Tag: chukchi sea

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Christine Hedge, September 15, 2009

NOAA Teacher at Sea
Christine Hedge
Onboard USCGC Healy
August 7 – September 16, 2009 

Mission: U.S.-Canada 2009 Arctic Seafloor Continental Shelf Survey
Location: Chukchi Sea, north of the arctic circle
Date: September 15, 2009

MST2 Tom Kruger and MST3 Marshall Chaidez retrieve a meteorological buoy on September 14.
MST2 Tom Kruger and MST3 Marshall Chaidez retrieve a meteorological buoy on September 14.

Weather Data from the Bridge 
Latitude: 730 22’N
Longitude: 1560 27’W
Temperature: 310F

Science and Technology Log 

The past few days have brought much change.  The depth of the ocean changed dramatically as we got closer to Alaska. The ocean went from depths of over 3500 meters to depths of less than 100 meters.  More birds are showing up and we are getting about 9 hours of darkness each day.  This morning at about 4 AM, the watch observed the Aurora Borealis and stars!!!  I am so jealous.

FOR MY STUDENTS: Why do you think we have more hours of darkness now? 

As we head home to Barrow, the science party is busily completing their “Cruise Reports” and making sure that their data is stored safely for the trip home.  Much has been accomplished on this trip:

  • 132 XBT deployments (measures temperature, depth)
  • 8 CTD deployments (measures conductivity, temperature, depth)
  • 5 Dredge operations and hundreds of pounds of rock samples collected and catalogued
  •  1 Seaglider deployed and retrieved
  • 2 HARP instruments retrieved and 3 deployed
  • 3 Ice buoys deployed
  • 8 Sonobuoys deployed
  • 9585.0 lineal kilometers of sea floor mapped
  • 1 METBUOY retrieved (meteorological buoy)

Coast Guard Marine Science Technicians  

MST3 Marshal Chaidez operates the winch during a dredging operation.
MST3 Marshal Chaidez operates the winch during a dredging operation.

Science parties come and go on the Healy, each doing a different type of research.  A constant for all the scientific cruises is the good work done by the Coast Guard MSTs (Marine Science Technicians). Running the winch, taking daily XBT and weather measurements, working the dredge, and helping to deploy buoys are just some of the many tasks these technicians do. The scientists could not get their experiments done without the assistance of our team of MSTs.

MST3 Daniel Purse, MST2 Daniel Jarrett, MST3 Marshal Chaidez, MST2 Thomas Kruger and Chief Mark Rieg have done a masterful job of helping the science party accomplish their goals. I asked them to tell me a little about their training for this job. Each MST attends a 10-week training school in Yorktown, VA. Most of their training involves how to clean up oil spills and inspect cargo ships which means they are usually stationed at a port. Being assigned to a ship is not the norm for an MST.  But, because the mission of the Healy is specifically science, a team of MSTs is essential.

MST2 Daniel Jarrett rigging the crane.
MST2 Daniel Jarrett rigging the crane.

Personal Log 

My commute to work is different lately. We have about 9 hours of darkness each day. It gets dark around midnight and stays dark until about 8:30 in the morning.  So, walking the deck to the science lab is a bit of a challenge at 7:45. It will be strange to drive to work in a few days! On September 16th, we will depart the Healy via helicopter if all goes according to plan.  It will be strange to be on land again.

We will be back in Barrow, AK on September 16th. I cannot believe that our expedition is almost over.  I have learned so much from the members of the science party and the crew of the Healy. They have been very gracious and patient while I took their pictures and asked questions. Now comes the task of sharing what I have learned with folks back home.  I know one thing for sure; the Arctic is no longer an abstract idea for me. It is a place of beauty and mystery and a place some people call home.  I hope to convey how important it is that we continue to study this place to learn how it came to be and how it is currently changing.

Jon Pazol and I next to the bowhead whale skull in Barrow. When we return to shore the bowhead hunting season will have started.
Jon Pazol and I next to the bowhead whale skull in Barrow. When we return to shore the bowhead hunting season will have started.

