Once the moon was an ocean; and the whale was there, and her name was Liwash. With her first breath she took in all its atmosphere, and the sea boiled away beneath her, and so she swam through the void tto the deepest places of Earth.
But she was not the first to arrive: there was Hufgafa, the beast whose arms fill the cracks at the center of the world. They battled, and when Liwash could tear one of Hufgafa’s arms away, magma escaped and formed these islands.
Why, yes, the same magma you see in the volcanoes.
They battle still.