In a groundbreaking collaboration with geologists Bruce Heezen and Marie Tharp at Columbia University, Berann painted the ocean floors — making the invisible visible. Between 1965 and 1978, he created detailed panoramic views of the Atlantic, Pacific, Indian, Arctic, and Antarctic ocean floors for the National Geographic Society and other publishers. The culminating world map of the ocean floor (1975–77) remains one of the most recognized scientific illustrations of the 20th century.

Ocean Floors, World Map

1975-1977

Ocean Floor: Antarctica

1972

Ocean Floor: Arctic

1971

Ocean Floor: Atlantic

1967

Ocean Floor: Indian Ocean

1965

Ocean Floor: Pacific Ocean

1969

Ocean Floor: Mediterranean

1970

Ocean Floor: North and Central Atlantic

1968

Ocean Floor around South Africa

1970

Ocean Floor: Pacific Hemisphere

1969

Ocean Floor: Pacific Hemisphere, Version 2

1967

Ocean Floor: Atlantic Hemisphere

1970

Ocean Floor, North America, Eastern Shelf

1978

Ocean Floor, North America, Western Shelf

1978