Thanks to the folks at NOAA Teacher at Sea, Captain Sommer, and chief scientists Larry Mayer and Andy Armstrong for allowing me to take part in this cruise.  You can be sure that I will be following Arctic research and the adventures of the Healy for many years to come.

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Christine Hedge, September 14, 2009

NOAA Teacher at Sea
Christine Hedge
Onboard USCGC Healy
August 7 – September 16, 2009 

Mission: U.S.-Canada 2009 Arctic Seafloor Continental Shelf Survey
Location: Chukchi Sea, north of the arctic circle
Date: September 14, 2009

Dr. Hall standing by the hovercraft before it is inflated
Dr. Hall standing by the hovercraft before it is inflated

Weather Data from the Bridge 
Latitude: 720 46’N
Longitude: 1580 24’W
Temperature: 350F

Science and Technology Log 

Doing science in the Arctic is challenging.  The weather is difficult, the ice is ever changing, and the expense of operating an icebreaker, aircraft, or helicopter is quite high.  So, how else can people get out onto the ice to study the ocean and the geology of the seafloor? One interesting project uses a hovercraft (think air hockey), which skims over the ice on a cushion of air. Using a hovercraft to study the most inaccessible places in the Arctic is not a new idea. But, Dr. John K. Hall, a member of our science party has taken this idea and run with it.   John has a long history of polar exploration under his belt. Including 13.5 months floating around the Arctic on a 90 square kilometer, 60-meter thick ice sheet known as Fletcher’s Ice Island (T-3) during the 1960’s. His latest project has been to purchase and equip a hovercraft to go where icebreakers cannot (areas of VERY thick ice).

Norwegian students parked on the ice doing research. The white tent protects the scientists while they collect data through a drill hole in the ice.
Norwegian students parked on the ice doing research. The white tent protects the scientists while they collect data through a drill hole in the ice.

The hovercraft was completed in 2007.  She is called the R/H Sabvabaa, which is the Inupiaq word for “flows swiftly over it.”  This hovercraft was designed specifically for doing science in Arctic conditions. It is equipped with all the comforts of home and all the latest technology.  From this research platform scientists have access to echosounding and seismic equipment to study the sea floor.  They can also park the Sabvabaa easily on a floe, get out on the ice to drill, photograph, and collect samples from under the ice.  This small 40-foot vessel (it fits in a semi-truck container) has great potential as a way for scientists to collect data in heavy ice conditions.  For more information about the Sabvabaa check out this website.

Classroom on the Ice 

Could you imagine being one of the first people to ride the hovercraft over the pack ice?  Since 2008, 16 lucky Norwegian high-school students have had that honor.  A competition was held as part of the Norwegian International Polar Year (IPY) program.  This competition set out to find Norwegian students ages 14-18 who are interested in careers in polar geophysics. A pair of students and a pair of researchers worked from the Sabavaa for one-week intervals. During their time on the Sabvabaa, the winning students participated in geophysical, geological, and oceanographic studies on drifting ice. They also had 4 encounters with polar bears!  What a great opportunity for these students. If you are interested in the student blogs from these trips (which are written in Norwegian) do a Google search for Sabavaa and have Google translate them.

FOR MY STUDENTS: Remember, not all scientists work in labs wearing white lab coats!  Many researchers lead exciting and adventurous lives. 

Paul Henkart teaching Nikki Kuenzel and Christina Lacerda.
Paul Henkart teaching Nikki Kuenzel and Christina Lacerda.

Personal Log 

As an educator, one of the best parts of this expedition has been to watch the mentoring that goes on. The scientists and professors in the science party have decades of research experience to share. It is not unusual to find one of these veteran Arctic explorers sharing their expertise with graduate students from the University of New Hampshire. Not only do these “mentor scientists” have great technical expertise. They are also really good at explaining complex ideas in a very simple way.   This has been wonderful for me since my background is in biology – so geophysics has been a challenge. The graduate students on board are not only learning science from the masters – they are hearing great adventure stories about past polar adventures before we had helpful technologies such as GPS and multibeam echosounders. Everyone on the Healy is in “learning mode”.  The Coast Guard crew, teachers at sea, scientists, and students are constantly asking questions and sharing expertise.

