The series of Landsat satellites has been collecting global imagery continuously since 1972. A total of eight satellites and millions of pictures (and trillions of pixels) has resulted in a hugh amount of imagery which, when compiled, visualizes the massive amount of global change over the past thirty+ years. Landsat satellites capture imagery of the same location on earth on average once every 16 days.
On April 21, 2008, the USGS announced it would be making Landsat image products free to the public. This led Google in 2009, to approach the USGS about combining Landsat imagery into timelapse video.
Google has teamed up with U.S. Geological Survey (USGS), NASA and TIME to produce timelapse video showing the progression of change across landscapes over a span of three decades. TIME has a writeup as part of its article about the Timelapse project detailing the amount of work Google went through in order to consolidate, digitize, and process the millions of images into the video. From Google’s Official Blog:
We started working with the USGS in 2009 to make this historic archive of earth imagery available online. Using Google Earth Engine technology, we sifted through 2,068,467 images—a total of 909 terabytes of data—to find the highest-quality pixels (e.g., those without clouds), for every year since 1984 and for every spot on Earth. We then compiled these into enormous planetary images, 1.78 terapixels each, one for each year.
More than just pretty pictures, the time lapse videos also provide researchers insights into global issues such as climate change, urban growth, and oil extraction. Below are some sample animated GIFs created by Google showcasing some areas of the world with dramatic change.
The timelapse video for Columbia Glacier from 1984 to 2011, in Prince William Sound, has lost 12 miles in length and nearly 1,300 feet in thickness whereas from 1794 until 1980 its presence and extent was pretty constant.
Between 1980 and today, the city of Las Vegas quadrupled in population, growing from 500,000 to roughly 2 million residents.
Changes in the Earth’s Surface
Lake Urmia, located in northwestern Iran, has shrunk by more than 60%, as the animated GIF below visualizes. The saltwater lake has an annual evaporation rate of 24 to 39 inches.
The image below shows the massive growth of irrigation for farmland in Saudi Arabia.
Explore Changes in the World Over Time
To explore more areas of change, visit TIME’s Timelapse page. You can view selected areas such as deforestation in the Amazon, the retreat of Mendenhall Glacier in Alaska, the drying up of Lake Urmia in northwestern Iran, and Dubai’s coastal expansion. Click on the “explore the world” option and then type in an address or place in the box in the lower right hand corner of the site to search by location to see time lapse imagery.
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