File:Activity at Sakura-jima and Kirishima, southern Japan (MODIS 2018-04-14).jpg

English: The many islands of Japan sit along the Pacific Ring of Fire, an area rich in both volcanic and seismic activity created by the subduction of the Pacific tectonic plate under other oceanic plates. Japan’s location at the junction of four tectonic plates (Pacific, Philippine, Eurasian, and North American) practically guarantees a high level of volcanic activity, so it’s no surprise that the country is home to more than 100 active volcanoes – about 10% of all the active volcanoes in the world.

On April 12, 2018, the Moderate Resolution Imaging Spectroradiometer (MODIS) on board the Terra satellite acquired a true-color image of two of Japan’s volcanoes in active eruption.

A thick plume of ash and gas was rising from Sakura-jima and was blowing eastward over southern Kyushu Island. Sakura-jima is one of the most active volcanoes in the word and is presently in constant activity. On April 11, the Tokyo Volcanic Ash Advisory Center (VAAC) reported an explosive eruption from Sakura-jima’s Aira caldera. By April 12 the major activity was heavy ash.

To the north, a red hot-spot marks the summit of the Kirishima volcano, where a moderately powerful explosion occurred on April 5. A small pyroclastic flow (lava) travelled down the southeast side and lava bombs landed up to 1000 meters (0.68 miles). Since that time there has been a slow effusion of lava along with intermittent small to larger explosions. The red hot-spot is an area where the thermal bands on the instrument detected high temperatures. In this case, the high temperatures are almost certainly caused by hot lava.