Rosalind Echols – NOAA Teacher at Sea Blog

August 6, 2013August 13, 2021

Rosalind Echols: Cool Science on the Ship and Final Reflections on My Rainier Adventure, July 30, 2013

NOAA Teacher at Sea
Rosalind Echols
Aboard NOAA Ship Rainier
July 8 — 25, 2013

Mission: Hydrographic Survey
Geographical Area of Cruise: Shumagin Islands, Alaska
Date: July 30, 2013

Current Location: 54° 55.6’ N, 160° 10.2’ W

Weather on board: Broken skies with a visibility of 14 nautical miles, variable wind at 22 knots, Air temperature: 14.65°C, Sea temperature: 6.7°C, 2 foot swell, sea level pressure: 1022.72 mb

Science and Technology Log:

Sometimes in school you hear, “You’ll need this someday.” You have been skeptical, and (at times) rightfully so. But here on the Rainier, Avery and I encountered many areas in which what we learned in school has helped us to understand some of the ship operations.

How does a 234 ft. ship, like the Rainier, float?

If you take a large chunk of metal and drop it in the water, it will sink. And yet, here we are sailing on a large chunk of metal. How is that possible? This all has to do with the difference between density (the amount of mass or stuff contained within a chunk of a substance) and buoyancy (the tendency of an object to float). When you put an object in water, it pushes water out of the way. If the object pushes aside an amount of water with equal mass before it becomes fully submerged, it will float. Less dense objects typically float because it doesn’t take that much water to equal their mass, and so they can remain above the water line. The shape of a ship is designed to increase its buoyancy by displacing a greater quantity of water than it would as a solid substance. Because of all the empty space in the ship, by the time the ship has displaced a quantity of water with equal mass to the ship itself, the ship is still above water. As we add people, supplies, gasoline and so on to the ship, we ride lower. As evidenced by the sinking of numerous ships, when a ship springs a hole in the hull and water floods in, the buoyancy of the ship is severely compromised. To take precaution against this, the Rainier has several extra watertight doors that can be closed in case of an emergency. That way, the majority of the ship could be kept secure from the water and stay afloat.

How does a heavy ship like the Rainier stay balanced?

Another critical consideration is the balance of the ship. When the ship encounters the motion of the ocean, it tends to pitch and roll. Like a pendulum, the way in which it does this depends largely on the distance between the center of gravity of the ship (effectively the point at which the mass of the ship is centered) and the point about which it will roll. Ships are very carefully designed and loaded so that they maintain maximum stability.

Ballast is often added to the hulls of ships for the following reasons:

to help keep them balanced when there is not enough cargo weight
to increase stability when sailing in rough seas
to increase the draught of the ship allowing it to pass under bridges
to counteract a heavy upper deck like that of the Rainier, which itself contains 64, 000 pounds of launches.

Ballast comes in many forms and historically rocks, sandbags and pieces of heavy metal were used to lower a ship’s center of gravity, thus stabilizing it. Cargo ships, when filling up at port, would unload this ballast in exchange for the cargo to be transported. For example, in the 1800s, the cobblestone streets of Savannah, Georgia were made with the abandoned ballast of ships. Today water is used as ballast, since it can be loaded and unloaded easier and faster. Most cargo ships contain several ballast tanks in the hull of the ship.

It is thought that the capsizing of the Cougar Ace cargo ship bound for the west coast of the US in 2006, was caused by a ballast problem during an open-sea transfer. The ship was required to unload their ballast in international waters before entering US waters to prevent the transfer of invasive species carried by the stored water. The result of the Cougar Ace snafu: 4, 700 Mazdas scrapped and millions of dollars lost. Oops!

Couger Ace capsized in open ocean — Cougar Ace capsized in open ocean

Because the Rainier is not loading and unloading tons of cargo, they use a permanent ballast of steel rebar, which sits in the center of the lower hull. Another source of ballast is the 102, 441 gallons of diesel which is divided between many gas tanks that span the width and length of the ship on the port and starboard sides. These tanks can be filled and emptied individually. For stability purposes the Rainier must maintain 30% of fuel onboard, and according to the CO, the diesel level is usually way above 30% capacity. The manipulation of the individual diesel tank levels is more for “trimming” of the boat which essentially ensures a smoother ride for passengers.

