Leyf Peirce, July 13, 2004

NOAA Teacher at Sea
Leyf Peirce
Onboard NOAA Ship Rainier

July 6 – 15, 2004

Mission: Hydrographic Survey
Geographical Area:
Eastern Aleutian Islands, Alaska
Date:
July 13, 2004

Time: 15:00
Latitude: N 55°17.29
Longitude: W 160°32.14
Visibility: 4 nm

Wind direction: 140
Wind speed: 6 knots
Sea wave height: 0 – 1 foot
Swell wave height: —
Sea water temperature: 10.0 °C
Sea level pressure: 1007.8 mb
Air temperature: 12.2 °C
Cloud cover: 8/8

Science and Technology Log

I awoke today to an announcement over the ships intercom saying, “Attention all hands, attention all hands, divers are in the water, please make sure all equipment is stored and locked”. I first checked to make sure it wasn’t me in the water, as exciting as that would have been, and then I raced out of bed to see what was going on. Apparently, since we have been anchored off the coast of Egg Island, we have had a very small oil leak. It was believed to have fixed itself after the first few hours of anchoring; however, yesterday many of the crew noticed that there was still a slick on the water off the port stern. To investigate, three NOAA certified divers dove down about 15 feet and inspected the hull of the ship. They saw that the oil was in fact coming from the left propeller, yet they could not directly identify the source of the problem, but speculate that there is a small leak in one of the o-rings. The only way to truly fix this problem is to dry-dock the boat. The closest dry-dock is in Seward, but we are scheduled to go to Kodiak first. Therefore, the plan is to see if the problem takes care of itself and if it is not better by the end of the stay in Kodiak, then take the boat to Seward. The amount of oil that is leaving the ship is very small and is escaping at an extremely slow rate. However, if this problem persists, it could become very serious.

I talked with ENS Lominkey about his dive this morning and about other dives he has made recently. He informed me that once you are NOAA certified, the equivalent of becoming a PADI or NAUI dive master, you will be allowed to help with dives that involve ship repair, tide gauge installation, or wreck surveying. In fact, only two weeks ago the RAINIER was performing hydrographic research and identified the fishing boat CONQUEST which sunk in 1994. ENS Lominkey and other certified divers dove the wreck to gather information about the wreck including its minimum depth which happened to be about 90 feet. To do this, they used a very sensitive depth gauge that relies on pressure changes. They would place this gauge at different locations on the wreck and record the various readings. ENS Lominkey also told me that they found another fishing boat wreck near the CONQUEST, but were unable to identify it. As I have developed my passion for diving over the past few years, I become more amazed at the opportunity to dive and explore uncharted waters knowing that the research you are conducting is contributing greatly to society. And, as technological advancements are made for both safer diving and better navigational charting, I can’t help but wonder how these will be further combined in years to come—a very interesting engineering design problem!

Personal Log

Today was mostly spent writing more lesson plans for my 6th, 7th, and 8th grade science classes as well as planning my 8th grade pre-algebra course. I also spent a lot of time talking with several officers about the amazing act of diving and how wonderful it would be to be paid to do something so adventuresome everyday. When sharing experiences, I did notice that the excitement of diving somewhat parallels the excitement of teaching; you never know what you are going to see, there are some dangers, but overall the experience is extremely rewarding. In both, you not only learn about other animals, or students as the case may be, but you also learn a lot about yourself, your goals and dreams, and your limits. While I am greatly enjoying my experience aboard the RAINIER, the more I think about my different classes and the students that I will see in the fall, the more excited I get about returning to the classroom!

Question of the Day:

How much oil would have to be in the water before it drastically starts harming marine life?

