User blog comment:Hyperborean/"The House of Hades" – official expectations blog/@comment-10867502-20130823184113/@comment-7742465-20130823191752

Poseidon is referred to In PJO and HOO as the the god of earthquakes as well as the sea. Whether Percy will have more earthquake based powers, we don't know yet, however he has used other weather related powers in the other books.