Category: Kathy Virdin

Posted on

Kathy Virdin, July 22, 2004

NOAA Teacher at Sea
Kathy Virdin
Onboard NOAA Ship Rainier
July 20 – 28, 2004

Mission: Hydrographic Survey
Geographical Area: Eastern Aleutian Islands, Alaska
Date: July 22, 2004

Latitude: 55 degrees 39’N.
Longitude: 157 degrees 54’W.
Visibility: 10 nautical miles
Wind direction: 270 degrees W.
Wind speed: 6 kts.
Sea wave height: 0-1 ft.
Swell wave height: 2-3 ft.
Sea water temperature: 12.8 C.
Sea level pressure: 1013.0 mb.
Cloud cover: Partly cloudy

Science and Technology Log

Today I interviewed several crew members, which gave me a much better perspective of the extent of work that is being conducted on the RAINIER. I first spoke with Jeremy Taylor, who is a survey technician whose job is to collect data on the ocean floor depths for the purpose of updating nautical charts. The RAINIER is dedicated to survey work that can enable all maritime vessels to successfully maneuver the ocean waters. As a survey technician, Jeremy is considered a scientist on board since the data he gathers is used by the scientific community. He collects the data from the multi-beam swaths and cleans it by deleting invalid or weak information, then sends it to other branches of NOAA (such as the cartographers) who review it, compare it to current nautical charts and then update those charts based on the new data. What is amazing to me is that the RAINIER does survey work in areas which may not have been surveyed since the 1800’s and have only had a few soundings listed. Their work is vital to commerce, fisheries management and the fishing industry. Jeremy said what he enjoys most about his job is being in Alaska, having the opportunity to go out in launches and receiving good data. He feels his job is extremely important since scientists need this data to find the habitats of various marine species. One example he gave was the fact that they can chart seamounts which are an area that contain a lot of marine life. This gives data that could help scientists discover new habitats for various species. Jeremy recommends a degree in hydrography to best prepare for this work, but also maintains that a degree in any area of science would be good basic preparation and on-the-job training would be supplied.

Next, I interviewed Briana Welton who is a Junior Officer, an Ensign in the Corps. She has a degree in math which has helped her greatly in her work. She is undergoing training to be an Officer of the Deck who will drive the ship. She also participates in the hydrographic surveys. She recommends students applying to the Maritime Marine Academy which is in New York. Briana loves the experience of being a hydrographic pioneer, as they are often charting unmeasured waters. She also loves being at sea and says it’s exciting to drive the ship. There are several divisions of ships that NOAA operates, such as the oceanographic studies, hydrographic and fisheries. The information gained by a hydrographic ship is first and foremost to be used for nautical charts, which are used by all mariners, from small fishing boats to large Navy vessels. The RAINIER also takes bottom samples that they can process in their lab to determine content and physical features of the ocean floor. The CDTs that they lower give temperature, salinity and density information to scientists that enable them to look for variations in the ocean climate that will affect marine habitats. Briana loves working on a ship and being part of a close-knit community.

Personal Log

This morning I thoroughly enjoyed talking with several crew members about their work and getting new information about all the facets of ship life. This afternoon I plan to work on lesson plans and tonight I’ll watch the survey technicians scan and clean up the data that comes in from the two launches that went out today. I also hope for some time to do more research on the complexities of the mission of NOAA and study some nautical charts. It’s amazing to me that I can walk out on deck at 10:30 at night and it will still be light. In Alaska in the summer there are about 19 hours of daylight.

Wow!

Posted on

Kathy Virdin, July 21, 2004

NOAA Teacher at Sea
Kathy Virdin
Onboard NOAA Ship Rainier
July 20 – 28, 2004

Mission: Hydrographic Survey
Geographical Area: Eastern Aleutian Islands, Alaska
Date: July 21, 2004

Time: 6:00p.m.
Latitude: 55 degrees 49.65 N
Longitude: 157 degrees 56 W
Visibility: 11 nautical miles
Wind direction: 350 degrees NW
Wind speed: 7 kts
Sea wave height: 0-1 ft.
Swell wave height:2-3 ft.
Sea water temperature: 12.2 C.
Sea level pressure: 1013.0 mb.
Cloud cover: Partly cloudy

Science and Technology Log

Today I was able to go out on a launch (small boat) that did survey lines for eight hours. After the launch got underway, we lowered the transducer into the water where it will send out a spray of sound (approximately 131 pings) that will be measured on the launch’s computers. We also did a Reson line measurement which can accurately measure depths of 40 meters. We drove the launch in a line that was approximately 4-5 miles long, then turned and went back on the next line. Each line took about 40 minutes and we were able to cover 7 lines today. So in all, we were able to chart an area of 4-5 square miles. We stopped every four hours to put down a CDT which checks salinity, density and temperature. This information was immediately fed into the computers so that it can adjust the speed of sound through the waters by these factors. This launch also has a motion sensor that can measure the pitch and roll of the boat and that is factored into the speed the sound travels, which gives the calculated distance to the ocean floor.

