A caldera is a cauldron-like volcanic feature usually formed by the collapse of land following a volcanic eruption. They are sometimes confused with volcanic craters. A collapse is triggered by the emptying of the magma chamber beneath the volcano.

Kilauea is the most active volcano on Earth. The magma feeding the volcano is basalt which is silica poor. As a result, the magma is much less viscous than the magma of a rhyolitic volcano, and the magma chamber is drained by large lava flows rather than by explosive events.

The foreground is the floor of the caldera (3 km x 5 Km). The right side of the image is the wall of the caldera, 165 m high.

Kilauea Caldera has an inner crater known as Halema‘uma‘u. The roughly circular crater floor is 770 metres (2,530 ft) x 900 metres (2,950 ft) and is 83 metres (270 ft) below the floor of Kīlauea caldera. Steam reveals the presence of magma beneath the surface. Halemaʻumaʻu is home to Pele, Goddess of Hawaiian Volcanoes, according to the traditions of Hawaiian mythology. The most recent eruption was in April 2008.


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