How do volcanoes make new land?

When magma reaches the surface, it becomes lava and can harden into new rock. If eruptions happen under the sea, the lava can pile up until it rises above the water, forming a volcanic island. Hawaii is one famous example of islands created by hotspot volcanism. On land, repeated eruptions can build large volcanic mountains such as Mount Fuji in Japan or Mount Etna in Italy. New land from volcanoes can be unstable at first, but it often becomes rich in minerals and important for ecosystems.