Gravity field

This episode focuses on the Earth's gravity field, a fundamental aspect of geophysics. We will explore how gravity is measured and how variations in the gravity field provide insights into Earth's internal structure and mass distribution. Building upon our understanding of geophysics and seismology, we will discuss how gravity anomalies can reveal subsurface features. This episode aims to provide a clear understanding of the principles of gravity and its applications in geological studies, without delving into related topics like geomagnetism or heat flow, which will be covered in future episodes. We will discuss the concept of gravitational acceleration, and how it varies across the earth's surface.

Check your understanding

These are the same multiple-choice questions you will see in the Quiz section after you listen to the episode. Use them here to preview or review the answers.

What does the Earth's gravity field represent?

  1. The magnetic force of the Earth
  2. The gravitational force exerted by Earth's mass
  3. The heat flow within the Earth
  4. The electrical resistivity of the Earth
  5. The seismic wave propagation
  6. The atmospheric pressure

What causes variations in the Earth's gravity field?

  1. Differences in rock density
  2. Geological structures
  3. Latitude and altitude
  4. Atmospheric temperature
  5. Ocean currents
  6. Wind speed

What instrument is used to measure gravity?

  1. Seismometer
  2. Gravimeter
  3. Magnetometer
  4. Thermometer
  5. Barometer
  6. Voltmeter

What does a positive gravity anomaly might indicate?

  1. A dense rock body
  2. A sedimentary basin
  3. An underground river
  4. A void in the Earth's crust
  5. A change in air pressure
  6. A change in temperature

How does the Earth's shape affect gravity?

  1. Gravity is stronger at the poles than the equator
  2. Gravity is stronger at the equator than the poles
  3. The shape has no effect on gravity
  4. The shape affects only the magnetic field
  5. The shape affects only seismic waves
  6. The shape affects only heat flow

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