Heather O’Connell: Surveying Tracy Arm, June 20, 2018

NOAA Teacher at Sea

Heather O’Connell

NOAA Ship Rainier

June 7 – 22, 2018

Mission: Hydrographic Survey

Geographic Area of Cruise: Seattle, Washington to Sitka, Alaska

Date: 6/20/18

Weather Data from the Bridge

Latitude and Longitude: 57°52.9’ N, 133 °38.7’ W, Sky Condition: Broken, Visibility: 10+ nautical miles, Wind Speed: Light Variable, Sea Level Pressure: 1013.5 millibars, Sea Water Temperature: 3.9°C, Air Temperature: Dry bulb: 17.8°C, Wet bulb: 14°C

Science and Technology Log

After the morning meeting of hearing everyone’s risk assessment before getting on the launches, I was part of the four person crew on launch RA-6. Our task for the day was to clean up the data, or collect data in places within the Tracy Arm polygon that weren’t already surveyed. We had to fill in the gaps in L and M polygons on the East point. The entire area of Tracy Arm needed to be surveyed because there are several cruise ships that are coming into this area now that Sawyer Glacier is receding and the area has not been surveyed since the late nineties. Navigation charts must be updated to ensure that the safety of the people that are visiting the area.

Launch going out to survey

Launch going out to survey

Once on the launch, the bright orange POS MV, or Positioning Orientation System Marine Vessel, must be powered to start the survey process. The new acquisition log was created as an excel spreadsheet to record the different casts along with the latitude and longitude, the maximum depth and the sound speed of the water at about approximately one meter. With all of the valuable data recorded, it is important to have a consistent system for managing all of the data so that it can be accessed and managed efficiently.

The EM-2040 Konsberg Sonar S.I.S., Seafloor Information System, program was powered on next. The EM processing unit, which is connected to the multi-beam sonar, has three lines of information when properly communicating with sonar. The right hand monitor in the launch displays the information from the sonar. Creating the file name is another crucial way of ensuring that the data can be managed properly. It is from this computer that you can manually adjust the angle of the beam swath with the sound pings.

Sonar Computer Systems

Sonar Computer Systems

Once the computers were started and communicating with each other, we completed a C.T.D. cast to obtain the sound speed profile of the water. There is also a device that measures this right on the multibeam sonar, but it is important that two devices have a similar sound speed profile to ensure data accuracy. If there is a large discrepancy between the two values, then another cast must be taken. Initially, the measuring sound speed profile at the interface was 1437.2 and the C.T.D. sound speed was 1437.8. The final algorithm that determines the depth of the water will take this information into account. Since we were somewhat close to a waterfall, the fresh water input most likely affected the sound profile of the water.

Preparing the CTD

Preparing the CTD

After viewing the data acquired in the sheet, or the assigned area of Tracy Arm to survey, Greg found areas where there were holes. He put a target on the map on the monitor on the left hand side computer. This HYSWEEP interface for multibeam and side scan sonar (which is a subset of HYPAC which is the multibeam software) screen shows a chart of the area with depths in fathoms and any rocks or shoals that would impede driving ability along with a red boat image of the vessel. This display is what the coxswain driving above also sees so that he or she is aware of what direction to travel. Once logging data, this screen also displays the beam so that you can ensure that all necessary data is being acquired. Previous surveys are depicted in a more subdued color so that you can see that the missing data is being collected. From the monitor, the survey technician must control the view of the map to be sure that it includes the targeted area, along with the path of the boat so that future obstructions can be avoided.

Multi-beam Sonar Work Station

Multi-beam Sonar Work Station

Since we were avoiding icebergs in the initial part of the clean up, we were going at about two knots. This slow pace allows for an increase in returns, nodes and soundings that increase the data density. Shallow waters take much longer to survey due to the smaller swath width. It is important to have accurate, high resolution data for shorelines since this is the area where many vessels will be traveling.  When a sonar pings, every swath, or fan-shaped area of soundings, returns five hundred soundings. Five hundred soundings times a rate of seven pings per second means there are thirty five hundred soundings per second total. This data density enhances the resolution of the maps that will be generated once the data has been processed.

Since there are sometimes safety hazards when surveying there are several different approaches that can be used to ensure the entire area is surveyed in a safe manner. Half stepping included going back over previous coverage far enough away from the hazard. Scalloping is another method which involves turning right before the rock or obstruction. This sends the beam swath near the rock without putting the vessel in danger. Some areas that were too close to icebergs could not be surveyed since it was not safe. But, this hydrographic survey was able to acquire data closer to the Sawyer Glacier than ever before. Being a part of this data collection was gratifying on many levels!

Personal Log

Seeing a white mountain goat amongst some of the most beautiful geological features that I have ever laid eyes on was another benefit of being out on the launch for the day. When a grizzly bear cub ran by a waterfall I continued to appreciate a day on the launch. Seals perched on icebergs were always a fun sight to see. And, the endless pieces of ice drifting by in the sea during our surveying never ceased to amaze me. 

Seals on an Ice Berg

Seals on an Iceberg

After a day of surveying, kayaking to a waterfall in William’s Cove and exploring proved to be another fun adventure.

