John Bilotta, Totally Awesome Turtle, An Ocean of Stars, and Fancy Fish – Days 7-9 in the South Atlantic MPAs, June 25, 2014

NOAA Teacher at Sea

John Bilotta

Aboard NOAA Ship Nancy Foster

June 17 – 27, 2014

 

Mission: South Atlantic Marine Protected Area Survey

Geographical area of cruise: South Atlantic

Date: June 25, 2014

 

Weather: Partly cloudy to sunshine.  27 degree Celsius.  8.0 knot wind from the southwest.

Locations:  North Cape Lookout 3 Proposed MPA, South Cape Lookout Proposed MPA (both off the coast of North Carolina) and the Edisto MPA (off the coast of South Carolina.)

LAT 32°24’N, 79°6’W  LON 32°24’N, 79°6’W

 

Hint:  See the pictures LARGER.

If you click on any of the pictures in any of my blogs, they should open up full screen so you can see the detail better.

 

Science and Technology Log  with more than 20 ROV dives completed, here are five new items to share

Science Part I.  Totally Awesome Turtle!

On Tuesday, June 24th during our first of four dives of the day a Loggerhead sea turtle came for a visit in front of the ROV.  Loggerheads are common for the MidAtlantic and other oceans in the mid-latitude regions. Loggerheads grow up to 250lbs and are named for their relatively large heads.

Loggerhead sea turtle. Photo credit to NOAA / UNCW ROV June 2014.
Loggerhead sea turtle. Photo credit to NOAA / UNCW ROV June 2014.

This was a dream come true for me.  I have always had this fascination with turtles stemming from catching them on Keller Lake in my early childhood to the snappers that have been visiting and nesting in our gardens the past few years at Goose Lake.  Every turtle is entitled to a name, this one I am calling “TJ.” (Hi Taylor!)   I hope we will see more.

Science Part II.  Discoveries of Dives in the Deep – the fish

Scamp Grouper

Scamp Grouper & Cubbya Dive067054 12 04 27
Scamp Grouper & Cubbyu. This grouper is probably 16-22 inches. Photo credit to NOAA / UNCW ROV. June 2014
Scamp Grouper. Photo by NOAA / UNCW ROV June 2014.
Scamp Grouper. Photo by NOAA / UNCW ROV June 2014.

Speckled Hind

Speckled Hind.  Photo by NOAA / UNCW ROV. June 2014.
Speckled Hind. Photo by NOAA / UNCW ROV. June 2014

Cornetfish

Cornetfish.  Photo by NOAA / UNCW ROV June 2014.
Cornetfish. Can grow to be 2-4 feet in length, 6 feet maximum. Although not possible to fully detect, when we photographed these it appears two males were courting a female. They almost danced together in the water. Photo by NOAA / UNCW ROV June 2014.

Science Part III.  An Ocean of Stars – Echinoderms and other Invertebrates

A brief bit of science, then you can see the pictures.  Echinoderms have three main characteristics:

1.  A body plan with 5-part radial symmetry
2.  A calcite skeleton
3.  A water-vascular system

Here are a few we have found on the ocean floor the past few days with the ROV.  By the way, it’s also a sky of stars at night from the ‘iron beach’ on the top deck aft of the bridge of the Nancy Foster.

Asterporpa Star wrapped around the backside of a diodiordia photographed during ROV dive.  Photo credit to NOAA / UNCW. June 2014.
Asteroporpa Star wrapped around the backside of a diodogorgia photographed during ROV dive. Look hard past the purple and you can see it. Photo credit to NOAA / UNCW. June 2014.
Seastar photographed during ROV dive.  Photo by NOAA / UNCW June 2014
Sea star photographed during ROV dive. Photo by NOAA / UNCW June 2014
Brittlestars photographed  during ROV dive.  Photo by NOAA / UNCW.  June 2014
Brittlestars photographed during ROV dive. I magnified this photo so you could see two close up, but in one of the photos we took with the ROV there were more than five visible. Photo by NOAA / UNCW. June 2014
Longspine Erchin.  Photo by NOAA / UNCW ROV. June 2014.
Longspine Urchin. Photo by NOAA / UNCW ROV. June 2014.

One of the mollusks we found. 

Thorny Oysters.  There are three in this picture.  Photo by NOAA / UNCW ROV 2014.
Thorny Oysters. There are three in this picture; the middle one is slightly open. Photo by NOAA / UNCW ROV 2014.

Science Part IV.  Iceberg Scours dead ahead!

Many of the ridges and valleys Stacey Harter our chief scientist choose for us to investigate with the ROV are actually scours along the Atlantic Ocean seafloor created by icebergs that moved in a southwesternly direction towards the Carolina’s. Yes, I said icebergs!  These scours I learned were probably created during the last deglaciation period, (~29,000-15,000 BP (before people)). I found this great blog post that summarizes some research on these and has a good graphic too.   The scours are revealed through the multibeam mapping (MB) that the science mapping team conducts overnight. The image below is a MB map that shows the ridges and valleys (iceberg scours) and the red dots that form the line our ROV took exploring it on Sunday.

Multibeam (MB) Map showing iceberg scours and ROV dive track.  Image courtesy of NOAA and Harbor Creek.  June 2014.

Multibeam (MB) Map showing iceberg scours. The red dotted line near the middle of the image is our ROV track from the dive, going east to west. Image courtesy of NOAA and Harbor Branch Oceanographic Institute . June 2014.

The earth science education I teach with the Earth Balloon and Earth Walk programs cover processes that shape and form the planet and I can’t wait to incorporate iceberg scours and the habitat they now provide into these programs!

A call out to Jennifer Petro and her class at Everitt Middle School in Panama City, Florida. Jennifer participated as a TAS in 2013 on this same research project. Her class sent a collection of decorated styrofoam cups with Andy David from the Panama City NOAA lab for us to bring to the bottom during one of our dives.  This is what happens when Styrofoam is subject to increasing pressure.

Styrofoam cups predive

Styrofoam cups postdive

Science Part V.  I think we placed it here…I think it is here…It is here!

Earlier this spring, the South Carolina Department of Natural Resources in cooperation with the Army Corp of Engineers sank two barges to create artificial reef systems and habitat for groupers, tilefish, and countless other species.

Artificial reef barge sank spring 2014 by the South Carolina Department of Natural Resources with cooperation from the Corp of Engineers.
Artificial reef barge sank spring 2014 by the South Carolina Department of Natural Resources with cooperation from the Corps of Engineers. Its difficult to say for sure, but to give you a sense of scale, typical shipping containers like the green on one on top are are 40-50 feet in length.

