We recently came across this interesting article about how the Joaquin Valley in California is sinking due to the extraction of ground water. It has an interesting map of the subsidence that was done in Google Earth. However, they do not seem to provide the KML file. We did find the source of the data is NASA’s UAVSAR program which you can read more about here. It basically consists of aerial radar surveys. Radar maps not only highlight different surface types but multiple surveys over time can show changes in elevation or land use such as the subsidence mentioned above.
It is possible to view some of the data and even download it to Google Earth. Use this map to find data strips. The data isn’t only of the US, but includes quite a lot from South America, Japan, Greenland, Iceland and a few other locations. You need to sign up to download the data as KML, but signup is free.
The imagery is quite low resolution but it highlights built up areas and farmlands clearly.
A strip of radar data in California.
Mount Aso, Japan.