NOAA Teacher at Sea
Tamil Maldonado
Onboard NOAA Ship Fairweather July 18 – 28, 2005
Mission: Hydrographic Survey Geographical Area: North Pacific Date: July 27, 2005
Science and Technology Log
During the day I talked with the captain about boat stability. Stability is defined as the ability of a vessel to return to its original condition or position after it has been disturbed by an outside force. Anyone who has been at sea and felt the vessel roll, for example, and then right itself (only to roll in the opposite direction and right itself again) has seen stability in action.
Outside forces include wind seas, adding/removing weight, and free surface. The six Motions of a Vessel in waves are rolling, pitching, yawing, heaving, swaying, and surging. Rolling is the motion about the vessel’s longitudinal axis. Pitching is the motion about the vessel’s transverse axis. Yawing is the motion about the vessel’s vertical axis. Heaving is the vertical bodily motion of the vessel (whole vessel moves up and down together). Swaying is lateral (side to side) bodily motion. Surging is the longitudinal (fore and aft) bodily motion. All or most of the motions can occur simultaneously and have their effect on the efficient operation of a vessel. While the ship’s officer cannot completely control these motions, there is much that can be done to diminish or alleviate their effects.
Motions of the Vessel and Governing Stabilities include: Roll- Transverse Stability, Pitch- Longitudinal Stability, Yaw- Directional Stability, Heave – Positional Motion Stability, Surge – Stability in motion Ahead or Astern, Sway – Lateral Motion Stability. The way a vessel rolls is a direct indication of her stability.
The condition of a vessel is determined almost solely by the location of two points: the Center of Gravity (G) and the Center of Buoyancy (B). G is the point at which all vertically downward forces of the vessel can be considered to act. In other words, the ship will behave as though all of its weight were acting downward through this point. B is the point at which all the vertically upward forces of support (buoyancy) can be considered to act, or, the center of volume of the underwater portion of the vessel. In other words, the ship will behave as if all of its support is acting up through this point. There are a lot of mathematical concepts and processes to compute stability. Theory of Moments, Inclining formula, Trigonometry, Change in Mean Draft are also implied in vessel stability.
During the afternoon I worked on the computer, and I put all my pictures on the FAIRWEATHER’s computer network.
We also had the drills: 1) Men on Board, 2) Abandon Ship, and 3) Fire and Emergency.
NOAA Teacher at Sea
Philip Hertzog
Onboard NOAA Ship Rainier July 25 – August 13, 2005
Mission: Hydrographic Survey Geographical Area: Aleutian Islands, AK Date: July 27, 2005
Securing the launch
Weather Data from Bridge
Latitude: 55˚ 53.3’ N
Longitude: 158˚ 58.4’ W
Visibility: 10 nm
Wind Direction: light
Wind Speed: airs
Sea Wave Height: 0 feet
Sea Water Temperature: 12.2˚ C
Sea Level Pressure: 1012 mb
Cloud Cover: 2, cumulus
Science and Technology Log
The RAINIER is now anchored for the next several days in Cushman Bay on the north side of Mitrofania Island. Today the ship’s crew began their first full day of mapping the bottom of the waters surrounding the island. The Captain assigned me to observe operations on board one of the RAINIER’s six survey launches. The launches are small craft equipped with sonar and computer equipment to collect bottom data as seen in the following photographs:
Each launch has a crew of three and four launches go out at a time. On my launch, Ensign Brianna Welton serves as the hydrographer in charge with Matt Boles as the Assistant Survey Technician. Able Body Seaman Corey Mussey drives the launch and makes sure it stays on course using a computer screen directs him where to go.
A winch lowered our launch into the water. We jumped about two feet from the side of the ship to get into the launch. We carried no equipment in our hands or on our backs and wore life jackets to ensure we safely crossed the deep water.
Once underway, Ensign Welton turned on the Differential Global Positioning System (DGPS). The DGPS uses satellite signals to determine our location and even can tell our direction and speed. Unfortunately, our DGPS did not work correctly and Ensign Welton and Matt Boles struggled over the next 2 hours to trouble shoot the problem. When out at sea and hundreds of miles from the nearest repair shop, the crew of the RAINIER has to become creative to solve problems in order to achieve their mapping mission. The DGPS problem finally got fixed after the antenna was taken apart and the connecting cables cleaned. Matt told me that whenever one starts a new field survey, you commonly find problems that must be fixed due to the difficulties of working in the harsh environments found at sea and in Alaska.
With the DGPS fixed, the crew sent a SEACAT probe through the water column to the bottom to collect temperature, salinity and pressure data. Sonar mapping works by bouncing sound waves off the bottom and measuring how fast the waves return to the ship. Sound travels through salt water at 1435 meters per second, but its speed can be changed by temperature, salinity or pressure. The computer takes the data from the SEACAT and makes corrections to the sonar data so we have a better measurement of the bottom depth.
