Ocean floor

by Marie Tharp
Global
1971


From the halls of Columbia and sometimes her desk at home, Tharp became an interpreter and artist, analyzing SONAR pings from vessels crisscrossing the ocean and then scribing the data on canvas by hand. As she meticulously crunched and plotted data sent from ships in the open sea, an unknown world unfolded before her eyes. Continental shelves dipped to deep abyssal plains that were interspersed with canyons, mountain ranges and seamounts. One feature, a deep, continuous trench splitting a mountain range along the entire Atlantic Ocean, seemed too important to dismiss. After extensive thought and recalculation Tharp proposed to Heezen, her superior, that they were looking at a rift valley—an area where the earth’s crust splits and magma rises to form new crust.



                                            Marie Tharp was an American geologist and oceanographic cartographer who, in partnership with Bruce Heezen, created the first scientific map of the Atlantic Ocean floor. Tharp's work revealed the presence of the Mid-Atlantic Ridge, causing a paradigm shift in earth science that led to acceptance of the theories of plate tectonics and continental drift.