OLYMPUS DIGITAL CAMERA

Waterfall in William’s Cove

Growing Muscle like Growing Character

The other day as I ran on the treadmill, I had a realization. While looking at the lifting weights, I realized that in order to build muscle, one must tear old muscles and rebuild new strands of protein. When these new fibers build on top of each other, muscles grow. I realized that new officers go through a similar process of developing skills and character. Junior officers come in with a two year responsibility where they learn an incredible amount. They are constantly put into new and challenging learning experiences where they tear their muscles. As they acclimate to these experiences, they build character, or muscle. The cycle repeats with subsequent occurrences.

Junior Officer ENS Airlie Pickett has a small triangle tattooed on her inner left bicep. When I asked her the significance of it, she said that the only way that you can truly understand something is to observe how it changes. In math, integrals and derivatives explain this change.

As I appreciated her tattoo, I considered that she must learn quite a lot about herself as a junior officer constantly learning new things. I’ve appreciated the opportunity to experience and observe myself in an unfamiliar surrounding on Rainier. It’s humbling to not understand the nautical terms, endless acronyms of surveying and NOAA Corps structure of life. I appreciated that all hands on Rainier made me feel welcomed, and were patient with explaining new concepts to me. I am grateful for the opportunity to experience the Inside Passage while learning about hydrographic surveying. Living on a ship, learning about navigation and meeting all of the hard working people on Rainier has been an unique experience. Overall, this has been an incredible opportunity. Mahalo nui loa! (Thank you very much). A hui hou Rainier! (Until we meet again)!

Did You Know?

Barometers measure atmospheric pressure in millimeters of mercury or atmospheres. An atmosphere is the amount of air wrapped around the Earth and one atmosphere, atm, is the amount of pressure at sea level at fifteen degrees Celsius. As altitude increases, the amount of pressure decreases since the density of the air decreases and less pressure is exerted. A decrease in altitude increases the amount of pressure exerted and the density of the air increases.

Changes in pressure can signify weather patterns. A drop in barometric pressure means a low pressure system is coming in and  there is not enough force to blow away the weather. Weather indicative of this includes windy, cloudy and/or rainy weather. An increase in barometric pressure means a high pressure system is coming in and  cool, dry air pushes out the weather resulting in clear skies.

https://www.nationalgeographic.org/encyclopedia/barometer/

 

Heather O’Connell: Using a Sextant, Distilling Glacial Water and Kayaking to Icebergs, June 18, 2018

NOAA Teacher at Sea

Heather O’Connell

NOAA Ship Rainier

June 7 – 22, 2018

Mission: Hydrographic Survey

Geographic Area of Cruise: Seattle, Washington to Southeast, Alaska

Date: 6/18/18

Weather Data from the Bridge

Latitude and Longitude: 57°55’ N, 133 °33’ W, Sky Condition: Broken, Visibility: 10+ nautical miles, Wind Speed: 10 knots, Sea Level Pressure: 1023.5 millibars, Sea Water Temperature: 3.9°C, Air Temperature: Dry bulb: 15.0°C, Wet bulb: 12.0°C

Science and Technology Log

Using a Sextant

Greg Gahlinger, H.S.S.T., hydrographic senior survey technician, shared his knowledge of using a horizon sextant. He traveled to Hawaii from San Diego and back using this technology when he was in the navy. Utilizing his Cassens and Plath horizon sextant when there was an atypically sunny day in Tracy Arm allowed me to experience this celestial navigation tool. While the sextant is easy to use, the calculations for placement can be more involved.

A sextant is used for celestial navigation by finding the angle of a celestial body above the horizon. Originally, the graduated mark only measured sixty degrees, thus the derivation of the name. The angle between two points is determined with the help of two mirrors. One mirror is half silvered which allows light to pass through and this is the one used to focus on the horizon. The other mirror attached to the movable arm reflects the light of the object, such as the sun, and can be moved so that the light reflects off of the first mirror. A representation of the object, or sun, superimposed on the horizon is seen and the angle between the two objects is recorded. Angles can be measured to the nearest ten seconds using the Vernier adjustment and it is this precision that makes the sextant such a useful tool.  One degree is divided into sixty minutes or sixty nautical miles. Each degree is divided into sixty seconds.

Horizon Sextant

Horizon Sextant

To use a horizon sextant, you hold onto the arm piece and look for the reflection of the sun from the mirror and through a horizon reflection onto the scope or the eyepiece. There are several different filters that make it safe to view the reflection of the sun. After you adjust the index, the rotating part on the bottom of the sextant, you align the reflection of the disk of the sun onto the horizon. If there is no actual horizon, as was the case when we were in the fjord, then you can align the image of the sun onto a false horizon. Once the reflected sun is sitting on the horizon, you can swing the frame back and forth until the sun lies tangent to the horizon. From here, record the angular measurement and use a table to determine your position of latitude. If you have an accurate time, you can also determine longitude using another set of charts.

Taking a sight of the sun at local apparent noon with a Sextant

Taking a sight of the sun at local apparent noon with a Sextant

Salt Water Distillation

While in transit to our survey location, First Assistant Engineer Mike Riley shared the engine room with me. There is a control panel for all of the different components of the ship along with the electrical circuit board. Amongst all of the parts that contribute to making the ship function, I was interested in the two evaporators.

The two evaporators change saltwater into potable water in a desalination process. These two stage evaporators are filled with seawater that comes into the vessel via suction into sea chests. If the ship is going at full speed, 12.4 knots, which varies depending on currents and tides, the distillers will make about 500 gallons of freshwater an hour, or 3,000 gallons a day. Engine heat is used to boil the sea water for the evaporation. The water goes through a booster heater to make it even hotter before coming into the tanks. The distilled water comes from the tank next to the current generator in use.