Where does all the freshwater come from for a crew of 50?

If only humans could drink saltwater, voyages at sea would be much easier and many lives would have been saved. Unfortunately, salt water is three times saltier than human blood and would severely dehydrate the body upon consumption leading to health problems such as kidney failure, brain damage, seizures and even death. So how can we utilize all this salt water that surrounds us for good use? Well, to avoid carrying tons of fresh potable water aboard, most large ships use some type of desalination process to remove the salt from the water. Desalination methods range from reverse osmosis to freeze thawing to distillation. The Rainier uses a distillation method which mimics the water cycle in nature: heated water evaporates into water vapor, leaving salts and impurities behind, condensing into liquid water as the temperature drops. This all is happening inside a closed system so the resulting freshwater can be kept. To speed up this process, the pressure is lowered inside the desalinator so the water boils at a lower temperature. Much of the energy needed to heat the water comes from the thermal energy or waste heat given off by nearby machines such as the boiler.

Distillation purifies 99% percent of the salt water and the remaining 1% of impurities are removed by a bromine filter. The final step of the process is a bromine concentration and PH check to ensure the water is potable. The bromine should be about .5 ppm and the PH between 6.8-7.2.

Everyday the Rainer desalinates 2500 gallons of saltwater to be used for drinking, cleaning and showering. The toilets, however, use saltwater and if you are lucky like me, you can see flashes of light from bioluminescent plankton when flushing in darkness. It’s like a plankton discotec in the toilet!

How does the chicken cross the road when the road is moving?

The difference between a road map and a nautical chart is that a road map tells you which way to go and a nautical chart just tells you what’s out there and you design your course. Thus, navigating on the ocean is not as simple as “turn left at the stop sign,” or “continue on for 100 miles”, like directions for cars often state. Imagine that the road beneath you was moving as you drove your car. In order to keep following your desired course, you would need to keep adjusting to the changes in the road. That’s a lot like what happens in a ship. If you want to drive due west, you can’t simply aim the ship in that direction. As you go, the ship gets pushed around by the wind, the currents, and the tides, almost as if you drove your car west and the road slid up to the north. Without compensating for this, you would end up many miles north of your desired location. If you have a north-going current, you have to account for this by making southward adjustments. In a physics class, we might talk about adding vectors, or directional motion; in this case, we are considering velocity vectors. When you add up the speed you are going in each direction, you end up with your actual speed and direction. In the ship we make adjustments so that our actual speed and direction are correct.

Which way to the North Pole?

Did you know that when you look at a compass, it doesn’t always tell you the direction of true north? True north is directly towards the North Pole, the center of the Earth’s axis of rotation which passes directly to the true south pole. However, compasses rely on the location of the magnetic pole which is offset somewhat.

Compass showing true north and magnetic north

The combination of the solid iron core and the liquid iron mantle of the Earth create a magnetic field that surrounds the Earth (and protects us from some really damaging effects of the sun). If you visualize the Earth like a bar magnet, magnetic north is located at an approximate position of 82.7°N 114.4°W, roughly in the middle of northern Canada. If you stood directly south of this point, your compass would point true north because true north and magnetic north would be on the same line of longitude. However, as you get farther away from this west or east, the North indicated by your compass is more and more offset.

Our navigational charts are made using “true” directions. Because of our location in Alaska, if we were steering by compass, we would have to offset all of our measurements by roughly 14° to account for the difference in true and magnetic north. Fortunately, due to the advent of GPS, it is much simpler to tell our true direction.

Why so much daylight and fog?

Every hour, the crew of the Rainier measures the air temperature, sea water temperature, atmospheric pressure, and relative humidity. Aside from keeping a record of weather conditions, this also allows the National Weather Service to provide a more accurate weather forecast for this geographical region by providing local data to plug into the weather prediction models.

Weather in the Shumagin Islands could be very different from that of the nearest permanent weather station, so this can be valuable information for mariners. In our time out here, we have experienced a lot of fog and cool temperatures (although the spectacular sunshine and sunsets of the past few days make that seem like a distant memory). One reason for this is our simultaneous proximity to a large land mass (Siberia, in far-east Russia) and the ocean. Cool air from the land collides with warm waters coming up from Japan, which often leads to fog.