During the overnight hours of June 24th & 25th the mapping science team (see below) set out to find these two barges somewhere within a 2 square mile box using the MB aboard the Nancy Foster; that’s a lot of ocean to cover!    I stayed up late with them and at about 10:00pm images began to emerge that resembled the barges.  By 10:30pm, the mapping team had combed through the data and generated 3D maps that were strong evidence they had found them.

MB barge1
3D multibeam image of one of the sunken barges near the Edisto MPA. The barge is the rectangle, however there appears to be a mass of objects off one of its corners – keep reading.

However, a hypothesis emerged; one of the barges may have flipped upside-down during its initial sinking and that some of the cargo containers had actually fallen off and came to rest on the ocean floor separate from the barge.  During this discussion with the mapping team, I had this huge smile and was in awe with what they could do with sound waves!

So on Wednesday afternoon, June 25th the ROV team went to work to explore the sunken barges.  I watched as Lance Horn slowly guided the ROV down below 100 meters.  Eventually we could make out the barge.  Lance had to use his many years of ROV piloting to carefully maneuver.   We could not let the umbilical fiber optic and power cord get caught on any of the metal debris and towers that projected outward.  What did we discover?  Unfortunately I am unable to show you the pictures.  At 90 meters in depth it was so dark, the digital camera could not capture quality images – even with two LED lights.  However, the HD video gave us clear visual and conclusions.  The barge settled upright on the sea floor (it wasn’t upside down).  However, we speculate that it came down with such force that the shipping containers and structures collapsed and broke away.  Indeed four of them are lying on the ocean floor off the northwest corner of the barge. It’s only been a few months so habitat and few fish have yet to call it home, but schools of Amberjack were all around.

 

Career highlight: 

Kayla Johnson and Freidrich Knuth are our mapping scientists we brought on board as part of the science team and Samantha Martin and Nick Mitchell are fulltime NOAA mapping scientists assigned to the Nancy Foster.  All four of them have very interesting stories about how they use their education and expertise to be eyes through the water column deep into the ocean.  Freidrich and Kayla accompanied the science team as graduates from the Department of Geology and Environmental Geosciences at Charleston College.

Mapping science crew aboard the Nancy Foster.  From left to right:  Freidrich Knuth, Nick Mitchell,Kayla Johnson.  Not pictured - Samantha Martin.
Mapping science crew aboard the Nancy Foster. From left to right: Freidrich Knuth, Nick Mitchell,Kayla Johnson. Not pictured – Samantha Martin.

It is really inspiring to hear about their experiences in MB mapping in many of the oceans worldwide.  They are experts of combing through data we receive through a number of ship-mounted devices, applying complex GIS software (geographic information systems), and creating 2D & 3D maps that the science team can use to direct the ROV to the next day – which means this team works through the overnight hours and sleeps during the day.

Personal Log:

I have been running on the treadmill which is located in a small fitness center low in the ship.  It’s a very awkward feeling when there are large waves and the treadmill and I are going up and down and swaying side to side.  The way I look at it I am running on water so it has to be easier on my knees.

I have lost track of the number of birthdays we have celebrated while offshore.  From somewhere, seemingly daily, birthday cards and cakes emerge.

And for another quote from The Big Thirst by Charles Fishman that I am reading while aboard the Nancy Foster.

“Water is a pleasure.  It is fun.  Our sense of water, our connection to water, is primal.  Anyone who has ever given a bath to a nine-month-old baby – and received a soaking in return – knows that the sheer exuberance of creating splashing cascades of water is born with us.  We don’t have to be taught to enjoy water.”  (p760)

We are sailing for the Florida MPA overnight tonight (10-12 hours) and will be ready to launch the ROV again tomorrow.

Glossary to Enhance Your Mind

Each of my logs is going to have a list of new vocabulary to enhance your knowledge.  I am not going to post the definitions; that might be a future student assignment.  In the meantime, some might have links to further information. 

NOAA’s Coral Reef Watch has a great site of definitions at

http://coralreefwatch.noaa.gov/satellite/education/workshop/docs/workbook_definitions.pdf

  • Ehinoderms
  • Radial symmetry
  • A ‘clip’
  • Latitude/Longitude
  • Heading
  • Hypothesis
  • GIS
  • TED – turtle exclusion device (Andy and I had a conversation about other work NOAA is doing in the Gulf related to turtles, TEDs and their work on trawlers.   Perhaps another NOAA at sea adventure for me in the future.)

Deborah Campbell: May 18, 2012

NOAA Teacher at Sea
Deborah Campbell
Onboard NOAA Ship Nancy Foster
May 14 – May 24, 2012

Mission:  Collecting Zebra Arc Shells and Multibeam Mapping
Geographical Area:  Gray’s Reef National Marine Sanctuary
Date: Friday May 18th, 2012

Weather Data from the Bridge:  Skies are overcast.  Temperature 75 degrees

Science and Technology Log

Teacher At Sea Deborah Campbell aboard NOAA Ship Nancy Foster

Today I want to talk about two research projects that are going on aboard NOAA Ship Nancy Foster. The first project is the Arca zebra collection.

Zebra Arc Shell collected by scientist J.D. on a dive mission.

Scientist, J.D. has completed eleven dives to collect ten samples of the Arca zebra, which are also known as “turkey wing” shells.  By collecting the arc shells, scientists can examine the soft tissue inside the shell to determine the ecological conditions at Gray’s Reef.  Human activities such as using pesticides can make their way to the reef.  If you have read “The Lorax”, by Dr. Suess, you know that human activities could cause habitat destruction.  By monitoring Gray’s Reef, scientists can assess how healthy the reef is.  Two thirds of the Gray’s Reef National Marine Sanctuary are used by recreational boaters, however no anchors can be used.  Anchors could damage habitats on the reef.  One third of the reef is used solely for scientific research.

Scientist J.D., Zebra Arc Shell Mission

The second research project is Multibeam Mapping of the ocean floor using the N.O.A.A. ship NANCY FOSTER multibeam sonar system.  Three people on board the ship monitor the computers for the mapping in the dry lab.  The dry lab and wet lab are next to each other.  No food or drinks are allowed in dry lab, because of the equipment.  Samantha Martin is the Senior Survey Technician and is in charge.  Kacey Johnson just graduated from the College of Charleston with a Bachelor’s degree in Geology.  Walter Potts is a Survey Technician.  All three rotate in shifts to monitor the mapping.

