Littoral cone

A littoral cone is a special kind of volcanic cone that forms when lava flows meet water. When lava touches water, it creates steam that breaks the lava into small pieces. These pieces pile up and form a new hill shaped like a cone.

These cones usually form from a type of lava called ʻaʻā. This lava is thick and rough. Littoral cones need large lava flows to form, so they are not found everywhere. They have been seen in places like Hawaii and other areas with active volcanoes.

Description

Littoral cones are special shapes that look like half-moons. They form when lava flows into water. The lava meets the water and makes steam explosions. These explosions break the lava into small pieces. The pieces pile up and make a cone shape on the land.

These cones are made from volcanic ash, lava bubbles, and pieces of lava. You can find them near big lava flows. They can be small mounds or larger shapes. 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.

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. 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.