Amanda Dice: Ending Week 1 at Line 8, August 26, 2017

NOAA Teacher at Sea

Amanda Dice

Aboard Oscar Dyson

August 21 – September 2, 2017

 

Mission: Juvenile Pollock Fishery Survey

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Oscar Dyson moves across the Shelikof Straight to collect the Line 8 samples

Geographic area of cruise: Western Gulf of Alaska

Date: August 26, 2017

Weather Data: 13.2 C, cloudy with light rain

Latitude 57 36.6 N, Longitude 155 .008 N

 

 

Science and Technology Log

As part of this survey, the scientists onboard collect data from what is known as “Line 8”. This is a line of seven sampling stations, positioned only a few miles apart, near the southern opening of Shelikof Straight between Kodiak Island and the Alaskan Peninsula. Water samples are taken at different depths at each sampling station to measure several different properties of the water. This study is focused on profiling water temperature and salinity, and measuring the quantities of nutrients and phytoplankton in the water.

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The CTD rosette is lowered into the water using a winch – as seen from above.

To collect this data, a conductivity and temperature at depth (CTD) instrument is lowered into the water. This instrument can take water samples at different depths, by using its eleven canisters, or Niskin bottles. The water collected in the Niskin bottles will be used to determine the nutrient quantities at each station. The rosette of Niskin bottles also has sensors on it that measure phytoplankton quantities, depth, temperature, and how conductive the water is. Scientists can use the readings from conductivity and temperature meters to determine the salinity of the water.

Each Niskin bottle has a stopper at the top and the bottom. The CTD goes into the water with both ends of each Niskin bottle in the open position. The CTD is then lowered to a determined depth, depending on how deep the water is at each station. There is a depth meter on the CTD that relays its position to computers on board the ship. The survey team communicates its position to the deck crew who operate the winch to raise and lower it.

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Niskin bottles are lowered into the water with the stoppers at both ends open.

When the CTD is raised to the first sampling depth, the survey crew clicks a button on a monitor, which closes the stoppers on both ends of Niskin bottle #1, capturing a water sample inside. The CTD is then raised to the next sampling depth where Niskin bottle #2 is closed. This process continues until all the samples have been collected. A computer on board records the depth, conductivity and temperature of the water as the CTD changes position. A line appears across the graph of this data to show where each sample was taken. After the Niskin bottles on the CTD are filled, it is brought back onto the deck of the ship.

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They let me take control of closing the Niskin bottles at the sampling depths!

CTD screen cropped

I used this screen to read the data coming back from the CTD and to hit the bottle to close each Niskin bottle. The purple horizontal lines on the graph on the right indicate where each one was closed.

Water is collected through a valve near the bottom of each Niskin bottle. A sample of water from each depth is placed in a labeled jar. This study is interested in measuring the quantity of nutrients in the water samples. To do this it is important to have samples without phytoplankton in them. Special syringes with filters are used to screen out any phytoplankton in the samples.

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Syringes with special filters to screen out phytoplankton are used to collect water samples from the Niskin bottles.

The “Line 8” stations have been sampled for nutrient, plankton, and physical water properties for many years. The data from the samples we collected will be added to the larger data set maintained by the Ecosystems and Fisheries-Oceanography Coordinated Investigations (Eco-FOCI), Seattle, Washington. This NOAA Program has data on how the marine ecosystem in this area has changed over the last few decades. When data spans a long time frame, like this study does, scientists can identify trends that might be related to the seasons and to inter-annual variation in ocean conditions. The samples continue to be collected because proper nutrient levels are important to maintaining healthy phytoplankton populations, which are the basis of most marine food webs.

 

IMG_1171

Collecting water samples from a Niskin bottle.

Personal Log

As we travel from one station to the next, I have some time to talk with other members of the science team and the crew. I have really enjoyed learning about places all over the world by listening to people’s stories. Most people aboard this ship travel many times a year for their work or have lived in remote places to conduct their scientific studies. Their stories inspire me to keep exploring the planet and to always search for new things to learn!

Did you know?

Niskin bottles must be lowered into the water with both ends open to avoid getting an air bubble trapped inside of them. Pressure increases as depth under water increases. Niskin bottles are often lowered down below 150 meters, where the pressure can be intense. If an air bubble were to get trapped inside, the pressure at these depths would cause air bubble to expand so much that it might damage the Niskin bottle!

Samantha Adams: Day 6 – Testing… 1 – 2 – 3, July 29, 2017

NOAA Teacher at Sea

Samantha Adams

Aboard NOAA Ship Hi’ialakai

July 25 – August 3, 2017

Mission: Woods Hole Oceanographic Institution (WHOI) Hawaii Ocean Time-series Station deployment (WHOTS-14)

Geographic Area of Cruise: Hawaii, Pacific Ocean

Date: Saturday, 29 July 2017

Weather Data from the Bridge:

Latitude & Longitude: 22o 45’N, 157o 56’W. Ship speed: 1.3 knots. Air temperature: 27.8oC. Sea temperature: 27.0oC. Humidity: 72%.Wind speed: 14 knots. Wind direction: 107 degrees. Sky cover: Few.

