Historical Shoreline Surveys

Coastal erosion is a theme which many teachers use Google Earth to explore, thanks perhaps to work by Bob Lang looking at the Holderness coast.
For more on that, you can check out the book 'GIS made Easy' that I edited. It contains all the details of an activity using Google Earth to measure coastal erosion and plan for the consequences in the future.

Now, NOAA has released thousands of old coastal surveys of the USA, which can be viewed overlain on Google Earth, and the historical time slider allows changes in the coastline to be viewed.