Leyf Peirce, July 6, 2004

NOAA Teacher at Sea
Leyf Peirce
Onboard NOAA Ship Rainier

July 6 – 15, 2004

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

Time: 20:00
Latitude: N 59°03.205
Longitude: W 150°41.139
Visibility: 10 + mi
Wind direction: 280
Wind speed: 11 knots
Sea wave height: 0 – 1 foot
Swell wave height: 3 – 4 feet
Sea water temperature: 12.2 °C
Sea level pressure: 1016.0 mb
Cloud cover: 4/8

Science and Technology Log

We left Seward today and are headed toward the Shumagin Islands to conduct hydrographic surveys to map the ocean floor and the coastline. The overall goal of this research is to update existing nautical charts. Most of the charts that are currently used have not been updated since the early 1930’s. After talking with ENS Brent Pounds, ENS Nicole Manning and P.S. Shyla Allen, I learned more about the tools and techniques used to map the ocean floor. Steve Foyd also provided me with an excellent pamphlet titled “Nautical Chart Programming”. From these sources, I learned the following information about data acquisition and analysis. The RAINIER will first be positioned using the Differential Global Positioning System (DGPS) near the desired area to be mapped. Then, the RAINIER launches up to 6 research vessels, each equipped with two main measuring devices. One device, the ELAC C-Beam 1180, is basically a side scanner that can scan a swath of the bottom of the ocean up to 200 meters using 180 individual sound beams. Any depth change will appear to be different shades on the sonogram. The heights of different points can then be calculated from this sonogram. In conjunction to the ELAC C-Beam 1180, the launch boats use an echo sounder mounted to the ship’s hull. While this can retrieve more accurate data, data with only a 0.1 m margin of error, it can also only scan an area up to 5 meters. However, using these two systems combined produces the most accurate data. The RAINIER also installs tide gauges that produce accurate data that can be added to the resulting nautical charts. Researchers aboard the RAINIER take this data, “clean it”, and eventually send it to the mainland to be used to create the new updated charts.

Personal Log

This day has been full of excitement as we are finally underway! The scenery is absolutely beautiful here, and the wild life is truly fascinating. The snow covered mountains dip into the water with an awesome power as sea otters and puffins play in that same water below. We have also seen several porpoises and one crewmember claimed he saw a whale. I am overcome with awe at how this ecosystem is filled with so much wonder and unknown as the mountain goats and moose mirror the whales and sea lions only to be separated by where the land and water meet. Life aboard ship is similarly full of excitement. It is like a finely tuned machine how well everyone works together to make this boat maneuver. As much as I am enjoying the sight seeing, I can’t wait for the research to begin. I am excited to have my engineering background meet my teacher profession!

Question for the Day:

It is summer here, and the tilt of the Earth causes the “sun to never go down”. One could even read a book in the middle of the night with no flashlight! As I was thinking about navigational techniques and the history of navigation, I couldn’t help but reflect on the importance of using the stars for guidance at night. The question for the day is: What did sailors use, before all of the GPS technology we have now, to navigate at night in these upper latitudes when it never got dark enough to see the stars at night?

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s