Sunset over the bow
We spent the rest of the day running transects to map the bottom. Transects are long, parallel lines that are spaced to ensure we cover the entire bottom of the area being mapped with some overlap. To better understand what “running a transect” means, think about mowing your lawn. When you mow the lawn, you run the mower in parallel lines, but you always go over part of the path you mowed before in the previous line. Just like mowing, the sonar is able to map the entire bottom of the map area by using a transect pattern.
Around 4:30 pm we returned to the RAINIER and the deck crew winched the launch back on board. I handled the stern line and threw it to a deck hand on the ship. I also attached the hook from the winch onto the launch, but I didn’t do it correctly on my first try. You have to be careful because the launch weighs 14,000 pounds and the seas can bounce it around. I got too close to the block and tackle on the winch, but Ensign Welton pulled me back and showed me how to properly connect the cables. To the right here is a picture of Ensign Welton correctly hooking up the launch.
Once the launch returned to the RAINIER, the mapping crew’s duties were not f inished. After supper, the crew down loaded the launch’s computers onto the ship’s main frame and “cleaned up” the data. Clean up consisted of looking at the data and matching it with maps on the main frame computer. The survey technician also had to correct the data with tidal information and look for false sonar signals to remove from the data set. Upon finishing clean up, an officer checked the work for quality. Here is a picture of Dan Boles, Matt’s older brother, cleaning up some data.
Personal Log
I had a great time today going out on the launch and learning what the survey crews do. The landscape overwhelms one with large open areas of water surrounded by mountains covered in green, low lying vegetation. Mount Veniaminof dominates the background with its glacier covered dome that rises 7,075 feet above sea level.
As we traveled in the launch, I could see whales blowing spray out their blow holes in the distance and pink salmon jumping out of the water. At the end of work, we took 10 minutes to fish off the launch and Matt caught a ling cod while I had one on the hook that got away.
I enjoyed talking to Matt Boles and learning about how he ended up on the RAINIER with his brother Dan. Matt has a two year college degree in computers and Dan has a Bachelors degree in geology and French. I see a lot of potential for my own students to get jobs aboard ships like the RAINIER and to have a great time exploring wild places like Matt and Dan.
Question of the Day
Why do temperature, salinity and pressure change the speed of sound in water?
NOAA Teacher at Sea
Mike Laird
Onboard NOAA Ship Rainier July 24 – August 13, 2005
Mission: Hydrographic Survey Geographical Area: North Pacific Date: July 26, 2005
Watching the monitors
Weather Data
Latitude: 55°53.3̍ N
Longitude: 158˚58.4 ̍ W
Visibility: 10 nautical miles (nm)
Wind Direction: 235˚
Wind Speed: 6 kts
Sea Wave Height: 0΄
Swell Wave Height: 0΄
Sea Water Temperature: 11.1˚ C
Sea Level Pressure: 1013.5 mb
Cloud Cover: Sky 7/8 covered, Cumulonimbus
Science and Technology Log
Operations for the day begin at 8:00 with crews of four launches assembling on the fantail for a pre-launch briefing giving final details of the day’s assignments and a review of safety procedures. Each launch crew is composed of three members: an Officer in Charge (OIC) who has overall responsibility of the launch, a coxswain who is responsible for the physical operation of the launch, and a survey crew member who assists in data collection in the assigned survey area. Some crews carry a fourth member who is frequently a Teacher at Sea or other visitor on the ship.
Once the briefing is completed, each crew assembles in their launch-loading zone and boards the launch as it is lowered into the water. I have been assigned to launch RA5 (RAINIER launch 5) and will be working with Ensign Mike Stevenson (the OIC), Carl Verplank the (coxswain), and Greg King (the survey technician). Our assignment is to work in conjunction with launch RA3 to collect seafloor data in Mitrofania Bay, an area to the northwest of the RAINIER’s anchor location. The area has been designated as Sheet AW. The area around Mitrofania Island has been divided into several sheet areas. Each sheet is composed of a map of the area overlaid by a set of parallel lines or tracks that the launch or ship will follow as it is recording data. During the two weeks we are working in the region, data will be collected for as many of those sheets as possible.
Having reached the target area, a “cast” must be taken before the actual scanning of the bottom can begin. The purpose of the cast is to gather information about the behavior of the water column we are working in. The waters’ conductivity, temperature, and pressure will all affect the velocity of sound traveling through the column, and will be factored into the processing of the collected data. The cast is conducted by lowering a CTD sensor, called a SEACAT, to the floor of the ocean. When the cylinder is raised back to the surface, the data is uploaded to the launch computers and we are ready to go. Launch RA5 is equipped with a Reson SeaBat 8101, a hull mounted extended echo sounder system. This system is used to record seafloor information in water depths not exceeding approximately 110 meters. This sonar system is a multi-beam system using 101 beams. Each beam is composed of pings emitted from the sounder. One beam drops vertically below the launch and fifty beams each fan out to the port and starboard sides.