Science and Technology Log:

The most difficult part of Thursday’s buoy deployment was making sure the anchor was dropped on target. Throughout the day, shifting winds and currents kept pushing the ship away from the anchor’s target location. There was constant communication between the ship’s crew and the science team, correcting for this, but while everyone thought we were close when the anchor was dropped, nobody knew for sure until the anchor’s actual location had been surveyed.

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Triangulation of the WHOTS-14 buoy’s anchor location. Look at how close the ‘Anchor at Depth’ location is to the ‘Target’ location — only 177.7 meters apart! Also notice that all three circles intersect at one point, meaning that the triangulated location of the anchor is quite accurate.

To survey the anchor site, the ship “pinged” (sent a signal to) the acoustic releases on the buoy’s mooring line from three separate locations around the area where the anchor was dropped. This determines the distance from the ship to the anchor — or, more accurately, the distance from the ship to the acoustic releases. When all three distances are plotted (see the map above), the exact location of the buoy’s anchor can be determined. Success! The buoy’s anchor is 177.7 meters away from the target location — closer to the intended target than any other WHOTS deployment has gotten.


After deployment on Thursday, and all day Friday, the Hi’ialakai stayed “on station” about a quarter of a nautical mile downwind of the WHOTS-14 buoy, in order to verify that the instruments on the buoy were making accurate measurements. Because both meteorological and oceanographic measurements are being made, the buoy’s data must be verified by two different methods.

Weather data from the buoy (air temperature, relative humidity, wind speed, etc.) is verified using measurements from the Hi’ialakai’s own weather station and a separate set of instruments from NOAA’s Environmental Sciences Research Laboratory. This process is relatively simple, only requiring a few quick mouse clicks (to download the data), a flashdrive (to transfer the data), and a “please” and “thank you”.

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July 28, 2017, 5:58PM HAST. Preparing the rosette for a CDT cast. Notice that the grey sampling bottles are open. If you look closely, you can see clear plastic “wire” running from the top of the sampling bottles to the center of the rosette. The wires are fastened on hooks which, when triggered by the computer in the lab, flip up, releasing the wire and closing the sampling bottle.

Salinity, temperature and depth measurements (from the MicroCats on the mooring line), on the other hand, are much more difficult to verify. In order to get the necessary “in situ” oceanographic data (from measurements made close to the buoy), the water must be sampled directly. This is done buy doing something called a CTD cast — in this case, a specific type called a yo-yo. 

The contraption in the picture to the left is called a rosette. It consists of a PCV pipe frame, several grey sampling bottles around the outside of the frame, and multiple sets of instruments in the center (one primary and one backup) for each measurement being made.

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July 28, 2017, 6:21PM HAST. On station at WHOTS-14, about halfway through a CDT cast (which typically take an hour). The cable that raises and lowers the rosette is running through the pulley in the upper right hand corner of the photo. The buoy is just visible in the distance, under the yellow arm.

The rosette is hooked to a stainless steel cable, hoisted over the side of the ship, and lowered into the water. Cable is cast (run out) until the rosette reaches a certain depth — which can be anything, really, depending on what measurements need to be made. For most of the verification measurements, this depth has been 250 meters. Then, the rosette is hauled up to the surface. And lowered back down. And raised up to the surface. And lowered back down. It’s easy to see why it’s called a yo-yo! (CDT casts that go deeper — thousands of meters instead of hundreds — only go down and up once.)

For the verification process, the rosette is raised and lowered five times, with the instruments continuously measuring temperature, salinity and depth. On the final trip back to the surface, the sampling bottles are closed remotely, one at a time, at specific depths, by a computer in the ship’s lab. (The sampling depths are determined during the cast, by identifying points of interest in the data. Typically, water is sampled at the lowest point of the cast and five meters below the surface, as well as where the salinity and oxygen content of the water is at its lowest.) Then, the rosette is hauled back on board, and water from the sampling bottles is emptied into smaller glass bottles, to be taken back to shore and more closely analyzed.

On this research cruise, the yo-yos are being done by scientists and student researchers from the University of Hawaii, who routinely work at the ALOHA site (where the WHOTS buoys are anchored). The yoyos are done at regular intervals throughout the day, with the first cast beginning at about 6AM HAST and the final one wrapping up at about midnight.

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July 29, 2017, 9:43AM HAST. On station at WHOTS-13. One CDT cast has already been completed; another is scheduled to begin in about 15 minutes.

After the final yo-yo was complete at the WHOTS-14 buoy early Saturday morning, the Hi’ialakai traveled to the WHOTS-13 buoy. Today and tomorrow (Sunday), more in situ meteorological and oceanographic verification measurements will be made at the WHOTS-13 site. All of this — the meteorological measurements, the yo-yos, the days rocking back and forth on the ocean swell — must happen in order to make sure that the data being recorded is consistent from one buoy to the next. If this is the case, then it’s a good bet that any trends or changes in the data are real — caused by the environmental conditions — rather than differences in the instruments themselves.

Personal Log:

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The Hi’ialakai’s dry lab. Everyone is wearing either a sweatshirt or a jacket… are we sure this is Hawaii?

