It's been three years since Google first released a timelapse visualisation of the Earth, in 2013. The company has now created an updated visualisation that builds an interactive experience allowing people to explore changes to the Earth's surface, whether it's the retreat of glaciers, the creeping growth of cities, or the construction of megastructures such as Bangkok's international airport.
The visualisation can be viewed online and it shows you a snapshot of different parts of the Earth, from 1984 to 2016 - each frame represents a year, so the jumps can be quite sudden. Watching Dubai for example, you see vast tracts of empty land, then around the year 2000 some development starts. By 2003, in just seconds, the first of the artificial islands is blossoming in front of you. The images themselves are impossibly detailed - each frame is a 1.7-terapixel snapshot, with new images collected each week and then composited into a single, cloud-free image for each year. Using petabytes of data, the result is a stunning image that shows you how the world we're living in is changing.
"Using Google Earth Engine, we combined more than 5,000,000 satellite images—roughly 4 petabytes of data—to create 33 images of the entire planet, one for each year," Google explains. "For this latest update, we had access to more images from the past, thanks to the Landsat Global Archive Consolidation Program, and fresh images from two new satellites, Landsat 8 and Sentinel 2."
"We then encoded the 33 new 3.95 terapixel global images into just over 25,000,000 overlapping multi-resolution video tiles, made interactively explorable by Carnegie Mellon CREATE Lab's Time Machine library, a technology for creating and viewing zoomable and pannable timelapses over space and time," it added.
Watching deforestation in Madagascar, or the shrinking of Great Salt Lake in Salt Lake City, USA, alongside the growth of Bangok, and Beijing, is sobering, and makes you realise that similar things are happening in our own country too.
This data isn't just important for building awareness though. According to Google, there have been multiple case studies based around the data collected for Google Earth. One study, for example, was able to use Google Earth data to track global forest cover change; while the University of Minnesota used this data to track wild tiger habitats over a 14 year period, across 13 different countries. According to Dr. Anup Joshi, Research Associate, University of Minnesota, the use of this data was able to speed up the research work tremendously. "It took us about 1.5 years each to do the previous two range-wide tiger habitat analyses, but with Google Earth Engine we were able to get it done in less than a week," he said.