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Christine Hedge, September 13, 2009

NOAA Teacher at Sea
Christine Hedge
Onboard USCGC Healy
August 7 – September 16, 2009 

Mission: U.S.-Canada 2009 Arctic Seafloor Continental Shelf Survey
Location: Chukchi Sea, north of the arctic circle
Date: September 13, 2009

Weather Data from the Bridge 
Latitude: 720 44’N
Longitude: 1560 59’W
Temperature: 350F

A Seasonal Ice buoy with a thermistor chain is deployed from the Healy. This buoy starts in open water and later may
A Seasonal Ice buoy with a thermistor chain is deployed from the Healy. This buoy starts in open water and later may freeze into the ice. This instrument collects ocean and air temperature data, barometric pressure data, and location data.

Science and Technology Log 

Buoys and Moorings And Gliders, Oh My!!! 
Exploring the oceans has a lot in common with exploring space.  NASA can send manned or unmanned missions into space.  Sending manned vehicles into space is more complicated than launching a probe or a telescope. The same is true for exploring the Arctic Ocean.  We can collect data on an icebreaker, manned with Coast Guard and science personnel or use instruments that can send back data remotely.  On this mission, many instruments have been deployed to send back data about the conditions in the Arctic. These instruments continue to do their work after the crew and scientists from the Healy have moved on.  Ice buoys, which float or freeze into ice floes, are one example.  The HARP instruments (High-frequency Acoustic Recording Package), which sit on the sea floor, are another.

A United States Navy team, under the supervision of Navy Commander William Sommer, has launched a very interesting instrument from the Healy called the Seaglider. We have been tracking its movements since it was launched on August 8th. The Seaglider collects information about the salinity, temperature, and optical clarity of the ocean. The Navy is interested in how sound travels through the oceans and this glider is an important tool for doing just that.

CDR Bill Sommer, AG1 Richard Lehmkuhl, and MST3 Marshal Chaidez deploy a Seaglider from the Healy in the Chukchi Sea. Data from the Seaglider will improve the performance, and aid in the evaluation, of the effectiveness of the ocean models in the Arctic. Photo courtesy of PA3 Patrick Kelley, USCG.
CDR Bill Sommer, AG1 Richard Lehmkuhl, and MST3 Marshal Chaidez deploy a Seaglider from the Healy in the Chukchi Sea. Data from the Seaglider will improve the performance, and aid in the evaluation, of the effectiveness of the ocean models in the Arctic. Photo courtesy of PA3 Patrick Kelley, USCG.

What makes the Seaglider unique is that instead of just drifting, it can be driven.  In fact, this instrument is directed via satellite from a computer lab in Mississippi!  The glider moves up and down in the water column and like an air glider it uses this up and down motion to move forward. It has a GPS and a radio so that it can communicate its location. The Seaglider deployed from the Healy in August was picked up today.

Final check of the Seaglider before it was launched.
Final check of the Seaglider before it was
launched.
The green dots indicate the path of the Navy Seaglider as it collected data in the Chukchi Sea.
The green dots indicate the path of the Navy Seaglider as it collected data in the Chukchi Sea.
Coast Guard and Navy personnel work together to retrieve the Seaglider on September 13.
Coast Guard and Navy personnel work together to retrieve the Seaglider on September 13.
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Christine Hedge, September 9-11, 2009

NOAA Teacher at Sea
Christine Hedge
Onboard USCGC Healy
August 7 – September 16, 2009 

Mission: U.S.-Canada 2009 Arctic Seafloor Continental Shelf Survey
Location: Chukchi Sea, north of the arctic circle
Date: September 9-11, 2009

Positions 
From Latitude: 790 6’N/ Longitude: 1550 47’W
To Latitude: 780 3’N/ Longitude: 1590 41’W

Alex Andronikov labels and bags rock samples for further study.
Alex Andronikov labels and bags rock samples for further study.