Two Stage Evaporator

Two Stage Evaporator

The two stage distillers have a demister screen in the middle. There are about twenty metal plates with grooves between them located on both hemispheres of the spheroid shaped distiller. The plates are sealed and the metal groove space, or gaskets, between them is open. Jacket water, a mixture of coolant, or propylene glycol, and water, that is already at about one hundred and seventy degrees comes in and fills the metal plates. The jacket water is heated from the exhaust from the generator. It is further heated from going through a vacuum and turns into steam. Salt water from the salt chest comes into the space between the metal plates over the grooves.

Metal plates and gasket inside of evaporator

Metal plates and gasket inside of evaporator

The porous demister screen keeps salt water droplets from going above and the brine water collects at the bottom and goes out the ejector pump. Once the steam from the lower part of the tank heats the water and it enters the upper part of the tank, the water is cleansed and condenses on the plates. From here it goes to a tank where it is heated before being stored in another tank and then being allocated to the appropriate area. This water is used to cool the engine, flush the toilets and provided distilled drinking water while in transit.

So, currently, all on Rainier are consuming filtered artesian drinking water and showering in distilled glacier water. Ship Rainier has been consistently surpassing all expectations.

Sources

http://www.pbs.org/wgbh/nova/shackleton/navigate/escapeworks.html

https://oceanservice.noaa.gov/education/kits/geodesy/geo03_figure.html

Personal Log

After dinner I decided to tag along with Able Seaman, or A.B., Dorian Curry, to kayak up close to some icebergs. Leaving the safety of the ship  docked by Point Asley, we headed towards Wood Spit Island. After about twenty minutes of paddling, I saw three distinctive spouts followed by some black dorsal fins surfacing to the northeast towards Sumdum Glacier. Orca whales were off in the distance. Soon these orca whales appeared closer and they were now about two hundred yards away. While the whales made the majestic sound of blowing bubbles in the water, I feared that they would approach the kayak. Putting the boats together in the hopes that these massive mammals would not think of us as prey seemed to be the logical thing to do.  It appeared that there was a mother and two juvenile killer whales.

Video Credit: Dorian Curry

This incredible opportunity to be so close to these creatures along with the terrifying reality that they may mistake me for a seal, proved to be an invigorating experience. The whales dove under and then once again appeared behind at a distance that was slightly too close for comfort in a kayak. At this point, I thought paddling away from these carnivorous predators would be the best approach. I paddled towards the smaller island south of Harbor Island and Round Islet, the place where the base station was set up just a few days earlier. After docking on the island shortly, I was grateful to be on shore post such a stimulating and intimidating experience.

Blue Iceberg

Blue Iceberg

Walking the kayaks over the beach and watching the channel where the Endicott Arm and Tracy Arm channels converged, proved to be a good strategy before paddling onward. A strong, circular current resulted from the two channels merging but was relatively safe due to the fact that it was ebb tide. After paddling strongly for a few minutes, smooth waters followed and I approached one of the most spectacular blue icebergs I have ever seen. The definition from all of the layers of different snowfalls that created this still existing piece of ice was truly amazing. Observing it from different angles overwhelmed me with the brilliance of this natural phenomenon. Next, I found myself paddling towards an iceberg with an eagle perched on it towards Sumdum Glacier.  Again, the different vantage points displayed various concentric circles and patterns of frozen ice accumulating over thousands of years. With only about an hour before sunset, the return journey to Rainier began and choosing to go to the west of Harbor Island to avoid the difficult channel of the now incoming tide made the return safe.

Iceberg

Iceberg

After almost four hours of paddling over a distance of about 8.4 nautical miles, or 9.6 miles, I found it difficult to use my upper body strength to ascend the ladder. Thanks to Airlie Pickett I safely stepped onto the Rainier and began to process this magnificent adventure that I had just embarked upon.

Did You Know?

Wind direction can be calculated by using a wind plotting board calculator. This dial allows you to rotate until the line matches up with the coarse bearing, then mark the wind speed on the clear dial with a grease marker, and then match this up with the angular measurement of the wind and mark this. Then, line up your two marks on a vertical line and this will provide the true wind direction.

Heather O’Connell: Soil Samples, Surveying and Sumdum Glacier, June 17, 2018

NOAA Teacher at Sea

Heather O’Connell

NOAA Ship Rainier

June 7 – 21, 2018

Mission: Hydrographic Survey

Geographic Area of Cruise: Seattle, Washington to Sitka, Alaska

Date: 6/17/18

Weather Data from the Bridge

Latitude and Longitude: 57°43.2’ N, 133 °35.7’ W, Sky Condition: Overcast , Visibility: 10+ nautical miles, Wind Speed: 2 knots, Sea Level Pressure: 1024.34 millibars, Sea Water Temperature: 7.2°C, Air Temperature: Dry bulb: 11.78°C, Wet bulb: 10.78°C

Science and Technology Log

I was part of the crew launched on RA-3 where I learned to turn towards a man overboard in order to ensure that the stern of the ship turns away from them. Communicating via the radio was another highlight where I was certain to follow the proper protocol.

RA- 3 Launch with Multi-beam sonar

RA- 3 Launch with Multi-beam sonar

Next, we moved onto deploying the C.T.D., conductivity, temperature and depth device to determine the sound profile of the water. The winch is a pulley system off the back of the launches that casts the C.T.D. and functions similar to a crab pot winch with an addition of a pressure bar to alleviate the weight of the thirty pound C.T.D.

Deploying the C.T.D.

Able Bodied Seaman Tyler Medley and Junior Officer Michelle Levano deploying the C.T.D.

After passing an iceberg with a seal, we began collecting soil samples with a device called a grab sampler. This was connected to the winch and went down about three hundred and thirty feet to collect a bottom sample. The first sample consisted of small shells of mostly barnacles, along with some medium grained sand and large silt submerged in solution.  The second sample was pristine clay with a slight green color created from the physical erosion of the surrounding rocks of the mountains. Soil sample data is collected and included in the data report because it can affect the sound speed of water. It can also provide useful information about the types of organisms that could live in this ecosystem, along with the types of resources available in this area.

Grab Sampler

Grab Sampler

Next, we connected with RA-6 and had a crew transfer so that I could learn how hydrographic surveying actually works. Newly certified H.I.C., hydrographer in charge, Audrey Jerauld was kind enough to share her knowledge of conducting surveying within Tracy’s Arm. Since Rainier surveyed most of the channel, RA-6 was simply collecting near shore data using the multi-beam sonar. The I.M.U., inertial measuring unit, (not to be confused with the Hawaiian imu which is an underground cooking pit) accurately records the pitch, roll, heave and yaw of the boat. This allows GPS receivers to function even when a satellite is not available. I learned that this is important since when surveying next to a steep cliff,when the satellite cannot reach the small launch, this provides an alternate, accurate means of placement. It determines a D.R., or dead reckoning based on the I.M.U. accelerators and creates a plot of where it thinks the launch is. 

deploying C.T.D.

Junior Officer ENS Collin Walker and H.S.T Audrey Jerauld deploying C.T.D.

Personal Log

The sun was shining yesterday afternoon and I loved soaking up the Vitamin D offered by the sun’s rays while practicing yoga on the flying bridge. When Junior Officer Ian Robbins invited me to go kayaking, I eagerly accepted the opportunity to explore Holkham Bay on a kayak with more maneuverability. I descended into the kayak via a rope ladder off the ship and paddled about three miles through a kelp forest to the nearby Sandy Island. Here, there were endless barnacles, urchins, starfish and kelp to explore near the shore in this inter tidal ecosystem. After pulling the kayaks up to shore and exploring land, I had the realization that with each step I was crushing more living organisms than I cared to consider. The rocks and shells soon turned to rye grass and marshland with some larger rocks.

Sunflower Star

Sunflower Star, Photo Credit: Ian Robbins

Seastar in Intertidal Zone

Seastar in Intertidal Zone

We eventually pulled the kayaks to the other side of the island and kayaked our way next to a blue iceberg. Seeing concentric circles and the intricate pattern of the frozen water crystals was a spectacular sight. Kayaking around such a beautiful natural phenomenon that has been in existence much before I have, was again, a humbling experience.

Iceberg off Sandy Island

Iceberg off Sandy Island

Paddling back to the ship with Sumdum glacier to the right and passing through a narrow channel that lead to the beautiful golden glow of the sun about to set proved to be a perfect ending to an exciting day. Feeling amazed at the sight in every direction made me once again feel extreme gratitude for this exceptional opportunity to be around such vast beauty.

Holkham Bay Sunset

Holkham Bay Sunset

Did You Know?

Mooring line, or the rope used to tie a ship to the dock, is often made of spectra. This synthetic polymer, spectra, doesn’t stretch and is extremely strong, so much so that it can bend metal if enough tension is put on it. It is three times stronger than polyester.

Heather O’Connell: Shore Party, Sumdum and Sawyer Glaciers, June 15, 2018

NOAA Teacher at Sea

Heather O’Connell

NOAA Ship Rainier

June 7 – 21, 2018

Mission: Hydrographic Survey

Geographic Area of Cruise: Seattle, Washington to Southeast, Alaska

Date: 6/15/18

Weather Data from the Bridge

Latitude and Longitude: 57°43.2’ N, 133 °35.7’ W, Sky Condition: Overcast , Visibility: 10+ nautical miles, Wind Speed: 2 knots, Sea Level Pressure: 1024.34 millibars, Sea Water Temperature: 7.2°C, Air Temperature: Dry bulb: 11.78°C, Wet bulb: 10.78°C

Science and Technology Log

Yesterday was my first small vessel operation where we took down a base station and set up a new system on an islet next to Harbor Island. We took RA-7, a skiff that used a crane to lift it off the flying bridge of the ship and into the water. This local satellite receiver allows for a reference point for data acquisition that occurs in Alaska, where the GPS system is not as dependable as the lower forty eight states. The positioning given from this high accuracy base station, called GNSS, will assist with nautical charts developed from the Tracy Arm project once time sonar data has been collected. Since the lower forty eight states have permanent base stations with this highly accurate positioning, there is no need to set up these stations.

