Mean sea level is defined as the average level of the ocean surface, typically measured over a period of time that smooths out short-term fluctuations caused by factors such as tides, waves, and meteorological conditions. It serves as a standard reference point for measuring elevation on land and is used as a baseline for determining sea depths, coastal flooding risks, and other oceanographic measurements.
Mean sea level is mainly determined by various factors such as gravitational forces exerted by the Moon and the Sun, as well as the Earth's rotation and shape. It is subject to both local and global variations due to factors such as changes in the volume of water in the oceans, variations in oceanic currents, erosion, and coastal land uplift or subsidence.
To accurately determine mean sea level, a network of tide gauges is deployed worldwide, which measure the height of the ocean surface relative to a fixed point on land. These measurements are then combined and analyzed to compute an average value over a specific period, typically calculated over several years to remove short-term anomalies.
Mean sea level is an important reference for cartographers, surveyors, and scientists working in various fields such as hydrography, climate change research, coastal engineering, and marine navigation. It provides a standardized and consistent benchmark for comparing and interpreting sea level changes globally and regionally.