Samantha Martin (left) and Kacey Johnson

During the Multibeam Mapping, the  NANCY FOSTER is moving.  The multibeam sonar system is sending out “pings” into the water.  The pings travel through the water until they reach a surface that reflects sound, such as the sea floor.  Then the sound travels back to the receiver.  The receiver can calculate the depth measurement for each “ping”.

The Multibeam Mapping can be compare to dolphins “echolocation”.  Dolphins send out sound wave that sound like a click, which hits an object and then bounces back.  Dolphins’ sound waves gauge the distance of the object, and also the shape.

Dolphin swimming alongside the Foster.

Personal Log

Friday’s dives were suspended early due to rough ocean conditions.  The crew told us stories about times the sea got rough.  There are railings on beds.  There is also an extra board you can slide on the side of your mattress to insure that you stay in the bed.  One crew member told me that they went airborne.  It has been raining on and off.  We may not be able to go on small boats on Saturday, unless seas calm down.

Quote: “Unless someone like you cares a whole lot, nothing is going to get better, it’s not”.  (The Lorax, by Dr. Suess)

Ocean Riddles:What do fish and maps have in common? They have scales…

Why are fish so smart? Because like Locke School students, they are in a school…

What has a beginning, middle, or end and touches every continent? The Ocean

What do you get when you graduate from scuba diving school? A Deep-loma

Deborah Campbell: Teacher at Sea

NOAA Teacher at Sea
Deborah Campbell
Aboard NOAA Ship Nancy Foster
May 14 – 24, 2012

Pre Cruise News !!

Deborah Campbell has been selected by the National Oceanic and Atmospheric Administration (NOAA) to participate in their Teacher at Sea  program.  Mrs. Campbell is a seventh grade science teacher at Locke Elementary School in Chicago.  NOAA has ships stationed all over the world.  On board the ships are crew members and scientists who monitor our oceans.  Every year, NOAA selects about twenty-five educators from all over the United States to travel aboard the NOAA ships to experience the work of the scientists first hand.  Mrs. Campbell will be sharing her experiences with the Locke School community, colleagues, family, and friends.

Mrs. Campbell is very excited to work with the crew and scientists aboard the NOAA ship Nancy Foster.  She will travel from Chicago to Charleston, South Carolina on May 13th, 2012.  The ship will return to Savannah, Georgia on May 24th, 2012.  When the ship leaves Charleston, it will head towards Gray’s Reef National Marine Sanctuary.  The chief scientist, Sarah Fangman, has planned some amazing scientific investigations.  Mrs. Campbell will be observing as well as assisting the scientists as they do their work.

There are several projects planned for this cruise.  Multibeam mapping of Gray’s Reef at night and some day time hours will occur.  Divers will collect zebra clusters which will be wrapped in foil, placed in ziplock bags, and analyzed later for chemical contaminants.  The clusters can help scientists monitor ecological conditions at Gray’s Reef.  Divers will survey marine debris (garbage).  A fine scale fish movement study will occur.   Acoustic tagging will be used to study fish movement, how fish use reef, the habitats they prefer, and if there is change over time.  Divers will be checking acoustic receivers within Gray’s Reef.  There will also be continuous photo and video documentation.  Mrs. Campbell will be keeping a journal, taking photos, and assisting the scientists aboard the Foster.

Follow Mrs. Campbell’s adventures aboard Nancy Foster in future blogs……

Karen Rasmussen, July 7, 2011

NOAA Teacher at Sea: Karen Rasmussen
Ship: R/V Tatoosh
Geographical area of the cruise: Olympic Coast National Marine Sanctuary
Date: July 7, 2011
Cruise to: Olympic Coast National Marine Sanctuary
Crew: Rick Fletcher, Nancy Wright, Michael Barbero, and Karen Rasmussen
Time: Start 6:30a.m.

Mission

Lowering the CTD
Lowering the CTD

The first part of mission is to conduct Multibeam mapping and to collect ground-truthings at the LaPush/Teahwhit areas of the Olympic Coast National Marine Sanctuary. We will also service the OCNM buoy, Cape Alava 42 (CA42). The second week of this mission is to explore the Teahwhit Head moorings, ChaBa and sunken ships, and North and South moorings.

Weather Data from the Bridge

Winds Lt. Confused seas
W. swell 5 to 7’ Waves 2’
Risk factor 18

Science and Technology Log

We were up at 5:00 a.m. and on the road to La Push, WA. Before leaving the dock, Michael and I measured out 100 meters of rope that will be tied to the CTD. We recorded as follows:

Number of/Color of tape Meters
1 Red 5
1 Yellow 10
2 Black 20
3 Black 30
4 Black 40
1 Green 50
1 Green/1 Yellow 60
1 Green/2 Yellow 70
1 Green/3 Yellow 80
1 Green/4 Yellow 90
2 Red/1 Blue 100

The tank of the boat was filled and all equipment was working. We completed a sound velocity test using a Seacat CTD which measures conductivity, temperature, and depth, as well as density. This device is deployed off the back of the vessel and receives information about ocean chemistry by taking multiple readings throughout the water column. Sound velocity data are used to measure the speed of sound in water, one of many factors used to correct multibeam data.

Doing Multibeam work on the Tatoosh
Doing Multibeam work on the Tatoosh
Doing Multibeam work on the Tatoosh
Doing Multibeam work on the Tatoosh

We found out that there are over 185 sunken vessels in the Marine Sanctuary. There are also 13 NOAA moorings within the Sanctuary. Multibeam surveys of two mooring sites off of La Push were successfully completed this morning. We also began another survey of the sunken ship, Milky Way. However high seas and high winds forced us to return to the harbor before the survey was complete.

I saw only two sea lions and one sea otter today. There were many sea birds including pelicans and puffins.

Personal Log

We had pretty rough seas today. We had to come in to port early today because of small craft advisory, so we docked at 2:30. We went back to ONRC (Olympic National Resource Center) in Forks this afternoon. Rick and Nancy are going over data. We plan on going out tomorrow to Cape Alava to continue with multibeam data collection. I enjoyed driving the Tatoosh today. The swells were amazing.

