national marine monument off northwestern Hawaii Papahānaumokuākea Marine National Monument quadrupled the size of a 583,000-square-mile national marine monument off northwestern Hawaii twice the size of Texas National Geographic national marine monument off northwestern Hawaii PapahÄnaumokuÄkea marine reserve last week national marine monument off northwestern Hawaii combined Expansion for Papahanaumokuakea Approved national marine monument off northwestern Hawaii told National Geographic national marine monument off northwestern Hawaii Obama just increased it National Geographic Obama expanded the monument to almost 600,000 square miles national marine monument off northwestern Hawaii quadrupled the size Papahānaumokuākea national marine monument off northwestern Hawaii Aug. 2016 national marine monument off northwestern Hawaii Geographic article Hawaii’s Papahānaumokuākea Marine National Monument oceans