Most of the science team’s time is divided between the Hi’ialakai’s deck and the labs (there are two; one wet, and one dry).  The wet lab contains stainless steel sinks, countertops, and an industrial freezer; on research cruises that focus on marine biology, samples can be stored there. Since the only samples being collected on this cruise are water, which don’t need to be frozen, the freezer was turned off before we left port, and turned into additional storage space.  The dry lab (shown in the picture above) is essentially open office space, in use nearly 24 hours a day. The labs, like most living areas on the ship, are quite well air conditioned. It may be hot and humid outside, but inside, hoodies and hot coffee are both at a premium!

Did You Know?

The acronym “CTD” stands for conductivity, temperature and depth. But the MicroCats on the buoy mooring lines and the CTD casts are supposed to measure salinity, temperature and depth… so where does conductivity come in? It turns out that the salinity of the water can’t be measured directly — but conductivity of the water can.

When salt is dissolved into water, it breaks into ions, which have positive and negative charges. In order to determine salinity, an instrument measuring conductivity will pass a small electrical current between two electrodes (conductors), and the voltage on either side of the electrodes is measured. Ions facilitate the flow of the electrical current through the water. Therefore conductivity, with the temperature of the water taken into account, can be used to determine the salinity.

Leah Johnson: Physical and Chemical Properties of Ocean Water (There’s More Here Than Just Fish!) , July 26, 2015

NOAA Teacher at Sea
Leah Johnson
Aboard NOAA Ship Pisces
July 21 – August 3, 2015

Mission: Southeast Fishery – Independent Survey
Geographical Area of Cruise: Atlantic Ocean, Southeastern U.S. Coast
Date: Sunday, July 26, 2015

Weather Data from the Bridge:
Time 12:38 PM
Latitude 34.24389
Longitude -76.6625
Water Temperature 23.75 °C
Salinity –No Data-
Air Temperature 28.6 °C
Relative Humidity 68 %
Wind Speed 12.6 knots
Wind Direction 67.01 degrees
Air Pressure 1014.8 mbar

Science and Technology Log:
The primary purpose of this cruise is to survey reef fish. Our main task is to collect data pertaining to presence and number of fish species, species length frequency, and sample materials for fish age and growth. However, other types of measurements are being made as well. For example, the CTD is an instrument that measures different properties of ocean water with depth. It is deployed every time the fish traps are dropped.

CTD instrument

The CTD sits on the starboard side of the deck of NOAA Ship Pisces.

The acronym “CTD” stand for conductivity, temperature, and depth. The instruments that measure these properties are affixed to a metal cylinder called a rosette. A range of sensors can be attached depending on what needs to be measured. Additionally, containers can be attached to the frame in order to collect sea water samples at different depths. When the ship reaches the designated coordinates, the survey technician calls to the deckhands and instructs them to use the winch to lower the CTD to a designated depth, and then haul it back up.

Deckhands assist with lowering the CTD

Deckhands assist with lowering the CTD.

Below you can see a graph of the data collected earlier in the week:

CTD Data

CTD Data

The y-axis represents depth in meters. The CTD actually measures water pressure, which is then converted to depth. Pressure and depth are directly related: as depth increases, pressure increases.

There are several different properties represented on the x-axes, shown in different colors:

light green = oxygen (mg/l)
orange = conductivity (S/m)
dark green = temperature (°C)
purple = salinity (PSU, or ppt)

What do these measurements mean? As depth increases, temperature decreases. Sunlight warms the sea surface, and wind and ocean currents distribute this heat energy throughout the upper waters. Beneath this mixed layer, temperature decreases steadily with depth. In deeper water (not at this location), this rate of change decreases and the temperature of deep ocean water is nearly a constant 3 °C. Salinity refers to the concentration of dissolved salts in the water. Average ocean salinity is 35 ppt (parts per thousand), though this varies by a few parts per thousand near the surface. Increased precipitation, runoff, or melting of sea ice can decrease salinity, and evaporation and ice formation can increase salinity. Conductivity (measured in Siemens per meter) is a measure of how much current can travel through the water, and this is affected by both salinity and temperature. Finally, fish and other marine organisms require dissolved oxygen to breathe. By measuring the amount of oxygen at different levels in the water column, we can determine how much sea life can be supported in a given area. Dissolved oxygen in the ocean comes from mixing at the surface, and is also produced by photosynthetic organisms. As temperature and salinity increase, dissolved oxygen levels decrease. Additionally, temperature and salinity data can be used to determine the water density, or the mass of water per unit volume. Different fish can tolerate certain ranges of all of these chemical and physical parameters.

With respect to the fish survey, this information is important because we can monitor the conditions of the water near the ocean floor where the traps are located. For scientists who are interested in characterizing reef fish habitat, this data is a critical component of their research.

There are other ways in which this data can be used. The depth profiles of each of the chemical and physical properties at a given site can be compared to other local sites in order to identify any spatial anomalies. This is of great interest for seafloor mapping and ocean exploration cruises. For example, a change in conductivity and temperature at a site in the middle of the ocean could indicate the presence of a hydrothermal vent. Or, a decrease in salinity in a region along a coastline could indicate freshwater runoff.

Additionally, as measurements are made at similar locations over a period of time, temporal changes may be observed. This could reveal seasonal changes, or a long-term trend. Because we are observing an increase in average global temperatures and experiencing global climate change, it is critical to collect data that can be used to assess changing ocean conditions.