Currents of the Pacific — Currents around Alaska

However, because we are pretty far north, we also experience a lot of daylight (although not the 24-hour cycles so often associated with Alaska). At this time of the year, even though the Earth is farther away from the sun that it is in our winter season, the axis of the Earth is tilted toward the sun, leading to more direct sunlight and longer hours of illumination.

Earth's orbit around the sun — Earth’s orbit around the sun

One slightly bizarre fact is that all of Alaska is on the same time zone, even though it is really large enough to span several time zones. Out in the west, that means that sunset is in fact much later than it otherwise should be. Our last few spectacular sunsets have all happened around 11pm and true darkness descends just past midnight. I have on several occasions stayed up several hours past my bedtime fishing on the fantail or getting distracted wandering around the ship because it is still light out at 11pm!

Rosalind and Avery at sunset — Rosalind and Avery (with Van de Graaf generator hair) at sunset

Personal Log:

After roughly a week back on land, I have already been inundated with questions about life on the Rainier, the research we were doing, the other people I met, and so on. It occurs to me that as challenging as it was to embark on this journey and try to learn as much as possible in three weeks, perhaps the greater challenge is to convey the experience to friends, family, and most importantly, my students. How will I convey the sense of nervousness with which I first stepped from the skiff to land, trying not to fall in the frigid north Pacific? What will I do in my classroom to get my students as excited about learning about the ocean and diving into new experiences as I was on this trip? How will I continue to expand on the knowledge and experiences I have had during my time on the Rainier? At the moment, I do not have excellent answers to these questions, but I know that thinking about them will be one of the primary benefits of this extraordinary opportunity.

For the moment, I can say that I have deepened my understanding of both the value and the challenge of working in collaboration with others; the importance of bringing my own voice to my work as well as listening to that of others; and the extent to which new experiences that push me out of my comfort zone are incredibly important for my development as an individual. I genuinely hope that I can develop a classroom environment that enables this same learning process for my students, so that, like the science I discussed above, they aren’t doing things that they will, “need some day,” but doing things that they need now.

Finally, I will say that I am finishing this trip even more intrigued by the ocean, and its physical and biological processes, than I was before. When one of the survey techs declared, “This is so exciting! We are the first people ever to see the bottom of this part of the ocean!” she wasn’t exaggerating. Even after my time on the Rainier, I feel like I am only beginning to scratch the surface of all of the things I might learn about the ocean, and I can’t wait to explore these with my students. I look forward as well to the inevitable research that I will do to try to further solidify my understanding and appreciation of the world’s oceans.

I leave with fond memories of a truly unique 18 day voyage aboard the most productive coastal hydrographic survey platform in the world: her majesty, the NOAA Ship Rainier. Thank you lovely lady and thank you Rainier crew for making this Teacher at Sea adventure so magical!

July 24, 2013August 13, 2021

Rosalind Echols: Sound Off! From Noise to Nautical Charts, July 22, 2013

NOAA Teacher at Sea
Rosalind Echols
Aboard NOAA Ship Rainier (NOAA Ship Tracker)
July 8 — 25, 2013

Mission: Hydrographic Survey
Geographical Area of Cruise: Shumagin Islands, Alaska
Date: July 22, 2013

Current Location: 54° 55.6’ N, 160° 10.2’ W

Weather on board: Broken skies with a visibility of 14 nautical miles, variable wind at 22 knots, Air temperature: 14.65°C, Sea temperature: 6.7°C, 2 foot swell, sea level pressure: 1022.72 mb

Science and Technology log:

“Teamwork, Safety First”, is inscribed boldly on the Rainier stern rafter and after being aboard for more than 2 weeks, it is evident this motto is the first priority of the crew and the complex survey operation at hand.

Rainier launch — This is one of the survey launches that we use to gather our survey data. In this case, the launch is shown approaching the Rainier, getting ready to tie up.

