Author: Sena Norton

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Sena Norton, July 8, 2004

NOAA Teacher at Sea
Sena Norton
Onboard NOAA Ship Rainier
July 6 – 15, 2004

Mission: Hydrographic Survey
Geographical Area: Eastern Aleutian Islands, Alaska
Date: July 8, 2004

Location: Sonar Patch cruise, SE of Devils Bay on AK peninsula
Latitude: 55 46.163 N
Longitude: 158 03.557 W
Visibility: < 1 nm
Direction: 229 degrees
Wind Speed: 16 kt
Sea wave height: 1-2 ft
Swell wave height: 1.2 ft
Seawater temperature: 8.9 deg C
Sea level pressure: 1021.1 mb
Cloud Cover: n/a fog
Weather: Fair and foggy, 8.9 deg C dry / 9.4 deg C wet

Plan of Day: 1.5 days of sonar readings in patch with lines of 2.5 hours each. Launch #5 boat for survey north of ship around a possible rock pinnacle.

Science and Technology Log

Sonar Systems on board RAINIER: How they work.

What is Sonar?

In its most basic sonar are sound waves that are produced and then bounced back off of an object and recorded. Since the speed of sound is a known figure, the amount of time it takes for the sound wave to return to the transmitter/receiver gives a collectable image of that object. The deeper objects are the longer the sound wave takes to bounce back. Two types of sonar are single beam and multi-beam. Single beam is able to give high detail to an object but only shows a narrow swath, while multi-beam has a large footprint and can show a larger over all area. There are limits to the depth sonar can go because of the density of the water column. If the water is very dense the sound waves are slowed down and do not transmit the correct timing, therefore the image will be distorted. All images created must be analyzed after the density, temperature and salinity of the water column is taken into consideration.

Sonar is a very powerful sound wave and it can be dangerous, although it is at a frequency that humans or marine mammals cannot hear. If a diver were scanned they would be susceptible to a high-level concussive power. The emitter itself requires a large volume of power and if a human were to be near it during an emission it would do a great deal of damage. Think of the concussion from a bomb or firework, sonar is many, many more times as powerful.

RAINIER’s Sonar:

The ship is equipped with a deep sonar transmitter; it is attached to the hull and is used for scanning deep water where resolution is not a large issue. The boat “mows the lawn” in a patch of ocean. Each pass is numbered and the data collected. The lines are about 2 hours at 7-8 knots long. For more detailed work or a smaller area the ship will use one of its 6 launches that are also equipped with various sonar transmitters. These small boats will conduct and similar pattern of lines and collect the data right on board. The data is then transferred to the computers on board to go through technician cleaning and final analysis.

Sonar Types:
Single-beam – one beam sent and received.

Multi-beam – up to 240 beams per 180 degrees sent and received. As depth increases the foot print widens.

Analysis of data:

When the soundings are collected they are run through a Carris computer program where the technicians can manually scan each line. There are techs assigned to each “sheet” or area. Each line is cleaned, meaning outliers are removed or other “noise” is deleted. Once the data is clean a complete 3-D image of the patch can be looked at with all the data points represented. Once an entire area has been scanned objects become very clear, as if you were looking at them. From outlines of sunken ships from the side to large monolithic rocks protruding from the ocean floor, the detail and accuracy of the image is amazing. Once there is enough data the sounds can be turned into color-coded overlays that fit right on top of the fathom charts, so as to give a 3-D view of what those fathom readings represent. Red and orange or shallow and the colors move through yellow, green and finally blues, which are the deepest readings. Mountain ridges, lava floes, old wrecks, valleys and monoliths all come to life on the chart.

Personal Log

Steve Foye gave me a quick training with another new member of the crew on the job of Lookout on the flying bridge last night. He reviewed the 32-point compass and the difference between saying North relative to the ship verses trying to figure out the “real” compass coordinate. He explained you could use directions (NW or SE) or give the coordinates (90 or 270). Dead ahead would be 000, north relative to the ship or 360, all are correct for locating something directly off the bow of the ship.

