The Secret Mission to Seize German Map Data in World War II

Greg Miller’s crackerjack story in the November 2019 issue of Smithsonian magazine is about the quest to capture German geodetic data—and German geographers—during the dying days of the Second World War. Said data was a strategically critical treasure trove, of immense interest to the U.S. War Department, and the team led by Floyd W. Hough was in a race to find it before it was destroyed, carried away by the enemy, or fell into Soviet hands.

Little is publicly known about the true scope of the information that Hough and his team captured, or the ingenuity they displayed in securing it, because their mission was conducted in secret, and the technical material they seized circulated only among military intelligence experts and academics. But it was a vast scientific treasure—likely the largest cache of geographic data the United States ever obtained from an enemy power in wartime.

The data seized by Hough’s team went on to form the basis of the ED50 geodetic datum, which in turn led to the Universal Tranverse Mercator system.

Seafloor Gravity Map

NASA Earth Observatory map by Joshua Stevens

The ocean floor is still very much terra incognita: only 5 to 15 percent of it has been mapped via bathymetry. But using military satellite measurements of the Earth’s shape and gravity field, a new map of the ocean floor has been created. “The result of their efforts is a global data set that tells where the ridges and valleys are by showing where the planet’s gravity field varies. […] Shades of orange and red represent areas where seafloor gravity is stronger (in milligals) than the global average, a phenomenon that mostly coincides with the location of underwater ridges, seamounts, and the edges of Earth’s tectonic plates. Shades of blue represent areas of lower gravity, corresponding largely with the deepest troughs in the ocean.”