It’s a rainy overcast morning here in SW Alaska and we are circled around the officers on the fantail for the daily safety meeting. Weather conditions, possible hazards, and the daily assignment for each launch are discussed. Per the instructions on the POD (Plan of the Day), handed out the previous evening, the crew then disperse to their assigned launches. The launches are then one-at-a-time lowered into the water by the fancy davit machinery and driven away by the coxswain to their specific “polygon” or survey area for the day. A polygon surveyed by a launch on average takes 2-3 hours at 6-8 knots to survey and usually is an area that is inaccessible by the ship. Many polygons make up one large area called a “sheet” which is under the direction of the “sheet manager”. Several sheets make up an entire survey project. Our hydrographic project in the Shumagins has 8 sheets and makes up a total of 314 square nautical miles.

This is a chart of the Shumagin Islands showing the 8 sheets (highlighted in green) that we are surveying.

Polygons — East side of Chernabura Island divided into survey “polygons”, each labeled with a letter or word. Notice how each polygon is a small subset of the larger sheet.

On board each launch we have a complex suite of computer systems: one manages the sonar, another manages the acquisition software, and the third records the inertial motion of the launch as it rocks around on the water (pitch, heave, roll). The acquisition system superimposes an image of the path of the launch and the swath of the sonar beam on top of a navigational chart within the polygon. Starting at one edge of the polygon, the coxswain drives in a straight a line (in a direction determined by the sheet manager), to the other end of the polygon, making sure there is some overlap at the boundaries of the swaths. He/she then works back in the other direction, once again making sure there is some overlap with the adjacent swath. We call this “mowing the lawn,” or “painting the floor” as these are visually analogous activities. Throughout the day, we pause to take CTD casts so that we have a sound velocity profile in each area that we are working.

Typical launch dispersal for a survey day. Launches are signified by “RA-number”. You can also see the location of our tide measurement station and GPS control station, both of which we use to correct our data for errors.

Mowing the lawn — This image shows the software tracking the path and swath of the launch (red boat shape) as it gathers data, driving back and forth in the polygon, or “mowing the lawn.” The darker blue shaded area shows overlap between the two swaths. The launch is approaching a “holiday”, or gap in the data, in an effort to fill it in.

You might be wondering, why the swath overlap? This is to correct for the outer sonar beams of the swath, which can scatter because of the increased distance between the sea floor and the sonar receiver below the hull of the boat. The swath overlap is just one of the many quality control checks built into the launch surveying process. Depending on the “ping rate”, or the number of signals we are able to send to the bottom each second, the speed of the boat can be adjusted. The frequency of the sound wave can also be changed in accordance with the depth. Lower frequencies (200 khz) are used for deeper areas and higher frequencies (400 khz) are used for shallower areas.

Rosalind in launch — Rosalind in front of the computers on the launch, checking for sonar quality (right screen) and observing the path of the ship, to make sure there are no gaps in the data, or “holidays”.

Despite what might seem like mundane tasks, a day on board the launch is exhausting, given the extreme attention to detail by all crew members, troubleshooting various equipment malfunctions, and the often harsh weather conditions (i.e. fog, swells, cool temperatures) that are typical of southwest Alaska. The success of the ship’s mission depends on excellent communication and teamwork between the surveyors and the coxswain, who work closely together to maximize quality and efficiency of data collection. Rain or shine, work must get done. But it doesn’t end there. When the launches arrive back at the ship, (usually around 4:30 pm), the crew will have a debrief of the day’s work with the FOO (field operations officer) and XO (executive officer). After dinner, the survey techs plunge head first (with a safety helmet of course) into the biggest mountain of data I have EVER witnessed in my life, otherwise known as “night processing”. We are talking gigabytes of data from each launch just for a days work. It begins with the transferring of launch data from a portable hard drive to the computers in the plot room. This data is meticulously organized into various folders and files, all which adhere to a specific naming format. Once the transferring of data has finished, the “correction” process begins. That’s right, the data is not yet perfect and that’s because like any good science experiment, we must control for extraneous factors that could skew the depth data. These factors include tides, GPS location error, motion of the launch itself, and the sound velocity in the water column.

Plot room — Our chief surveyor works in the plot room cleaning and correcting data.

