NOAA Teacher at Sea
Theresa Paulsen
Aboard NOAA Ship Okeanos Explorer
March 16 – April 3, 2015
Mission: Caribbean Exploration (Mapping)
Geographical Area of Cruise: Puerto Rico Trench
Date: March 17, 2015
Weather Data from the Bridge: Partly Cloudy, 26 C, Wind speed 12 knots, Wave height 1-2ft, Swells 2-4ft.
Science and Technology Log
Elizabeth “Meme” Lobecker, Physical Scientist Hydrographer with the NOAA Office of Ocean Exploration and Research and our Expedition Coordinator, gave the science team aboard the vessel an overview of our expedition on Sunday after an evening of becoming acquainted with the ship and other members of the science team.
She explained how oceanic exploration research is different from the rest of the scientific community and even other projects within NOAA, because it focuses purely on exploration and discovery that can generate hypotheses. In other areas, a scientist has a hypothesis first and sets out to test it through research and experimentation.
The information gained on our mission could generate hypotheses in all kinds of areas of research such as geology, fisheries, oceanography, marine archeology, and hydrography. It could help us identify areas that need protection, such as spawning grounds for commercial fish populations. Meme and her team will turn the data over to the National Coastal Data Development Center within three weeks. From there, it goes to the National Geophysical Data Center and the National Oceanographic Data Center, where it is freely accessible through public archives within 60-90 days of the end of the cruise. From there, any entity, public or private, can access the data for use in their work. Have you ever wondered how Google Earth and Arc View GIS get the background data for their ocean floor layer? This data contributes to those layers. Now you know! Public data access is through www.ngdc.noaa.gov and www.nodc.noaa.gov.
While we currently have low resolution data from satellites, less than 5% of the oceans have high-resolution images. We have better data now about the features of Mars than we do about our oceans on earth. Why? Because ocean surveying is difficult and time-consuming. High resolution maps cannot be made of the ocean floor with current technology on satellites. The technology is getting better and better, though. The image below shows the progression from a leadsman dropping a 10 pound weight attached to a line in the water to the multibeam sonar being used as I type.
Learn more about the history here.
The multibeam sonar aboard the Okeanos Explorer sends out a ping at 30 kHz that bounces off the seafloor and returns to the transducer that is equipped with sensors oriented in 432 different directions receiving up to 864 beams per swath. This method has been tested in depths of up to 8000 meters. It can give us not only bathymetry data, but also water column backscatter and bottom backscatter data. This allows us to know if there are features in the water column like gaseous seeps escaping from the ocean floor. We can also tell something about the surface features, whether they are soft sediments or hard rock, from the bottom back scatter.
Meme has a crew of mappers working with her including Scott Allen, Senior Survey Technician; Melody Ovard and Jason Meyer, Mapping Watch Leads; and several interns. Another important part of the mission is to train a new generation of ocean explorers. These interns, Chelsea Wegner, Kristin Mello, and Josue Millan, come from colleges all over the country. Their main job is to make sure the data is good and to create logs to document data collection. They have to correct the multibeam sonar data by deploying XBTs (Expendable Bathythermographs) that determine the temperature changes within the water column because sound speed increases as water temperature increases. They also use sensors on the ship to measure the conductivity and therefore determine the salinity of the water. Since sound waves penetrate saltier water more easily, the salinity affects the sound intensity measurements. Pressure must also be calculated into the equation because sound speed also increases with increasing pressure.
The vessel’s attitude also has to be factored into the sonar (like teachers need to factor in student attitudes when planning a lesson!) Similar to an airplane, a boat can pivot on its center of gravity in all three-dimensional axes: Pitch, Yaw, and Roll. Think about your own head. Pitch is like nodding your head in agreement, yaw is like shaking your head to say no, and roll would be like putting your ear to your shoulder. Gives new meaning to the phrase “Heads are going to roll,” doesn’t it? Boats also heave, or move up and down as swells pass beneath them.
The screen shot above shows the data as it is being collected by the mappers. In the main window in the upper right is the bathymetry data. Below that is the water column backscatter. In the bottom left is the attitude of the vessel on all axes. The center left gray image shows the bottom backscatter while the number 421 above is the current depth beneath the vessel. Finally, the display on the top left indicates the quality and intensity of each of the 432 beams.
We also have a team of researchers from the University of Puerto Rico that are deploying free vehicles to study water masses within the Puerto Rico Trench. More about them in the next blog!
Safety First! On Monday, we had our first drills as part of our safety training. We practiced the “Abandon Ship” and “Fire” drills. We tested the fire hoses and donned our gumby suits. Mrs. Paulsen is looking pretty good, eh? It is comforting to know I’ll be well-protected by good equipment and a great crew in the event of an emergency.
After mapping all morning, we learned we had to return to port due to a medical issue. I discovered that engineers are vital to the operation. Without them, we don’t sail – and they are hard to come by. All of my students interested in marine engine repair should consider NOAA in the future. The pay is good and the adventure is awesome!
I took the time in port to work in the galley helping to make lunch with the chefs. They are a friendly bunch. We made fajitas of all kinds and swordfish. Delicious! I also learned how to garnish a buffet line and even washed dishes afterward. In my high school and college days I worked in many restaurants, but they never let me work in the back. They said I was too much of a “people person” and so I was always waiting on customers. Today I got to cook on one of those large grills I see on cooking shows. Fun to cook on, but not fun to clean. The Chief Steward, Dave Fare, said he brought 5000 lbs of food on board for our trip! We’ll be eating well! Good thing there is a fitness room on board too!
Personal Log
After training on Sunday I had some time to take in a little of the history and culture of San Juan, Puerto Rico. It is a lovely place filled with beautifully colored buildings and fun music. The history is fascinating. According the National Park Service, this is where Chrisotopher Columbus landed on his 2nd voyage and laid claim to the land for Spain. Under Juan Ponce de Leon, Spain took control of the island, displacing the Taíno Indians in 1508. An enormous wall of defense was built to keep hold of the island. Trade winds and ocean currents allowed ships to easily sail here from the east. The fortifications on the island took 10 generations to build.
Spain kept control of the island against invaders until the Spanish-American war in 1898 when Puerto Rico became a US Territory. The fortress including the Castillo de Felipe del Morro and the Castillo San Cristobal are now historical sites managed by the National Park Service. You can learn more here.
After touring the city, I found my way to the sea! I watched children running from the waves. This reminded me of my childhood. My father used to take us to the coast when we lived in California and Oregon. That is where my love of the sea began. Both of my parents have adventurous spirits and strong work ethics. They taught me that anything is possible if you are willing to take the chance and put in the effort. This is a belief I hope I pass on to my students.
Question of the Day
Can you identify this crustacean I found along a beach in San Juan?
