Theresa Paulsen: Mission Accomplished, April 2, 2015

NOAA Teacher at Sea
Theresa Paulsen
Aboard NOAA Ship Okeanos Explorer
March 16-April 3rd

Mission: Caribbean Exploration (mapping)
Geographical Area of Cruise: Puerto Rico Trench
Date: April 2, 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:

What are the mappers up to?

After we completed our two priority areas of the cruise, the mappers have been using Knudson subbottom sonar to profile the bottom of the trench. Meme Lobecker, the expedition coordinator sends that data directly to the United States Geological Survey (USGS) for processing. They returned some interesting findings.

The subbottom sonar sends a loud “chirp” to the bottom. It penetrates the ocean floor. Different sediment layers reflect the sound differently so the variation and thickness of the layers can be observed. The chirp penetration depth varies with the sediments. Soft sediments can be penetrated more easily. In the picture below, provided by USGS, you can see hard intrusions with layers of sediments filling in spaces between.

image

The intrusions are basement relief, likely uplifting deformation ridges created by the subduction of the North American Plate. The subduction is now oblique, with the North American and Caribbean plates mostly sliding past each other now – sort of like the San Andreas Fault – but there is still some subduction happening. Subbottom Image and caption courtesy of USGS.

How does the bathymetry look?

In the last two days, I have been really enjoying the incredible details in the bathymetry data the multibeam sonar has gathered. We mapped over 15,000 square miles on our voyage! Using computer software we can now look at the ocean floor beneath us. I tried my hand at using Fledermaus software to make fly-over movies of the area we surveyed (or should I say swim-over movies). Check them out:

I also examined some of the backscatter data. In backscatter images soft surfaces are darker, meaning the signal return is weaker, and the hard surfaces are whiter due to stronger returns. One of the interns, Chelsea Wegner, studied the bathymetry and backscatter data for possible habitats for corals. She looked for steep slopes in the bathymetry and hard surfaces with the backscatter, since corals prefer those conditions.

Intern poster project

Intern Poster Project by Chelsea Wegner

Chelsea Wegner Poster (pdf)

On the next leg, the robotic vehicle on the ship will be used to examine some of the areas we were with high-definition cameras. You can watch the live stream here. You can also see some of the images and footage from past explorations here.
This is a short video from the 2012 expedition to the Gulf of Mexico to tempt you into tuning in for more.

Personal Log:

The people on this vessel have been blessed with adventurous spirits and exciting careers. Throughout the cruise, I heard about and then came to fully understand the difficulty of being away from family when they need us.

I would like to dedicate this last blog to my father, Tom Wichman. He passed away this morning at 80 years of age after battling more than his share of medical issues.  As I rode the ship in today I felt him beside me. Together we watched the pelicans and the boobies fly by. I am very glad I was able to take him on a “virtual” adventure to the Caribbean. He loved the pictures and the blog. I thank the NOAA Teacher at Sea program for helping me make him proud one last time.

My parents

My Parents, Tom and Kate Wichman

“To know how to wonder is the first step of the mind toward discovery” – L. Pasteur. These words decorate my classroom wall but are epitomized by the work that the NOAA Okeanos Explorer and the Office of Exploration and Research (OER) do each day.

Thank you to the Meme, the CO, XO, the science team, and the entire crew aboard the Okeanos for teaching me as much as you did and for helping me get home when I needed to be with family. I wish you all the best as you continue to explore our vast oceans! My students and I will be watching and learning from you!

I would also like to thank all of the people who followed this blog. Your support and interest proves that you too are curious by nature. Life is much more interesting if you hold on to that sense of wonder, isn’t it?

Answers to My Previous Questions of the Day Polls:

1.  Bathymetry is the study of ocean depths and submarine topography.

2. The deepest zone in the ocean is called the hadal zone, after Hades the Greek God of the underworld.

3.  It takes the vessel 19 hours and 10 minutes to make enough water for 46 people each using 50 gallons per day if each of the two distillers makes 1 gallon per minute.

4.  NOAA line offices include:

  • National Environmental Satellite, Data, and Information Service
  • National Marine Fisheries Service
  • National Ocean Service
  • National Weather Service
  • Office of Marine & Aviation Operations
  • Office of Oceanic and Atmospheric Research

5. The pressure on the a diver at 332.35m is 485 pounds per square inch!

6.  The deepest part of the Puerto Rico Trench is known as the Milwaukee Deep.

Thank you for participating!  I hope you learned something new!

Lauren Wilmoth: “Wreckish looking rock?” October 15, 2014

NOAA Teacher at Sea
Lauren Wilmoth
Aboard NOAA Ship Rainier
October 4 – 17, 2014

Mission: Hydrographic Survey
Geographical area of cruise: Kodiak Island, Alaska
Date: Wednesday, October 15th, 2014

Weather Data from the Bridge
Air Temperature: 4.4 °C
Wind Speed: 5 knots
Latitude: 57°56.9′ N
Longitude: 153°05.8′ W

Science and Technology Log

Thank you all for the comments you all have made.  It helps me decide what direction to go in for my next post.  One question asked, “How long does it take to map a certain area of sea floor?”  That answer, as I responded, is that it depends on a number of factors including, but not limited to, how deep the water is and how flat the floor is in that area.