Personal Log:
“Will you be eating a lot of fish on the ship?” I heard this question a lot before I left for this cruise. I wondered myself. It seemed reasonable that fish would be prepared for meals because, well, we will be living at sea! On the other hand, I wondered if everyone on board would be sick to death of fish because we would be looking at them all day. As it turns out, fish is prepared for nearly every meal; however, there is often another meat option, as well as a variety of other non-meat dishes. Now we know!

ship mess

Ship mess

Did You Know?
There are many fish that make a grunting sound. When we have tubs full of tomtates in the wet lab, it sounds like a bunch of miniature pigs making snorting noises!

tomtates and nurse shark

Still from video of tomtates near a trap. A nurse shark can be seen in the background.

Theresa Paulsen: Where There is a Will, There is a Way! April 1, 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 1, 2015

Weather Data from the Bridge:  Partly Cloudy, 26˚C, waves 1-3ft, swells 3-6ft.

Science and Technology Log:

Dr. Wilford (Bill) Schmidt has demonstrated the saying, “Where there is a will, there is a way,” throughout this  entire cruise.  He knew this voyage would put his new free vehicle design to the test and he came prepared to modify this, tweak that, collaborate with the crew, confer with his university team, test, and repeat.  He is an engineer and that is the name of the game.

1.  The first deployment looked great. The vehicle reached 1000m.  The magnetometer and 3-axis accelerometer worked great.  All systems were a go.  A water sampling device was used as a dummy payload.

FV Dummy Test

The free vehicle with a water sampling device as a dummy payload.

 

Test Data

Data from the Test Deployment

 

Crossing fingers for more success.

2.  The next step was to attach a CTD (a probe that measures Conductivity, Temperature, Depth).  The deployment and retrieval process again went smoothly, this time to 2126m, but there was a problem retrieving the log file from the bottom sphere and one of the anchor burn wires did not burn.

 

FV with CTD

The free vehicle with CTD attached.

Collaboration required with folks on shore and the electronics technicians on this ship.  Tweak this, fix that.

Troubleshooting

Dave Blessing, Electronics Tech, and Bill Schmidt troubleshooting.

Bill opened the spheres to change the batteries for the satellite transponder.

Open Sphere

One of the opened spheres

Keeping a log

Zamara Fuentes keeping a log of all of the adjustments and parameters

Repressurizing the sphere

Rolf Vieten pressurizing the sphere

All systems were a go again.

3.  The crew deployed the free vehicle with the CTD to 4679 m.  It took a little longer to find and retrieve the vehicle.

FV Retrieval

Retrieval of the free vehicle

The data files indicated that the galvanic releases released the anchor prematurely, at about 100 meters from the bottom.  Both spheres worked during the mission.  Data files were retrieved from each.  During inspection water was found in the bottom sphere.  Spalling of the glass (flaking) was seen on the inside.  The leak is assumed to have taken place as the surface under low pressure conditions, otherwise the damage would have been worse.  The electronics were in good shape but the bottom sphere had to be retired.

Oh no!  Is that the end?  Not when you have great minds on board!

This is where engineering in the ocean environment gets tricky.  Bill can’t just head back to the university and make the necessary repairs.  Instead he needs to make use of the very valuable ship time by pinch-hitting.  Bill recalculated the buoyant force on the vehicle with only one sphere.  It might just work!

Tweak this, lighten that, new attachments there. Ready for a float test!

Single sphere float test

The single sphere float test was a success!

Will the single sphere allow it to ascend from the bottom fast enough for us to deploy and retrieve it during our mission?  That question required further testing.  So the crew planned to lower it into the water a short distance with the winch and allow it to float back up.  The weather would not allow it.  The seas were too rough to allow the ship to stay in one place during the vehicle test without dragging the free vehicle thereby negating the results of the test.

Operations team meeting

Operations team meeting

Plan B?  The operations team hatched a plan to tie the free vehicle to buoys on a long rope.  That allowed the vehicle to sink and be recovered easily if it rose too slowly. First a buoyancy test had to be done to make sure the buoys wouldn’t sink with the vehicle.

Buoy Float Test

Buoy float test

The vehicle rose in less than 10 minutes so the team was back on track!  With a few extras like flags for better visibility, the vehicle was ready to dive!

Preparing for the big dive to 8000+ meters!

Preparing for the big dive to 8000+ meters!

4.  The deployment into the trench went smoothly.  The crew had that routine down pat.  After 10 hours it was time for the retrieval.  Everyone gathered at the bridge to try to spot it.

FV lookout

On the lookout for the free vehicle.

Port side lookouts

Port side lookouts

Free Vehicle Returns

The free vehicle returns from the deep!

It successfully collected data down to the bottom at 8379m, a possible record for a free vehicle!

Successful Dive

Bill content with a successful dive

The CTD data was processed and looked great during the descent.

FV CTD data

Free vehicle CTD data from the Puerto Rico Trench

Inspection of the data log showed that while the vehicle was ascending from the bottom, something was triggering a mission cancel order – 28 times!  This bug required more testing and mission simulating before another deployment in the trench.  Just after 8pm, Bill announced his equipment was ready to go for a 6 am deployment the next day.

