One of my favorite features of Google Earth is the historical imagery tool. Being able to click a button and view imagery from years past is an amazing. If you’re not familiar with this feature, here’s a quick overview of how it works:
Taking advantage of this feature, Brian Schrock has set up a blog called the Google Earth Time Machine, which shows comparisons of various locations via the historical imagery tool. A great example are the two images below, which show the results of when a dam was placed on the Berg River in South Africa.
He’s also posted some animations that make it easy to see the changes to a particular area. A great example of that is London as they prepared for the 2012 Olympic Games. This image shows the area in 2006, 2008, 2010 and 2012:
Brian has posted dozens of examples over the past few years, and it’s worth your time to check them out at googleearthtimemachine.blogspot.com.
(via +Google Earth Community)