GPS base station

Setting up a high-accuracy GPS base station

The base stations work by comparing the satellite positioning to a theoretical ellipsoid that was generated in Canada to standardize positioning. Before this, different areas would utilize various landmarks as the reference point and this inconsistency proved challenging when comparing data internationally or even across the states. So, geodesists, scientists who study geometric shape, positioning in space and gravitational field, generated a theoretical ellipsoid. This was created by rotating the shorter axis of an ellipse to mimic the shape of the Earth. Since the poles of the Earth are flat and the equator bulges, this ellipsoid is an accurate representation. This system gives all points on Earth a unique coordinate, similar to an address, and is extremely helpful in developing nautical charts. However, the limitations of this theoretical ellipsoid include its inability to take into account the actual shape of the Earth.

Setting up Base Station on Harbor Island

Setting up Base Station on Harbor Island

While being on the skiff and learning about theoretical positioning ellipsoids, I heard a lot of talk about RA-2, one of the shoreline launches on Rainier.  I learned that in addition to a single beam sonar, this vessel also has LIDAR. LIDAR, Light Detection and Ranging, can be used in bathymetric data acquisition and is currently used for shoreline data on Rainier. This remote sensing technology can survey up to seventy meters of depth in coastal waters by sending out a laser. LIDAR sends out light pulses and senses the time it takes for these lasers to return to the sensor, to gather data on different land structures. LIDAR gets cloud point data and dots make up the image of the ocean floor. From this, three dimensional maps can be generated. Since the light can penetrate a canopy just like the sun, this technology is used in South America to find hidden cities under tree lines. This technology can also be mounted on planes and is most likely the future direction of shoreline data acquisition. Lasers survey the land and they get the height of different landmasses and can be used for bathymetric data or topographic data.

Sources –

https://oceanservice.noaa.gov/education/kits/geodesy/geo03_figure.html

https://oceanservice.noaa.gov/facts/lidar.html

Personal Log

Tracy and Endicott Arms are part of two alpine, or tundra, ecosystem areas that ship Rainier will survey. Twenty percent of these areas are covered in glaciers and snow fields and are too cold to support trees. The coastal areas of Tracy and Endicott Arms are part of the Terror Wilderness, which is part of Tongas National Forest, the largest national coastal temperate rainforest. Observing my first glacier, Sumdum Glacier, off the coast of Harbor Island while we were at the inlet of Tracy and Endicott Arms, reminded me of a time much before humans existed.

Sumdum Glacier

Sumdum Glacier

Here, out of Holkham Bay, I experienced my first expedition in a skiff, RA-7, to remove a horizontal control base and help set up a new one.  Stepping foot on an actual landmass with all of the different living parts of an ecosystem was a treasure and it most certainly felt like a shore party, as the name suggests. I observed several calcium carbonate shells of urchins, amongst kelp, mussels, and barnacles. The shells transitioned into a forest with Devil’s Club, the only member of the ginseng family present in Alaska, with woody, prickly stems.  This shrub was growing under a Sitka Spruce forest with cone-bearing trees present among the steep rocks of granite. These trees can grow up to one hundred and seventy feet tall and can be as old as seven hundred and fifty years old in Southeast Alaska. After an exciting afternoon of a shore party, we safely returned to the ship and headed into Tracy’s Arm.

Proceeding into the Southern arm of Tracy’s Arm, I saw calves of the tidal glacier that we would soon see. The refrozen and pressurized snow became glacial ice and carved the valleys to form the deep inlets with massive granite slabs on either side of us. South Sawyer glacier was off to the East and the air seemed to get colder as we approached it. Even in the rain and weather, I couldn’t pull myself away from the incredible beauty of this inlet. After endless waterfalls, we approached Sawyer Glacier which was once big enough to cover all of Tracy’s Arm. This acted as a reminder of the Ice Age and its effect on geology.

Sawyer Glacier

Sawyer Glacier

During this journey through Tracy’s Arm, I saw two eagles perched on an iceberg and shortly afterwards three orca whales showing their dorsal fins and playing in the water. As XO informed me, orca whales are actually the largest species of dolphins and these carnivorous mammals can weigh up to six tons. These creatures use echolocation to communicate to their pods, and I wonder how the multi-beam sonar affects this form of communication.

Eagles on Iceberg

Eagles on Iceberg. Photo Credit: Jonathan Witmer

 

Sources  

Studebaker, Stacy. Wildflowers and Other Plant Life of the Kodiak Archipelago.

National Geographic Orcas

Did You Know?

When glacier ice melts, it is filled with air bubbles. As new layers of ice form on top of the old ice, the ice gets denser and the air bubbles get smaller. As the human eye detects the yellow and red light reflected from glacial ice, it appears a spectacular blue. Since snow is full or air bubbles, it reflects the entire spectrum of light and appears white.  

https://www.livescience.com/51019-why-is-antarctica-ice-blue.html

Heather O’Connell: Misty Eyed for Misty Fjords, June 12, 2018

 

NOAA Teacher at Sea

Heather O’Connell

NOAA Ship Rainier

June 7 – 21, 2018

Mission: Hydrographic Survey

Geographic Area of Cruise: Seattle, Washington to Southeast, Alaska

Date: 6/12/18

Weather Data from the Bridge

Latitude and Longitude: 55°33.1’ N, 133 °16.1’ W
Sky Condition: Overcast
Visibility: 10+ nautical miles
Wind Speed: 23 knots
Sea Level Pressure: 1008 millibars
Sea Wave Height: 2 feet
Sea Water Temperature: 8.9°C
Air Temperature: Dry bulb: 12.8°C, Wet bulb: 9.6°C

Science and Technology Log

After discussing geology with resident expert Amanda Finn, I developed the following understanding of the geology of Alaska. Alaska accreted, or merged with the larger continent, from the Pacific Plate colliding with the North American plate. These shifting tectonic plates created catastrophic earthquakes and many of the rock formations that you see in Alaska today. The three thousand foot metamorphic rock mountains in Misty Fjords were most likely formed from these collisions. Initially, there were sedimentary rocks that were changed from heat and pressure into metamorphic rocks. Because the sedimentary rocks were altered, the original age of these rock structures cannot be determined.