Data cleaning. — Data showing the consequences of the tide changing. The orange disjointed surface shows the data before it was adjusted for the tide changing. You can see how the edges between swaths (i.e. red and olive green) do not match up, even though they should be the same depth.

Sound speed artifact — This image shows the edge effects of changing sound speed in the water column. The edges of each swath “frown” because of refraction owing to changing density in the water column. This effect goes away once we factor in our CTD data and the sound speed profile.

In previous posts, I discussed how we correct for tides and the sound velocity. We also correct for the GPS location of the launch during a survey day, so that any specific data point is as precisely located as possible. Although GPS is fairly accurate, usually to within a few meters, we can get even more precise by accounting for small satellite errors throughout the day. The Coast Guard provided Differential GPS allows us to position ourselves to within a meter. To get even more precise, within a few centimeters, we determination location of a nearby object (our Horizontal Control, HorCon, Station) very precisely, and then track the reported position of this object throughout the day. Any error that is recorded for this station is likely also relevant for our launch locations, so we use this as the corrector. For example, if on July 21, 2013, at 3pm, the GPS location of our Bird Island HorCon station was reported 3cm north of its actual location, then our launches are also probably getting GPS locations 3cm too far north, so we will adjust all of our data accordingly. This is one of the many times we are thankful for our software. We also account for pitch, heave, and roll of the launch using the data from the inertial motion unit. That way, if the launch rolled sideways, and the center beam records a depth of 30 meters, we know to adjust this for the sideways tilt of the launch.

HorCon station — This shows the set up of our Horizontal Control and tide gauge station. The elevated rock position was chosen to maximize satellite visibility.

After all correctors have been applied (and a few software crashes weathered), the survey technicians then sort through all the data and clean out any “noise.” This noise represents sound reflections on sea life, air bubbles, or other items that are not part of the seafloor. Refraction of sound waves, as mentioned in the last post, is caused by density changes in the water due to changes in the temperature, pressure, or salinity.

Dirty data — This shows sonar data with “noise”. The noise is the seemingly random dots above and below the primary surface. On the surface itself, you can see data from four different swaths, each in a different color. Notice the overlap between swaths and how well it appears to be matching up.

Cleaned surface — This shows sonar data after the “noise” has been cleaned out. Notice how all data now appears to match a sea floor contour.

Many of the above correctors are applied the same day the data is collected, so the sheet manager can have an up-to-date record of the project’s progress before doing final planning for data collection the next day. After a sheet has been fully surveyed and ALL correctors applied, the sheet manager will complete a “descriptive report”, which accompanies the data and explains any gaps in the sonar data (“holidays”) and/or other errors present. This report, along with the data, is sent to the Pacific Hydrographic Branch for post-processing and Quality Control. After that the data is forwarded to the Marine Charting Division where the data undergoes a final set of Quality Assurance checks and is put in a format that can be printed on a paper nautical chart. From acquisition on the launches to publication on a chart, the process can take up to two years! The length of the process is designed to ensure maximum accuracy as many mariners rely on accurate charts for safe navigation.

Personal Log

As the saying goes, “When in Rome, do as the Romans.” One of the attractions of life in Alaska is access to excellent fishing, and a wide variety of tasty fish species. Although I normally consider myself to be a fairly outdoorsy person, thus far in my life this had not extended to the activity of fishing. However, inspired by Avery’s enthusiasm, and her first successful halibut catch, I decided at least give it a try, obtaining an Alaska fishing license and preparing myself for yet another adventure. I am, after all, always encouraging other people to try new things, especially things that make them a bit nervous, so it only felt right to follow some of my own advice. Honestly speaking, though, the thought of catching the fish and then having to deal with the consequences made me a little anxious.

Rosalind with fish — Rosalind with her first ever fish catch, trying very hard to keep her fingers away from the tip of the hook and the very spiny and painful back fin of the fish. Black rock fish have venomous points on their fins.

