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 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.
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.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.
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.
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!
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 operationDredges 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.
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: Beaufort Sea, north of the arctic circle Date: September 7, 2009
The empty dredge being lowered into the ocean.
Weather Data from the Bridge
Latitude: 790 ’24N
Longitude: 1540 27’W
Temperature: 290F
Science and Technology Log
Today we deployed our first dredge in hopes of collecting some samples of bedrock from the Arctic Ocean. A dredge is a basket made of metal chain link with a sharp edged bottomless tray on top. A wire cable connects this dredge to the Healy. Our echosounding instruments show us what the sea floor looks like. Maps reveal ridges, seamounts, flat abyssal plains, and raised continental shelves. But, how did all these features form? How old are they? What type of rock are they made from? What kinds of forces created this ocean surrounded by continents? Where are the plate boundaries? Collecting rock samples will help us to answer some of these questions.
Sifting through the muddy sediment in search of rocks
FOR MY STUDENTS: Can you predict what type of rock we might find by sampling oceanic crust? Continental crust?
Here is how dredging works:
The dredge is deployed over a seafloor feature with a steep slope. Lowering the dredge takes a long time as the huge spool of cable unwinds. The top speed for the cable is 50 meters/minute. Today, the cable with the dredge attached rolled out 3850 meters before it stopped. The Healy then moves slowly up the slope dragging the dredge behind. The metal plates at the top of the dredge catch on rock outcrops as it is dragged up the side of the slope. Pieces of rock and sediment fall into the basket. The dredge is pulled up by the cable and lowered back on to the deck of the Healy. The dredge is dumped and scientists pick through all the mud and find the rocks.
Full dredge is safely landed on the deck of the Healy.
This first dredge brought back 400 pounds of mud and rock. Unfortunately, most was mud and only 10% was rock. Dredging is tricky business. Sometimes the dredge gets stuck and needs to be cut free. Sometimes it collects only mud and no bedrock. We will be dredging at different sites for the next few days in the hope that good examples of bedrock will be collected. The rocks we find will be catalogued and the chemistry of the rocks will be analyzed. Hopefully, the rocks will help to answer some of the questions we have about the geologic history of the Arctic Ocean.
Personal Log
Examples of rocks that were collected from our first dredge site.
When you work at a school, you get used to drills. Fire, severe weather, and intruder drills help to ensure that students and teachers will know what to do in the event of a real emergency. The Coast Guard has drills each Friday to ensure the Healy will be ready to handle any emergency. I have observed the crew practicing what to do in the event of fire, flooding, collision with another ship and various other scenarios. Last Friday, I was lucky enough to watch the crew in action.
The crew is suiting up for a Friday drill. Each member of the crew is trained to do many different jobs in case of an emergency.Emergency medical situations are often a part of the training. Friday’s drill included this mock-amputation of a crewmembers hand. (Note the fake rubber hand)If a compartment is flooded; the crew needs to do their best to contain the water. This hatch is braced with wood and mechanical shoring.
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: Beaufort Sea, north of the arctic circle Date: September 6, 2009
Weather Data from the Bridge
Latitude: 760 51’N
Longitude: 1380 54’W
Temperature: 300F
Rachel is showing me how the data we collect is processed.
Science Party Profile—Rachel Soraruf: Working For NOAA
Are you the kind of kid who buys rocks when you visit a museum gift shop? When you walk down the beach – is your head down searching for shells and stones? If so, maybe you should consider studying geology in college. Rachel Soraruf was one of those kids and now she works for NOAA. This year, NOAA sent her to the Center for Coastal and Ocean Mapping/Joint Hydrographic Center (CCOM/JHC) at the University of New Hampshire. (That’s a mouthful!!) At CCOM, she is a graduate student learning about the latest technologies in ocean mapping.
Rachel decided to major in Geology during her sophomore year at Mt. Holyoke College. According to Rachel, geology is a fun major because you get to “Do What You Learn”. In addition, there are lots of field trips that complement your lab and classroom work. Her next educational move was to earn a Masters Degree in Geosciences from the University of Massachusetts. By studying the geochemistry of a stalagmite for her thesis (final project) – Rachel was able to look back 5,000 years and determine climate changes that occurred over the centuries.
FOR MY STUDENTS: Have you ever gone caving? Did you know stalagmites could reveal climate history?
Ten-foot swells caused the ice floes to roll and bump. September 6th was the roughest ride of this trip.
Rachel has always liked the idea of “science with a purpose” – and NOAA offers her just that. Her job is to plan the field seasons for NOAA vessels as they update the Hydrographic Charts of the waters around the United States. People’s lives depend on these charts. In order to safely navigate an oil tanker, cruise ship or fishing vessel – up to date charts are essential. The work she does makes a difference. It truly is science with a purpose.