While tectonic plates created the landmass, glaciers contributed to the structure of the mountains in Southeast Alaska, creating fjords. A fjord is a narrow inlet of the sea created by a glacial valley with steep cliffs. Seventeen thousand years ago, Misty Fjord was covered in ice. As the ice melted, long narrow inlets were created that filled with ocean water. Mineral springs and volcanic activity still exist around these areas where they are closer to fault lines. It was determined by NOAA scientists in 2013 that Misty Fjord has a sunken cinder cone volcano that must have formed after the glaciers created the fjords thirteen thousand years ago. As Amanda explains, “The disappearance of all the pressure from the overlying ice caused Earth’s crust to bounce back in the area, uplifting rock and carrying magma chambers closer to the surface, causing the volcano to form. This added traces of igneous rocks to the metamorphosed sedimentary rock in the form of quartz deposits. As more ice melted and the water level rose, the cinder cone was eventually submerged underwater.”

 

Sources 

Alaska Geology

Connor, Cathy. Roadside Geology of Alaska.

Adjusting a Compass

I met a compass adjuster who was picked up in a launch from San Juan islands who learned his skill from an apprentice. He carried a wooden box with his equipment and seemed like he arrived from another time period. I was fortunate to witness this annual ritual that compares the direction of the ship according to the magnetic compass with true magnetic North in a process known as swinging the compass  A compass adjuster observes the difference between the ship’s compass and the four cardinal and four intercardinal directions to determine the difference. Since North and South were only one degree off, the magnets on the compass did not need to be adjusted. If there were a larger discrepancy between the two values, then magnets would be moved around until the directions came into alignment.

Captain Keith Sternberg swinging the compass from the flying bridge

Captain Keith Sternberg swinging the compass from the flying bridge

A compass functions based on the Earth’s inner molten iron core which generates a magnetic field around the Earth. The needle in a compass points towards the magnetic pole, which is not necessarily the same as the geographic pole. This difference between magnetic North and true North is known as magnetic variation. In addition to magnetic variation, each ship has a magnetic fingerprint that alters the magnetic compass slightly. If welding were done with metal, especially iron, this would change the magnetic signature of the ship. The combination of compass deviation and magnetic variation alters the true bearing of the ship and must be considered when viewing the bearing of the compass.

Since a magnetic compass differs from a true bearing, NOAA Ship Rainier has two gyrocompassses that are actually used for navigation. Each of these have a wheel spinning a gyroscope which is parallel to the Earth’s center of rotation, and do not rely on magnetism but depend on the Earth’s rotation and gravity. The spinning gyroscope, based on inertia, will always maintain its plane of rotation. Since these gyrocompasses are not altered by the magnetic signature of the ship and provide a true North reading, they are utilized in navigation. The NOAA Corps navigator plans the track lines of the course of the ship based on the true North reading of the gyroscope compass and is the bearing that is observed from the bridge of Rainier. The magnetic compass acts as a backup if the vessel were to lose power.

Gyrocompass

Gyrocompass on Rainier

Sources

http://www.skysailtraining.co.uk/compass_variation_deviation.htm

https://www.marineinsight.com/marine-navigation/gyro-compass-on-ships-construction-working-and-usage/

Personal Log

As I was relaxing in the lounge about to watch Black Panther yesterday evening, a call came in requesting my presence on the Bridge. When I entered the fresh air, granite mountains with ridges full of melting snow waterfalls and a breathtaking view welcomed me. To say I was awe inspired would be an understatement. We were in Misty Fjords within the Tongass National Forest, part of the nation’s largest forest about 22 miles west of Ketchikan. Observing a sliver of this almost 17 million acre temperate rainforest with evergreen trees amongst misty clouds for a brief period of time includes a moment that I will treasure. I was happy to share this experience with other crew, survey technicians and NOAA Corps members who weren’t currently on shift. While appreciating  this beauty, I thought of a Japanese saying, “Iche-go Ich-e,” which means this moment only happens now. Observing the still glassy water reflecting the cloudy sky against green islands and three thousand foot mountains touched my soul. The enormity of the steep granite humbled me as I appreciated it in its untouched state. This pristine environment existed from a landscape formed ten thousand years ago by a massive glacier that created this geological phenomenon. Luckily, this Tongass National Forest was claimed to be a protected zone in 1978 by the president. I’m grateful for this natural beauty that invites a tranquil, peaceful feeling. When a blow spout of a whale appeared off the port side of the vessel, my elation couldn’t be contained and I was overwhelmed with gratitude.

Observing Misty Fjords in the Inner Passage

Misty Fjords in the Inner Passage

 

Did You Know?

Lookouts use a coordinate plane-like reference for directions. If you are standing at the center of the Bridge, similar to the origin of a coordinate plane, then the y-axis would be dead ahead. The x-axis, or 90 degrees to the right would be beam starboard, while to the left would be beam port. To the right forty five degrees would be broad off starboard, while to the left forty degrees would be broad port. If you count the three equidistant points leading up to forty five degrees on the right hand side of the ship, you would command one off, two off or three off starboard respectively.

