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Geology 2112 – Principles and Applications of Geophysical Methods WEEK 5
Lecture Notes – Week 5 PART 2
The Geoid
Reading: Fowler Chapter 5.4, 5.6.2
Objectives: Discuss the concept of the ‘Geoid’ and how we use it to describe the shape of the earth.
The Reference Ellipsoid (or Oblate Spheroid):
• So far we’ve seen the evolution of our understanding o f the shape of the earth from flat, to round (spherical) to the ‘oblate spheroid’ or ellipsoid • A ‘perfect’ ellipsoid can be characterized (relative to a sphere) by a ‘flattening parameter: