Littoral cone

A littoral cone is a special kind of volcanic cone that forms when lava flows meet water. When lava touches water, it causes steam explosions that break the lava into small pieces. These pieces can pile up and create a new cone-shaped hill.

These cones usually form on a type of lava called ʻaʻā, which is thick and rough. Littoral cones need big lava flows to form, so they are not common everywhere. They have been found in places like Hawaii and other areas where volcanoes are active.

Description

Littoral cones are special semicircular shapes made when lava flows into water. They form when lava meets water, causing steam explosions that break the lava into pieces. These pieces can pile up and create a cone shape on the land.

These cones are made from volcanic ash, lava bubbles, and pieces of lava. They are usually found near big lava flows and can range in size from small mounds to larger formations. They are common in places like Hawaiʻi, where they often appear in pairs on either side of a lava flow.

Examples

Pseudocraters and littoral cones have been found in many places, such as Iceland, Hawaiʻi, Cerro Azul in the Galápagos Islands, Deception Island, Antarctica, Réunion, and Medicine Lake Volcano in California. Sometimes people use the words "pseudocrater" and "littoral cone" to mean the same thing. Littoral cones usually disappear quickly because they get covered by new lava flows or worn away by the sea, so they rarely stay as part of the landscape for long.

Scientists have found prehistoric littoral cones along the coast of Hawaiʻi, near big volcanoes like Mauna Loa and Kīlauea. These cones were named "littoral cones" in 1938. About 50 large cones exist on these two volcanoes, but only three formed during recorded history. Small littoral cones also appeared during eruptions at Puʻu ʻŌʻō and Mauna Ulu on Kīlauea. Other examples include a cone formed at Piton de la Fournaise on Réunion in 2007 and several cones in places like Sierra Negra in the Galápagos and Hengill in Iceland.