NOAA has about 8 or 9 ships that do hydrography work which is extremely important to scientific research, as well as commerce. About 90-95% of all goods used in the U.S. are brought to us by ships! So it’s vital that they have accurate information to chart their path through our waters. The RAINIER is the only ship in the world that can do all the hydrographic survey work that it does. It’s an honor to work on a NOAA vessel and all members of the NOAA corps must have a degree in one of the sciences. The swath or path of the sonar beam that our launch is sending out covers about 200 meters. We’re seeing the data that tells us that the depths in this area are 100 meters. We have successfully measured our plot of the chart today with multi-beam swaths that intersect at the outskirts with one another. This is another measure taken to ensure accuracy.

Personal Log

I asked a lot of questions today while we were surveying, as the field operations officer with us had time to answer them. The work was mostly being done by the computers, so we were watching and checking them periodically. I learned that the launches are expensive boats because of all the high-tech equipment they carry (all of it necessary to get the job done). When we came back to the RAINIER, the sun came out and we went up on the deck to enjoy the view. I saw puffins flying over the water, and one of them flapped its wings across the water as it skimmed along the surface. This was a treat to watch the puffins as they entertained us with their antics. Tomorrow, I’m looking forward to following up on the data that was gathered from the two launches that went out today. It will be scrutinized and evaluated by the survey technicians and then stored in the folder for the day.

Posted on

Kathy Virdin, July 20, 2004

NOAA Teacher at Sea
Kathy Virdin
Onboard NOAA Ship Rainier
July 20 – 28, 2004

Mission: Hydrographic Survey
Geographical Area: Eastern Aleutian Islands, Alaska
Date: July 20, 2004

Time: 2:20 p.m.
Latitude: 55 degrees 39.4 N
Longitude: 158 degrees 00.3 W
Visibility: 10 nautical miles (nm)
Wind direction: Northwest
Wind speed: 7 kts
Sea wave height: 0-1 ft.
Swell wave height:2-3 ft.
Sea water temperature:13.3 degrees Celsius
Sea level pressure:1010.1mb.
Cloud cover:3/8 partly cloudy

Science and Technology Log

Today we reached the point where we would begin our surveys. I watched the survey technicians lower a Seabird (sound velocity profile unit) into the water, then raise it back up and hook it into a computer, where they could download the information. This will give them the salinity (salt content), temperature and pressure of the water. They lowered the Seabird 117 meters down into the water, before retrieval. At the same time, from the hull of the ship, a transducer sound wave emitter is sending sound waves to the bottom and measuring the time it takes for their return. From this information, they will calculate the distance to the floor of the ocean. They use this data from the Seabird to help them make corrections in the sound wave speeds from the transducer. The salinity, temperature and pressure will cause variations in the speed of sound, so they need to correct for this effect to gain an accurate depth measurement.

This information is being processed and viewed by cartographers (map designers) who will take what data the RAINIER gives them to update old maps or develop new maps and charts. These maps are used by fishermen, geologists or anyone who navigates through these Alaskan waters. We are headed for the Shumagin Islands where we will send out launches (smaller boats) to measure depths in places where the Rainier might not otherwise go. I found it interesting to note that environmentalists would also use this information, since they know where certain species of fish are likely to live, and they can decide how best to protect them if they are endangered. We will go back and forth three times in one plotted line to make sure our data is accurate and complete. When we send out a launch in more shallow water, they will use a different sonar device, called a Reson. It emits higher sound waves which will give a more accurate reading. For middle to deep depth measurement, they will use the Elac sonar and a vertical beam echo sounder which goes straight down that can be used for shoreline measurements. Because Alaska has such rough terrain, it’s important to get accurate measurements for those who use her waters.

Personal Log

I am amazed by how specific the data is that the survey technicians collect and how well everyone knows their job. This is truly a finely tuned, professional organization. Everyone has been so kind to answer my many questions even though I’m sure I’ve gotten in their way. I’ve spent a lot of time in the Plot room, where the data is logged into the computers and then interpreted by the technicians. Outside, it’s a beautiful, sunny day, which is the first pretty weather we’ve had. We saw a pod of whales, recognizable by the blow of water coming from their nostrils. I could see them really well through the high-powered binoculars that belong to the ship. I am working on a list of questions that I will use to interview different members of the crew, as well as the scientists so I can take this information back to my students, as they learn what the roles are on a NOAA vessel. Someday, I want my students to be the next generation of scientists that use the knowledge we are gaining today to frame the discoveries they will make in the future.