Today’s Image of the Day from NASA Earth Observatory features São Miguel, the most volcanically active island of the Azores archipelago in the eastern mid-Atlantic Ocean.
The island chain, which is an autonomous region of Portugal, began to form about 10 million years ago over a hotspot in Earth’s mantle. According to NASA, the archipelago lies at the junction of the North American, Eurasian, and African plates.
“At 760 square kilometers (290 square miles), São Miguel is the largest of the nine Azores islands and home to half of its people—most of whom live in Ponta Delgada, the economic capital of the Azores. The island’s highest point is Pico da Vara, which rises to an elevation of 1,080 meters (3,545 feet) above sea level,” reports NASA.
“São Miguel comprises six volcanic zones that formed in the last 3 million to 4 million years. But the island didn’t take on its modern shape until about 50,000 years ago, when an eruption of land-forming lava joined the eastern and western volcanic massifs.”
“The oldest of the six volcanic zones is in the east; the youngest is in the west, where the most recent volcanic activity occurred. Three of the volcanos are still active, though dormant, including Sete Cidades, which last erupted from a submarine vent off the west coast in 1880.”
The image was captured on December 9, 2018 by the Operational Land Imager (OLI) on Landsat 8.
Image Credit: NASA Earth Observatory