NOAA Teacher at Sea
Aboard NOAA Ship Rainier
August 16 – September 5, 2014
Mission: Hydrographic Survey
Geographical Area of Survey: Woody Island Channel, Kodiak, Alaska
Date: August 24, 2014
Temperature & Weather: 12° C (54° F), Cloudy with Drizzly Rain
Science & Technology Log
Survey work continues today (Yes- even on the weekend) in the Woody Island Channel. While it is easy for me to see why this area is navigationally significant, it made me think about how one would identify which areas need to be surveyed. The National Ocean Service compiles data and prioritizes areas in need of surveying. Examples can be seen here for NOAA’s survey priorities in and around Alaska.
Using the areas of critical priority the Hydrographic Surveys Division (HSD) writes project instructions. Project instructions include all necessary data and guidelines, including: project name, project number, assigned field unit (ship), assigned processing branch, planned acquisition time, purpose and location of survey, and necessary supporting documents. On the project instructions, the Hydrographic Surveys Division also splits the assigned survey areas into sheets, or manageable sections.
Each sheet is then assigned to a Hydrographic Survey Technician (HST), a Hydrographic Senior Survey Technician (HSST), or a NOAA Corps Officer. Usually, one person will be the sheet manager and another will be the sheet assistant. The sheet manager is often teaching and guiding the sheet assistant, to train them to be able to do this work on their own in the future. The sheet manager is also responsible for dividing the sheets into polygons. Polygons for hydro surveys are used to divide the survey into smaller sections. When planning polygons, it is important for the sheet manager to follow specific guidelines- shapes cannot just be randomly drawn on a sheet or chart. The deeper the water, the larger the polygon can be; the more shoal the area, the smaller the polygon should be. Polygons should be drawn with the ocean contours, and should be planned for launch boats to run them from offshore to nearshore. This is a safety step in that launches should be working from deeper areas up to shoaler areas near the shore. As the boats move back in forth collecting data, it is as if they are mowing the lawn. The boats always try to slightly overlap the last strip so that no data is missed. If a small spot or strip of data is missed, its like that little area of grass that didn’t get mowed. It is called a Holiday in the data, because we have to make a special trip back to gather data on that spot.
Once plans are completed, the Field Operations Officer (FOO) can plan how many survey launch boats will be deploying, who will be aboard each, and what polygons they will aim to cover each day. Aboard each launch a skilled coxswain (driver) and a Hydrographer in Charge (HIC) are needed. There is almost always a third person on board, as it is best/safest to deploy boats with one person at the bow (front), one at the stern (back) and one in the driver’s seat. Once on the water, the HIC and Coxswain have to cooperate and communicate to make an efficient and safe plan for the day.
Every day is an adventure! I so enjoy learning – and it’s a good thing – because just about everything here is new to me!
For My Students
The survey says…
*What observations did you make in trying to answer the trivia question about what I found in the water? Did you decide you saw Harbor Seal, Otter, Octopus, Plants, or Aliens?
You were actually seeing a plant/plants called kelp. Kelp is a large brown seaweed that often has a long, tough stalk. Kelp can often be found growing in and around shoal, rocky areas in the ocean. A lot of kelp in the area is a warning to boats and other vessels that shallow areas or rocky obstructions may be near by, and caution is needed.
A new question for you:
1) What is a polygon?
2) What experiences have you had with the ocean?