Fortunately, I had excellent guidance in this activity, setting out with Avery and two very patient crew members, who put up with my initial lack of skill and muscle, and intense enthusiasm about even the smallest jellyfish in the water. I had realized after my shoreline rock verification expedition that pointing at everything in the water and shouting “Look!” was probably not that helpful if we were trying to identify rocks, but here it seemed more appropriate. At least if you think jellyfish are cool. After several lackluster hours, we finally found a spot where a group of Black Rock Fish were schooling, and caught quite a few very quickly. Not surprisingly, the fish aren’t that happy about being caught and flail around a fair amount. Considering that they have pointy, venomous spines in their dorsal fin, it takes great care to get the fish in the bucket without injury, but we successfully managed it.

Rosalind cleaning — Rosalind learning how to fillet a black rock fish. Notice the safe distance between knife and fingers!

Somehow, in all my years of school, I never actually dissected anything, and have always felt a little squeamish around dead animals. However, after helping catch the fish, I couldn’t very well leave my colleagues alone to deal with the arduous task of filleting and cleaning the fish, so I decided to do my best to participate. It actually went much better than I expected, and I learned quite a bit about fish anatomy along the way. For example, fish have an air bladder that allows them to float. They look much less impressively large when this is deflated.

Fish fillets — A sampling of our collection of black rock fish fillets, mid-way through cleaning. I am proud to have contributed to this!

All in all, it was a very satisfying experience. It is nice to be able to say that I have developed a somewhat useful life skill (fishing as well as avoiding my fingers with large knives). Our wonderful cook, Kathy, even used some of the fish for a delicious lunch of fish tacos, which I hope to try to replicate myself some time in the near future.

FIsh tacos — Delicious fish tacos made from Black Rock Fish caught by Rainier crew and Teachers at Sea Rosalind and Avery!

Fun Fact: a fathom, a maritime measurement for depth equal to six feet, was originally based on the distance between a man’s outstretched finger tips. The word itself derives from an Old English word meaning outstretched or embracing arms. Given that we use it to measure depth, it is also interesting to note that it is related to the word to fathom something, or the adjective unfathomable, meaning immeasurable. The word is also related to the phrases “six feet under” and to “deep six” something.

July 20, 2013August 13, 2021

Rosalind Echols: Beaming With Excitement – Sound Waves and the Sea Floor, July 19, 2013

NOAA Teacher at Sea
Rosalind Echols
Aboard NOAA Ship Rainier (Ship Tracker)
July 8-25, 2013

Mission: Hydrographic Survey
Geographical Area of Cruise: Shumagin Islands, Alaska
Date: July 19, 2013

Current Location: 54° 49.684 N, 159° 46.604 W

Weather Data from the Bridge: Foggy and overcast, wind 21 knots, 11.5° C

Science and Technology Log:

Foggy islands — View from the launch while gathering our multibeam sonar data.

As the fog horn sounds every two minutes and we sail solitary through the ocean, we are now in full swing surveying the Shumagin Islands, between and around Nagai, Bird, and Chernabura Islands. Unlike the old-time surveyors who used lead lines (lead weight attached to a long string), we are using a multibeam sonar system, which enables us to gather a large quantity of very accurate data in a more efficient and timely fashion.

3D sea floor — Processed sonar data showing 3D image of the sea floor.

Sonar, (SOund Navigation And Ranging) uses the principle of sound wave reflection to detect objects in the water. Just as our eyes see the reflection of visible light off of the objects around us to create a visual image, when a sound wave hits something, it reflects off that “thing” and returns to its starting point (the receiver). We can measure the time it takes for a pulse to travel from the Sonar device below the boat to the ocean floor and then back to the receiver on the boat. Using a simple distance=speed * time equation, we can get the water depth at the spot where each beam is reflected.

The skiff that we use for the shoreline activities discussed in the last post has a single-beam sonar system that directs a pulse straight down beneath the hull to get a rough depth estimate. However, for our hydrographic work on the ship and launches, we use a multibeam system that sends 512 sound pulses simultaneously towards the sea floor over a 120° angle. When many sound waves or “beams” are emitted at the same time (called a pulse) in a fan like pattern (called a swath), the reflected information creates a “sound picture” of the objects or surface within that swath range. The actual width of this swath varies with the depth, but with 512 beams per pulse, and sending out between 5-30 pulses every second, we acquire a lot of data. If you piece together many swaths worth of data you get a continuous topographical or physical map of the ocean floor, and thus the depth of the water. For more information about the specific sonar system used aboard the Rainier and its launches, check out the ship page or the NOAA page about their hydrography work.