To help picture this, imagine a set of right triangles below the launch. Each triangle originates with the junction of the vertical beam and seafloor where two opposed right angles are formed. The hypotenuse of each triangle is one of the fifty beams to the left or right of the vertical beam, and the seafloor forms the base of the triangle. Collectively the bases are referred to as the footprint (area covered by the sounding). This footprint increases in size as the depth of the water increases. As the size of the footprint grows, additional “noise” or interference is introduced into the sound wave pattern in those beams further from center. This less accurate data will usually be eliminated during data analysis.
We spend the day transiting the lines designated on our sheet as the sonar feeds seafloor data to the launch computers. At the end of the day, the launch nested safely back on the RAINIER, the data is downloaded from the launch to the ship. Now begins the next phase analysis and “cleaning” of the raw data. However, that is for another day!
Note: This is my understanding of the information I received. If there are errors or inaccuracies, I apologize.
Personal Log
We have been very fortunate so far – the weather has been great since we arrived in Mitrofania. Partially cloudy but lots of sun! The salmon (pinks and silvers) are constantly rolling and jumping. I tried my hand at a little salmon fishing yesterday with mixed results. I hooked two! Key word there hooked. I didn’t land them – both shook the hook. Pretty lame, but I’ll get them next time! Other crew members have tried some halibut fishing, but so for have only brought up what they call Irish Lords (“An ugly, junk fish.”) The fish is unique – a tan, brown and black with bulging eyes and poisonous spines that apparently cause pain and discomfort if you are cut or poked.
NOAA Teacher at Sea
Tamil Maldonado
Onboard NOAA Ship Fairweather July 18 – 28, 2005
Mission: Hydrographic Survey Geographical Area: North Pacific Date: July 25, 2005
Personal Log
We sailed through Sitkalidok Strait, southeast of Aliulik, Kodiak Island. I got up seasick at 1:30 a.m. and stayed awake till 4:30 in the morning. I went back to sleep and after lunch I took a seasick pill to feel better. It just made me sleepy.
In the afternoon I interviewed one of the student scientists, Dylan Righi. He is a programmer and his work deals with wavelets using drifters to recollect data. He also “cleans” the data, since there is always some noise to be corrected. He graphs the path of different types of drifters into the water and does some numerical analysis. He runs a FORTRAN code on a UNIX system parallel to a computer back in Seattle. His data analyses are from the North East Pacific regions. The resolution of the wavelets is approximately 9 km, 520 points. Anyone interested on the code or data could get it from FOCI website.
Sick 1:30 a.m.gt Sleep Talked with a programmer scientist about wavelets
NOAA Teacher at Sea
Mike Laird
Onboard NOAA Ship Rainier July 24 – August 13, 2005
Mission: Hydrographic Survey Geographical Area: North Pacific Date: July 25, 2005
Mike Laird, Teacher at Sea
Weather Data
Latitude: 55°37.1̍ N
Longitude: 156˚46.6 ̍ W
Visibility: 10 nautical miles (nm)
Wind Direction: 140˚
Wind Speed: 5 kts
Sea Wave Height: 0-1΄
Swell Wave Height: 2΄
Sea Water Temperature: 12.2˚ C
Sea Level Pressure: 1009.8 mb
Cloud Cover: Stratus
Science and Technology Log
My name is Mike Laird, and I am a 5th and 6th grade Science and Math teacher from Flagstaff, AZ. I am onboard the NOAA ship RAINIER participating in a three-week hydrographic research cruise. The primary objective of the scientists and crew of the RAINIER is to gather data that can be used to create accurate maps of the ocean floor and coastline. I joined the team in Kodiak, AK.
We put to sea Monday afternoon after completing repairs on one of the six survey launches carried by the RAINIER. Our destination is Mitrofania Island, a small island southwest of Kodiak. This location has been selected for data collection, because there is little information available on current nautical charts. Our route took us through Shelikof Strait (between the Alaska Peninsula and Kodiak Island).
We then tracked south between the Semidi Islands and Chirikof Island. As we transited this track, the RAINIER used its onboard sonar to gather ocean depth information for this location. As other NOAA hydrographic ships follow this course, they will also gather data. Over time and using all the data collected by the various ships, an accurate nautical map of this area will be constructed.
Having completed this pass, we headed northwest toward Mitrofania. We sailed around the southern tip of the island and head for Cushing Bay, where we anchored for the initial phases of the data collection work. As we neared Cushing Bay, a small work team was deployed in one of the ship’s skiffs to check a temporary (in place for thirty days or less) tide station. The station must be checked to insure that it is operating correctly and transmitting accurate information back to the RAINIER. Data from the temporary tide station will be compared to data from the nearest official Coast Guard Tide Station and accurate tidal information for the area around Mitrofania Island can be derived. Accurate tidal information is critical, since it is used in the processing of the collected data. In addition to checking the tide station, the work crew will attempt to locate a spot on the shore to install a temporary GPS system. The closest land-based GPS systems are a distance away and could introduce error of up to three meters in the collected data. The successful installation of a closer, more reliable GPS would help increase the reliability of the data the team collects.
The end of the day has come. We are anchored in Cushing Bay, and I eagerly await tomorrow’s arrival as I will be joining the launch 5 survey team.
