Daily Update: Checking all systems
April 1, 2001
By Amy Nevala

After a night of choppy seas, this morning we stopped to test Knorr's dynamic positioning (DP) system and a piece of scientific equipment, the Conductivity-Temperature-Depth sensor, or CTD.

Both are important to the success of our expedition.

The DP system automatically keeps Knorr from drifting out of a specific position. The navigator enters the position into a computer that controls the ship's thrusters, or propellers. Using navigation information from satellites, the computer then moves the ship to the correct position and holds it there.

This is critical when we have equipment thousands of feet below working at the seafloor.

This morning's DP test "was a success," said DSOG navigator Tom Crook. "The ship held position without moving more than a few meters, plus or minus. And that's just what we're looking for."

Testing the CTD, which is used to detect hydrothermal plumes, drew a crowd to the ship's starboard side. Seaman Ed Graham stood at the crane controls while others adjusted lines to help prevent the CTD from swinging while hoisted over the ship's rail. "People down below, we are ready to go over," Ed yelled.

The crane whirled as the conducting cable slowly lifted the CTD ten feet off the deck and lowered it with a splash into the water.

For 90 minutes, it traveled down 4000 meters, about two and a half miles. The CTD finally stopped about 10 meters, or 33 feet, above the Indian Ocean floor. Ed then hauled in on the winch. By 2:30 the CTD reappeared on the surface, in good shape after its inaugural journey this expedition.

The verdict of the CTD test?

"We found a bunch of things that work just fine and a few things that we need to fix - like the temperature sensors," said oceanographer Bob Collier. By tomorrow afternoon they will make the repairs and ready the CTD to search for hydrothermal vents.

Dive and Discover Water Word Puzzle [Click here for a printable version of Dive and Discover Water Word #1] Click here for the solution.

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