BackgroundThe caldera trucates a 20 km wide seamount and was formed about 60,000-30,000 years ago.
Shirane, a dacitic lava dome, is located inside the sumberged caldera and reaches to 8 m below the sea surface. It is 3 km wide and 800 m high. The shallow Shirane rock mass rises to within 7 m depth below the sea surface and is the youngest part of the volcano.
On the outer flanks of the seamount, basaltic, andesitic and rhyolitic lava flows have been sampled. Two large submarine cones, Sumisu Knolls No. 1 and 2, lie west of the caldera.
See also: Sentinel hub | Landsat 8