Seafloor Mapping: Marie Tharp, Bruce Heezen and the Mapping of the Ocean Floor

Maptime SF / Oakland
Maptime SF / Oakland
Public group

GreenInfo Network

2201 Broadway (suite M5) · Oakland , CA

How to find us

Take BART to 18th, walk up Broadway and sign into at 2201

Location image of event venue


Journalist and map-fan Betsy Mason, author of All over the Map (2018), will invite Maptimers to examine the first relief mapping of the ocean floor--made by Marie Tharp and Bruce Heezen in the late 1950s, a time when women were not even allowed to work aboard ocean vessels. The detailed observations that Tharp collated from thousands of sonar readings to create maps of sections of the ocean provided the first exact information about the contours, depths, or stratigraphy of the ocean floor--the seventy percent of the globe that lies under water. The map provided a basis for Tharp to advance her discovery of the volcanic chain of the mid-Atlantic ridge, key to the acceptance of plate tectonics.

Betsy Mason will show how Tharp began to map the largely unknown ocean floor, and the instruments she and Heezen used to create the first scientific record of the floor from sounding numbers--and the motivations for its construction. The compelling map provided of underwater geography changed acceptance of continental drift. **SPECIAL MAPTIME BONUS: Betsy will be signing copies of her beautiful _All Over the Map: A Cartographic Odyssey (2018; $50). Please specify in your RSVP if you would like us to hold your copy!**

Do note that we are meeting on Monday this month!