Karen Rasmussen, June 28, 2011

NOAA Teacher at Sea: Karen Rasmussen
Ship: R/V Tattoosh
Geographical area of the cruise: Olympic Coast NMS
Date: June 28, 2011
Cruise to: La Push
Crew: Rick Fletcher, Nathan Witherly, Karen Rasmussen
Time: Start 9:25 – End 16:00

Mission
The first part of mission is to conduct Multibeam mapping and to collect ground-truthings at the LaPush/Teahwhit areas of the Olympic Coast National Marine Sanctuary. We will also service the OCNM buoy, Cape Alava 42 (CA42). The second week of this mission is to explore the Teahwhit Head moorings, ChaBa and sunken ships, and North and South moorings.

Weather Data

Wind 5 to 10 Knots
SW Swell 4 to 7’
Science and Technology Log

Seal Rocks
Seal Rocks

We began this morning at 8:00. We loaded the boat and filled the tanks with diesel. Rick completed the safety brief (Risk Factor 21 today). Then we went over roles and responsibilities, PFD’s (personal floatation devices), Immersion Suits (location of, and completed drill- all crew completed), Emergency Situations of fire, abandon ship, MOB (Maintain Lookout, Notify Skipper), and communication systems. We left Port Angeles at 9:25 with Rick and Nathan. Nancy is driving all of our supplies to Forks. We will be spending the next three nights in Forks, WA at the Olympic Suites.

Seal Rocks

The water was choppy today with swells of about 7 feet, which makes it difficult to write in a journal. Our first stop was off of Seal Rocks. We observed sea lions and many different seabirds. An airplane was flying low over and around the islands, which was a concern because there are distance parameters that are enforced for the sea life on and around coast islands. We also noted a small boat. I tried to take a picture of the plane for further reference. The plane and small boat turned out to be State/Federal wildlife resource people doing a mammal count on the islands.

Rick servicing the Cape Alava 42 buoy.
Rick servicing the Cape Alava 42 buoy.

Our next stop was at the Cape Alava 42 buoy. The “42” indicates meters in depth. Nathan piloted the boat and Rick put on protective raingear and boots. His job consisted of standing on the swim deck while Nathan maneuvered the boat as close as he could to the buoy. When we were in the correct position, Rick pulled the buoy up while I controlled the winch. He replaced the current meter which measures how fast the current is going in that area. The buoys in the Sanctuary are serviced about once every six weeks.

From Cape Alava we continued to travel south down the coastline to LaPush. We cleaned up, hosed the Tatoosh off, and packed up stuff. Nancy met us in La Push. We loaded up the car and headed to Forks for the night. Nancy and Rick continued the work from one of the hotel rooms on how to get the technology of this mission up and running correctly.

Personal Log

I had a great time today. I have to admit I was a little worried about traveling from Port Angeles to La Push in such a small vessel. We bounced a lot, but the weather was wonderful. I was very impressed with Nathan Withery’s ability to manipulate the Tatoosh in such swells. I also observed how Rick and Nathan can walk the deck with such ease. We talked a little about how much energy is used to be onboard a small vessel all day. We all are famished!
Rick servicing the Cape Alava 42 buoy.

Karen Rasmussen, June, 27, 2011

NOAA Teacher at Sea: Karen Rasmussen
Ship: R/V Tattoosh
Geographical area of the cruise: Olympic Coast NMS
Date: June 27, 2011
Cruise to: Port Angeles Harbor
Crew: Nathan Witherly, Karen Rasmussen
Time: Start 10:30 – End 12:2

Mission
The first part of mission is to conduct Multibeam mapping and to collect ground-truthings at the LaPush/Teahwhit areas of the Olympic Coast National Marine Sanctuary. We will also service  the OCNM buoy, Cape Alava 42 (CA42). The second week of this mission is to explore the  Teahwhit Head moorings, ChaBa and sunken ships, and North and South moorings.

Weather Data
Calm seas/wind

Science and Technology Log

The Tatoosh at dock
The Tatoosh at dock

We began this morning at 8:00 a.m. Tatoosh had been dry  docked at the Port of Port Angeles to have the multibeam  fixed. This mission was to  have started last week but had  to be postponed because of a small leak in the multibeam. This morning the Tatoosh was  lowered into the water to take the measurements in order to  check the accuracy of the multibeam. Nathan drove the boat to Hollywood Beach (Port Angeles, WA) so we could help take readings. Rick and Nancy stayed onshore and used a surveyor’s tripod with an optical level. I held the surveyor’s rod and we completed a dynamic draft measurement of the Tatoosh. Rick took 3 readings from each position the Tatoosh was in over approximately two hours. Later Nancy and I entered their data into the Hypack software program. I read the data as she typed it in. We finished and found that our computer software programs are not interfacing with each other.

Here we are on the Tatoosh trying to work with the computer programs that will collect the data we need.
Here we are on the Tatoosh trying to work with the computer programs that will collect the data we need.

The HYPAK Program Inc. is Windows-based software created for the hydrographic
and dredging industries. It includes ways to complete surveys, collect data, process it, and generate final products.  It can be used on small or large vessels and is also used to collect environmental data.

HYSWEEP is a module of HYPACK and is used with multibeam and side scan sonar.  It gives on-the-spot information  about the ocean’s bottom  condition and data quality from  your multibeam devise.

HYSWEEP measures:

  • Depth – Nadir beam depth in survey units (ten units to one foot)
  • Time (Event)
  • Tide  Corrections
  • Draft Correction
  • Heave (in survey units, positive upward)
  • Roll – port side
  • Pitch – bow up
  • Heading
  • Easting/Northing (Like XY coordination, X= Easting, Y=Northing)

Personal Log
My learning curve is tremendous today and I am extremely tired. Last night I stayed at the Red Lion in Port Angeles. I was up until almost 4 a.m. Apparently, they are having teenager issues. Lots of horn blowing, yelling, and fighting all night long. I am hoping that tonight will be better.

I really enjoyed being part of the team today. Nancy, Rick, and Nathan have been wonderful with answering all of my questions.  Some of the questions I’ve been asking must seem so obvious to them, but my knowledge of underwater geography is so limited. Every aspect of this day has been interesting. I am truly amazed at what these people are doing with the limited and older materials they are using.

Beth Carter, July 10, 2007

NOAA Teacher at Sea
Beth Carter
Onboard NOAA Ship Rainier
June 25 – July 7, 2007

Mission: Hydrographic Survey
Geographical Area: Gulf of Esquibel, Alaska
Date: July 10, 2007

Weather Data from the Bridge
Visibility:  2 nautical miles
Wind direction:  125 degrees
Wind speed:  11 knots
Sea wave height: 0-1 feet
Swell wave height: none
Seawater temperature:  11.7 degrees C
Dry bulb temp: 12.8 degrees C; Wet bulb temp:  12.2 degrees C
Sea level pressure:  1021.0 mb
Cloud cover: 8/8, fog and drizzle

The NOAA ship RAINIER, also known as S221, at anchor in Alaska.
The NOAA ship RAINIER, also known as S221, at anchor.

