Question

What is a mean sea level?AND HOW IS THIS USEFUL.

Answer 1

We often hear reports that sea level is rising due to global warming but what is sea level and how is sea level measured? When it is stated that "sea level is rising," this usually refers to "mean sea level," which is the average sea level around the earth based on numerous measurements over a long period of time. The elevation of mountain peaks are measured as the height of the peak of the mountain above mean sea level.