How to get a quick idea of future sea-level rise using Google Earth Pro

Our benefactors at Google were kind enough to make Google Earth Pro available for free. Just agree to the terms here and get the version that works on your system.  Just use your e-mail and GEPFREE as the license key to start working.

Firstly make sure that you have the correct settings (Look under Preferences… in the Google Earth Pro Toolbar Menu. Here are mine:

Screen Shot 2015-11-04 at 2.05.09 pm

You can customize the settings to your needs but ensure that the Terrain settings are the same as mine. Also ensure that the Terrain layer is turned on under the Layers box. You can turn the other layers off.

Screen Shot 2015-11-04 at 2.08.20 pm

Then navigate to the area you want to consider. I wanted to look at Auckland, New Zealand.

Screen Shot 2015-11-04 at 2.09.31 pmNext, download this image file that I made. You could use any image file but this one is blue and square, which is perfect for our application. SeaLevelThen you need to insert this image onto the map using the Add Image Overlay tool in the toolbar at the top. That’s the one on the Left in this picture:

Screen Shot 2015-11-04 at 2.19.48 pmGive your object a title, click Browse and point to SeaLevel.png (or the image file of your choice). You could also change the transparency if you want.

Screen Shot 2015-11-04 at 2.26.10 pmClick on the Altitude tab and set the desired sea level height. Make sure Absolute is selected.

Screen Shot 2015-11-04 at 2.26.46 pmMake sure that the image covers the area you are interested in. If it doesn’t, use the green handles on the map windows to change the size and rotation.

Screen Shot 2015-11-04 at 2.33.06 pmIf everything looks good press OK. The map will look a bit splotchy but as soon as you zoom in the terrain data should resolve and the border between the land and the new sea-level should become clear.

Screen Shot 2015-11-04 at 2.36.30 pmAs you can see Auckland won’t cope well with a 50m rise in sea levels.

Note:

This method is “quick & dirty”. The terrain data used in Google Earth is not super accurate. Also, I will leave the research up to you, dear reader, to determine what scenario of sea level rise is the most accurate. It works well for sea-level rise in the double digits but single digit rise does not even register above the inaccuracy of the terrain data. At some future date I will describe how to determine the sea-level rise more accurately using digital terrain data.