Science and Technology Log

Yesterday, I went out on launch #6, which utilizes a sonar system called the “C3D,” that produces interferometric sonar, which is a combination of side scan and multibeam sonar, to produce bathymetry.  Interferometric sonar is the latest technological advance in hydrographic mapping. This is the third technology I’ve been able to observe at work. The RAINIER has two launches that use single beam technology ( June 29 log), three launches that use multibeam technology (June 28 log), and Launch 6 has the side scan sonar.  There are advantages and disadvantages to each. Erin Campbell, my Tarheel buddy who is a physical scientist from the Pacific Hydrographic Branch of NOAA, took the time to explain some of the features and limitations of side scan sonar. The greatest advantage to side scan is that it produces sound waves that can cover a much wider swath of ocean floor, with very good resolution. This means that NOAA can be more fuel-efficient with its launches and cover more floor in less time.  Side scan can form accurate 3-D images of rocks, wrecks, and features of concern and interest on the ocean floor.  Hydrographers say that the side beam enables them to “paint the ocean floor.”

Erin Campbell, physical scientist, and Beth Carter, Teacher at Sea…two Tarheels at a rainy beach party near Bushtop Island, Alaska.
Erin Campbell, physical scientist, and Beth Carter, Teacher at Sea…two Tarheels at a rainy beach party near Bushtop Island, Alaska.

The greatest disadvantage to side scan sonar is that it does not actually provide depths associated with those features.  In other words, the hydrographers can look at the side scan images and locate a downed plane accurately on the ocean floor, but not know the exact depth of the plane. Another disadvantage to use of side scan in Alaska is that the extreme angles of slope of the islands and landforms cause the sound waves to create shadows on the resulting data. This means that some features in the shadows are missed.  Side beam sonar is used with great success on the eastern coast of the U.S., where the sea floor is sandy, is more uniform, and has less slope than in Alaska. Therefore, NOAA uses side scan to cover wide areas of territory, and then examines the images collected.  If the technicians see rocks or other potential hindrances to navigation, they send out the multibeam sonar launches to collect more detailed information on the depths.  If the concern is in a really shallow area, they might send out the single beam launches, which can get into shoal areas more easily with less threat of damage to the sonar equipment.

The C3D sonar transducer on the hull of the launch
The C3D sonar transducer on the hull of the launch

Side scan sonar is still evolving as a technology. NOAA provides valuable feedback and information to the makers of this technology, which enables the manufacturers to fine-tune and improve the technology. As I prepare to leave the RAINIER, I am impressed with the depth of knowledge of the Commanding Officer, the survey crew, and officers on the ship. They take very seriously their work, which is to take information gathered utilizing sonar, and to produce the most accurate bathymetric products possible.  The resulting charts and hydrographic maps are critical aids to shipping companies and fishermen, whose lives and safety and economic livelihood depend on the accuracy of the maps. I’ve also learned that NOAA hydrographers are called in to assist after hurricanes.  Erin, for example, was called upon to join a NRT (Navigational Response Team) after Hurricane Katrina.  There were many container ships and other ships waiting in the Gulf of Mexico for the hydrographers to survey the waters in order to locate hazards (debris in the water, wrecks, storm damage) in the water that were blocking the port and docks. NOAA has six such teams that assist when there are oil spills, wrecks, storms, etc.

Erin Campbell operating the C3D sonar aboard the launch.
Erin Campbell operating the C3D sonar aboard the launch.

Terms Used

Bathymetry:  the science of measuring ocean depths.  It is the underwater equivalent to altimetry, or measuring altitude of land forms.  Bathymetry is utilized to create DTM’s, or digital terrain models, or three-dimensional models of the ocean floor.

Hydrography: the study and science of ocean mapping.

Questions of the Day: 

  1. What kind of sonar would be best utilized in the search for a tugboat that sank unwitnessed, suspected to be in a deep harbor – vertical beam, multibeam, or sidescan sonar?
  2. To see an example of a chart created with interferometric sonar, take a look at this website.

Personal Log

I want to close out my last log with a few pictures, which definitely communicate the Alaska experience better than my words.  I also want to thank the entire crew of the RAINIER for its kind hospitality, for teaching me so much, and for reminding me what it feels like to not understand something.  I can empathize with my students so much better, as I have been in their shoes now for almost 3 weeks…struggling to understand technologies that were totally unfamiliar to me, feeling frustrated, feeling glimmers of hope when a few concepts dropped into place in my brain. Alaska is incredibly beautiful, incomprehensibly vast…I hope to return someday.

A humpback whale breaching… breathtaking sight!
A humpback whale breaching… breathtaking sight!
A bald eagle on the fly above Alaskan waters.
A bald eagle on the fly above Alaskan waters.
Alaska…known for its snow-topped majestic mountains.
Alaska…known for its snow-topped majestic mountains.  

Beth Carter, July 9, 2007

NOAA Teacher at Sea
Beth Carter
Onboard NOAA Ship Rainier
June 25 – July 7, 2007

Mission: Hydrographic Survey
Geographical Area: Gulf of Esquibel, Alaska
Date: July 9, 2007

Weather Data from Bridge 
Visibility:  6 miles
Wind direction:  135 degrees
Wind speed:  9 knots
Sea wave height: 0-1 feet
Swell wave height: none
Seawater Temperature:  12.2 degrees C
Dry Bulb: 11.1 degrees C  Wet Bulb:  11.1 degrees C
Sea level pressure:  1022.1 mb
Cloud cover: 8/8, fog & drizzle
Depth: 22.6 fathoms

This is a view of strands of kelp as seen from the launch.  Kelp appears as brown masses in thick beds.
This is a view of strands of kelp as seen from the launch. Kelp appears as brown masses in thick beds.

Science and Technology Log: 

Bull kelp…just amazing stuff.  Today I want to focus upon bull kelp and its role in the Alaskan coastal ecosystem, and its impact on hydrographers and fishermen. First of all…it is a fast-growing type of brown algae that can grow in strands from 40-65 feet long. It grows close into shore and anchors itself to rock surfaces by a root-like growth called a holdfast.  The scientific name is nereocystis leutkeana. Bull kelp has leaves called blades that grow outward from the main stem, but its most distinguishing feature is its long (2-3 feet) “bullwhip” stalks that have air bladders on their ends that can be 4” in diameter…rather like a stiff rope with a hollow onion on the end. Bull kelp can live for eight years, and reproduces via spores. Rocky substrates just off the coasts and islands of Alaska provide perfect places for the kelps’ holdfasts, and large kelp beds form in and around the islands of southeastern Alaska where the RAINIER is sailing.

