NASAさんのインスタグラム写真 - (NASAInstagram)「After three years of quiet, Shishaldin erupted again this summer. 🌋 Mount Shishaldin is a cone shaped stratovolcano that is one of the most active volcanoes in the Aleutian arc in Alaska. On July 11, the Alaska Volcano Observatory observed elevated surface temperatures and seismic activity. Then, in the early hours of July 14, a significant explosion sent an ash cloud 6 to 7.5 miles (9 to 12 kilometers) into the air which drifted south over the Pacific Ocean. Two smaller explosions occurred on July 14 and 15, launching ash plumes about 3 miles (5 kilometers) above sea level. Ash fallout from the eruptions can be seen on the southern flanks of Shishaldin in this image, acquired by the Operational Land Imager on Landsat 8 on July 17. An eruption on July 18 generated another large ash cloud that led the National Weather Service to issue a warning to pilots to avoid the area. Even though the area is remote, plumes of volcanic ash can contain sharp objects that can damage jet engines, so letting pilots know about these explosions is essential. Image description: Satellite image of the Shishaldin Volcano. There are white clouds surrounding the top half of the image. Then green vegetation covers on the bottom half. The center of the volcano is black. Beside the ash on the volcano is white snow.」9月3日 2時27分