To make things easier, the crew uses an Excel spreadsheet with mathematical equations already built-in to determine the approximate amount of time it will take to complete an area.  That answer is a bit abstract though.  I wanted an answer that I could wrap my head around.  The area that we are currently surveying is approximately 25 sq nautical miles, and it will take an estimated 10 days to complete the surveying of this area not including a couple of days for setting up tidal stations.  To put this in perspective, Jefferson City, TN is approximately 4.077 sq nautical miles.  So the area we are currently surveying is more than 6 times bigger than Jefferson City!  We can do a little math to determine it would take about 2 days to survey an area the size of Jefferson City, TN assuming the features are similar to those of the area we are currently surveying.

Try to do the math yourself!  Were you able to figure out how I got 2 or 3 days?

Since we’re talking numbers, Rainier surveyed an area one half the size of Puerto Rico in 2012 and 2013!  We can also look at linear miles.  Linear miles is the distance they traveled while surveying.  It takes into account  all of the lines the ship has completed.  In 2012 and 2013, Rainier surveyed the same amount of linear nautical miles that it would take to go from Newport, Oregon to the South Pole Station and back!

Area we are currently surveying.

Area we are currently surveying (outlined in red) with some depth data we have collected.

Casting a CTD (Conductivity, Temperature, and Depth) gauge.

Casting a CTD (Conductivity, Temperature, and Depth) gauge.

Monday, I went on a launch to collect sonar data.  This is my first time to collect sonar data since I started this journey.  Before we could get started, we had to cast a CTD (Conductivity, Temperature and Depth) instrument.  Sound travels a different velocities in water depending on the salinity, temperature, and pressure (depth), so this instrument is slowly cast down from the boat and measures all of these aspects on its way to the ocean floor.  Sound travels faster when there is higher salinity, temperature, and pressure.  These factors can vary greatly from place to place and season to season.

Imagine how it might be different in the summertime versus the winter.  In the summertime, the snow will be melting from the mountains and glaciers causing a increase in the amount of freshwater.  Freshwater is less dense than saltwater, so it mainly stays on top.  Also, that glacial runoff is often much colder than the water lower in the water column.  Knowing all of this, where do you think sound will travel faster in the summertime?  In the top layer of water or a lower layer of water?  Now you understand why it is so important to cast a CTD to make sure that our sonar data is accurate.  To learn more about how sound travels in water, click here.

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I’m driving the boat.

After casting our CTD, we spent the day running the sonar up and down and up and down the areas that needed to be surveyed.  Again, this is a little like mowing the lawn.  At one point, I was on bow watch.  On bow watch, you sit at the front of the boat and look out for hazards.  Since this area hasn’t been surveyed since before 1939, it is possible that there could be hazards that are not charted.  Also, I worked down in the cabin of the boat with the data acquisition/sonar tuning. Some important things to do below deck including communicating the plan of attack with the coxswain (boat driver), activating the sonar, and adjusting the sonar for the correct depth.  I helped adjust the range of the sonar which basically tells the sonar how long to listen.  If you are in deeper water, you want the sonar to listen longer, because it takes more time for the ping to come back.  I also adjusted the power which controls how loud the sound ping is.  Again, if you are surveying a deeper area, you might want your ping to be a little louder.

Eli working the sonar equipment.

Eli working the sonar equipment.

Tuesday, I helped Survey Tech Christie Rieser and Physical Scientist Fernando Ortiz with night processing.  When the launches come back after acquiring sonar data, someone has to make all that data make sense and apply it to the charts, so we can determine what needs to be completed the following day.  Making sense of the data is what night processing is all about.  First, we converted the raw data into a form that the program for charting (CARIS) can understand.  The computer does the converting, but we have to tell it to do so.  Then, we apply all of the correctors that I spoke about in a previous blog in the following order: POS/MV (Position and Orientation Systems for Marine Vessels) corrector, Tides corrector, and CTD (Conductivity, Temperature, and Depth) corrector.  POS/MV corrects for the rocking of the boat.  For the tides corrector, we use predicted tides for now, and once all the data is collected from our tidal stations, we will add that in as well.  Finally, the CTD corrects for the change in sound velocity due to differences in the water as I discussed above.

