Vickie Obenchain: Starting a Hydrographic Survey, June 28, 2018


NOAA Teacher at Sea

Victoria Obenchain

Aboard NOAA Ship Fairweather

June 26 – July 6, 2018

 

Mission: Arctic Access Hydrographic Survey

Geographic Area of Cruise: Northwest Alaska

Date: June 28th, 2018

Weather from the Bridge

  • Latitude: 54o 25.5’ N
  • Longitude: 134o 13.7’ W
  • Wind Speed: 13 Knots
  • Wind Direction: South, Southwest
  • Temperature: 12.2 oC
  • Visibility: 10 nautical miles
  • Wave Height: 1 foot
  • Current Sky Conditions: Overcast

 

Science and Technology Log

This morning I spent some time on the bridge with the officers. NOAA Ship Fairweather is manned day and night with men and women making sure we are safely on course. While the ship is equipped with GPS, the ship is also full of experienced mariners who plot our position on paper nautical charts to help guarantee the technology is working correctly and helps the officers orient themselves with the area.  Every 15 minutes, an officer plots our position either by using GPS coordinates, radar returns, or fixed land triangulation using an alidade. This last mode of determining our coordinates, at least to me, is the most difficult. You must use 3 fixed land points on either side of the ship, determine their direction using the compass on the alidade and then using sliding protractors plot our triangulated position on the chart. Both Executive Officer (XO) Michael Gonsalves and ENS Cabot Zucker have been incredibly helpful in teaching me these different plotting techniques.

plotting our course

XO Gonsalves in the foreground and ENS Zucker in the back plotting our course.


Today we are headed to the Queen Charlotte-Fairweather Fault System. This is a strike slip fault line extending 746 miles off shore of Vancouver Island to the Fairweather range in southeast Alaska.  USGS has partnered with NOAA Ship Fairweather to help to create part of a comprehensive map of one of the fastest moving underwater tectonic plates in the world, moving of a slip rate of 2 inches a year. Over the next 24 hours they will survey the area using multibeam sonar to help complete the mapping which as taken almost 4 years to complete.

To start this, the survey team had to deploy a Moving Vessel Profiler (MVP) into the water. The MVP follows behind the ship and by detecting water temperature and salinity of the water, the MVP can then determine the speed of sound in water needed to accurately detect the sea floor. With this knowledge the survey team can correctly calibrate their sonar to map the sea floor. Below you will see Sam Candio and Simon Swart of the survey team deploying the MVP.

 

Next blog will cover the amazing people working with the sonar, all times of day and night to make the sea floor maps! (Stay tuned!!)

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Another short term visitor on this ship is a college student from Loyola University Chicago, Paul Campion, who is on board doing an internship with NOAA. Each year NOAA accepts approximately 130 college sophomores into their two-year-long Hollings internship program to give students an opportunity to take part in research, gain job experience and see what NOAA does.  While on board, Paul has been working with the survey team to learn how they do their work, as well as create his own project.  Paul has been looking at the electronic navigational charts (ENC) used today by most mariners which show the depth of the sea floor. As NOAA Ship Fairweather surveys an area, these ENC’s can then be updated with more accurate and up to date data. While some areas may remain the same, some areas may show changes or even characteristics which may not have been mapped prior and need to be highlighted.  Paul has been working to help create an efficient way to show where the ENCs are different to the new NOAA Ship Fairweather data and may need to be altered or updated.

Paul Campion

Paul Campion pointing out a beautiful glacier!

Personal Log

Since we are out in the sea, and do not have neighboring island chains around us, the boat has been tossed around a bit more and is definitely rolling around in the waves. Luckily, I have not been sick… yet. I have been taking sea sickness pills, and making sure I get plenty of fresh air, but the boat is definitely more difficult to work in. You find yourself moving both with the boat’s inertia and then having to fight against it to move. Walking uses walls and railings, sitting requires holding on to the closest counter top or nailed down object and to get into rooms you need to shove doors away from you to open them, yet hold on so they don’t swing completely away from you and slam the opposite wall. It is kind of challenging and yet amusing.

After lunch today, I went to take a shower. I was given some good advice since I had not done this when the boat was in open water. These words of advice included: Use the walls, kind of squat down to lower your center of gravity, don’t take a razor with you (nothing good will come of that), and if the soap drops be especially careful! All things I took to heart and I am glad to report I am clean, unscratched and ready for another day.

 

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