From Space to the Seafloor

July 26, 2010

Lat/Lon: 41°59.68'N /063°11.83'W
Air Temp: 19.9*C /67.82*F
Wind Speed: 27.45 kts
Humidity: 68%
Water Temp: 21.35*C /70.43*F
Salinity: 32.53 psu
Depth: 2510 m /2.5 km / 1.55 miles

Chief Mate Matt McInteyer on the bridge

Our 8 hour transit ended with a knock on the door at 12:30 am waking us for a gravity core. As it turns out we had a bit of a wait as there was yet some surveying to complete at Sable Island. The gravity was followed by a 2:30 am multicore and a 4 am long core.

One of the most amazing technologies I have come across on this research cruise is "DP" - Dynamic Positioning. Anchors just don't cut it out in the deep ocean. It is this technological marvel that allows the science team to safely and effectively core the ocean floor.

The photo to the right is from earlier in the cruise but I'm using it here to emphasize the importance of the DP technology. The gravity core pictured in this photograph strikes me as so very thin and fragile (of course when you're hefting that core full of mud and your team is working to move it, it doesn't feel quite so fragile!) It is vital that the ship maintain it's position so the coring equipment is not damaged.

Since the launch of Sputnik in 1957 humans have been launching satellites into space for all kinds of reasons. Today there are hundreds of satellites orbiting earth that are used as tools for things such as weather forecasting, monitoring the earth systems, communication and entertainment and navigation. The R/V Knorr uses satellites not only for navigation but also for maintaining position at coring sites.

The picture to the right shows the the controls for the R/V Knorr's three thrusters involved in the DP system: the top for the bow (900 horsepower) and the two sides for the port and starboard thrusters aft (each 1500 horsepower). The central control is the autopilot.

Waves and currents cause the ship to move in distinct ways: heave and yaw, roll and surge, pitch and sway. Sensors monitor and measure the amount of each type of motion and the DP system calculates the forces necessary to maintain a single position. Once the ship arrives at the desired location (for our cruise it's a coring location) the on-ship computer communicates with navigation satellites and identifies this location. After this has been set the on-ship computer constantly checks its location with the satellite and, factoring for the movements of the ship with the wind, waves and currents, adjusts the thrusters as needed to maintain the desired position.

Just amazing!

Chief Mate Matt McInteyer (pictured at the top of today's blog), former ship captain for the American President Lines (APL) which is a top container transport and shipping company in the world, spent time explaining the R/V Knorr's technology and the ins and outs of their daily routines. He explained that there are such differences between the R/V Knorr and the 900+ft barges he sailed for the last 20 years. One of the big differences is the motion of the ship. He said that on those barges there needs to be a LOT of wind and wave action for you to feel any motion on those big ships. Here on the R/V Knorr the constant motion is exhausting. This, of course, made us feel better because we're all ready to lay down and sleep whenever we get the chance!

After several days of listening to the fog horn I was anxious to learn about how they could navigate the boat through the thick fog. The picture to the left shows our ship (brightest spot) and a barge just to the left (the smaller bright spot) on a radar screen. See the picture below for a visual of the same barge - red on the horizon.

This barge may look quite far off to you but to us it looked way too close for comfort after we've spent two weeks at sea with only one other ship sighting!

We're off to the New England Seamounts

1 comment:

  1. Aw, this was a really quality post. In theory I'd like to write like this too - taking time and real effort to make a good article... but what can I say... I procrastinate alot and never seem to get something done.
    paper core pipe