After applying all of the correctors, we have the computer use an algorithm (basically a complicated formula) to determine, based on the data, where the sea floor is.  Basically, when you are collecting sonar data there is always going to be some noise (random data that is meaningless) due to reflection, refraction, kelp, fish, and even the sound from the boat.  The algorithm is usually able to recognize this noise and doesn’t include it when calculating the location of the seafloor.  The last step is manually cleaning the data.  This is where you hide the noise, so you can get a better view of the ocean floor.  Also, when you are cleaning, you are double checking the algorithm in a way, because some things that are easy for a human to distinguish as noise may have thrown off the algorithm a bit, so you can manually correct for that. Cleaning the data took the longest amount of time.  It took a couple of hours.  While processing the data, we did notice a possible ship wreck, but the data we have isn’t detailed enough to say whether it’s a shipwreck or a rock.  Senior Tech Jackson noted in the acquisition log that it was “A wreckish looking rock or a rockish looking wreck.”  We are going to have the launches go over that area several more times today to get a more clear picture of is going on at that spot.

H12662_DN195_2804 This is an example of noisy data. In this case, the noise was so great that the algorithm thought the seafloor went down 100 extra meters. Manually cleaning the data can adjust for this so our end product is accurate. The actual seafloor in this case is the relatively straight line at about 100 meters depth.

This is an example of noisy data. In this case, the noise was so great that the algorithm thought the seafloor went down 100 extra meters. Manually cleaning the data can adjust for this so our end product is accurate. The actual seafloor in this case is the relatively straight line at about 100 meters depth.

Personal Log 

Monday was the most spectacular day for wildlife viewing!  First, I saw a bald eagle.  Then, I saw more sea otters.  The most amazing experience of my trip so far happened next.  Orcas were swimming all around us.  They breached (came up for air) less than 6 feet from the boat.  They were so beautiful!  I got some good pictures, too!  As if that wasn’t good enough, we also saw another type of whale from far away.  I could see the blow (spray) from the whale and a dorsal fin, but I am not sure if it is was a Humpback Whale or a Fin Whale.  Too cool!

Bald Eagle Sighting!

Bald Eagle Sighting!

Sea otter

Sea otter

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Orca!

Very close orca!

Very close orca!

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Did You Know? 

Killer whales are technically dolphins, because they are more closely related to other dolphins than they are to whales.

Lauren Wilmoth: Shore Party, October 12, 2014

NOAA Teacher at Sea
Lauren Wilmoth
Aboard NOAA Ship Rainier
October 4 – 17, 2014

Mission: Hydrographic Survey
Geographical area of cruise: Kodiak Island, Alaska
Date: Sunday, October 12, 2014

Weather Data from the Bridge
Air Temperature: 1.92 °C
Wind Speed: 13 knots
Latitude: 58°00.411′ N
Longitude: 153°10.035′ W

Science and Technology Log

The top part of a tidal station.  In the plastic box is a computer and the pressure gauge.

The top part of a tidal station. In the plastic box is a computer and the pressure gauge.

In a previous post, I discussed how the multibeam sonar data has to be corrected for tides, but where does the tide data come from?  Yesterday, I learned first hand where this data comes from.  Rainier‘s crew sets up temporary tidal stations that monitor the tides continuously for at least 30 days.  If we were working somewhere where there were permanent tidal station, we could just use the data from the permanent stations.  For example, the Atlantic coast has many more permanent tidal stations than the places in Alaska where Rainier works.  Since we are in a more remote area, these gauges must be installed before sonar data is collected in an area.

We are returning to an area where the majority of the hydrographic data was collected several weeks ago, so I didn’t get to see a full tidal station install, but I did go with the shore party to determine whether or not the tidal station was still in working condition.

A tidal station consists of several parts: 1) an underwater orifice 2) tube running nitrogen gas to the orifice 3) a nitrogen tank 4) a tidal gauge (pressure sensor and computer to record data) 5) solar panel 6) a satellite antennae.

Let me explain how these things work.  Nitrogen is bubbled into the orifice through the tubing.  The pressure gauge that is located on land in a weatherproof box with a laptop computer is recording how much pressure is required to push those bubbles out of the orifice.  Basically, if the water is deep (high tide) there will be greater water pressure, so it will require more pressure to push bubbles out of the orifice.  Using this pressure measurement, we can determine the level of the tide.  Additionally, the solar panel powers the whole setup, and the satellite antennae transmits the data to the ship.  For more information on the particulars of tidal stations click here

Tidal station set-up.  Drawing courtesy of Katrina Poremba.

Tidal station set-up. Drawing courtesy of Katrina Poremba.

Rainier is in good hands.

Rainier is in good hands.

The tidal station in Terror Bay did need some repairs.  The orifice was still in place which is very good news, because reinstalling the orifice would have required divers.  However, the tidal gauge needed to be replaced.  Some of the equipment was submerged at one point and a bear pooped on the solar panel.  No joke!

After the tidal gauge was installed, we had to confirm that the orifice hadn’t shifted.  To do this, we take manual readings of the tide using a staff that the crew set-up during installation of the tidal station.  To take manual (staff) observations, you just measure and record the water level every 6 minutes.   If the manual (staff) observations match the readings we are getting from the tidal gauge, then the orifice is likely in the correct spot.