5.  The next day, the retrieval took a bit longer due to choppier sea conditions.

The crew bringing the free vehicle aboard.

The crew bringing the free vehicle aboard.

Again the vehicle logs showed “cancel mission” messages during the ascent.  It is confounding Bill and his team back home, because during mission simulations the mission goes to completion without a problem.

In all the voyage has been very constructive for Bill’s engineering team.   They successfully deployed the vehicle to the bottom of the Puerto Rico Trench known to be the deepest part of the Atlantic Ocean.  That is something to celebrate!  They have learned a great deal about what types of modifications they should make to improve the retrieval process.

This was a great first test of the free vehicle design.  The next time out at sea will come soon enough and Bill’s team will be ready!

Personal Log

As the voyage comes to an end and we travel nearer to shore, I am filled with mixed emotions.  I will miss the ocean, the feeling of being a part of an exploration expedition, and these people.  I am also very happy to be going home to my family and my students.  I am looking forward to sharing what I have learned.  I will be looking for partnerships to help get students involved in reseach on our inland sea, Lake Superior.  If you have any suggestions, please leave a comment below!

Exciting moments?  Seeing these creatures!

Whale

Small whale swimming next to the vessel.

Dolphin

A dolphin playing in our wake. Photo credit: Jossue Millan

Other great moments include driving the ship and making video fly-bys of the ocean floor with the bathymetry and backscatter data.  Very awesome!  The videos will be coming soon so stay tuned!

Did you know?

Do you remember the flying fish I wondered about a few blogs ago?  I have never seen them before.  At first I thought I was seeing things.  I thought I saw a very large dragonfly dive into the water.  Then I saw more.  – schools of them jumping away from the boat all at once.  In a blink of an eye they were gone.

A flying fish.  Image courtesy of “Bermuda: Search for Deep Water Caves 2009 Exploration,”  NOAA Ocean Explorer

According to Wikipedia, there are 64 species of flying fish!  They fly out of the water to evade predators.  That’s a pretty cool adaptation!  You can learn more here.

Question of the Day:

Theresa Paulsen: How Low Can You Go? March 29, 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: March 29, 2015

Weather Data from the Bridge:  Partly Cloudy, 26.7˚C, waves 1-3ft, swells 2-4ft.

Science and Technology Log:

We launched and recovered a CTD earlier this week.

A CTD (Conductivity, Temperature and Depth probe) is used to study the characteristics of ocean water masses, as well as to insure data quality and accuracy from XBTs (Expendible Bathythermograph). In a previous blog, I discussed how the XBT is used to measure the temperature of the water to a depth of about 760 meters. That coupled with the conductivity sensors on the vessel are used to calculate salinity and pressure to derive a measure of the velocity of sound through water, an important factor when collecting sonar data.

An XBT can be launched while the vessel is underway without pausing the sonar, but it doesn’t collect data all the way to the bottom of the water column.

Launching an XBT

Trying my hand at launching an XBT

A CTD can go all the way to the bottom, depending on the depth of the ocean, the length of the tether cable, and the pressure rating of the frame and equipment making up the CTD.  The titanium frame and equipment making up the CTD currently aboard the Okeanos can be lowered to 6500 meters.   It is very large and requires the vessel to stay put during the entire process since it is tethered to the ship.

Since a CTD collects all three factors involved in the computation of speed of sound in water (salinity, temperature, and depth) and is therefore more accurate than an XBT which only collects temperature, it is used at least annually to provide comparison data for the XBT measurements. This is the reason our scientists used it on this cruise.  Additionally, scientists on board a vessel may want to deploy a CTD more often if water masses are expected to change, or if they are interested in studying other features of the water column such as particulates, gaseous seeps, dissolved oxygen or oxygen reduction potential, or if they want to collect water samples at different depths.

The CTD

Survey Tech, Scott Allen and the CTD.

In the above photo the small red arrow is pointing to the water sample tubes, the large blue arrow to the CTD, and the large red arrow to the altimeter which senses when the probe is within 200 meters from the bottom allowing winch operators to slow the descent to avoid damaging equipment.  Scott Allen is the Survey Tech on board.  His job is to maintain and calibrate the CTD.  He helps launch and recover the CTD and then operates the software to collect and process the data.

CTD Data

Our first CTD launch data.

The CTD software plots the temperature (green), sound velocity (pink), conductivity (yellow), and the salinity (blue) on the x-axes against depth on the y-axis.  You can see locations on the graph where the values for temperature and salinity shift in a significant way with changes in depth.  These shifts can indicate a boundary between different water masses.  The upward spikes in the data are likely caused by some error in the equipment connections.

Let’s conduct an experiment!

Have you ever wondered what would happen to a styrofoam cup if you lowered into the water 2100 meters? The folks here tell me you get some pretty interesting results, so we had to give it a try.

Problem:  Determine the effect of extreme pressure on a styrofoam cups.

Background:  Styrofoam, properly called expanded polystyrene foam, is made by infusing air into polystyrene (a synthetic polymer) using blowing agents. Learn more here.

Hypothesis:  What is your hypothesis?  What do you think will happen to the air pockets if we send the cups to the depths of the ocean?