Question of the Day:

When is the ship required to sound foghorn and place lookouts on the Bow/Flying Bridge?

When the visibility gets below 1 nm the ship is required to blow the foghorn or ring a bell every 2 minutes. A lookout is placed on the flying bridge during hours of darkness or low visibility. They move to the bow when the foghorn is turned on so they do not damage their ears.

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Sena Norton, July 7, 2004

NOAA Teacher at Sea
Sena Norton
Onboard NOAA Ship Rainier
July 6 – 15, 2004

Mission: Hydrographic Survey
Geographical Area: Eastern Aleutian Islands, Alaska
Date: July 7, 2004

Location: In transit to Shumagin Is. Via Shelikof Strait
Latitude: 57 43.2 N
Longitude: 154 58.4 W
Visibility: 10+
Wind Direction: 280 degrees
Wind Speed: 18 kt
Sea wave height: 2-4 ft
Swell wave height: 2-4 ft at 210 degrees
Seawater temperature: 10.6 C
Sea level pressure: 1020.1 mb
Cloud cover: PC 2/8
Weather: 12.2 C, sunny with moon visible straight off bow

Science and Technology Log

I learned about the NOAA Nautical Charting Program today. A nautical chart shows the marine environment in a visual format for navigation purposes primarily. Any mariner needs to have an ability to use fixed points to plot a course and know/avoid any underwater or other hazards along the way. Most charts show hazards, natural and dredged channels, water depth and other features that are needed for safe navigation. The National Ocean Services marine Chart Division is in charge of 1,000s of charts. Most mariners use these charts along with the U.S. Coast Pilot when ever they are out. When changes are charted a new chart is made. From the time the NOAA Ship RAINIER makes their readings it takes between 3-5 years to be produced in chart format and readily made available. New charts are asked to be made for uncharted, poorly charted or changed areas. The three hydrographic ships that NOAA maintains do on average 50 charting runs a season for updates. However, with the current backlog of changes only 200-300 items are updated a year. The cycle of a update goes as follows: first chart users relay needs, second the Hydrographic Surveys Division prioritizes the resources and produces survey instructions, third, a NOAA field unit travels to the location and conducts the hydro survey, fourthly, the data is examined at a on shore branch and prepared for application on new chart and finally the Marine Chart Division is complied and printed. NOAA is not the only team member on this mission; other important organizations provide data for new charts. U.S. Army Corps of Engineers provide dredge and channels depths, U.S. Coast Guard maintains navigational aids, GPS beacons and other communication sources, while the Photogrammetry unit of NOAA complies aerial photos for shoreline and landmark additions.

The bridge is an important part of the overall ship function. The ship is driven from this location, the progress made is plotted and recorded and hourly logs are kept with various location and condition data. I take my condition and location directly from the ships log when I write these logs. Today there were a few ships on the radar and the officers wanted to make visual contact with them. I got to keep a lookout for the one off the port/south side of the ship with binoculars. The helm is where the ship is driven from and is kept on course with direction relation to the nautical chart and heading. Small adjustments have to be made from time to time to keep the correct bearing due to changed in sea swell and wind direction. The bridge is always manned 24 hours a day because of the importance of what is done there. We are making about 13 knots today with a friendly wind and hope to be anchored in the Shumagin Is. by tomorrow. We will commence the ships hydro at 0300 tomorrow morning to begin the surveying of the area.