Just to be sure that the staff didn’t shift, we also use a level to compare the location of the staff to the location of 5 known tidal benchmarks that were set when the station was being set up as well.  As you can see, accounting for the tides is a complex process with multiple checks and double checks in place.  These checks may seem a bit much, but a lot of shifting and movement can occur in these areas.  Plus, these checks are the best way to ensure our data is accurate.

Micki and Adam setting up the staff, so they can make sure it hasn't moved.

ENS Micki and LTJG Adam setting up the staff, so the surveyor can make sure it hasn’t moved.

Mussels and barnacles on a rock in Terror Bay.

Mussels and barnacles on a rock in Terror Bay.

Leveling to ensure staff and tidal benchmarks haven't moved.

Leveling to ensure staff and tidal benchmarks haven’t moved.

 

 

 

 

 

 

 

 

Today, I went to shore again to a different area called Driver Bay.  This time we were taking down the equipment from a tidal gauge, because Rainier is quickly approaching the end of her 2014 season.  Driver Bay is a beautiful location, but the weather wasn’t quite as pretty as the location.  It snowed on our way in!  Junior Officer Micki Ream who has been doing this for a few years said this was the first time she’d experienced snow while going on a tidal launch.  Because of the wave action, this is a very dynamic area which means it changes a lot.

In fact, the staff that had been originally used to manually measure tides was completely gone, so we just needed to take down the tidal gauges, satellite antenna, solar panels, and orifice tubing.  The orifice itself was to be removed later by a dive team, because it is under water.  After completing the tidal gauge breakdown, we hopped back on the boat for a very bumpy ride back to Rainier.  I got a little water in my boots when I was hopping back aboard the smaller boat, but it wasn’t as cold as I had expected.  Fortunately, the boat has washers and driers.  It looks like tonight will be laundry night.

Raspberry Bay

Driver Bay

Personal Log 

The food here is great!  Last night we had spaghetti and meatballs, and they were phenomenal.  Every morning I get eggs cooked to order.  On top of that, there is dessert for every lunch and dinner!  Don’t judge me if I come back 10 lbs. heavier.  Another cool perk is that we get to see movies that are still in the theaters!  They order two movies a night that we can choose from.  Lastly, I haven’t gotten seasick.  Our transit from Seward to Kodiak was wavy, but I don’t think it was as bad as we were expecting.  The motion sickness medicines did the trick, because I didn’t feel sick at all.

Did You Know? 

NOAA (National Oceanic and Atmospheric Administration) contains several different branches including the National Weather Service which is responsible for forecasting weather and issuing weather alerts.

Animal Spotting

There are sea otters everywhere!

Sea otter (Enhydra lutris) sighting.

Sea otter (Enhydra lutris) sighting.

 

Lauren Wilmoth: Safety First, October 8, 2014

NOAA Teacher at Sea
Lauren Wilmoth
Aboard NOAA Ship Rainier
October 4 – 17, 2014

Mission: Hydrographic Survey
Geographical area of cruise: Kodiak Island, Alaska
Date: Wednesday, October 8, 2014

Weather Data from the Bridge
Air Temperature: 3.82 °C
Wind Speed: 6.1 knots
Latitude: 60°07.098′ N
Longitude: 149°25.711′ W

Science and Technology Log

Junior Officer Micki Ream diving in Thumb's Cove.  Photo courtesy of Junior Officer Katrina Poremba.

Junior Officer Micki Ream diving in Thumb’s Cove. Photo courtesy of Junior Officer Katrina Poremba.

The launch that I participated in on Tuesday was awesome!  We went to an area called Thumb’s Cove.  I thought the divers must be crazy, because of how cold it was.  When they returned to the boat from their dive, they said the water was much warmer than the air.  The water temperature was around 10.5°C or 51°F while the air temperature was hovering right above freezing.  One diver, Katrina, took an underwater camera with her.  They saw jellyfish, sea urchins, and sea stars.

The ride to and from the cove was quite bouncy, but I enjoyed being part of this mini-adventure!  Later that day, we did what is called DC (Damage Control) familiarization.  Basically, we practiced what do in case of an emergency.  We were given a pipe with holes in it and told to patch it with various objects like wooden wedges.  We also practiced using a pump to pump water off of the ship if she were taking on water.  Safety drills are also routine around here.  It’s nice to know that everyone expects the best, but prepares for the worse.  I feel very safe aboard Rainier.

Seastar from Katrina Poremba from the dive at Thumb's Cove.

Sea star and anemones taken by diver Katrina Poremba at Thumb’s Cove.

This source diagram from Kodiak Island shows when the latest data was collected in for an area.  We will be working near the red x.

This source diagram from Kodiak Island shows when the latest data was collected in for an area. We will be working near the red x.

Today, I got a chance to meet with the CO (Commanding Officer), and he explained the navigational charts to me.  Before the ship leaves the port, there must be a navigation plan which shows not only the path the ship will take, but also the estimated time of arrival to various points along the way.  This plan is located on the computer, but also, it must be drawn on a paper chart for backup.