Procedure:

1.  Decorate your cups, leaving one as a control for comparison after submersion.

Styrofoam Cups

Decorating 12 oz styrofoam cups

Cup Decorations

More cup designs

The Before Picture

2.  Place the cups in a mesh dive bag and attach to a CTD.

Cups ready

Our cups are ready to dive!

3. Lower the CTD to 2100 meters

Launching the CTD

Launching the CTD

4.  Raise the CTD and examine the cups.

Raising the CTD

Raising the cups and CTD

Analysis:

So how much pressure was exerted on the cups at 2100 meters?  We can use this formula to calculate it:

P = pgh

Pressure in a fluid = (density of water) x (acceleration due to gravity) x (height of the fluid above the object).

If the density of seawater is 1027 kg/cubic meter, the acceleration due to gravity is 9.8 m/s/s and the depth is 2100 meters, what is the pressure?

You should get 21 million Pascals (Newtons/square meters) or 21,000 kPa.  If 1 kPa = 0.145 psi, how many pounds of pressure per square inch are exerted on each cup?   About 3000 pounds per square inch.  That’s about the weight of a compact car over each square inch!  For comparison, at sea level the atmospheric pressure is 14.7 psi.

So what happened to our cups under all that pressure?  Check it out!

Cups after dive

Our cups after a dive to 2100m. They are tiny!

Shrunken cups

More shrunken cups.

Shrunken cups

Showing off my shrunken cups.

Conclusion:

Was your hypothesis supported or refuted?  What happened to the air trapped in the styrofoam?

Air extraction is the reason that Dr. Wilford Schmidt uses iron rebar rather than cement to provide the anchor for his free vehicles.  The cement crumbles as the air pockets give way and air is squeezed out.  Cement is not as flexible as the polystyrene.

Free Vehicle

The free vehicle with rebar anchor

What other materials might change under pressure?  If you don’t have access to the deep ocean or a CTD, you could always try a pressure cooker – but be safe!

Personal Log:

I am inspired by all the people working on this vessel.  They are so adventurous and have seen so much.  I wondered what inspired them to do what they do.  Here are some of their answers:

Mapping Intern, Kristin Mello:  Took a class in scuba diving and realized she loved it and wanted to learn more.  Her dive instructor encouraged her to do an internship as a research diver and she has been studying the ocean ever since.

Free Vehicle Tech, Zamara Fuentes:  Built a model of a volcano in school became very interested in geology.  Now she studies tsunami impacts on the Caribbean islands.

NOAA Corps Officer, Nick Pawlenko:  Had never really spent much time on boats as a kid, but was inspired by Clive Cussler novels to explore the ocean.

Expedition Coordinator, Meme Lobecker: Her love of the oceans made her want to put her geography skills and interest in data collection to work in the ocean environment.

Engineer, Chris Taylor:  Wanted to put his love of engineering to work for good pay.  “There is never a dull moment,” he says.

Mapping Watch Lead, Melody Ovard:  Just likes being near the ocean.  “It’s a proximity thing.  I am curious about what goes on in it,” she says.

Free Vehicle Scientist, Bill Schmidt:  Loved surfing and was interested to learn what caused the changes in the surfing conditions day-to-day.  Then he read Willard Bascom’s book, Waves and Beaches, and was hooked.

NOAA Corps Officer, Bryan Pestone:  Swimming competitively and lifeguarding on the beach led him to a degree in marine biology.

Mapping Intern, Jossue Millan:  An astrobiology poster caught his eye in his physics class, which peaked his interest in life in extreme environments.  He enjoys the interdisciplinary sciences.

Teacher at Sea, Theresa Paulsen:  I am inspired by the wonder in a kid’s eye or on a proud parent’s face and by the beauty that surrounds us from the depths of the oceans to the expanses of space.  Life is amazing – and far too short to waste, so we have to make the most of it while we can.

Sunset Image

Thanks for the inspiring conversation everyone!

What inspires you?  Post a comment and let me know!

Did You Know?

For every 10 meters you go below the surface, pressure increases by one atmosphere (14.7 psi).  Scuba instructors typically don’t recommend diving deeper than 40m to decrease the risk of decompression sickness, known as “the bends,” or equipment failures that could lead to drowning.

Question of the Day:

The deepest successful dive in the Guiness Book of World Records is currently 332.35 meters (1090ft)!  Yikes!  Read about it here.

Theresa Paulsen: Intriguing Deployments, March 19, 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: March 19, 2015

Weather Data from the Bridge:  Partly Cloudy, 26.7˚C, waves 1-3ft, swells 2-4ft.

Science and Technology Log:

This morning at breakfast Commanding Officer Mark Wetzler, or CO, explained that we would be deploying instruments today.  The first one was a glider for the Navy. The Slocum electric glider is like a tiny, unmanned submarine built like a non-explosive torpedo with small wings. It has the ability to be remote-controlled for weeks to months at sea operating 24 hours a day even in the worst weather.  They can be programmed to travel back and forth, dive, and rise periodically to communicate data back to the mainland and accept new missions.  These autonomous underwater vehicles (AUVs) can collect many different types of data such as temperature, conductivity, or audio recordings, depending on the sensors attached. Gliders like this one can help detect tsunamis or other changes in the ocean.

