Aira Caldera

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Aira Caldera
Sakura-jima from space.jpg
Space radar image of Aira Caldera, with Sakurajima in the bay formed by the caldera.
Highest point
Coordinates31°40′01″N 130°40′01″E / 31.667°N 130.667°E / 31.667; 130.667Coordinates: 31°40′01″N 130°40′01″E / 31.667°N 130.667°E / 31.667; 130.667
Aira Caldera is located in Japan
Aira Caldera
Aira Caldera
Mountain typeCaldera
Somma volcano
Last eruptionc. 22,000 years ago

Aira Caldera (姶良カルデラ, Aira-Karudera) is a gigantic volcanic caldera in the south of the island of Kyūshū, Japan. The caldera was originally thought to have been created by a massive eruption, approximately 22,000 years ago[citation needed]. This eruption, whose widespread deposits are generically known as the Aira-Tanzawa tephra, is now thought to be rather older. The latest/best age estimates derive from cores from Lakes Biwa and Suigetsu and they indicate an age of 29,430-30,150 years ago. Eruption of voluminous pyroclastic flows accompanied the formation of the 17 × 23 km-wide Aira caldera. Together with a large pumice fall, these amounted to approximately 400 km3 of tephra (VEI 7).

The major city of Kagoshima and the 16,000-year-old Sakurajima volcano lie within the caldera. Sakura-jima, one of Japan's most active volcanoes, is a post-caldera cone of the Aira caldera at the northern half of Kagoshima Bay.

Relief Map


  • Smith, V.C. (2013). "Identification and correlation of visible tephras in the Lake Suigetsu SG06 sedimentary archive, Japan". Quaternary Science Reviews. 67: 121–137.

External links[edit]

  • Aira - Smithsonian Institution: Global Volcanism Program
  • Aira Caldera - Geological Survey of Japan