Heather O’Connell: Voyage through the Inside Passage, June 9, 2018

NOAA Teacher at Sea

Heather O’Connell

NOAA Ship Rainier

June 7 – 21, 2018

Mission: Hydrographic Survey

Geographic Area of Cruise: Seattle, Washington to Southeast, Alaska

Date: 6/9/18

Weather Data from the Bridge:

Latitude and Longitude : 49°49.7’ N, 124 °56.8’ W, Sky Condition: Overcast , Visibility: 10+ nautical miles, Wind Speed: 5 knots, Air Temperature: 12.2°C

Science and Technology Log

Today while in transit through the Inside Passage, I learned to mark the position of the vessel from the pilot house, or Bridge of the ship, using three different methods thanks to Junior Officer Airlie Pickett. Utilizing this triangulation of data ensures accuracy in the placement of the ship on the two dimensional chart located on the port side of the bridge. This process must be completed every fifteen minutes when the ship is in motion close to small landmasses or every thirty minutes when further from land.

The first method involves choosing three different landmarks and recording the angular measurement to the body using alidades. Alidades are located on the port and starboard sides directly outside of the Bridge. When looking at your landmark, it is important to choose the easternmost or westernmost side of the body with a more prominent feature. When viewing the landmass through the alidade, there will be a bearing of the object in relation to the bridge. Once you have the measurements, use the north lines on the map as the zero degree of the protractor and mark a line with the proper angular measurement from the landmass. Repeat this process for the other two locations. Then, draw a circle within the triangle formed from the three intersecting lines along with the time to mark the placement of the ship.

Alidade on the port side of ship

Alidade on the port side of ship

Another way to mark the placement of the vessel visually is to look at the radar for three known landmarks. Record the distance to each landmark. One nautical mile equals one minute of latitude. Longitude cannot be used for distance since these values change as you approach the poles of the Earth. Use a compass to mark the appropriate distance from the scale on the perimeter of the map. Then, draw an arc with the compass from the landmass. Repeat this process for both of the other landmarks. The three arcs intersect at the current location of the vessel and should be marked with a circle and the time.

Protractor and compass

Protractor and compass used to mark the course of the ship on the chart.

The two visual methods for marking the placement of the vessel are used in conjunction with an electronic fix. The digital latitude and longitude recording  from the G.P.S, or Global Positioning System, provides the third check. This data is recorded and then charted using the latitude and longitude marks on the perimeter of the chart.

Another responsibility of the navigator is to mark on the nautical chart the approximate location of the ship moving forward. This is called D.R, or dead reckon, and it shows where you would be if you were to continue on coarse at the current speed for up to two hours.

Personal Log

As we approached the Inside Passage, a feeling of peace and serenity came over me as I viewed snow capped mountains beyond islands with endless evergreen trees. The feelings of the navigators may be different since this is a treacherous journey to traverse, although it is preferred to the open sea. The Inside Passage proves to be a great learning opportunity for new junior officers without much navigation experience. However, due to the weather issues and narrow passages, the Commanding Officer, Senior Watch Officer and Officer of the Deck have extended experience navigating the Inside Passage.

The strong currents at Seymour Narrows in British Columbia can make this voyage dangerous. This was taken into consideration and we crossed them during slack tide, the time between high and low tide, with a current of only about two knots. Tides can get as high as 15 knots during maximum ebb and flood tides. The visible circular tides, or eddies, are created from the current coming off of Vancouver Island being forced into a narrow channel. As Senior Survey Technician Jackson shared, the Seymour Narrows once had Ripple Rock, a two peak mountain, that caused several shipwrecks and was home to the largest non-nuclear explosion in North America in 1958.

Inside Passage by Seymour Narrows

Inside Passage by Seymour Narrows

As we entered the Inside Passage, islands covered in Western red cedar, Sitka spruce and Western hemlock provided the beautiful green amongst the spectacular ocean and sky blue. These colors paint the canvas indicative of the Pacific Northwest that make my soul feel at home. The cloud covered sky could be seen in every direction. We saw moon jellyfish floating by from the flying bridge and later a group of porpoises jumping up out of the water. The watch from the deck crew would spot lighthouses and fishing boats with binoculars well before anyone with a naked eye. I observed the approaching sunset from the bow of the ship and felt gratitude for the day.

Approaching sunset in Inner Passage

Inner Passage Sunset

Did You Know?

There are two different types of radar on the Bridge. S Band radar sends out pulses between 4 and 8 centimeters at 2-4 GHz and can go over longer distances. This is helpful to determine what is happening far from the boat. The X Band radar sends out smaller pulses of 2.5 -4 cm at 8-12 GHertz and can create a clear image of what is occurring close to the boat. Both radar systems provide useful information and must be used in conjunction with one another to have an understanding of what is happening near and far from the ship.

