What is Geoid?

The geoid is defined as the equipotential surface that best approximates the mean sea level. It is the theoretical surface of the Earth's gravitational field that is perpendicular to the direction of gravity at every point on the surface. The geoid is considered as a reference surface for measuring elevations and depths. It is used to define the shape of the Earth, and to interpret phenomena related to gravity and its variations.

How is it measured?

The geoid is measured through satellite altimetry and gravity field modeling. This involves the use of satellites to measure the Earth's gravity field and its variations. These measurements are used to create a mathematical model of the geoid, which is then used to determine elevations and depths at any point on the Earth's surface.

Applications of Geoid

The geoid has many applications in various fields, including:

- Surveying and mapping: The geoid is used as a reference surface for measuring elevations and depths. It is used in surveying and mapping to determine the height of mountains, the depth of oceans, and the shape of the Earth.

- Geophysics: The geoid is used to study the Earth's gravitational field and its variations. It is used to understand the Earth's interior structure, and to study phenomena related to gravity, such as tides and the movement of the Earth's crust.

- Oceanography: The geoid is used to study ocean circulation and currents. It is used to determine the shape of the ocean surface, and to measure changes in sea level due to factors such as tides and climate change.

- Climate change: The geoid is used to study the effects of climate change on the Earth's surface. It is used to measure changes in sea level, and to monitor the melting of glaciers and ice caps.

Conclusion

In conclusion, the geoid is a fundamental concept in the study of the Earth's gravitational field and its variations. It is an important reference surface for measuring elevations and depths, and has many applications in surveying, mapping, geophysics, oceanography, and climate change research.

Geoid is a shape which is exactly like a sphere but geoid's poles are flat