NOAA Teacher at Sea
Onboard NOAA Ship Fairweather
April 25 – May 5, 2006
Mission: Hydrographic Survey
Geographical Area: Aleutian Islands, Alaska
Date: May 1, 2006
Weather Data from Bridge
Visibility: 10 nautical miles (nm)
Wind direction: 182°
Wind speed: 14 kt
Sea wave height: 1 ft.
Swell wave direction: 235
Swell wave height: 1
Sea water temp: 7.5
Sea level pressure: 1029.6 mb
Present weather: Partly cloudy
Temperature: °C~ 7.5 dry/6.0 wet
Science and Technology Log
The ship performed a procedure for collecting data from a selected area of the Gulf of Esquibel analogously compared to ‘mowing the lawn.’ In this process the ship actually sails up and down the selected area within the Gulf collecting various data. As the ship sails, parallel lines are produced on the hydrography chart. The hydrography chart is viewed via the DELPHMAP system during this entire process in the pilot’s house and the plotroom. In the plotroom, rotating survey technicians monitor the area being covered with four computer screens and communicate with the pilot’s room when data collection is paused and when it is resumed.
The ship performs this process rather than the launches because the ship works in deeper water than the launches. Sound data was collected today with an instrument called the Seacat. In order to collect sound data with the Seacat the ship has to come to a complete stop. The Seacat is manually attached to cable that is housed with a structure called the ‘J’ frame. The cable travels through two rotating blocks and the Seacast is manually deployed into the water until it reaches the bottom of the water. It is immediately pulled back onto the ship, detached from the cable, and attached to a computer for prompt reading of the data known as a Conductivity, Temperature, and Density (CTD) caste.
Thanks to FAIRWEATHER shipmates for answering all of my questions either verbally, with hand-drawn illustrations, or through demonstrations. The tide staff stop observations that Ensign Gonsalves and I made were consistent with the automatic tide gauge readings. I’ve got the results to prove it!
Question of the Day
Geospatial Semester and Environmental Science Students
Give the length and width of the Gulf of Esquibel. Also, include the name and geographic location of its land boundaries.