How does Jiya's awe of an angry sea foreshadow what the sea is ultimately capable of?

Jiya often looks out to sea to make sure the ocean is not angry because he does not want to be on the island when the ocean rages. When Kino objects that they never do anything to anger the sea, Jiya explains that no one knows why the sea gets angry. The sea will indeed get angry very soon in the story, and Kino will understand its wrath.