This astronaut photograph highlights the 24-kilometer (15-mile) wide Aso caldera on the Japanese Island of Kyushu. Shadows highlight the caldera rim at image right, while green vegetation covers slopes between the rim and caldera floor at image left.
Aso formed during four explosive eruptions that took place between 300,000 and 90,000 years ago. These eruptions produced pyroclastic flows and airfall tephra that covered much of Kyushu. As the eruptions emptied the magma chambers beneath those ancient volcanoes, they collapsed and formed the caldera.
Volcanic activity continued after the formation of the caldera, as evidenced by 17 younger volcanoes in the area, including Naka-dake—one of Japan’s most active volcanoes and the site of ash plumes as recently as June 2011. The nearby Kusasenri crater is the site of the Aso Volcano Museum and of pastureland for cows and horses.
The floor of Aso caldera is largely occupied by urban and agricultural land uses that present a gray to white speckled appearance. Fields and cities surround the younger volcanic structures to the north, west, and south. Tan to yellow-brown regions along the crater rim—and along the lower slopes of the younger volcanic highlands in the central caldera—are lacking the dense tree cover of some of the greener areas in the image.
Astronaut photograph ISS033-E-22852 was acquired on November 18, 2012, with a Nikon D3S digital camera using a 400 millimeter lens, and is provided by the ISS Crew Earth Observations experiment and Image Science & Analysis Laboratory, Johnson Space Center. The image was taken by the Expedition 33 crew. It has been cropped and enhanced to improve contrast, and lens artifacts have been removed. The International Space Station Program supports the laboratory as part of the ISS National Lab to help astronauts take pictures of Earth that will be of the greatest value to scientists and the public, and to make those images freely available on the Internet. Additional images taken by astronauts and cosmonauts can be viewed at the NASA/JSC Gateway to Astronaut Photography of Earth. Caption by William L. Stefanov, Jacobs/ESCG at NASA-JSC.
The approximately 4-kilometer-wide Dendi Caldera includes some of this silica-rich volcanic rock: the rim of the caldera, visible in this astronaut photograph, is mostly made of poorly consolidated ash erupted during the Tertiary Period (approximately 65–2 million years ago).