KEY POINTS

  • The OLI instrument on Landsat 8 captured an image of a "volcanic potpourri" in Iceland
  • The image highlights various volcanic features from rootless cones to a volcanic crater
  • Iceland is just one of the islands in the Mid-Atlantic Ridge system

When people think of potpourri, they think of the mixture of dried spices and petals that makes a room smell nice. However, an image shared by the NASA Earth Observatory is a different kind of potpourri. Taken by the Operational Land Imager (OLI) on Landsat 8, the image shows what NASA calls a “volcanic potpourri.”

Volcanic Potpourri

In an image taken by the OLI instrument on NASA and the United States Geological Survey’s Landsat 8 satellite, a “potpourri” of the volcanic features in a part of Iceland’s Northern Volcanic Zone can be seen. For example, one of the most prominent features visible in the image is the distinctively circular crater of Hverfall, a tephra cone volcano that had a massive eruption about 2,500 years ago.

Iceland's North Volcanic Zone Image: A part of Iceland's North Volcanic Zone, showing the different volcanic features of the landscape. Photo: Landsat 8/NASA Earth Obervatory

Just west of Hverfall, another interesting feature is also highlighted in the image. Called rootless cones, the circular features look like craters but they were, in fact, created when lava flows passed wet surfaces and created steam explosions. They are not connected to underground magma chambers.

North of Hverfalls, the Námafjall geothermal area, is where pools of bubbling mud and fumaroles can be seen. These fumaroles are actually openings in the Earth’s surface in the form of holes, fissures or cracks near active volcanoes. Because it is hissing out noxious fumes such as carbon dioxide and sulfur dioxide, the area sees minimal vegetation.

The image also highlights the bright blue pools of Myvatn Nature Baths, a popular tourist attraction.

Mid-Atlantic Ridge

The Mid-Atlantic Ridge (MAR) is a mostly underwater mountain range in the Atlantic Ocean that was discovered in the 1950s. Although most of the system is underwater, it actually forms land as a set of islands, including Iceland. There, people can explore the ridge on dry land.

Other islands in the ridge system are Jan Mayen in Norway, Azores in Portugal, St. Paul’s rock in Brazil, Bouvet Island also in Norway and U.K. islands namely Ascension, St. Helena, Tristan da Cunha and Gough.

MAR separates the North American Plate from the Eurasian Plate in the North Atlantic, as well as the South American Plate from the African Plate in the South Atlantic. These plates are still moving, making the Atlantic grow at the ridge by 2.5 centimeters per year.