3. when the ocean floor was mapped in the 1940's and 1950's, it chan topography. what were the surprising major ocea n the 1940's and 1950's, it changed our understanding of the ocean nic features discovered by these mapping efforts?

Here's some history on the research of the ocean

I've had this in my google docs so hopefully it helps

Time Line 1912-1970

Scripps Institution of Oceanography becomes affiliated with the University of California. Scripps is one of the world's leading marine research centers and is located in La Jolla, California, just north of San Diego. Canadian inventor Reginald Fessenden uses an oscillator to bounce sound waves between an iceberg and the sea floor. This test marks the beginning of acoustic exploration of the sea. The technology will eventually lead to the development of sonar, allowing submarines to signal each other and allowing ships to detect icebergs. The White Star Liner Titanic sinks after striking an iceberg in the North Atlantic Ocean. Over 1500 passengers lose their lives during one of the worst peacetime maritime disasters in history. This tragedy leads to a concerted effort to devise an acoustic means of discovering objects in the water ahead of a moving vessel. The German vessel Meteor sails around the Atlantic Ocean taking detailed measurements of the ocean floor using echosounding equipment. These voyages reveal new information about the shape and structure of the ocean floor. In Cape Cod, Massachusetts, the Woods Hole Oceanographic Institution is founded. Woods Hole would become one of the world's leading oceanographic research institutions. William Beebe and Otis Barton embark on a deep sea expedition in a tethered sphere known as a bathysphere. They reach a depth of a 3,000 feet (914 meters) off the coast of Bermuda and discover a previously unseen world of bizarre, luminescent creatures.   Researchers at the Coast and Geodetic Survey invent an automatic telemetering radio sonobuoy. This instrument eliminates the need for manned station ships during Radio Acoustic Ranging (RAR) navigation operations. This instrument is considered to be the first offshore moored telemetering instrument.  Geophysicist and oceanographer Athelstan Spilhaus invents the bathythermograph, a measuring device that continuously records temperatures. The invention's name stands the test of time, and is still in use today. Fishermen off the coast of South Africa pull up a five-foot fish identified as a coelacanth, a living fossil thought to be extinct since the days of the dinosaurs. Since then, several live coelacanth have been discovered in African coastal waters. During World War II, electronic navigation systems are developed for precision bombing. A few years later, the Coast and Geodetic Survey conducts its first hydrographic surveys using these systems. Research during the war leads to many new tools for ocean exploration, including deep-ocean camera systems, early magnetometers, sidescan sonar instruments, and early technology for guiding Remotely Operated Vehicles (ROVs).  Underwater explorers Jacques Cousteau and Emile Gagnan develop the first modern scuba system. They modify a breathing regulator to create the Aqua-Lung. This ground breaking invention allows divers to stay underwater for extended periods and more effectively explore the ocean realm. This single event revolutionizes the science of underwater exploration. Swiss physicist Auguste Piccard dives in his newly designed vehicle known as a bathyscaphe. It is the first untethered craft to carry people into the oceans deep waters. His son, Jacques Piccard, would soon take the bathyscaphe to the deepest point in the ocean.