Source – https://www.everythingweather.com/weather-radar/bands.shtml

Heather O’Connell: Sound in Seawater and Sleeping at Sea, June 8, 2018

NOAA Teacher at Sea

Heather O’Connell

NOAA Ship Rainier

June 7 – 21

Mission: Hydrographic Survey

Geographic Area of Cruise: Seattle, Washington to Southeast, Alaska

Date: 6/8/18

Weather Data from the Bridge: Latitude: 48.15° N, Longitude: 122 ° South 58.0’  West, Visibility: 8 nautical miles, Wind: 24 knots, Temperature: 14.2° C

Science and Technology Log

I was fortunate enough to sit in on a survey orientation for new survey technicians and junior officers with Lieutenant Steven Loy. He was on Rainier as the Field Operations Officer, F.O.O., in the past and is currently here as an augmenter filling the role of Senior Watch Officer since he has navigated through the Inside Passage several times. In his two hour orientation, he shared a wealth of knowledge and discussed how multibeam sonar and ultrasounds are two opposite ends to the ultrasonic pulse spectrum.

Multibeam sonar sends out sound and measures the time it takes to return to calculate the depth of the ocean floor. The accuracy of the depth data generated from the multibeam sonar relies on the sound speed profile of the water. The combined effects of temperature, salinity and pressure generate a sound speed profile. Because of the inherent importance of this profile, there are several different ways to measure it. The sound velocity profiler measures this right at the interface of the multibeam sonar. C.T.D.s., or conductivity temperature and depth machines, measure water profile while the ship is stopped. M.V.P.s, or moving vessel profilers, take the water profile as the vessel is moving. Lastly, XBTs are expendable bathythermographs that measure temperature while the ship is in motion.

Sound is affected by different variables as it is energy that travels through a medium as a wave. Lieutenant Loy shared an informative website, The Discovery of Sound in the Sea, where I was able to enhance my understanding. Sound can travel through a liquid, such as water, a gas like air, or a solid like the sea floor. On average, sound travels about 1500 meters per second in sea water. However, the rate changes at different times of day, various locations, changing seasons and varying depths of the water. By looking at sound speed at one particular place in the ocean, you can determine how the different variables affect this sound. Usually, as depth increases, temperature decreases, while salinity and pressure increase.

A multi-beam sensor has a metal plate receiver and a transmitter perpendicular to one another. This array geometry enhances sound.  The sound velocity profiler is next to the receiver and measures right at the interface. To determine the speed of sound right where the beam is generated, sonar is used to measure speed sound across a known distance. This information is then utilized in the overall determination of the depth of the ocean floor. Once this cast is taken, the Seafloor Information System (SIS), can adjust sonar measurements accordingly.

Another way to measure the sound profile of water includes a C.T. D.  This device measures the conductivity, temperature and depth of the water. Conductivity measures the electrical current of the water. The more dissolved salt, or ions in solution, the greater the conductivity and salinity of the water. The depth of the water is directly related to the pressure of the water. Salinity, temperature and pressure affect the sound speed profile of water. This machine has a high data rate that goes up and down the water column. The titanium C.T.D. operates at a high pressure and costs about forty thousand dollars. This accurate technology can only be utilized when the boat is stopped and is used on the smaller survey launches.

C.T.D. used for sound speed profile of water

C.T.D. used for sound speed profile of water

A third method of measuring sound profile is the M.V.P., moving vessel profiler, which takes the data when the ship is moving. These are calibrated before a survey begins and are an efficient way to collect data. An expansive crane lowers the metal torpedo with the sensor off the fantail, the overhanging back part of the ship, into the water to collect the data. The fish is programmed to stop twenty meters above the ocean floor, at which point it returns to its docked position. On ship Rainier, the deck department deploys the fish with a cable wire and the plot room with the survey technicians controls the sensor.  

Boatswain Kinyon and Survey Technicians Finn and Stedman releasing the torpedo of the M.V.P. into the water

Boatswain Kinyon and Survey Technicians Finn and Stedman releasing the torpedo of the M.V.P. into the water

Another way to collect the sound profile of water with a moving vessel is to use an expendable probe. As temperature decreases, the sound speed decreases. Since temperature is the most important factor affecting the speed of sound, an X.B.T., Expendable Bathythermograph, or expendable probe created by the military. With bathy relating to depth and thermo meaning heat, this measures the temperature of the water at a cost of about one hundred dollars. These probes descend at a known rate, so, depth is a function of time.

Sources – Discovery of Sound in the Sea

Personal Log

We left port yesterday at 16:30, which has been a highlight of my NOAA Teacher at Sea Experience thus far. Before leaving port, all hands were assigned a different assignment to help with the launch. I watched the crew bring in the gangway that connects the ship to the port then disassemble it. The crew with hard hats and orange work vests took down poles and neatly tied up different sections by knotting ropes. We slowly progressed out of the port after a cargo ship passed us.  

The deck crew preparing to leave port

The deck crew preparing to leave port

Once the ship picked up speed and the ocean breeze was in my hair, I felt a new kind of freedom. With the Seattle skyline behind us and the beautiful green peninsulas in front of us, I was content to be moving forward. Everyone seemed to feel relieved once we were underway. I felt gratitude as I enjoyed watching the sunset from the flying bridge, the area of the ship above the bridge at the front of the ship.

Seattle Skyline

Seattle Skyline

After sunset, I returned to my berth, or sleeping quarters, located in the bow of the ship on the C-deck. I heard the constant white noise of the propellers that got much louder when the pitch, or angle, of them changed. This sound of seawater combined with the rocking motion of the ship lulled me to sleep on our first night at sea.

20180607_203558.jpg

Sunset

Did You Know?

Juneau, the American capital of Alaska, can only be entered by plane or boat. It is inaccessible by roads due to large mountain ranges on either side.