In a closer view, bull kelp has some very stiff “bullwhip” like strands with air bladders on its ends.  The air bladders are hollow, and look like onions or bulbs.
Bull kelp has some very stiff “bullwhip” strands with hollow air bladders on the end that look like onions or bulbs.

Bull kelp provides food and protective cover for all types of fish, invertebrates, birds and marine mammals.  Kelp beds are literally teeming with life.  Kelp waves and moves with the currents and tides. Sea otters are the most visible of the animals who depend on kelp.  They feed off the sea urchins and other invertebrates that live at the bases of the kelp. Sea urchins feed upon the holdfasts that anchor the kelp, so the sea otters keep the urchins in check in a healthy kelp bed. The otters can be seen bobbing in the kelp, lying on their backs enjoying snacks of sea urchins, clams, etc. Commander Guy Noll of the RAINIER says that kelp is a natural navigational aid in Alaska and Pacific coastal waters. If you are in a boat of any kind and you see kelp strands on the surface of the water, stay clear. Hydrographers are not particularly fond of kelp.  On the one hand, the presence of kelp indicates a rocky bottom, which is one of the features that chartmakers want to indicate on their maps.  But.RAINIER’s launches try to stay out of kelp beds, as the kelp can become caught on the sonar transducers, which are suspended from the hulls of the boats. Kelp can also be a “heads up” that there may be a hidden rocky feature that is a danger to navigation.  The launches are very careful around kelp.

The sound waves that hydrographers use for charting can also be distorted by kelp, as it is very dense in its coverage. Also, the whips and floating blade “bladders are hollow, so the echoes do not reach the underlying rocky ground. NOAA sometimes has to send divers down to get a least depth in kelpy areas, and diving in kelp is difficult because of entanglement issues. Fishermen give kelp beds a wide berth to avoid fouling their nets and equipment in the heavy, leafy, stalky bull kelp. However, they will sometimes try to trawl near kelp beds, as the kelp provides excellent cover for salmon and other fish as they hide from orcas and other predators.

Small leaves, or blades of bull kelp washed into shore add decorations to the black pebble beaches.
Small leaves, or blades of bull kelp washed into shore add decorations to the black pebble beaches.

Personal Log 

I became fascinated by kelp last week as I kayaked through some island passages that were thick with kelp. As you look into the water, you see dozens, hundreds of small snails on the blades of the kelp…I think they were black turban snails.  I tasted some of the kelp and found it, predictably…salty!  It was also chewy and gummy and difficult to swallow. Perhaps there are wonderful ways to prepare kelp to eat, but out of the water as a snack – not for me. From the launches, it is fun to see the sea otters’ heads pop up in and near the kelp beds. They manage to get their heads and shoulders out of the water…they must be standing on the kelp to get such a clear look at us! Several of the moms we saw had babies hitching rides on their bellies, or perhaps nursing. They are unbelievably cute and quick, and I am too slow to get good photographs of them.

Correction! 

Early in the trip, I wrote about the GPS, Global Positioning Satellites, and stated that there are 11 in geosynchronous orbits above the earth.  I looked up GPS on the NOAA website and found that there are 24 satellites, so I stand corrected!

Questions of the Day

1. What do you think would be the environmental impact of an oil spill on or near the rocky coasts of Alaska?  

2. What effects would it have on kelp beds? If you want a real life example of what could and has happened, “Google” the story of the Exxon Valdez, which created a huge oil spill in Prince William Sound, Alaska in 1989.

* Note: Commander Guy Noll explained that the RAINIER was one of the responding vessels after the Valdez oil spill. RAINIER did the hydrographic work needed by the Navy ships that did the cleanup. At that time, the world’s focus turned upon Prince William Sound, and as the RAINIER did the surveying, they discovered many chart errors. They spent a great deal of time surveying the area, and provided more accurate charts for the cruise ships and tourists that became interested in the beautiful area in and around Prince William Sound.

This sea otter mom and baby are floating near a kelp bed. This photograph is courtesy of Ensign Tim Smith, an excellent officer and photographer on the RAINIER.
Sea otter mom and baby are floating near a kelp bed. Photograph courtesy of Ensign Tim Smith.

Beth Carter, July 4, 2007

NOAA Teacher at Sea
Beth Carter
Onboard NOAA Ship Rainier
June 25 – July 7, 2007

Mission: Hydrographic Survey
Geographical Area: Gulf of Esquibel, Alaska
Date: July 4, 2007

Weather from the Bridge
Visibility:  10 miles
Wind Direction:  080
Wind Speed:  3 knots
Sea wave height: 0-1 feet
Swell wave height: none
Seawater temp: 12.2 degrees C
Dry bulb temp: 12.2 degrees C; Wet bulb temp:  11.1 degrees C
Sea level pressure:  1012.2 mb
Cloud Cover: Partly cloudy, 5/8
Fathoms:  18.3

Survey technicians Shawn Gendron and Matt Boles are retrieving the “grab” from sampling the bottom.
Survey technicians Shawn Gendron and Matt Boles are retrieving the “grab” from sampling the bottom.

Science and Technology Log

On July 2, I went on launch #2 to observe the process of bottom sampling.  I would like to write in simpler language so that perhaps my first graders can read this and understand what we did. Our boat driver today Corey Muzzey, and the two surveyors were Matt Boles and Shawn Gendron. Their job today was to take samples of the sea floor. To do that, they use a special brass “claw” that is weighted down by a lead weight. They drop the claw down on a very long rope, and when it hits the bottom, a spring snaps the claw shut, and it grabs whatever is on the bottom. Then, they pull the rope and claw back up with a special winch and pulley, and look at what they got.

Sometimes, the claw picked up seaweed and mud.  Sometimes, the claw grabbed pebbles, coarse sand, fine sand, or gravel. A few times, it didn’t pick up anything, because the claw landed on solid rock. The boat driver had a special chart that he looked at to find the 19 places where they were supposed to drop the claw. Some of the spots were over 300 feet deep! They were taking these samples for two reasons: 1) The RAINIER is checking for new, safe places for anchoring for boats that use this area.  2) It is important to know what the sea bottom is like because different kinds of animals live on different types of bottom. Note that sound waves bounce off sand and rock and pebbles in very different ways. For example, sound waves that hit mud return to the boat softly. Sound waves that hit rock bounce back with more “force”, and the surveyors can tell the difference!

