This littoral, or steam, explosions occurred when hot lava entered the sea along the Kalapana shoreline on the southeast coast of Hawaii. In this image we see an explosion of lava fragments showering into the air beneath a roiling steam and hydrochloric acid cloud, most likely above an open vent in a lavatube system; it is also proably showering molten fragments to earth around the vent, forming a cone (unseen here). Other fragments fall into the sea, where they are carried by ocean currents and deposited in bays to form black sand beaches.