Science and Technology Log 

Exploring the Unknown 
Geologically speaking, parts of the Arctic Ocean are some of the least explored areas on earth because they are often covered with thick ice. Geologists know there is an ultra-slow spreading center (where seafloor pulls apart) called the Gakkel Ridge.  They know where major features such as abyssal plains, plateaus, and ridges are, but the story of how this area formed is still the subject of much discussion. Where exactly are the plate boundaries in the Arctic?  Which direction are they moving?  Which forces formed the Arctic Basin?  These are great questions that geologists continue to investigate. In 7th grade we study plate tectonics.  Our textbooks contain maps showing where the plates are pulling apart (divergent boundaries), pushing together (convergent boundaries), and sliding past one another (transform boundaries). I had never noticed before this trip that clear plate boundaries are not shown under the Arctic Ocean.

FOR MY STUDENTS: There are some great animations showing plate movements at this site.

Looking Back in Time with Rock Samples 

Kelley Brumley and Alex Andronikov are geologists on board the Healy. They have been analyzing the data collected by the echosounding instruments to better understand the forces at work here. But what they have really been looking forward to is seeing what type of rock the seamounts, ridges, and plateaus below the Arctic Ocean are made of, and how these features were created.

Our first 2 dredge sites brought up muddy sediment and lots of:

  • Ice rafted debris: These are rocks that are frozen into ice that breaks from shore and carried out to sea. They can come from glaciers, or river deltas or any shoreline.  Some show glacial striations (scratches left behind by glaciers).
  • Coated sediments: These are crumbly, compressed mounds of sediment coated with a dark precipitate.
Dredge #2 was a muddy affair. Using the hose, I helped separate the sediment from the rocks. That’s me in the turquoise gloves!
Dredge #2 was a muddy affair. Using the hose, I helped separate the sediment from the rocks. That’s me in the turquoise gloves!

The next 3 dredges broke off rock samples from the steep slopes over which they were dragged. This was what the geologists were hoping for – samples of bedrock.  The rock samples that were dredged up show us that the geological history of the region is very complex.  Analyzing the chemistry and mineral composition of these rocks will help to answer some of the questions Kelley, Alex, and other Arctic geologists have about this part of the Arctic Ocean.  The rocks are cleaned, carefully labeled, and shipped to Stanford University, the University of Michigan, and the USGS (United States Geological Survey) for further study. Who knows, maybe the rocks that were collected today will help to clarify models for the geologic history of this part of the Arctic Ocean.

Personal Log 

On September 11, I was able to call my students in Indiana. Jon Pazol, (ARMADA teacher at sea) has an Iridium satellite phone that he graciously allowed me to borrow.  How fun to stand on the helicopter pad of the Healy and field questions from Carmel, Indiana.

Rock samples from a successful dredge operation
Rock samples from a successful dredge operation
Dredges sometimes bring up more than rocks and sediment. This arthropod came up with one of the dredge samples.
Dredges sometimes bring up more than rocks and sediment. This arthropod came up with one of the dredge samples.
Calling my students. You can see in the background that there is much more ice than a few days ago.
Calling my students. You can see in the background that there is much more ice than a few days ago.
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Christine Hedge, August 19, 2009

NOAA Teacher at Sea
Christine Hedge
Onboard USCGC Healy
August 7 – September 16, 2009 

Mission: U.S.-Canada 2009 Arctic Seafloor Continental Shelf Survey
Location: Chukchi Sea, north of the arctic circle
Date: August 19, 2009

Weather Data from the Bridge   

Brittle star
Brittle star

LAT: 810 23’N
LONG: 1560 31’W
Air Temp: 28.27 0F

Science and Technology Log 

My fellow teacher at sea, Jon Pazol, and I wonder, “What kind of brittle star is this?” We think it is a Gorgonocephalus cf arcticus.
My fellow teacher at sea, Jon Pazol, and I wonder, “What kind of brittle star is this?” We think it is a Gorgonocephalus cf arcticus.

There isn’t much biology to be done on this cruise.  Our mapping mission is the main focus.  But, living things find a way of working their way into the picture.  We have a marine mammal and a community observer on board looking for whales, seals, polar bears, sea birds and other Arctic animals. Yesterday, a small Arctic Cod found its way into the seawater pipe in the science lab. And a few days ago, when the HARP instrument was pulled up, there was a brittle star attached to it. Jon Pazol (the ARMADA Teacher at Sea) and I are both biology types and we got excited about the opportunity to identify this creature from the Arctic Ocean.