Matt is holding a mixture of mud and shells that came out of the grab.
Matt is holding a mixture of mud and shells that came out of the grab.

The RAINIER’s small boats, or launches, use the sound waves much as bats use them to locate obstacles when they fly. Dolphins also send out high-pitched sounds to “echolocate” their food or enemies or boats. The RAINIER uses sound waves to create maps of the sea floor. They do this by sending out sound waves, or sonar, from the bottoms of the launches.  Then they watch and record carefully how the sound waves bounce back.  They turn those recordings into maps of the ocean floor.  So, the bottom samples help them to label the maps and charts for fishermen and boaters.  They write labels on the charts like “RKY” for “rocky” areas, and “S” for sand, “SH” for shells, etc.

Personal Log 

Today we had some crazy weather. First it was sunny and calm, then windy, cloudy, rainy, and then calm again.  We saw several whales feeding near us. We also saw a small rocky island that had 30-40 Steller sea lions…the males were huge! They have just had their pups, but we couldn’t get close enough to them to see the pups.  It was a bit rough out today, and so when I tried to shut a door, I banged my shin on a door frame.  I bled so much my whole sock was bloody!  I was glad the boat had a great first aid kit.   

Questions

  1. When I saw the “claw” (look at the picture), I thought of two things…one is a piece of construction equipment, and one is a game that you can usually find at a video arcade or place like “Jungle Rapids” in Wilmington, N.C.  Can you imagine what I am thinking of?
  2. Why does it matter to a fisherman how deep the water is where he is fishing, or what kind of bottom there is below him?
A colony of Steller sea lions lies on jagged rocks in the Arriaga Passage.
A colony of Steller sea lions lies on jagged rocks in the Arriaga Passage.

Beth Carter, July 1, 2007

NOAA Teacher at Sea
Beth Carter
Onboard NOAA Ship Rainier
June 25 – July 7, 2007

Mission: Hydrographic Survey
Geographical Area: Gulf of Esquibel, Alaska
Date: July 1, 2007

Weather Data from Bridge
Visibility:  4 miles
Wind direction:  calm
Wind speed:  calm
Sea wave height: none
Swell water height: none…flat, flat, flat
Seawater temperature:  12.2 degrees C
Sea level pressure:  1016.6 mb
Dry bulb temperature: 12.2 degrees C; Wet bulb temperature:  11.7 degrees C
Cloud cover: Fog, cloudy, 8/8
Depth: 18 fathoms,
New anchorage: near Sonora Island, part of Maurelle Island group

This is a single beam transducer on the hull of launch #1. The small blue oval on the hull is a “fish finder” or depth sounder.
This is a single beam transducer. The small blue oval on the hull is a “fish finder” or depth sounder.

Science and Technology Log

On Friday, I went out on the RA-1 boat with Coxswain Leslie Abramson, Seaman Surveyor Corey Muzzey, and Survey Tech Marta Krynytzky. The #1 boat is a jet boat, which operates like a jet ski…it has a nozzle that shoots water out, and it only draws one foot of water. The RAINIER likes to use the #1 boat in very shallow water, as it is able to get into shallow places without running aground. #1 is also has a single beam sonar, which means it is sending out “pings” in a single direction directly underneath the boat. Thursday night, Marta drew a grid of lines for the RA-1 to survey.  The FOO (Field Operations Officer) asked her to develop a tight grid, with the lines being only 5 meters apart. If you have driven a boat, you know that this means that as you go up and down the parallel lines, your turning ratio is quite tight, and there will be wake and bubbles formed.  The problem with this is that bubbles throw off the single beam sonar, and it “scrambles” the feedback from the sea floor. 

This is the Echosounder machine that records the data from the single beam transducer.
This is the Echosounder machine that records the data from the single beam transducer.

We were operating in Warm Chuck Inlet, which has some freshwater creeks feeding it.  Marta taught me to do a little part of the recording on the Echosounder machine, which is called doing “paper control.”  She tracked our progress on her computer, and when we were over an area that needed to be mapped, she would say, “Start recording,” and I would hit a button that started the paper moving. The machine creates a line graph similar to that a seismograph might create during an earthquake, or in a medical scenario, it is similar to that of an EKG that graphs the activity of your heartbeat.  When we ran through our own bubbles, it created dense gray shaded areas that obscured the data. We had to slow down, and change our course several times to allow for which way the tide was flowing so that tidal movements would carry our bubbles away from the next line we wanted to drive.

The single beam technology is rather outdated, and NOAA prefers to use the multibeam, as it creates real-time, 3-D pictures of the ocean floor. However, the multibeam transducers are very expensive, and very vulnerable to damage caused by running aground, and so the RAINIER uses both technologies to get as much information as possible without damaging or destroying the multibeams. After we returned to the ship, the RAINIER weighed anchor and moved to a new anchorage near Sonora Island in the Maurelle Islands group.

This is a sample of the paper “picture” of the bottom recorded by Launch #1.
This is a sample of the paper “picture” of the bottom

Personal Log 

Friday was an interesting day, as most of the time, I was helping Marta with the recording. I goofed up a few times, as you have to stay so focused and attend to detail constantly. The survey techs have my true admiration…they go out day after day in cool to cold weather, rain or fog or drizzle, and collect intensely detailed data.  There are no days off on the ship, really.  Actually, everyone on the RAINIER is amazing with his/her ability to focus and stay on-task and get jobs done…from the cooks (who are great!) to the deck crew to the officers to the engineers. Last night (Saturday), Raul Quiros was fishing and caught a small shark…maybe 2 feet long. He cut him off the line, and had a bit of trouble picking him up to release him. The shark was gasping, so I tentatively grabbed his belly and threw him over the side.   Then, a few of us saw some whales playing off the starboard side of the ship.  I ran and got my videocam…finally!  I actually got some footage of a whale!  He was rolled over on his back, and slapping the water with both fins, over and over and over.  It was amazing.  Some people say whales breach and do these “slaps” to remove barnacles, but it looked to me as though he was just having fun!

Question of the Day 

  1. Go to the website and click on the “movie” on multibeam surveying.  What do you think would happen if the boat passed over a whale or a sunken ship?  What would NOAA do with information on sunken ships if they discovered some?
  2. For my first graders:  Look at a picture of a humpback whale and a jet plane.  Can you see any ways that they are alike? Also, try that website in #1…the movie is definitely something you will understand!

