# Is there a formula to calculate shoreline length or water position from ocean?

Assuming in the past the water of the oceans were lower does it also mean that the water was not where it is right now?

If yes, then how do we calculate approximately where the water would have been 300 or 1000 years ago?

• If there is a slope in the shoreline then lower sea surface means different shoreline location. You could improve your question by stating what factors do want to include on the answer. For example rising and sinking of ground or perhaps just the location of shorelines as a factor of sea surface height. Do you know the sea surface height relative to current 300 or 1000 years ago? Jul 4, 2017 at 8:32
• Sure, I have data from previous year's Sea Elevation/Altitudes. I am not referring to erosion or any other such attribute that might influence shorelines. I am trying to figure our in a general prospective if shorelines became smaller/larger in the past 1000 years and if YES, then I would need to figure out by what % or measure they shrank/expanded. Jul 4, 2017 at 15:38
• If you have a map of sea elevation relative to current, and depth of the ocean in each point, then you can determine the position of the new shoreline. The calculation of the length of shorelines is a known paradox (en.wikipedia.org/wiki/Coastline_paradox). And thus the relative change can have various results on the method you use to calculate the coastline length. Jul 5, 2017 at 6:47