Personal log 

Yoann, a student from France, enjoys his first corndog
Yoann, a student from France, enjoys his first corndog

I did not grow up in Indiana and have avoided eating a corndog until now.  Yoann Ladroit (from France) and I (from Connecticut) had our very first corndogs for lunch yesterday. We have enjoyed many different types of food on the Healy. Imagine stocking a ship with enough food for 120-130 people for months in the Arctic. When the Healy left Seattle they had a food inventory valued at $300,000. Ideally, this ship leaves port with enough food for a year. This is more than most Coast Guard cutters carry – but the Arctic is a unique place.  In other oceans, cutters can pull in to port and purchase fresh supplies. In the Arctic there are few ports and where there are ports – the food is VERY expensive. The Healy needs to be prepared to feed the crew, just in case they get beset (stuck in ice). So, they have staple foods ready for an emergency situation.

A forklift carries food supplies to the Healy
A forklift carries food supplies to the Healy

In Barrow, the Healy picked up many forklifts full of fresh produce and eggs. This will be the last fresh produce we get until September 16th when we return to shore. The Healy is one of the newest ships in the Coast Guard and has spacious facilities in the galley (kitchen) and the mess decks (dining room).  There are huge refrigerators, storage rooms and freezers for food. The gleaming stainless steel galley has computerized ovens with probes that sense when the food has reached the correct temperature and a huge and speedy dishwasher. As a newcomer to the ship we were warned about the powerful microwave oven, which heats anything in 10 seconds and garbage disposal (affectionately called the Red Goat) which grinds up all food waste instantly.

This area, called the mess, is where we eat our meals.
This area, called the mess, is where we eat our meals.

We eat in the mess decks.  Our mess decks are twice the size of those on other Coast Guard cutters.  Meals are served 4 times each day. Breakfast, lunch, and dinner are served at the regular times.  Since people work 24/7, a fourth meal called Mid-rats (midnight rations) is served each night at 11pm.   One of the interesting features in the mess decks is the operating room set up over one of the tables. Although the Healy has a state of the art sick bay, what if the sick bay was unusable because of a fire or some other crisis? It seems that in a mass casualty situation, the mess decks doubles as a medical space, which would be used to tend to wounded personnel.

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Christine Hedge, August 18, 2009

NOAA Teacher at Sea
Christine Hedge
Onboard USCGC Healy
August 7 – September 16, 2009 

Mission: U.S.-Canada 2009 Arctic Seafloor Continental Shelf Survey
Location: Chukchi Sea, north of the arctic circle
Date: August 18, 2009

Weather Data from the Bridge   
Lat: 800 32’N
Long: 1540 04’ W
Temp:  28.720 F

Science and Technology Log 

Mrs. Hedge fills the weather balloon
Mrs. Hedge fills the weather balloon

Twice each day, AG1 (Aerographers mate 1st class) Richard Lemkuhl launches a weather balloon. Today, at 6 AM I assisted with the launch. The balloon is filled with helium and attached to a device powered by a 9-volt battery. The weather balloon sends back temperature, pressure, and humidity data along with GPS derived winds to a radio receiver on the bridge of the Healy. This profile of the atmospheric conditions can be injected into global weather models to help predict the weather. On the Healy we use this information for flight operations (the helicopter). Helicopters, ships, and planes all need current weather conditions to navigate safely.  Data from weather balloons can help determine if there might be icing, turbulence, wind driven ice or the possibility of thunderstorms.

FOR MY STUDENTS: All kinds of scientists use models to help explain, predict, and understand the world around them. Can you think of a model you have used in science? 

Radio Receiver on the bridge of the Healy
Radio Receiver on the bridge of the Healy

AG1 Lemkuhl works for the Naval Maritime Forecast Center in Norfolk, Virginia. He is part of a group of U. S. Navy personnel on board the Healy to better understand how to operate Navy vessels in the Arctic. The dynamic weather patterns he experienced as a child in Oklahoma sparked his interest in meteorology.  His very first weather balloon was launched in 8th grade under the watchful eyes of Mrs. Stevens, his science teacher in Clarksville, Tennessee. AG1 enjoyed learning about Earth Science as a middle school student, which lead to studying geography and climatology in college.  The Navy has added to his education and after a year of school he is currently an Assistant Operational Meteorologist.

