the measurement
of physical properties of
the Earth

Students learn to:

•    outline the evolution of geophysical investigation and its relationship with improvements in instrumentation

•    describe the properties of earth materials that are studied in geophysics — particularly elasticity, density, thermal, magnetic and electrical properties

•    identify the principal methods used in geophysics as seismic, gravity, magnetic, palaeomagnetic, electrical, electromagnetic, radiometric and geothermal and describe the type of information that each of these methods can provide

•    deduce the types of methods that might provide useful information given the properties of the materials in an area

Students:

•        identify data sources, gather and process information to discuss Huygen’s and Newton’s investigation of the shape of the Earth using pendulum measurements

•    plan, chose equipment or resources for, and perform first-hand investigations to gather data and use the available evidence to analyse the variation in density of different rock types

•    solve problems, analyse information and use available evidence to compare the thermal properties of different substances

2.   Some physical phenomena such as gravitation and radiation provide information about the Earth at a distance from it

Students learn to:

•    recall the variation in properties of electromagnetic waves

•    describe how absorption and reflection of radiation can provide information about the reflecting surface

•    explain how remote sensing techniques can be used to monitor climate, vegetation and pollution

•    summarise uses of the remote sensing of radiation in mineral exploration

•    explain why gravitational attraction of a small mass at a point can be studied as the vector sum of attraction by a number of bodies

•    outline reasons why the gravitational field of the Earth varies

•    describe how the paths of satellites are used to study the Earth’s gravity

•    outline the structure and function of a gravity meter

•    describe the purpose of data reduction in gravity surveys

•    recount the steps involved in gravity data reduction — latitude correction, free air correction and Bouguer correction

•    identify and describe the uses of gravity methods in resource exploration and archaeology

Students:

•    plan, chose equipment or resources for, and perform a first-hand investigation to gather data to demonstrate the relationship between the nature of a surface and the radiation reflected from it

•    process information to describe the significance of Jean Richers experiments with the pendulum in disproving the spherical Earth hypothesis

•    solve problems and analyse information to calculate the mass of the Earth given g
and the diameter of the Earth

•    perform an investigation and gather and analyse data to identify the value of g using a pendulum

•    solve problems and analyse information to calculate the mass of the Earth given the period of a satellite:

•    perform an investigation, using second hand data, to discuss changes that occur during data reduction of gravity data

 3.   Seismic
methods provide information about the large scale structure of the Earth
and the detailed structure of
its crust

Students learn to:

•    describe the properties of P waves and S waves

•    outline how a seismic wave‘s path is affected by the properties of the material it travels through

•    explain how seismic waves are reflected and refracted
at an interface

•    outline the structure and function of geophones and seismometers

•    summarise the evidence for a liquid outer core and a solid inner core of the Earth

•    outline the methods of seismic reflection and refraction

•    discuss the uses of seismic methods in the search for oil and gas

Students:

•  solve problems and analyse information to calculate the diameter of a planetary core using a distance-travel-time graph

•  perform an investigation to model the principles of the reflection and refraction of seismic methods

•  analyse information from a graph of travel time versus shot-to-geophone distance
for a single layer

•  gather, process and present diagrammatic information to show the paths of P and S waves through the Earth

4. Studies of past and present physical phenomena indicate that
the Earth is dynamic

•    describe the Earth’s current magnetic field

•    account for the evidence that the Earth’s magnetic field varies over time

•    explain how magnetic anomalies are used to date the age of the oceanic crust

•    summarise the geophysical evidence that supports the theory of plate tectonics

•    discuss the initial reluctance of the scientific community to accept the mobility of the Earth’s plates

•  perform an investigation
and present information to demonstrate how the inclination of the Earth’s magnetic field varies with latitude

•  solve problems and analyse information to calculate the spreading rate of an ocean using a magnetic polarity time scale and a magnetic anomaly profile

•  gather secondary information to analyse the nature of heat flow and seismicity at the edges of a crustal plate

5. Geophysics provides information
that is of economic
and social benefit

•    examine the role of geophysics in exploration using a case study

•    explain the benefits of geophysical methods in mineral exploration and environmental monitoring

•    describe the role that geophysicists have played in one of the following:

     –     our current understanding
       of the age of the Earth

     –     monitoring nuclear test
       ban treaties

     –     natural hazard reduction

•  identify data souces, plan, chose equipment or resources for, and perform an investigation to demonstrate the use of a geophysical method in the field

•  identify data sources, gather, process, analyse information and use available evidence to asses the impact of technological developments increasing an understanding of the Earth’s structure and behavior