This illustrates again how redundancy, as I discussed in my last blog post, is a very important part of safety on a ship.  Every ship must have up-to-date paper charts on board.  These charts get updated with the information collected from the hydrographic surveys.  The ocean covers more than 70% of our planet which is why Rainier‘s mission of mapping the ocean is so important.  There are many areas in Alaska where the only data on the depth of the water was collected before sonar technology was used.  In fact, some places the data on the charts comes from Captain Cook in the 1700s!  If you look at the chart below the water depth is measured in fathoms.  A fathom is 6 feet deep.  Places that are less than 1 fathom deep have a 05 where the subscript indicates how deep the water is in feet.

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One of the nautical charts that will help Rainier navigate back to its home port in Newport, Oregon. Notice the ocean depth marked in fathoms.

CO (Commanding Officer) and me after discussing nautical charts.

CO (Commanding Officer) and me after discussing nautical charts.

Today, I also spoke with the AFOO (Acting Field Operations Officer), Adam, about some work that he had been doing on Rainier‘s sister ship NOAA Fairweather.  One project they are working on is connecting hydrographic data to fish distribution and abundance mapping.  Basically, they want to find out if it is possible to use sonar data to predict what types of fish and how many you will find in a particular location

They believe this will work, because the sonar produces a back scatter signature that can give you an idea of the sea floor composition (i.e. what it is made of).  For instance, they could tell you if the sea floor is rocky, silty, or sandy using just sonar, as opposed to, manually taking a bottom sample.  If this hydrographic data is integrated with the data collected by other NOAA ships that use trawl nets to survey the fish in an area, this would allow NOAA to manage fisheries more efficiently.  For example, if you have map that tells you that an area is likely to have fish fry (young fish) of a vulnerable species, then NOAA might consider making this a protected area.

Personal Log

Artwork from the SeaLife Center created by high school students to illustrate how much trash ends up on our beaches.

Artwork from the SeaLife Center created by high school students to illustrate how much trash ends up on our beaches.

On Tuesday, I had a little extra time in the afternoon, so I decided to ride my bike down to the Alaska SeaLife Center which is a must-see if you ever find yourself in Seward.  There were Harbor Seals (Phoca vitulina), Stellar Sea Lions (Eumetopias jubatus), Puffins (Genus Fratercula), Pacific Salmon (Genus Oncorhynchus) and much more.  I really appreciated that the SeaLife Center focused on both conservation and on organisms that live in this area.  A local high school even had their art students make an exhibit out of trash found on the beach to highlight the major environmental issue of trash that finds its way to the ocean.

Can you think a project we could do that would highlight a main environmental concern in Eastern Tennessee?  I also thought is was really interesting to see the Puffins dive into the water.  The SeaLife Center exhibit explained about how Puffin bones are more dense than non-sea birds.  These higher density bones are an adaptation that helps them dive deeper.

Puffin at the Alaska SeaLife Center

Puffin at the Alaska SeaLife Center

I officially moved into the ship today.  Prior to that, I was staying at a hotel while they were finishing up repairs.  We are expected to get underway on Friday afternoon.  I am staying in the princess suite!  It is nice and cozy.  I have all of the essentials.  I have a desk, bunk beds, 2 closets, and one bathroom (head).

Rainier, my home for the next week and a half, in Seward Alaska

Rainier, my home for the next week and a half, in Seward, Alaska

My berthing area (where I sleep) nicknamed "The Princess Suite."

My berthing area (where I sleep) nicknamed “The Princess Suite.”

 

Did You Know? 

Junior Officers get homework assignments just like you.  At the navigation briefing today, the CO (Commanding Officer) told the Junior Officers what that they needed to review several documents before going through the inside passage (a particularly tricky area to navigate).  He is expecting them to lead different parts of the next navigation briefing, but he isn’t going to tell them which part they are leading until right before. Therefore, it is important that they know it all!  It’s a little like a pop quiz and presentation in one.

Word of the Day

Bathymetry – the study of the “beds” or “floors” of bodies of water.

Lauren Wilmoth: Introductions, October 7, 2014

NOAA Teacher at Sea
Lauren Wilmoth
Aboard NOAA Ship Rainier
October 4 – 17, 2014

Mission: Hydrographic Survey
Geographical area of cruise: Kodiak Island, Alaska
Date: Tuesday, October 7, 2014

Weather Data from the Bridge
Air Temperature: 0.77 °C
Wind Speed: 12 knots
Latitude: 60°07.098′ N
Longitude: 149°25.711′ W

Science and Technology Log

Our departure from Seward was originally scheduled for today, but the ship is having some repairs done, so our expected departure is now Wednesday or Thursday.  In case you were wondering, this doesn’t delay my return date.  Regardless of the fact that we are not underway, there is still so much to learn and do.