Beth Carter, June 29, 2007

NOAA Teacher at Sea
Beth Carter
Onboard NOAA Ship Rainier
June 25 – July 7, 2007

Mission: Hydrographic Survey
Geographical Area: Gulf of Esquibel, Alaska
Date: June 29, 2007

Weather Data from the Bridge
Visibility:  8 miles
Wind Direction:  Light
Wind Speed:  Aires
Sea Wave Height:  None
Swell Wave Height:  None
Seawater Temperature: 12.8 C
Dry bulb Temperature: 13.3 C, Wet Bulb Temperature:  12.2 C
Sea level Pressure:  1009.4 mb
Cloud Cover: Cloudy, light rain, 8/8
Depth: 31 fathoms

ENS Meghan McGovern and Elishau Dotson are recovering the CTD.  After recovery, Elishau connects the CTD to her computer and downloads the readings on temperature, conductivity (a function of salinity), and depth. NOAA uses Wilson’s Equation of Sound Velocity to convert the CTD information to something usable in the software
ENS Meghan McGovern and Elishau Dotson are recovering the CTD. After recovery, Elishau downloads the readings on temperature, conductivity (a function of salinity), and depth. NOAA uses Wilson’s Equation of Sound Velocity to convert the CTD information to something usable in the software

Personal Log (Just have to tell you about the whale first!) 

On Thursday, Aug. 28, I went out on the #4 launch from the RAINIER.  When the hydrographic team goes out, they go out for the whole day…8:15 until 4:30 p.m.  It was sunny and clear, our first sunny day! I went out with ENS Meghan McGovern, Elishau Dotson, Assistant Survey Tech, and our pilot, Jodie Edmond, Able Bodied Seaman – an all female boat crew! First, I have to focus on the wildlife that we saw – it was totally incredible!  We saw several sea otters floating on their backs, whiskery and cute!  We saw a doe leading her two fawns on the shore of an island. Eagles soared overhead all throughout the day, and one dove to catch a fish (missed), but later, he grabbed one in his talons.  We got a quick glimpse of a mother harbor porpoise and her calf feeding near the shore.

The highlight of the day, though, was seeing a humpback whale breaching near the boat – to say that I was totally enthralled is not adequate.  I don’t think the dictionary has any words that truly fit! First, I saw a silver/gray shape under the water near the stern, and thought it was a stingray, a common sight on the East Coast. Then, I heard a gasp/blow as the whale surfaced to breathe. The sound was like the “grunt” that Monica Seles makes as she serves up a tennis ball, only lower and longer.   We saw the whale surface a few more times, and then his great leap.  I was trying to videotape, and of course, I missed it.  But it will stay in my memory forever, if not on a memory card.

Science and Technology Log 

This is the multi-beam transducer mounted on the hull of the #4 launch of the RAINIER.  It can produce a broad band of sounds to “ping” off the bottom of the sea, and provide the data to create a 3-D picture of the ocean floor under and near the boat.
This is the multi-beam transducer on the hull of the #4 launch. It can produce a broad band of sounds to “ping” off the seafloor and provide the data to create a 3-D picture.

Now, to focus upon the hydrographic mission!  Before beginning the surveying, the crew lowers a CTD to the sea floor to collect a reading on the Conductivity, Temperature, and Depth of the water. The way that the sonar “pings” travel through water is affected by all three factors.  The higher the percentage of salinity, the greater is the ability of the water to conduct sound waves. Higher temperatures also increase sound conductivity in water, and deeper water also conducts sound waves better than shallow water. For example, if the launch is surveying the sea floor in an area near where a freshwater creek is flowing in, the conductivity of the water would decrease; therefore, the survey tech crew that does the night processing of the data would be able to correct the resulting data taking into account the lower conductivity. Number 4 launch has a multibeam sonar transducer mounted on the hull. The transducer produces a broad band of sound “pings” that bounce off the sea floor and return to the launch to be recorded by a sophisticated computer with four screens. The operator of the sonar equipment can see a digital display of the depth, and a real-time three-dimensional picture of the sea floor beneath and around the launch. The boat driver is constantly aware of the depth, so as not to run the launch aground on rock formations. 

Elishau is monitoring the real-time data streaming in from the transducer as Jodie drives the “lines” to create pictures of the ocean floor.
Elishau is monitoring the real-time data streaming in from the transducer as Jodie drives the “lines” to create pictures of the ocean floor.

The driver steers the boat along a pre-set grid of lines that are programmed into the ship’s computer the night before.  Jodie said it is rather like “mowing the grass,” on the surface of the water. You “mow” the water in neat rows until you’ve mowed over every line on the chart established by the hydrographers. After all the lines were run, we returned to the ship, and then, other hydrographic scientists began to run a correction program on the data we gathered. In this way, they clean out errors that are caused by extraneous noises, kelp, echoes, and other obstacles. In the afternoon, we were “snagged” by a gigantic clump of kelp that got wrapped around the transducer. There was so much kelp, the launch could not maneuver effectively.  ENS McGovern stabbed the kelp with a boat hook, and Jodie reversed the engines until we shook the kelp loose.  Learn more about seafloor mapping here.

Questions of the Day

Later that night, Martha Hertzog, Physical Scientist, looks at the data from the #4 launch, and applies a correction program to the data to eliminate errors.  The night processors often work until 11:00 p.m. in order to process the day’s data collections from the 3-4 launches that were out that day.
Later that night, Martha Hertzog, Physical Scientist, looks at the data and applies a correction to eliminate errors. The night processors often work until 11:00 p.m. in order to process the day’s data collections.

These questions are particularly for Ms. Southgate’s oceanography students at Hoggard High School in Wilmington, N.C. (and any other curious people!)

  1. I’m learning that salinity affects conductivity of sound waves. Why does a high concentration of salt in water make sound travel faster? Does electricity travel faster or slower through fresh and salt water? Why?
  2. As we drove different lines yesterday, we took three different CTD readings?  Why do you think the hydrographers felt we should collect data three times?
  3. The islands here are very craggy and steep, and made up largely of granite and limestone rock.  Much of the sea floor is also rock.  Why is the coast of Alaska so vastly different to America’s Eastern coast?
  4. The islands here drop very sharply off into deep water.  For example, just 3-4 meters from shore, the depth can drop to 20 meters.  Why is this common here? How much is 20 meters measured in feet?  In fathoms?