Claim: Hope Basin extends from the outer continental shelf of the Seward Peninsula for about 700 km (430 mi) westwards off the coast of Chukotka towards Wrangel Island; and is limited on its northeastern side by the Herald Arch.
Evidence: Its area extends from the outer continental shelf of the Seward Peninsula for about 700 km (430 mi) westwards off the coast of Chukotka towards Wrangel Island. The Hope Basin is limited on its northeastern side by the Herald Arch (Herald Thrust), a basement uplift cored by Cretaceous thrust faults.