NOAA Teacher at Sea
Onboard NOAA Ship Thomas Jefferson
August 7 – 18, 2006
Mission: Hydrographic Survey
Geographical Area: Northwest Atlantic
Date: August 7 -12, 2006
“Ships have many pieces of complicated equipment!”
Hello, greetings from Teacher at Sea Candice Autry. I teach science to middle school students at a wonderful school called Sheridan School in Washington, DC. I have been given the great opportunity to sail with the crew on the NOAA Ship THOMAS JEFFERSON. Our cruise has been delayed several days due to unforeseen problems with some of the complex and necessary equipment on the ship. It is important to be flexible with any kind of change, so these past few days have given me the opportunity to explore the ship as we wait for final repairs. The objectives of this particular ship primarily involve hydrographic surveys. Hydrography is the science that has to do with measuring and describing physical characteristics of bodies of water and the shore areas close to land. Thanks to hydrographic surveys, ships, ferries, pleasure boats, and other vessels can safely navigate in busy waters without hitting any obstructions on the bottom of a harbor.
Hydrographic surveys can also locate submerged wrecks in deep waters; examples include unfortunate events such as shipwrecks out at sea as well as plane crashes over the ocean. These surveys are done by using technology that involves side scan sonar and multi-beam sonar technology. The combination of these two types of technologies can create a clear picture of a barrier on the ocean floor and the depth of the obstruction.
The THOMAS JEFFERSON holds several smaller boats including two launches (one launch is visible in the picture, it is the gray boat) that have this sonar technology located underneath the vessel. The instrument that collects data is often called a “fish.” The data can be seen on a computer screen so that the surveyors can view the data being collected. Once we reach our destination, we will use these launches, one equipped with a fish that uses multi-beam sonar technology and the other with a fish that uses side scan sonar to create a chart of what is on the bottom of a very busy harbor!