Personal Log
Today we are in an area with thin ice and 10-12 foot swells. It is an amazing sight to see the ice on the surface of the Arctic Ocean rolling with the swells. The Captain reminded us to tie down our possessions so that cameras and laptops wouldn’t go flying off our desks. It was good advice! I had not closed my file cabinet drawers completely and they were opening and closing as the ship rolled with the swells. I brought seasickness patches and pressure point wristbands to help me in case of seasickness and used them both today.
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: Beaufort Sea, north of the arctic circle Date: September 5, 2009
Weather Data from the Bridge
Latitude: 770 13’N
Longitude: 1370 41’W
Temperature: 290F
Science and Technology Log
The two icebreakers are tying up side-by-side so that we can visit each other.
More Ways to Use Sound to See Beneath the Sea Floor
Today we “rafted” with the Louis (the ships tied together side by side). I have been eager to see the science instruments that the Canadian ship is carrying. Once the ships were securely tied together we could just walk back and forth between them and tour the Canadian vessel.
The Healy has been breaking ice so that the Louis can have an easier time collecting data using seismic reflection profiling. The goal is for the Canadian scientists to determine how deep the sediments are in this part of the Arctic Basin. The sound waves their instrument sends out can penetrate about 1500 meters below the seafloor. Using sound they can “see” inside the earth – amazing!
FOR MY STUDENTS: Remember your Latin/Greek word parts? Look up “seism”.
Seismic sled being hauled out of the water on the Louis. (Photo courtesy of Ethan Roth)
Here is how it works. The Louis steams forward at a low speed following in the path that the Healy has created through the ice. The Louis tows behind a weighted sled with 3 airguns suspended from the bottom. This sinks about 10 meters below the water. Attached to the sled is a long tube filled with hydrophones (underwater microphones) called a streamer. This streamer is about 400 meters long and stretches out behind the ship. It is best for the ship to move continuously so that the streamer will not sink or float to the surface.
FOR MY STUDENTS: Try to picture a 400-meter long “tail” on a ship. That is longer than 4 football fields.
The airguns create a huge air bubble in the water. When it collapses, it creates a sound pulse. Two of the guns use a low frequency, which will penetrate deep into the sea floor but will create a low-resolution image. The other gun uses a high frequency, which does not penetrate as deep but gives a high-resolution image. The 16 sound recorders in the streamer record the echo created by these sounds reflecting from the sediment layers below the sea floor. The final product this instrument creates is an image of a cross section through the Earth. Scientists can look at these by observing this geologic history, the scientists are looking back in time. You can imagine that ice can cause lots of problems when a ship is towing a 400-meter long streamer behind it. This is why we are working on collecting this data together. One ship breaks, the other collects the seismic reflection data.
Steamer on deck of Louis. The blue steamer is out of the water and lying on deck when we visit the Louis.
Personal Log
The crew has been looking forward to the two ships tying up together for the entire cruise. Everyone is curious about the other ship. What are the staterooms like? What is the food like? How is their bridge different from our bridge? And of course there is shopping!! Both of the ship stores had their best Louis and Healy gear ready for the eager shoppers.
After learning about the science instruments aboard the Louis, it was nice to finally see the seismic sled, streamers, and the computer nerve center where the seismic images are received. The ships are pretty different in their appearance. The Louis is an older vessel and has wooden handrails, panels cover the wires in the ceiling, and there are some larger windows with actual curtains. The Healy was built to be a science research icebreaker and so has many large spaces for science and looks generally more industrial. The Louis was an icebreaker first and some of their science spaces have been added later and are less spacious.
The bubble created by the airguns on the Louis. (Photo Courtesy Pat Kelley USCG)
Shopping and tours were fun but the most anticipated events of the day were the evening meal, contests and games. The ship’s officers exchanged gifts in a formal presentation and then we had an amazing buffet together. Personnel from both ships enjoyed scallops, halibut, salmon, shrimp, lobster, pork, beef, cheese, salads, and desserts. This was an exceptional meal and a great social event. The idea of having Teachers at Sea (TAS) was a new one for most Canadians I spoke with and as we talked they seemed to think this TAS would be a great idea to stimulate interest in young Canadians about maritime careers. The evening concluded with some friendly competitions between the crews and the science parties. This entire event was a lot of work for the Coast Guard crews. The science party really appreciates all the hours they put into planning this event!
Behind the wheel on the bridge of the Louis S. St. Laurent.