Sena Norton, July 11, 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 11, 2004

Location: At anchor Popof Strait, Shumagin Islands, AK
Latitude: 55 deg 17.30’ N
Longitude: 160 deg 32.14’ W
Visibility: 5 nm

15:00

Direction: 110 deg
Wind Speed: 10 kts
Sea wave height: 0-1 ft
Swell wave height: n/a
Seawater temperature: 10.0 deg C
Sea level pressure: 1018.2 mb
Cloud Cover: 5/8
Weather: Fair to Partly cloudy, spots of fog dissipating. 12.12 deg C

Plan of the Day:
Continue the launch survey with 2 boats. In house data cleaning and processing. Meeting with LIDAR tech stationed in Sandpoint.

Science and Technology Log

I personally spoke with a survey technician, Amanda McKinney on board to gather more information on hydrography and the process behind it. There were two main topics that we discussed: Application and history of marine survey, and the math/science behind the techniques.

Application/History

The technology used for marine survey has been improving by leaps and bounds and we are currently using a collection of old and new technology to gather data. Many nautical charts have not been charted for almost 80 years or more and some areas have never been accurately charted at all. The old process was to drag a lead line behind a transiting ship. This process was full of errors because you could never accurately know your depth, even if the length of the line was known; it was drug and therefore skewed the data. Very often a charted depth from these old processes are found to be dangerous wrong. Another mode of survey is the wire drag, where multiple ships drag a wire through the water column. Once a target has been hit, the depth of that underwater target is calculated, but never truly charted accurately. Side scan sonar came around and improved the survey capability, but it too has its drawbacks. Because the “fish” is towed there are many more mathematical corrections that must be made in order to get a reading that is close to the actual target. It does produce wonderfully clear pictures of what is around the “fish” but those images lack depth of field and the sonar cannot read directly below the transmitter. Quite often with side scan images, divers are needed to dive the sight of a possible target to get accurate readings. Multi-beam sonar can be used in conjunction with side scan to better improve the over all picture of the underwater area. Because multi-beam is able to give more accurate readings and the data is complied in 3-D images, surveyors can have both a clear image and precise depth reading all together. It is hoped in the future that there will be new sonar systems that can scan at 480 beams over .25 x .25 deg per beam with 40+ pings per second. The highest level of technology currently used by NOAA is the Reson 8125 (this system is attached to two boats currently) and it sends out 240 beams over 0.5 x 1 deg / beam at 15 pings per second and runs with 455kHz. Remember, that a short pulse (wavelength) will give better vertical resolution and higher frequencies give shorter pulses or wavelengths.

The math required to figure the depth is not very difficult, however in the case of the ocean, the computers must adjust all readings for depth, salinity, temperature and density, which in a way makes the math more difficult if done by hand.

Depth=Speed+ Time/2

Personal Log

I was able to spend some time with the survey tech’s today and got through some of the PowerPoint presentations that are available here on the intranet to educate myself more on the technology and process. I was pleased to see that I can apply some of the simple ideas to my classroom. When I teach certain science skills I will have real life data sets and examples for the kids to analyze. I also hope to get some of the kids excited in the field of sonar and survey, much needs to be done to improve the accuracy and reliability of these systems and the product they produce.

Sunday equals fishing off the fantail in between shifts. We have a resident pack of gulls that have found it much to their benefit to hang out for the halibut leftovers that get tossed overboard or that slip from bait hooks.

I found a whale bone yesterday on Egg Island and had the boat shop guys saw it in half so that both of us TAS’s could bring something back for the classroom. It is not a large chunk, but authentic to say the least. I also gathered some sea sponge that had washed up and a very unique white rock.

I was very surprised to see the people working on a Sunday. No one should ever question the dedication of the folks on board or say that this is an easy job. One of the engineers has not had a day off in two months or more. The ship is something that has to be tended too by her crew and command 24 hours a day 7 days a week. Self-sufficiency comes with some responsibilities!

Question of the Day

Which is better: side scan or multi-beam sonar?

There is not one that is better than the other so much as they can compliment each other to produce and more detailed and accurate product, namely the nautical charts and other products that use the information gathered via the sonar medium.