Our vessel also records data 24 hours a day but is limited in its duration at sea by the needs of the people and fuel onboard.  Have you wondered how we can stay out at sea for nearly 3 weeks at a time without hitting the grocery store or service station?  I’ll explain more about that in a future blog.

Navy Glider

Close-up of Navy glider

Deploying the Navy Glider

Navy Glider Deployment

Navy Glider at Sea

Navy Glider at Sea

 

The next deployment was a test run of a “free vehicle.”  Dr. Wilford “Bill” Schmidt, and his assistants, Rolf-Martin Vieten and Zamara Fuentes from the University of Puerto Rico, Mayguez (UPRM) are testing the design of vehicles that can be deployed from a vessel like the Okeanos Explorer or a smaller ship.  These vehicles are inexpensive to make, easy to deploy, and do not need to be tethered to the ship.  They can be programmed to dive to the deepest parts of the ocean, or whatever depth desired, in order to take samples or record data.  Once the vehicle has completed data collection or sampling, it releases its anchor and rises the surface where it is retrieved.  Meanwhile the deployment vessel can continue other operations such as mapping.  Time is not wasted on a research vessel!  On this cruise they will use the device to sample the conductivity, temperature and depth of the water column.  This will help them learn more about the interaction between different water masses in the Puerto Rico Trench.

 

Bill's Team

Wilford “Bill” Schmidt, Zamara Fuentes, and Rolf-Martin Vieten with the Free Vehicle

Water masses in the trench are of particular interest to Bill, a professor of physical oceanography, because they could hold a key to understanding the flow of different ocean currents.  He explained that water masses form at the surface at a particular temperature and with a certain salinity corresponding to the surface conditions at the time.  Temperature and salinity are conservative properties, meaning they don’t change as the water mass moves.   So as a water mass formed in Antarctica sinks and moves toward the deepest parts of the ocean due to its density, its cold temperature and salinity don’t vary significantly. So temperature and salinity can serve as fingerprints of water masses.  Therefore as he measures these factors through the entire water column in the trench, we would expect to see the values change as we move from the North Atlantic Deep Water to the Antarctic Bottom Water.  The image below shows a generalized representation of the typical flow pattern of large water masses.

Ocean Circulation

The ocean circulation system. Image courtesy of NASA.

Bill’s work is supported by NOAA and the National Science Foundation. The NOAA Office of Exploration and Research recently provided him with an award to produce 5 free vehicles with his university team.  The fact that Bill’s vehicles are able to travel untethered into the hadal zone at a very low cost makes them uniquely valuable to researchers.  Data from the hadal zone is virtually non-existant because only enormous vessels would be able to support winches that could handle the 10,000+ meters of cable that would be required for the tethered vehicles currently used.  Since the average depth of the ocean is only 4000m, there is not a large enough demand to make manufacturing such large winches economically feasible.

Also, Bill’s free vehicles are small and can be deployed on very short notice, allowing them to capture data as major events occur. The vehicles can carry interchangeable payloads that could be used in all scientific disciplines. A biologist could request water or bottom substrate samples to examine life forms in the hadal zone that may not exist elsewhere.  A geologist might also like to sample the bottom substrate or might wish to record seismic activity at the bottom of the trench to better understand plate interactions.  A chemist interested in oceanography could examine the water for trace elements or compounds that were emitted into the air at one point in time, such as chloroflourocarbons (CFCs) that were once used but are now illegal in the US due to their impact on the ozone layer, or tritium (H-3) remnants from nuclear bombs used in WWII. This could provide us with an estimate of how long ago the water mass was at the surface and help us determine the rate of flow into the trench.  The research possibilities are endless.

FV Test

The first free vehicle test of the voyage

Initial tests looked good. During our 19 day voyage, Bill’s team and the crew will deploy the vehicle up to 11 more times with up to 6 locations strategically placed in the Puerto Rico Trench.

Personal Log:

Are you interested to know what the accommodations are like aboard the Okeanos?  They are comfortable enough for a work boat.  Take a look for yourself!

Porthole

The porthole in my room.

 

My Bed

My Bed

I love the curtain around my bottom bunk.  It reminds me of the forts my brothers and sisters and I built as kids.  I have slept like a baby ever since arriving.  The rocking of the boat is very calming.

There are a couple of nice spots to relax and chat, and write in my blog.  Here are the library and the lounge.

Library

Chris Taylor and Nick Pawlenko in the library

Lounge

The Lounge

I am surprised that I really haven’t been seasick. Motion sickness medication really helps. If you really get sick, there is a medical officer on board and sick bay.

The Sick Bay

The Sick Bay

I showed you the galley in the last post.  We eat in the Mess Hall.  The Chief Steward puts tennis balls on the bottom of the chairs to avoid scratching the finish on the floor.  Good thinking!

The Mess Hall

The Mess Deck

And when I have eaten too much, there is the fitness room!  There is a scale in the fitness room, but when you stand on it, the action of the boat rocking causes the scale to oscillate by 30-40 pounds.  It is a great demonstration of the difference between mass and weight!

Fitness Room

The Fitness Room

The best place to hang out is outside, of course, where you can possibly see a spouting whale or swimming dolphin.  I have seen both on this trip already but I need to be quicker with the camera!  Maybe next time!!