FOR MY STUDENTS:  What have you studied in school that has sparked your interest? 

Personal Log 

AG1 Lemkuhl holding the weather balloon instrument
AG1 Lemkuhl holding the weather balloon instrument

Yesterday the sun came out and the sky was blue.  What a difference that blue sky made!  There isn’t much color in the Arctic – especially when it is foggy.  The inside of the ship is tan. The ice and sky are white. Blue sky brought more people out on deck just to enjoy the color change.  We also saw more seals out on the ice. Could it be that they like to bask in the sun as well?

Today, as we backed and rammed through 2.5 meters of ice, I saw my first fish!  They were small, about the size of my palm.  Could these be the Arctic Cod I have read about??

FOR MY STUDENTS: Look at my current latitude.  What day will the sun finally set at this latitude???

AG1 Lemkuhl shows Mrs. Hedge how to launch a weather balloon.
AG1 Lemkuhl shows Mrs. Hedge how to launch a weather balloon.
Blue Sky in the Arctic! This is the CCGS Louis S. St. Laurent. The Healy is breaking ice for her.
Blue Sky in the Arctic! This is the CCGS Louis S. St. Laurent. The Healy is breaking ice for her.
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Christine Hedge, August 13, 2009

NOAA Teacher at Sea
Christine Hedge
Onboard USCGC Healy
August 7 – September 16, 2009 

Mission: U.S.-Canada 2009 Arctic Seafloor Continental Shelf Survey
Location: Chukchi Sea, north of the arctic circle
Date: August 13, 2009

Weather Data from the Bridge  
Long: 14809.54199W
Lat: 78017.31641N
Air Temp: 31.08 0F

Science and Technology Log 

A CTD, above, is much bigger than an XBT, which I’m holding in the picture below.
A CTD, above, is much bigger than an XBT, which I’m holding in the picture below.

Sound waves travel at different speeds through different substances.  If you look up the speed of sound in air you will find it to be about 300 meters/second, in water 1500 meters/second.  But these numbers are not constants.  In water, the temperature, the amount of salt, and the pressure can all impact how fast sound waves travel.  In other words, all water is not created equal.  Our mapping mission depends on data collected from bouncing sound waves off the sea floor.  In order to get an accurate image of what the sea floor looks like and how deep it is – we need to measure precisely how fast the sound waves are traveling.  This means we need to have a handle on any variable that might change the speed of the sound waves.  Measuring the speed of sound in the water column is an important part of data collection for accurate mapping.

So, how does the Healy measure the speed of sound? Sometimes we use a Conductivity-Temperature-Depth instrument (CTDs).  The ship needs to be stationary to deploy these instruments so they don’t happen very often while we are cruising. CTD measurements record conductivity of the water, which gives us the salinity (how much salt is in the water), temperature, and the depth at which these measurements were taken. Four times a day instruments called Expendable Bathythermographs (XBTs) are deployed off the moving ship. These XBTs measure the temperature as the device travels through the water. As pressure increases, (the deeper you go) the speed of sound increases. As temperature decreases, the speed of sound decreases. Four times a day the Healy science crew gets new data so that they can determine more precisely the speed of sound and therefore interpret what the sound waves are telling us.

Here I am deploying the XBT into the Arctic.
Here I am deploying the XBT into the Arctic.

Today, MST-2 (Marine Science Technician) Daniel Jarrett let me participate in the deployment of an XBT. As the device travels through the water it sends back temperature data from different depths to a computer on board.

The data travels through a very thin copper wire attached to the instrument. A graph of this data is observed and that information is used to create a profile of the speed of sound in that part of the Arctic Ocean at that moment in time.