Yesterday, I met with Christie, one of the survey techs, and learned all about the Rainier’s mission.   The main mission of the ship is to update nautical charts.  Up-to-date charts are crucial for safe navigation.  The amount of data collected by Rainier if vast, so although the main mission of the Rainier is updating nautical charts, the data are also sent to other organizations who use the data for a wide variety of purposes.  The data have been used for marine life habitat mapping, sediment distribution, and sea level rise/climate change modeling among other things.  In addition to all of that, Rainier and her crew sometimes find shipwrecks.  In fact, Rainier and her crew have found 5 shipwrecks this season!

 

This is what a shipwreck looks like to the sonar. This is a picture of a shipwreck found by another NOAA hydrographic ship. Photo courtesy of NOAA.

 

Simplified, hydrographic research involves sending multiple sonar (sound) beams to the ocean floor and recording how long it takes for the sound to come back.  You can use a simple formula of distance=velocity/time and divide that by two because the sound has to go to the floor and back to get an idea how deep the ocean is at a particular spot.  This technique would be fine by itself if the water level weren’t constantly fluctuating due to tides, high or low pressure weather systems, as well as, the tilt of the ship on the waves.  Also, the sound travels at different speeds according to the water’s temperature, conductivity and depth.  Because of this, the data must be corrected for all of these factors.  Only with data from all of these aspects can we start to map the ocean floor.  I have attached some pictures of what data would look like before and after correction for tides.

 

This shows the advantages of using multibeam sonar to complete surveys. Photo courtesy of NOAA.

Hydrographic data with correction for tides.  Photo courtesy of Christie.

Hydrographic data with correction for tides. Photo courtesy of Christie.

Hydrographic data without correction for tides.  Photo courtesy of Christie

Hydrographic data without correction for tides. Photo courtesy of Christie

I was also given a tour of the engine room yesterday.  Thanks, William.  He explained to me how the ship was like its own city.  In this city, there is a gym, the mess (where you eat), waste water treatment, a potable (drinkable) water production machine, and two engines that are the same type of engines as train engines.  Many of my students were interested in what happens to our waste when we are aboard the ship.  Does it just get dumped into the ocean?  The answer is no.  Thank goodness!  The waste water is exposed to bacteria that break down the waste  Then, salt water is used to produce chlorine that further sterilizes the waste.  After those two steps, the waste water can be dumped.  The drinking water is created by evaporating the water (but not the salt) from salt water.  The heat for this process is heat produced by the engine.  William also explained that there are two of everything, so if something fails, we’ll still be alright.

Me working out at the Rainier gym.

Rainier’s gym

Rainier's back-up generator.

Rainier’s back-up generator 

Personal Log

Sunday, I drove from Anchorage to Seward.  The drive was so beautiful!  At first, I was surrounded by huge mountains that were vibrant yellow from the trees whose leaves were turning.  Then, there was snow!  It was actually perfect, because the temperature was at just the right point where the snow was melted on the road, but it had blanketed the trees.  Alaska is as beautiful as all of the pictures you see.  The drive should have been about 2.5 hours, but it took me 3.5 hours, because behind each turn the view was better than the previous turn, so I had to stop and take pictures.  I took over 100 pictures on that drive.  Once I arrived in Seward, I was given my first tour of the ship and then I had some time to explore Seward.

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One of the views on my drive from Anchorage to Seward

 

Trying on my survival (gumby) suit

Trying on my survival (gumby) suit

Yesterday (the first official day on the job), I learned so much.  Getting used to the terminology is the hardest part.  There are acronyms from everything!  Immersion is the best way to learn a foreign language, and I have been immersed in the NOAA (National Oceanic and Atmospheric Administration) language.  There is the CO (Commanding Officer), XO (Executive Officer), FOO (Field Operations Officer), TAS (Teacher at Sea or Me!), POD (Plan of the Day) and that is just the tip of the iceberg.  I also had to learn all of the safety procedures.  This involved me getting into my bright red survival suit and learning how to release a lifeboat.

Today, I am going on a dive launch.  The purpose of this launch is to help some of the divers get more experience in the cold Alaskan waters.  I will get to ride on one of the smaller boats and watch as the Junior Officers scuba dive.

Did You Know? 

NOAA Corps is one of the 7 branches of the U.S. uniformed services along with the Army, Navy, Coast Guard, Marine Corps, Air Force, and the Public Health Service Commissioned Corps (PHSCC).

Emina Mesanovic, Acoustic Lab: Let’s Make Some Maps, July 28, 2014

NOAA Teacher at Sea

Emina Mesanovic

Aboard the NOAA Ship Pisces

July 20 – August 2, 2014

 Mission: Southeast Fishery- Independent Survey

Geographic area of the cruise: Atlantic Ocean, off the coast of North Carolina and South Carolina

Date: July 28, 2014

Weather Information from the Bridge

Air Temperature: 27.5 C

Relative Humidity: 86%

Wind Speed: 15.03 knots

 Science and Technology Log

There is a lot of work that goes into allowing the fishery team to be able to set traps every day. The acoustics lab/ night shift is responsible for creating the maps of the seafloor that will be used the following day. The team consists of David Berrane a NOAA fisheries biologist, Erik Ebert a NOAA research technician, Dawn Glasgow from the South Carolina Department of Natural Resources and a Ph.D student at the University of South Carolina, as well as Mary a college student studying Geology at the College of Charleston and Chrissy a masters student at the University of South Carolina. This team is amazing! Starting at around 5:00 pm the day before they stay up all night mapping the ocean floor.

