Vikings colonized new areas while exploring and raiding the waters of which ocean?

This would be the Atlantic Ocean, mainly the northern reaches of it toward the Arctic. Vikings have their ancestry in the Norse countries and areas of northern Europe, which lies on the outskirts and seas bordering the Atlantic. During their travels, they would explore these waters and find new lands (one being the New World later discovered by Spanish, Portuguese, and English explorers some 500 years in the future).