ously too narrow to allow ships to travel and pass in opposite directions.
A massive expansion project was started in 2014 to increase the depth of the existing channels and create a separate shipping lane along a major portion of the Suez Canal. The project took one year to complete and included 22 miles (35 kilometers) of new channel near Ismailia, Egypt. This new shipping lane will dramatically shorten the travel times for ships traveling in both directions.
This series of Landsat 8 images shows the area before, during, and after construction. The first image (August 2014) shows the Suez Canal near the time construction began. The new route is faintly visible in the second image (December 2014) while construction was in progress. The third image (August 2015) shows the completed and operational canal project, with the new shipping lane filled with water and clearly visible.
The 40+ year archive of Landsat imagery is a valuable resource for monitoring land use changes over time.
Island-Building in the South Pacific August 4, 2015
An undersea volcano between the two small islands of Hunga Tonga (right) and Hunga Ha’apai (left) began erupting in early December 2014. After about a month of eruptive activity, a new landmass had formed, nearly joining the two islands.
This series of Landsat 8 images shows the two islands in October 2014 (before eruptions), in December 2014 (during the eruptions), and in July 2015 (after the eruptions).
Along with creating new landmass, the volcanic activity has also radically changed the islands’ ecology. The first panel shows vegetation cover (green) on both of the original islands. The predominantly gray and brown colors in the third image now indicate bare land surface, especially on the southeastern island.
Landsat images are often useful for mapping changes to the Earth’s land surface. Future images will also allow scientists to monitor any changes and long-term recovery of vegetation and land cover
Laguna Pastos Grandes is a shallow salt lake located in Bolivia’s Pastos Grandes volcanic caldera. Fed by intermittent rivers and springs, the lake contains high concentrations of lithium, potassium, and boron. These three images show how Landsat 8’s extended spectral capabilities can be used to highlight various surface features, often with vibrant results.
The left image uses the three visible bands from Landsat (red, green, and blue) to create a natural color representation. In this image, the ground features appear in colors very similar to what would be seen by the human eye. Non-vegetated ground is brown, and water appears dark. The bright areas indicate salt and other evaporated deposits in dry or very shallow areas of the lake.
Along with the visible wavelengths, Landsat 8’s extended spectral bands show additional details that cannot be seen by the human eye. The middle image uses two infrared bands that can be used to highlight the water bodies (red), salt and evaporated deposits (yellow, gold), and varying composition of other materials (green, tan) within the basin. The right image also uses infrared bands, but in a different combination which accentuates the salt and evaporated deposits (light blue) and the geologic features within the surrounding volcanic region (brown, green).
The many spectral bands available on Landsat provide an important set of tools for scientists, geologists, and others to study and map features on the Earth’s landscape. These features cannot always be seen by the human eye alone.
Near the western edge of the Sahara Desert is a feature that resembles a large eye when viewed from space. The Eye of the Sahara, also known as the Richat Structure or Guelb er Richat, is a symmetrical dome of eroded sedimentary and volcanic rock. The outermost rings measure approximately 40 km (25 miles) across. Persistent northeasterly winds keep much of the dome free from sand, exposing the various layers of rock. The circular feature was initially interpreted to be an asteroid impact structure, but most scientists have now concluded that it was caused by geologic uplift.
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