Multibeam — Graphic showing an example of the multibeam swath below a launch. Notice how the swath gets wider as the depth increases.

Multibeam data — Cross section of sea floor data showing dot for each multibeam measurement. Notice how many individual measurements are represented in this one section.

Swath data — Cross section of sea floor data. Each color represents data from one swath. Notice the overlap between swaths as well as the width for each one.

3D floor image — Processed sonar data showing 3D image of the sea floor.

In order to understand the complexities of sonar, it is important to understand the properties of sound. Sound is a pressure wave that travels when molecules collide with each other. We know that sound can travel in air, because we experience this every day when we talk to each other, but it can also travel in liquids and solids (which whales rely on to communicate). As a general rule, sound travels much faster in liquids and solids than in air because the molecules in liquids and solids are closer together and therefore collide more often, passing on the vibration at a faster rate. (The average speed of sound in air is about 343 meters every second, whereas the approximate speed of sound in water we have been measuring is around 1475 meters every second). Within a non-uniform liquid, like saltwater, the speed of sound varies depending on the various properties of the saltwater at the survey site. These properties include water temperature, dissolved impurities (i.e. salts, measured by salinity), and pressure. An increase in any of these properties leads to an increase in the speed of sound, and since we’re using the equation distance = speed * time equation, it is crucial to consistently measure them when seeking depth measurements.

CTD Data — Data from CTD showing temperature vs. sound speed from one data set. Notice how the temperature and sound speed seem correlated.

To measure these properties, a device called a CTD (Conductivity-Temperature-Depth) is used. Conductivity in this acronym refers to the free flowing ions in salt water (Na and Cl, for example), which are conductive and the concentration of these ions determines the salinity of the water. The CTD measures these three properties (Conductivity, Temperature and Depth) so the speed of sound in the water can be calculated at every point in the water column

To use the CTD, lovely humans like Avery and I will drop it into the water (it is attached to a winch system) at the area where we are surveying and as it travels to the sea floor, it takes a profile of the three saltwater properties mentioned before. Back in the computer lab, software takes this profile data and and calculates the sound velocity or speed of sound through the water in that region. As a crosscheck, we compare our profile data and sound velocity figures obtained at the site to historical measured limits for each property. If our measurements fall significantly outside of these historical values, we might try casting again or switch to a different CTD. However, because we are surveying in such a remote area, in some cases, data outside historical limits is acceptable.

CTD graphs — Graph of our sound speed vs. depth data showing comparison to historical data.

Given that we are trying to determine the water depth to within centimeters, variations in the sound speed profile can cause substantial enough errors that we try to take a “cast” or CTD reading in each small area that we are gathering data. The software the survey team uses is able to correct automatically for the sound velocity variations by using the data from the CTD. This means that the depth profile created by the sonar systems is adjusted based on the actual sound velocities (from the CTD data) rather than the surface sound speed. We are also able to account for speed changes that would cause refraction, or a bending of the beam as it travels, which would otherwise provide inaccurate data about the location of the sea floor.

Rosalind CTD 1 — Rosalind lowers the CTD into the water for a “cast”. The CTD needs to sit in the water for a few minutes to acclimate before being lowered for a profile.

Rosalind CTD 2 — Rosalind operating the winch on to pull the CTD back up out of the water. It’s important to pay attention to the flexible white bar to make sure the CTD isn’t caught on anything at the bottom.

Rosalind CTD 3 — Rosalind pulling the CTD out of the water, successfully taking a cast and not falling in the water. Safety first!

Did you know? Sonar works a lot like the echo sounding of a bat, and its development was partially prompted by the Titanic disaster.

Personal Log:

On a ship with a crew of more than 50 people, you encounter people with a wide variety of backgrounds and stories about how they came to be here. Whether it is the NOAA corps officers, the members of the deck department, the engineers, the stewards and cooks, or the members of the hydrographic survey department, each person has a unique life experience that led them to be here on the Rainier. The advantage of being in close quarters for three weeks is that there are lots of opportunities to talk to people about what brought them here. Contrary, I think, to the messaging we sometimes get about needing to pick a life path early and stick to it, the people here have shown me the importance of being flexible and leaving yourself open to new and exciting opportunities professionally. One of the current members of the deck department was also in the navy for a long time, served several tours in Iraq and was trained as a Navy diver. Now, he is moving over to the survey department, and will be attending the NOAA dive school and hydrographic training this fall and winter, which I think is amazing. Case in point: it’s never too late to change your mind about what you want to do with your life.

