In researching his past, overlays can be a very valuable tool as he explains here:
I have used overlay for flying routes, shipping lanes, and mostly used for plat maps. I love plat maps, it’s like my little window to the past. You can take a plat map, stretch it over the township your ancestors lived in and then use that to figure out where things from the past laid in today’s land. For instance, how many times have you see a old farm field turn into a subdivision? What I have done is place that plat map over the township and then used placemarkers to mark the Church, School, and Cemetery and then my polygons to mark the farm.
Back in April, the Bingham Canyon Mine was home to the largest non-volcanic landslide in the history of North America, when nearly 70 million cubic meters of dirt and rock collapsed into the pit. The NASA Earth Observatory website has posted imagery of the post-collapse site, which can be seen here:
You can view that imagery in Google Earth by loading this KML file.
Fortunately, because of the forethought of mine ownership, no one was injured or killed in the collapse:
The company that operates the mine had installed an interferometric radar system months before the event that made it possible to detect subtle changes in the stability of the pit’s walls. Signs of increasing strain prompted the mine’s operators to issue a press release seven hours before the collapse, with a warning that a landslide was imminent. All workers were evacuated and production had stopped before the landslide occurred; as a result, no one was injured.
Selected maps from the North Carolina Maps project can be viewed as Historic Overlay Maps, layered directly on top of current road maps or satellite images. By fading or “seeing through” the historic maps, users are able to compare the similarities and differences between old and new maps, and to study the changes in North Carolina over time.
The Historic Overlay Maps are presented with a historic map placed on top of a current Google street map. The historic map has been geo-referenced, meaning that it should line up very closely with the current map.
We’ve seen global overlay files before on Google Earth, including items such as the popular blue marble overlay. The folks at KMZmaps.com have created a variety of very high-quality overlays for use in Google Earth. They’re not free, but they’re reasonably priced and quite impressive. Here are few of them: Natural Globe: A more realistic view of Google Earth, very similar to the blue marble overlay but of considerably higher quality.
Colored Edges: There are a variety of Photoshop-edited overlays in here as well; various blurs and effects. Here is one called “colored edges” that is pretty neat.
They also have a collection of solid color overlays. These overlays are completely solid, effectively hiding the base imagery so that roads, borders and other items are more well-defined. Here is the dark red version of that, with the “Borders and Labels” and “Roads” layers turned on.
Like most maps of this variety, it fades away as you zoom in closer to reveal the base imagery. This allows you to run your favorite overlay all the time, as it will automatically hide itself when you zoom in close enough to look at the details of a specific location. The exception is a special version of the “solid black earth”, which is set to never turn off when you zoom in. They offer both versions, so the choice is up to you.
As I said at the beginning, the big drawback to these files is that they’re not free. They cost roughly $6/each (some vary a bit), with the full collection available for $24.95. However, they also offer a demo map so you can get a feel for how it works. It’s covered with “www.KMZmaps.com” text, but you can get a feel for the quality of the imagery and the way the “auto-hide on zoom” works. You can download the sample KMZ file here. To see more of what they have to offer, visit their site at www.kmzmaps.com.
If you know of other overlays like this, free or paid, leave a comment and let us know.