Short answers, pulled from the story.
The Norwegian Sea began to form approximately 250 million years ago when the Eurasian Plate and the North American Plate started moving apart. This movement widened and deepened an existing narrow shelf sea between Norway and Greenland.
Two deep basins exist within this vast expanse, separated by a low ridge with its deepest point reaching 3,000 metres. The southern basin is larger and deeper, containing large areas between 3,500 and 4,000 metres deep.
The blooming of phytoplankton peaks around the 20th of May, dominated by chlorophyll and diatoms such as Thalassiosira and Chaetoceros. After the spring bloom, haptophytes of the genus Phaecocystis pouchetti become dominant.
Jan Mayen island was discovered in 1607 and became an important base for Dutch whalers. The discovery occurred after the Carta marina of 1539 represented the Norwegian Sea as coastal waters.
Systematic oceanographic research started in the late 19th century when declines in cod and herring yields off Lofoten prompted government investigation. Zoologist Georg Ossian Sars and meteorologist Henrik Mohn persuaded the government in 1874 to send out a scientific expedition.