NOAA Teacher at Sea
Jacob Tanenbaum
Onboard NOAA Ship Miller Freeman
June 1 – 30, 2006
Mission: Bering Sea Fisheries Research
Geographic Region: Bering Sea
Date: June 16, 2006
Weather Data from the Bridge
Visibility: 14 miles
Wind Speed: 27 miles per hour
Sea Wave Height: 7 feet
Water Temperature: 41.7 degrees
Air Temperature: 42.4 degrees
Pressure: 1013.8 Millibars
Personal Log
NOTE: We will arrive in the port of Dutch Harbor, Alaska on June 20. As the project draws to a close, I would like to evaluate how effective it was. There is a link to an electronic survey. I would like to ask students, teachers, parents, and other visitors to the site to take a few moments to let me know what you think of this idea. The survey is all electronic and only takes a minute or two to complete. Thank you in advance for your time. Click here to access the survey. How do you find your way around when you can’t see any land? I spent some time with Ensign Lindsey Vandenberg, on NOAA Ship MILLER FREEMAN.
Every 30 minutes or so, the bridge officers take a “fix” on their position. How do they do it? When they are out at sea, they take the latitude and longitude from the GPS and plot their exact position on a chart. A GPS is a machine that uses satellites to display the exact longitude and Latitude on a screen. The charts also have the latitude and longitudes written on them, but there is a problem. The longitude and latitudes scales on the chart are on the side and bottom of the chart, not where the ship is located. Every so often, there is a line across the entire chart. The navigator must use a tool, like the same compass you might use in math class, to mark the distance to the exact point on a scale from a line on the chart. She can then use the same tool to mark the distance in the part of the chart where we actually are. This must be done for both the longitude and latitude of the ship.
When we are near land, we can use Terrestrial Navigation. This means we can use the distance to an object on the shore, such as a lighthouse, to find out wherewe are. With a large ship close to shore, it is very important that we know exactly where we are so that we don’t wind up in shallow water. Ensign Vandenberg uses a tool called an alidade to help her. She puts the alidade over a large compass outside of the ship. The instrument reflects the compass into the viewer so she can see both the object on shore and the exact compass heading. If she takes a few bearings to objects on shore, she can use tools to chart her exact position on the chart.
Science Log:
I’ve been asking many of the people on the ship what becomes of the data that we are collecting. This survey will be used to set quotas for one of the most important fisheries in the world. Here is how it works. If too many fish are caught in an area, there will not be enough fish left for the species to come back the next year. That is bad for the fish, and bad for the fisherman. To prevent this “overfishing,”. A quota, or limit to the number of fish that can be safely caught, is established. Methods are put in place to make sure that all fishing boats in the area respect the quotas. Do you want to learn more? Take a look at this short video on the subject.
Question of the Day:
It is about 8:00 AM on Saturday morning. If the ship uses 2100 gallons of fuel a day, how many gallons of fuel will we need to get to Dutch Harbor on Tuesday Morning at about 8:00 AM?
Answers to Yesterday’s Question:
If our ship wants to do a trawl 50 meters below the surface, how much wire would it need.
The ship must put out two feet of wire for every one foot of depth. So you have to multiply 50 x 2 which gives 100 meters of wire. Each net has, not one, but three wires holding it to the ship. So you would need 3 wires. All three are 100 meters in length. That gives us 300 meters of wire to do our trawl.
Answers to Your Questions:
Hello to all who wrote today.
Colin, no seawater on the equipment yet. They have a couple of computers in the lab where we process fish that can be drenched with water and will still work. Maybe I need one of those.
Mrs. Z. Click here to see the route we have taken so far. I do not think it will give you exact miles, but you can get a good idea of our total.
Thanks for writing.
