Over the past three millennia, sea level has fluctuated by approximately 0.1 metres, roughly the size of a palm. However, we are currently experiencing the early stages of a new inundation. Sea level serves as a fixed reference point for both terrestrial altitude and marine depths, acting as the interface between the ocean and the atmosphere. It is influenced by various factors, including the moon, tides, salinity, local gravity, atmospheric pressure, water density and temperature, storms, and sea circulation. Calculating the average level across all tide phases determines sea level as the basis for surveying and measuring. Today, high-resolution orbital measurements and physics models are used to determine the datum, enabling planning processes to safeguard against floods and develop and maintain infrastructure. These measurements indicate a highly dynamic system that requires rapid adaptation. The sea surge is projected to exceed two metres in the coming century, with the first metre already occurring this century. This surge will cover areas currently inhabited by over a billion people.
Digital Elevation Model