The night shift working together

The night shift collecting data

Every night Zeb Schobernd lets the night shift know which boxes they will work on. These boxes are created in the offseason by the research scientists, they base their selection on information from fishermen, the proximity to already mapped areas, weather and previous experiences. The first step in creating a bathymetric map is to create a line plan, which lets the ship know which area will be covered. The average line takes about half an hour to complete but they can take up to several hours. The ship drives along these lines all night long while the team uses the information that is gathered to create their maps.

So how do they get this information? The ship uses sonar to collect data on the water column and the ocean floor. The Pisces has a 26 multi-beams sonar system, which allows the research team to create a better picture, compared to using single beam sonar. The beams width is about 3 times the depth of water column. This means that depending on how deep the water is in any given location, it will determine how many lines need to be run to cover the area.

Multibeam sonar

Multi-beam sonar (picture from NOAA)

The picture below is one of the computer screens that the scientists look at throughout the night. It provides the sonar information that will then be used to map the floor. Sonar works by putting a known amount of sound into the water and measuring the intensity of the return. A rock bottom will yield a stronger return while a sand bottom will absorb the sound and yield a less intense return. In the image red means that there is a more intense return while blue and yellow signifies a less intense return. You will notice in the center screen there is a strong red return at the top of the beam this is because the ship is sending out the sound and it takes about four meters until you start recording information from the sea floor.

SIMRAD70 (multi-beam sonar)

SIMRAD (multi-beam sonar)

Finally before the maps can be created the team has to launch an XBT (expendable bathy thermograph) two times per box or every four hours. The XBT measures the temperature and conductivity of the water, this is important because sound travels at different rates in cold versus warm water. This information is then used when the scientists calculate the sound velocity, which is used to estimate the absorption coefficient of sound traveling through the water column.

 

Once the data is collected the team begins the editing process. First they have to remove random erroneous soundings in order to get an accurate map; they fondly call this process dot killing (this basically means getting rid of outliers). They do this by drawing a box around the points of data they want to remove and deleting the point. Next they apply tide data to account for the deviations in the tides, this information is obtained from NOAA and is based on the predicted tides for the area. Finally they apply the sound absorption coefficient.

Editing the data (killing dots)

Editing the data (killing dots)

The final product is put into GIS (Geographic Information Systems), which the chief scientists will use to determine where the traps should be set the following morning. On the map below blue indicates the deepest areas while red shows the shallowest. The scientists want to place the traps in areas where there is a large change in depths because this is usually where you will find hard bottoms and good fish habitats.

Finished map (red shallow, blue deep)

Finished map

Personal Log

I have spent the past three nights in the Acoustics/Computer Lab with the night shift mapping the ocean floor. While the ship sails along the plotted course, I have had the opportunity to see the sunrise and sunset on the Pisces as well as a lightning storm from the top deck.

images

Lighting on the ocean (picture from sciencedaily)

On Thursday night a little after midnight after launching the XBT we see decided to go onto the top deck of the Pisces to get a better look at the lighting storm in the distance. Even at night it was still humid and hot and as we climbed up to the top deck it was dark all around us until suddenly there would be a flash of color in the clouds and you could see everything, until it went dark again. We tried to take a picture but the lightening was just too fast for our cameras. This is the closest picture I could find to what it was like that night except the water was not calm.

 

SPOTLIGHT ON SCIENCE

Name: Erik Ebert                  Title: Research Technician

Erik editing data collected on Sunday July 26th.

Erik editing data collected on Sunday July 26th.

Education: Cape Fear Tech (Wilmington, NC)

How long have you worked for NOAA/NOS: 6th field season, 5th year

Job Summary: I work on ecosystem assessments throughout the Gulf of Mexico South Atlantic & Caribbean

– Team oriented production of ocean floor maps

– System setup & keeping the acoustic systems operating correctly

How long have you participated in this survey: Since 2010

What do you like about your job: That the data we collect, and the maps we create can be used again for different studies. The types of data we collect includes bathymetric data, information on the water column, & fish that populate the water column.

How many days are you at sea: 60 days (April-November)

What do you do when you are not on the boat: Process & produce fish density maps from the data collected during the cruises. I also work for National Ocean Services (provide data to policy & decision makers to the state of the ecosystem)

Most challenging about research on a ship: Being away from home is the biggest challenge.

What would be your ideal research cruise: My ideal research cruise would be a cruise similar to what we just completed in Flower Garden Banks in the Gulf of Mexico. It was a 3-year assessment of the reef ecosystem using ROV, Diving and Acoustics to study how the ecosystem changed over time.

