Jacob Tanenbaum, October 13, 2008

NOAA Teacher at Sea
Jacob Tanenbaum
Onboard NOAA Ship Henry Bigelow
October 5 – 16, 2008

Mission: Survey
Geographic Region: Northeast U.S.
Date: October 13, 2008

Old fashioned navigation
Old fashioned navigation

Science Log

Happy Columbus Day everyone, and, since were in Canada, Happy Thanksgiving. Yes, that’s right, Thanksgiving. Here in Canada, Thanksgiving is celebrated on the second Monday in October. So a special note to my son Nicky: Happy Canadian Thanksgiving!  Back to Columbus Day, though. Since that’s probably what your all talking about at home. In honor of Columbus Day, I thought I would try something interesting.

I made a replica of the instrument Columbus used to navigate his ship. It is called a Quadrant. Columbus would sight the North Star with his quadrant and measure its angle above the horizon. That angle is equal to your latitude. He used a quadrant to measure that angle.

A quadrant
A quadrant

This is what a quadrant looks like. You hold it up so you can see the star you want in your site. The weighted rope simply falls over the scale of numbers and indicates the angle. What instrument in math looks like this? Post your answers on the blog if you think you know. So did I beat the GPS? You will have to watch this video to find out.

Want to try sighting the North Star yourself? Here is how: Find the Big Dipper. Trace an imaginary line from the spoon up. The first bright star you come to is the North Star. Want to find our more about using the stars to find your way, or Celestial Navigation, click here.

We are fairly far out to sea right now. There is a point of land in Nova Scotia, Canada about 100 miles to our north, but most land is around 200 to our west. We are seeing a lot of off-shore birds like the Shearwaters pictured here. These little birds spend most of their lives in the open water feasting on fish. They come on shore only to breed, so landlubbers don’t see them very much. What a treat. They were part of a large flock that was foraging in the nets yesterday afternoon during a tow.


We also have a few land birds on board. They may have been blown out to sea by storms and have stopped on our ship for a rest. Several were eating what they could find out of the nets on deck yesterday. The nets on the Bigelow have 6 sensors, each reporting different variables, such as depth, the width of the net opening and the height of the opening back to the scientists on deck. One of the sensors stopped working and had to be replaced yesterday. Take a look at this video of how the repair was done.

The water temperature outside is changing. It is now much colder than it was. When we were further west, we were towards a warm current called the Gulf Stream that moves north along the east coast of the USA. The water was about 63 degrees. Now we are in a cold water current called the Labrador Current. This current brings water south from the Arctic along the Canadian coast and ends in the Gulf of Main. The water here is about 55 degrees or so. We are not seeing the dolphins anymore and some of the science crew thing the water temperature may be too cold for them. Take a look at this map of the water temperatures. Brighter colors are warmer in this picture. We have moved from the warmer greener colored water into the cooloer blue colored water. The red line represents our course.

Water temperature illustration
Water temperature illustration

WOS students who have not had a chance yet, should compare our ship to the one Columbus Sailed. Go back and look through the blog at the pictures of Snuggy and Zee in the different parts of our ship to help you. Post your answers on the blog. Finally, something very interesting came up in our nets today. We got this off the bottom in 1000 feet of water. It is wood. Clearly cut and shapped by a person and for a purpose. It appears to have been down there for a long time. How do you think it got there? Post your answers on the blog!

CLE students, try using these images of ships in the past as a story starter. Write me a short story about a trip on an old sailing vessel and incorporate some of what you have learned about their technology in your story. Can you tell me the story of how that wood ended up on the bottom of the ocean? Please don’t post these to the blog. They will be too long. Print them and show them to me when I get back on land next week.


IMG_6782-766424And now some answers to your questions:

RM – Good question: A sea spider is a sea-creature related to the horseshoe crab. It just looks a lot like the spiders we see on land.

Have we seen any sharks? We have seen a lot of dog-fish, which are a type of shark, but are not very ferocious. Our captain saw a great white off the bridge. Unfortunately, I was working below decks at that moment and did not get out to see it in time.

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