Personal Log 

All the things I do at home also have to be done on board ship. I eat, sleep, shower, exercise, and do laundry. The food is excellent so far. I love not having to cook or plan meals.  There is fresh fruit, a salad bar, and a huge hot breakfast every day. It will be a rude awakening when I return home and have to plan and cook meals again! My daily routine does not involve much physical activity and I worry about gaining weight while on board. In order to stay in shape, it seems everyone uses the gyms or runs on deck. I have been working out on the treadmill or elliptical every day faithfully to avoid a severe weight gain.

Was the data good? Did the deployment work?
Was the data good? Did the deployment work?

The laundry and all other facilities are really nice. I have a 25-year-old washer/dryer at home and was pleasantly surprised to find state of the art, low-water-usage, front-loading washers on board the Healy. From what I can see the United States Coast Guard is working hard to become a “green” organization.  Trash is separated and recycled when possible. People are encouraged to reduce their water usage. Extreme care is given to filtering and recycling wastewater and any kind of oil or lubricants. It is great to see the amount of thought and energy that is being put into helping the community on board the Healy to “walk lightly” on the Earth.

The Healy is very careful to treat the arctic with care
The Healy is very careful to treat the arctic with care
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Christine Hedge, August 10, 2009

NOAA Teacher at Sea
Christine Hedge
Onboard USCGC Healy
August 7 – September 16, 2009 

Mission: U.S.-Canada 2009 Arctic Seafloor Continental Shelf Survey
Location: Chukchi Sea, north of the Arctic circle
Date: August 10, 2009

Science and Technology Log 

Christina with a CTD
Christina with a CTD

This trip is all about data collection.  In addition to our main seafloor mapping mission, each day there are buoys, sensors, or weather balloons deployed each collecting important data to help us understand the Arctic environment.  This ocean is a harsh place. The objects that are placed underwater to collect data (like the HARP instruments that were retrieved earlier this week) need to be able to withstand cold, salt, pressure, and for those on the surface, wind and waves. Designing such a device to work for long periods of time in the Arctic must take great engineering skills.

The pressure of the deep ocean is an amazing force.  If you have ever lost your goggles in the deep end of a pool – you know that water pressure increases with depth. Water is much heavier than air (about 1000 times heavier).  Any instrument sent to the bottom of the Arctic Ocean is under a column of water that literally squeezes it with massive weight.  In fact, the weight of just a 10 meter thick slice of ocean is equivalent to the weight of the entire atmosphere.  Of course there is a scientific name for this increase of pressure due to the weight of the water above you. It is called hydrostatic pressure.

A simple experiment to illustrate the type of forces these scientific instruments endure involves Styrofoam cups!  In fact, yesterday folks were encouraged to decorate a Styrofoam cup.  The cups were gathered into a mesh bag and sent down 3800 meters attached to a device, which measures the conductivity, temperature, and depth of the water as it descends (a CTD).

Styrofoam cups after their trip on the CTD
Styrofoam cups after their trip on the CTD

Styrofoam can be thought of as plastic netting filled with air.  This is why it is such a good insulator and so light.  If we squeeze it with our hands, we can make the netting tighter and the Styrofoam becomes tight balls of plastic.  If we lower the Styrofoam cups to great depths within the ocean – just think of the huge amount of hydrostatic pressure they are under!!!

The cups went to a depth of 3800 meters and shrank from about 4 inches to less than 2 inches!  The weight of the water above them squeezed the air from the Styrofoam and gave us teeny cups – the shape didn’t change much – just the size. When engineers build instruments to study the ocean – such forces must be considered carefully.

Something to Think About 

Besides diving into a swimming pool, can you think of another place in your world where pressure changes impact the environment?

Personal Log 

Sea ice
Sea ice

I’m getting used to the life on board a ship. The crew is very helpful. They point me in the right direction when I get lost (which happens a lot) and help me to find basic comforts such as ice, the gym, and the laundry.  I am amazed at how many doors I have to open and close to get from one place to another. The doors, designed to withstand water and fire, are heavy and take some upper body strength when we are in windy conditions.

They can also be very noisy and since someone is always sleeping on a ship that operates 24/7 we need to be considerate and move through them quietly.  The further north we go the calmer the water gets.  It is a real treat to walk out on deck and see the water smooth as glass, the blue and white ice chunks, and nothing but sky in front of us.