View from the bow

The view from the bow of the ship

Question of the Day:

Carol Glor: Awe Shucks! The Mission Continues, July 9, 2014

NOAA Teacher at Sea

Carol Glor

Aboard R/V Hugh R. Sharp

July 5 – 14, 2014

Mission: Sea Scallop Survey, Third Leg

Geographical area of cruise: Northwest Atlantic Ocean

Date: July 9, 2014

Weather data from the bridge: Wind 204* 15 knots, Seas 4-6-10-12 ft. mixed directions, Visibility – overcast

Science and Technology Log:

Today we began dredging for scallops. The ship follows a predetermined path and the dredge is lowered to the ocean floor at specific locations along the path. These locations are chosen by the Scallop Assessment Biologist at NOAA because they are an accurate representation of the scallop population in the Northwest Atlantic Ocean. The area that we are focused on is known as Georges Bank. It is a broad, shallow submarine plateau forming the seaward boundary of the Gulf of Maine. The average depth is between 30 and 75 meters deep. It is home to an assortment of marine life including the Atlantic Sea Scallop. Several computers are employed to record all of the data that is pertinent to each dredge event. These include: ocean depth, air temperature, salinity, barometer, air speed, wind direction, fluorometer, and wind direction. The lab is in constant communication with both the bridge and the engineer who operates the winch system. Depending upon the ocean depth at the dredge station location, a specific amount of dredging cable (called line) to which the dredge net is attached, is released in order to create the best angle for the dredging operation.

 

map of Georges Bank

3D map of Georges Bank at the Woods Hole Aquarium.

map

Map of dredge stations.

offloading the dredge

The dredge is offloaded onto the sorting table.

After 15 minutes the dredge is hauled up to the surface and the net is emptied out onto the sorting table. All members of the science team are poised and ready to sort the catch. Each sorter is outfitted with foul weather gear. This consists of rubberized jacket, coveralls and rubber boots. Also required is a life vest, heavy duty gloves, and a hard hat (if the winch is in use). Several baskets and buckets are arranged around the sorting table. One is reserved for scallops, one for assorted fish and skate, one for crabs and whelk, and the last is for items that are not part of the study. This is known as trash.

When everyone has completed their preliminary sorting, it is time to count and sort each species that was collected. Trash is also accounted for. Each basket that is returned to the ocean is counted and data is recorded. The sorting and trash data is entered into the computer system inside the wet lab (also known as the van). At the three stations inside the van, a measuring tray is utilized to quickly measure and record the length of certain fish, scallops and skate. The first large scallop from each dredge event is photographed as a representation of that event. All large scallops are then weighed and shucked and the scallop is sexed (recorded as a male or female). The sex organ is weighed as well as the meat. The shells of the large scallops are cleaned, labeled, and placed into a muslin bag in order to be further analyzed at a NOAA laboratory back on shore. At the conclusion of the dredge event and sorting process, the lab is cleaned and prepped for the next event.

During our first watch, our team completed seven dredge events. Each event can take more than an hour from start to finish. Our catches included a variety of marine species: scallops, sand dollars, ocean pout, windowpane flounder, yellowtail flounder, four spot flounder, and gulfstream flounder, silver and red hake, quahogs, barn-door and winter skate, haddock, sand lance, cancer and hermit crab, sea mouse, sea sponge, fawn cusk eel, wave whelk, and monkfish (goosefish).

Sorting

Sorting the dredge.

skate

Carol measures a skate inside the lab

Baby Scallops

Baby Scallops to be counted, weighed, and measured.

 

Personal Log:

As an inexperienced sailor and scientist, the NOAA staff all worked hard to train me to complete many of the tasks required during our watch. Scientific method and protocol was followed to a “T”. It was an awesome and intense responsibility to fly the HabCam, annotate images recorded by the HabCam, monitor environmental data, set up the dredging event on the computer system, and record the sample data. Throughout the scheduled watch we witnessed whales spouting and breaching, and porpoise antics. During our down time we enjoyed the company of each other as well as the delicious meals prepared by Chef Paul.

Life at sea can be challenging. The weather is checked often in order to adjust the dredging route. High waves can make a dredge event difficult. They can also be a safety issue out on deck. For this reason, each person is required to wear a life vest and boots. Anyone on deck during a dredge drop or haul back is also required to wear a hard hat.

After a long, hard day, sleep is usually the best thing that you can do for yourself. The cabin area is quiet at all times because everyone is on a different shift. I am in a 4-person cabin but my roommates are all on the opposite shift. The rocking of the ship, and background engine noise makes it easy to fall asleep for long periods of time.

Did you know?

Scallops can be male or female. The simplest way to determine the sex is to open the scallop shell and examine the gonad. Female scallops have a pink gonad and males are cream-colored.

male and female scallops

Female scallop is on the left and a male scallop is on the right.

Photo Gallery

sea stars

An assortment of Sea Stars

Fin back whale

Fin Back Whale sighting

dolphins

Dolphins at play

Ocean Pout

Ocean Pout – eats sand dollars

Answer to last poll:

The R/V Hugh R. Sharp has at least 88 computer monitors on board. An equal number are part of the navigational  and monitoring systems as well as the scientific research components.