Google Earth Blog

The amazing things about Google Earth


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Average Cloud Cover Map and Map Projections

We recently came across this article about a recently released map of average cloud cover for the last 13 years produced by NASA.

The map is provided in the form of an image and a high resolution version can be downloaded from NASA. It would have been nice to view it Google Earth. However, it is provided with a different map projection than is used by Google Earth image overlays. This is usually not much of a problem for small image overlays, but for global maps it is critical. Google Earth image overlays need to be in the Equirectangular Projection. The NASA cloud cover map is provided in the Hammer Projection.

Do any of our readers know of an easy way to convert global images from one projection to another? NASA provides this tool to convert from the Equirectangular Projection to a wide variety of other projections, but it doesn’t convert the other way.

NASA does provide daily and monthly images of cloud cover maps in the Equirectangular Projection. NASA includes the option to download them as KMZ files ready to be viewed in Google Earth.


NASA’s average cloud cover map for April, 2015 as seen in Google Earth. To see it for yourself download this KMZ file

Antarctica is of particular interest. It appears to have three distinct zones of cloud density. We guess that these correspond to:

  • A region offshore with pack ice.
  • The coastal ice shelves.
  • The actual land, which is higher than the ice shelves.

Can any of our readers give a more scientific explanation?

Surface deformation from the Nepal Quake

We recently came across this article about a map from NASA that shows the deformation caused by the recent earthquake that struck Nepal.

The above map can be downloaded and viewed in Google Earth using this KMZ file.

The movement being measured is the overall vertical movement of the ground as a result of the earthquake. If I read the map correctly, the ground moved upwards with maximum movement at a point just North of Kathmandu. In the above screenshot we have turned on the ‘Earthquakes’ layer (found in the Gallery layer) in Google Earth which shows that the centre of the initial magnitude 7.8 earthquake was further to the North West (the largest Earthquake icon).

DigitalGlobe captured satellite imagery of the region soon after the earthquake and has made it available for free to emergency responders under a Public License for Humanitarian purposes.

It is possible to see the imagery on DigitalGlobe’s website and you can help with the crowdsourcing campaign on the Tomnod website.

We have not yet found a way to download the imagery for viewing in Google Earth.

Amazing extratropical cyclone over the United Kingdom

The NASA Earth Observatory site is constantly releasing amazing images from space, including items such as this awesome image of Mount Everest, lava flow shapes, Laguna Verde, and many others. Their latest image is a stunning view of an extratropical cyclone over the United Kingdom that was captured last week.

extratropical cyclone

This particular cyclone brought winds of over 100 miles per hour, and caused power outages to more than 700,000 people. They released a large image to show it off, which I’ve matched up in an image overlay and included in this KML file for you to view directly in Google Earth.

Read more about this cyclone on the Earth Observatory site or see other images from the Earth Observatory that we have showcased.

Awesome Google Earth image of Mount Everest from NASA

We’ve talked about Mount Everest quite a few times on Google Earth Blog.  Natural formations such as mountains and volcanoes tend to look stunning in Google Earth, and Everest is no exception.  In the past we’ve shown you a panorama from the summit, a map of the ice on the mountain, Street View imagery from it, and last year we commemorated the 60th anniversary Sir Edmund Hillary’s historic ascent.

The NASA Earth Observatory has just put out an image of the mountain that is simply awesome.

everest

The image was actually captured back in 2011, but it’s a stunning look at the mountain.  You can read more about the image here, or grab this KML file to view it directly in Google Earth as an image overlay.

For more, check out the main Earth Observatory site to see some of the great new items they’ve been publishing.

Lava flow shapes in Google Earth

Because of the way Google Earth work, volcanoes are almost always amazing to view inside of it.  3D terrain combined with high-resolution imagery makes for some stunning views, as we explained a while back in our “A to Z” post about Volcanoes.

The NASA Earth Observatory recently posted an image and article about “lava flows”, seen here:

zhupanovsky

From their article:

Streams of molten rock that ooze from gaps or vents in the Earth’s surface are called lava flows, and they can pose a hazard to everything in their paths. These rivers of rock can take many shapes and move at very different rates depending on the viscosity of the magma, the slope of the land, and the rate of an eruption.

While viscous lava flows are defined by steep flow fronts and pressure ridges, low-viscosity lavas tend to move faster and create longer, narrower shapes. They also tend to have smaller flow fronts and levee-like structure along their edges. Many characteristics of a low-viscosity lava flow are visible in this image of Zhupanovsky and Dzenzursky volcanoes on Russia’s Kamchatka Peninsula. The image was acquired by the Operational Land Imager (OLI) on the Landsat 8 satellite on September 9, 2013.

To see this volcano for yourself, simply download this KML file and load it in Google Earth.  For more, you can read the full story on the NASA Earth Observatory site.