Favorite fish: Trigger Fish “cool swimming behavior”

More information about See Floor Mapping   http://www.noaa.gov/features/monitoring_1008/seafloormapping.html

COOL CATCH

Crab with three sea anemones attached to its shell

Crab with three sea anemones attached to its shell

Kevin McMahon: Midnight Mapping! July 13, 2014

NOAA Teacher at Sea

Kevin McMahon

Aboard the NOAA ship Pisces

July 5 – July 18, 2014

 

Mission: Southeast Fisheries Independent Survey

Geographic area of the cruise: Atlantic Ocean, off the coast of North Carolina and South Carolina

Date: July 13, 2014

Weather Information from the Bridge

Air Temperature:            27.6 °C

Relative Humidity:         73%

Wind Speed:                  5.04 knots

 

Science and Technology Log

Someone is always working on the Pisces. When Nate Bacheler and the other fishery scientists have finished their work for the day collecting fish, it is show time for the hydrographers, the scientists who map and study the ocean floor. Their job is to map the ocean floor to help Nate find the best places to find fish for the next day.  Warren, Laura, David and Matt were kind enough to let me join them and explained how they map the ocean floor while on board the Pisces.

People have learned over the years that some fish like to hang out where there is a hard bottom, not a sandy bottom. These hard bottom areas are where coral and sponges can grow and it also happens to be where we usually find the most fish.

Instead of using a camera to find these hard bottom habitats, the mapping scientists use multibeam sonar. Here is a simple explanation on how sonar works. The ship sends a sound wave to the bottom of the ocean. When the sound wave hits the bottom, the sound bounces back up to the ship.

Since scientists know how fast sound travels in water, they can figure out how far it is to the ocean floor. If the sound wave bounces back quickly, we are close to the ocean floor. If the sound wave takes longer, the ocean floor is farther away. They can use this data to make a map of what the ocean floor looks like beneath the ship.

The neat thing about the Pisces is that it does not send down one sound wave only. It sends 70 waves at once. This is called multibeam sonar.

Single Beam versus Multibeam sonar.  Can you see why scientists like to use multibeam sonar?

Single Beam versus Multibeam sonar. Can you see why hydrographers like to use multibeam sonar? Credit: NOAA

So, now you know how sonar works in simple terms.

But it gets a little more complicated. Did you know that sound speed can be affected by the water temperature, by how salty the water is (the “salinity”), by tides, and by the motion of the ship?  Computers make corrections for all of these factors to help get a better picture of the ocean floor. But, computers don’t know the physical properties of our part of the ocean (because these properties change all the time) so we need to find this information and give it to the computer.

To find the temperature of the ocean water, the mapping scientists launch an “XBT” into the water.  XBT stands for “expendable bathythermograph.”  The XBT records the changes in water temperature as it travels to the ocean floor.  It looks like a missile.  It gets put into a launcher and it has a firing pin. It sounds pretty dangerous, doesn’t it!  I was excited to be able to fire it into the water.  But, when I pulled out the firing pin, the XBT just gently slid out of the launcher, softly plopped into the ocean, and quietly collected data all the way to the ocean floor.

 

Kevin McMahon nervously holding the XBT Launcher and waiting for the order to fire.

Kevin McMahon nervously holding the XBT Launcher and waiting for the order to fire.

                 

Kevin McMahon watches as the XBT gently plops out of the launcher.

Kevin McMahon watches as the XBT gently plops out of the launcher.

 

With the new data on water temperature, the hydrographers were able to create this map of the ocean floor.

Example of an Ocean Floor Map

Example of an Ocean Floor Map

 

In the map above, blue indicates that part of the ocean floor that is the deepest. The green color indicates the part of the map that is the next deepest. The red indicates the area that is most shallow.

Nate talks to the hydrographers early in the morning and then predicts where the hard bottom habitats might be. In particular, Nate looks for areas that have a sudden change in elevation, indicating a ledge feature.  If you had Nate’s job, where would you drop the 6 traps to find the most fish?  Look at the map below to see where Nate decided to deploy the traps.

 

The green dots are the spots where Nate dropped the traps in hopes of finding fish.

The green dots are the spots where Nate dropped the traps in hopes of finding fish.

 

To find out more about using sound to see the ocean floor and to see an animation of how this works, click on this link:

 NOAA: Seeing the Ocean Floor

               

Personal Log

 

We have now gotten into a regular routine on the ship.   The best part of the day for me is when we are retrieving the traps. We never know what we will see. Sometimes we catch nothing. Sometimes we find some really amazing things.

 

Here are a few of my favorites:

 

Closer view of sharksucker on my arm

Closer view of sharksucker on my arm

 

Somebody is crabby.

Somebody is crabby.

 

Sea stars with beautiful navy blue colors

Sea stars with beautiful navy blue colors

 

A pair of butterflyfish

A pair of butterflyfish

 

Did you know?

The ocean is largely unexplored.  Maybe someday you will discover something new about the ocean!