In 1968, a groundbreaking map of the Atlantic Ocean floor

In 1968, a groundbreaking map of the Atlantic Ocean floor was published, based on extensive deep-sea soundings compiled by oceanographer Bruce Heezen and geologist/cartographer Marie Tharp, and artistically illustrated by Heinrich Berann. This work became a milestone in both geology and cartography, serving as a key scientific and visual reference.

Marie Tharp (1920–2006), in collaboration with Heezen, created the first detailed scientific map of the Atlantic Ocean floor, revealing the Mid-Atlantic Ridge for the first time. This discovery played a critical role in the acceptance of continental drift and plate tectonics, transforming our understanding of Earth’s dynamics.

The Mid-Atlantic Ridge is an underwater mountain range stretching roughly 16,000 km from the Arctic to the South Atlantic, forming part of the world’s largest mountain system. In the North Atlantic, it separates the Eurasian and North American plates, while in the South Atlantic, it separates the African and South American plates. Although most of the ridge is underwater, some sections, such as Iceland, rise above sea level, forming the Reykjanes Ridge.

This mid-ocean ridge is a divergent plate boundary, where magma rises from the mantle, solidifies, and creates new oceanic crust. The ridge spreads at an average rate of about 2.5 cm (1 inch) per year, gradually widening the Atlantic Ocean.

The artistic work of Heinrich Berann was essential for making the scientific data visually accessible and compelling, allowing both scientists and the general public to understand the ocean floor’s complexity.

The legacy of Tharp and Heezen goes beyond geology: they challenged scientific and social norms of their time, demonstrating the power of interdisciplinary collaboration and inclusive science. The 1968 map remains a fundamental reference for oceanographers, geologists, and educators, symbolizing one of the most important discoveries about the structure of our planet.