Question of the Day:

How far is a fathom? 6 feet
How many people are on board? 74 crew/officers 5 visitors / 79 total

Day Activities:

  • Interviewed Chief Yeoman Paul and discussed his role/responsibilities on the ship. He in charge of bills, keeping track of expenses, ordering fuel and stores, personnel changes and promotions, a liaison between crew and command and manages expenses overall.
  • Visited the bridge and interviewed various officers and crew about bridge processes and equipment.
  • Wrote down some possible classroom curriculum options.
  • Discussed curriculum with fellow TAS, read some NOAA research and PR.
  • Downloaded some important pictures for use in curriculum/reports from ships computer network.
Personal Log
The night was a little rough with the swell height and wind direction and speed. They call my room the anti-gravity chamber and every once in awhile I could tell why. Today the rocking and rolling is much better and at times I think that I have my sea legs back. It is still unique to walk around on a ship that is bobbing; you get a different feeling when the deck is not where your foot thought it should be. I have put much thought into what I can turn this experience into as far as curriculum goes and my fellow TAS and I have been bouncing some ideas off of each other. There is much to say about the value of sharing this experience with a colleague as well as having the chance to discuss in general with that same colleague. I think that there is a professional connection being made thanks to the NOAA Teacher At Sea program! The science behind the survey process with help and that is a main goal to learn about, however there is something more to this experience that I haven’t put my finger on yet…give it some time…something that the sea is very well trained at allowing you to have.

For now,
S.

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Sena Norton, July 6, 2004

NOAA Teacher at Sea
Sena Norton
Onboard NOAA Ship Rainier
July 6 – 15, 2004

Mission: Hydrographic Survey
Geographical Area: Eastern Aleutian Islands, Alaska
Date: July 6, 2004

Location: In transit to Shumagin Islands, outside of Seward inlet.
Latitude: 59.31 N
Longitude: 149.41 W
Visibility: To horizon
Wind Direction: NW
Wind Speed: 20 kt
Swell wave height: 6ft
Sea level pressure:
Cloud cover: High sparse cloud cover

Personal Log

Day Activities

  • Ship paper work
  • Assign and don Survival Suit (communally called Gumby suit)
  • Took part in Abandon ship and fire drill. Got to my muster stations with ease and with all the required equipment and needs. Aided in hose management and stow.
  • Issued Mustang jacket and flotation vest for use on launches and skiffs.
  • Observed getting underway from the flying wing.
  • Took nature sightings: whale in distance, porpoise pod of 12+, puffin and gulls/seabirds.
We are in transit to our survey location and will be for the next 24-36 hours. Most personnel are on 4-hour watches and shifts. I watched the deck crew take care of the lines and stow all the equipment in its correct areas, which took longer than I first would have expected.
The “Gumby suit” was interesting to put on and try to get back into its bag. I could not believe how snuggly it fit around the wrist and neck…of course to be water proof that is the requirement. I feel very safe in knowing that I could survive if the need arouse.

I am a little queasy with the boat today…there isn’t much of a sea but just getting used to the motion is going to be interesting. I have my patch on but many people have told me my berth is nicknamed the ANTI-GRAVITY CHAMBER…not very good words for a land lover like myself.

It is proper etiquette to keep your rack light on at all times unless you are trying to sleep. That is a cue to your roommate to be quiet. If the light is on all clear…if the light is off “shhhhhh”. I didn’t know that even with my prior experience.

The weather is going to be very nice for the next 6 days according to the weather report I received via email from the XO today. We are to expect light winds and the 3-6 foot sea swell. That is cause for good science and nice observations. We are scheduled to begin the hydro survey on Thursday.

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Sena Norton, July 4, 2004

NOAA Teacher at Sea
Sena Norton
Onboard NOAA Ship Rainier
July 6 – 15, 2004

Mission: Hydrographic Survey
Geographical Area: Eastern Aleutian Islands, Alaska
Date: July 4, 2004

Inport Seward, AK, Cruise Ship dock
Weather: Partly Cloudy, occasional fog, calm wind

Personal Log

I was met at the train depot by two of the Junior Officers from the RAINIER and brought on-board. After a quick tour of the common areas I was shown to my berth and allowed to get settled in. I will be sharing the room with one of the survey techs on board in a 4 person room. I met two more of my berth area mates while I was unpacking and settling in.