Today we know more about the topography of the moon and mars than we do about our own planet s sea floor.
First map of the ocean floor.
Revealed to the world in 1977 this is the first map of the earth s ocean floor.
To complete a map of earth s ocean floor you ve got to take to the high seas by boat.
The publication of heezen and tharp s physiographic map of the north atlantic in 1957 was the first map of the sea floor that enabled the general public to begin to visualize what the ocean floor really looked like.
The following features are shown at example depths to scale though each feature has a considerable range at which it may occur.
Typically finely wrought ocean maps have been the result of extensive sonar.
This graphic shows several ocean floor features on a scale from 0 35 000 feet below sea level.
But in the 1950s and 60s when this feat of cartography was being assembled by us cartographers marie tharp and bruce heezen we knew almost nothing.
Topographic maps of the sea floor produced at a 1 100 000 scale that contain loran c rates bottom sediment types and known bottom obstructions.
We ve come a long way in ocean exploration since the days of the hms challenger launched in 1858.
Continental shelf 300 feet continental slope 300 10 000 feet abyssal plain 10 000 feet abyssal hill 3 000 feet up from the abyssal plain seamount 6 000 feet.
These early maps based on hundreds of thousands of hand picked depths provided the context for the plate tectonics revolution.