2Early sailors cared little about the sea floor unless it was too shallow. The first attempt to study and map the deep ocean was made by “H.M.S. Challenger” in its pioneering circumnavigation voyage of 1872 – 76.
3The HMS Challenger, like all vessels up till then, determined depth to the sea floors by dropping a weighted line. Their measurements at least permitted the first rough understanding of the topography of the ocean bottoms.
4How Low Can You Go? – Beebe’s “Bathysphere” In the 1930s, William Beebe and Otis Barton descended more than half a mile in this steel ball. It is now on display at the Aquarium for Wildlife Conservation in Coney Island.Copyright: National Geographic Society
5SONAR In the 1920s, a new technique—SONAR-- was developed. Sound Navigation and Ranging provided a rapid method of looking through water to identify features in the water beneath a vessel and on the sea floor.The next slide represents how a ship can send down a signal and detect the echo.
7Also in the 1940s, Jacques-Yves Cousteau and colleagues in the French Navy invented SCUBA (Self-Contained Underwater Breathing Apparatus.) This allowed people to explore and study the shallow floors more efficiently.
8In the 1960s, Cousteau developed habitats so “aquanauts” could stay underwater for weeks. His 1964 film “World Without Sun” won an Academy Award.
9Piccard’s “Trieste”By 1960, Swiss inventor Auguste Piccard, with support from the U.S. Navy, developed the bathyscaphe “Trieste.” This “underwater balloon” took Jacques Piccard and Lt. Donald Walsh to the bottom of the Mariannas Trench. They proved that life can exist even in the greatest depths of the oceans.
11Now, small maneuverable research submersibles, such as the “ALVIN” operated by Woods Hole Oceanographic Institution, provide access to deep-sea features not otherwise accessible.
12Drilling through the Crust Following up on the success of the “Trieste” in reaching the bottom of the ocean, the next challenge became finding a way to try to drill through the crust into the mantle.“Project Mohole” was initiated in the early 1960s to accomplish this.
13The Glomar Challenger was built as the world’s first deep-sea drilling ship to test the promise of Project Mohole.
14FLIPThe Research Platform FLIP is a 355 foot long manned spar buoy designed as a stable research platform for oceanographic research.This ship has been used for over 50 years to gather important data.
16CorerThe Giant Gravity Core uses inexpensive PVC pipe as its barrel/sample liner and has been used to recover cores up to 6.5 meters in length. Normally operated from a hydrographic winch, this gravity core can travel through the water column at speeds up to 125 meters a minute.
18DredgeDredging equipment includes chain bag dredges of various sizes and configurations. Just the thing to get samples from hard bottom areas.
19Nansen BottleThe Norwegian explorer and scientist Fridtjof Nansen ( ) invented a water-sampling bottle. The Nansen Bottle, which is named in his honor, is still used today. It is used to collect water samples from different depths in the water column.
20Conductivity, Temperature and Depth (CTD) Sensors A CTD is a package of sensors that record conductivity, temperature, and depth information. A remotely operated device allows the water bottles to be closed selectively as the instrument ascends.
21Conductivity, Temperature and Depth (CTD) Sensors
22RAFOS FloatsRAFOS Floats are neutrally buoyant, free drifting instruments, which are launched from a ship in the research area. Once deployed the float will settle to a predetermined depth (typically from meters) and remain there for up to two years. Much sub surface current information comes from these.
24The Secchi DiskThis disk is dropped into the water to the length of the rope. The rope is then pulled up slowly. As soon as the secchi disk is visible to the naked eye the length of the ropes is measured and a general photosynthesis zone is determined.