Tasman Sea, an arm of the Pacific Ocean between Australia and New Zealand. It is as much as 1,400 miles (2,250 km) wide and more than 17,000 feet (5, 180 m) deep. The sea is located in a region of prevailing westerly winds known as “the roaring forties,” and is frequently stormy. It was named for the Dutch explorer Abel Janszoon Tasman, who discovered New Zealand and Tasmania in 1642.