Rocky shoreline — One of the many stunning views we have seen during our surveying activities.

In these conversations, it always comes out that I teach students physics. Regardless of the job someone does here on the Rainier, it seems inevitable that each person has a story about his or her own experience with physics. It seems that in the majority of cases, even for people who are now very successfully scientists, the experience was not positive. People all the time tell me that they didn’t really understand physics, or weren’t a physics person, and yet this same person can explain in great detail how we can use the ship to create a “duck pond” to bring in the launches in foul weather, or fix the engine of one of the launches, or determine the appropriate course of the ship to account for the swell and current to head in a particular direction. All of these unquestionably involve an application of physics, which suggests to me that the issue is not necessarily that physics is beyond some people, but that we don’t always teach students in ways that will work for them. This certainly gives me a lot to think about as a teacher, and hopefully I can maintain this awareness in my teaching.

July 17, 2013August 13, 2021

Rosalind Echols: Is it an Island or Just an Ink Blot? July 16, 2013

NOAA Teacher at Sea
Rosalind Echols
Aboard NOAA Ship Rainier (NOAA Ship Tracker)
July 8 — 25, 2013

Mission: Hydrographic Survey
Geographical Area of Cruise: Shumagin Islands, Alaska
Date: July 16, 2013

Current Location: 54° 55.8’ N, 160° 09.5’ W

Weather on board: Overcast skies with a visibility of .5 nautical miles, South wind at 18 knots, Air temperature: 10°C, Sea temperature: 7.2°C, 1-2 foot swell

Science and Technology log: Shoreline Verification

When you think of a shoreline, you might think of a straight or curved “edge” made of sandy beaches that gradually retreat into deeper and deeper water. In the Shumagin Islands, a sandy cove is a rare occurrence and a place for a beach party! Towering, jagged cliffs patched with Artic moss and blanketed by a creeping fog are the typical “edges” here. Below the cliffs, in the water, lie sporadic toothed rocks and beds of dense rooted bull kelp, swaying with the current. As I sit on the edge of the skiff (small dinghy-like boat), which gently trudges along the outside of the protruding rocks, I think to myself how this place evokes an ethereal mood and you really feel like you are in one of the most remote places in the world.

Navigating through Bull Kelp bed — Navigating around Bull Kelp bed

Remote it is and that is why we are here. These are, for the most part, uncharted or poorly documented waters and shorelines and in this post, I am going to talk about the shoreline aspect. Besides taking bathymetric data (depth data), hydrographic ships like the Rainier must also verify that the shorelines of various land-masses are portrayed accurately and that all necessary “features” are documented correctly on nautical charts. Features include anything that might be a navigational hazard such as rocks, shoals, ledges, shipwrecks, islets (small islands) and kelp beds. For shoreline verification, a 19 foot skiff is used for maneuverability and shallow water access. This boat will go out during the “shoreline window”, when the tide is the lowest, with the hopes that if there is a dangerous feature present, it will be visible above the water. In the best case scenario, we can investigate the shoreline fully with the skiff before sending in the bigger launches to survey the area with the sonar, so that we know they won’t hit anything.

Shoreline verification crew hard at work. From left: Randy (Coxswain), John (NOAA Corps. Officer), Chief Jacobson (Chief Survey Tech), Steve (NOAA Corps. Officer)

Rosalind in skiff. — Rosalind all bundled up for a day out in the skiff looking for rocks, kelp, and of course, wildlife.

The main goal of the scientists aboard the skiff is to establish a “navigational area limit line” (NALL). This is a boundary line delineating how far off shore the launch boats should remain when they are surveying. This boundary line is obtained in one of three ways:

1) presence of a navigational hazard such as a dense kelp bed or several protruding rocks

2) a depth of 4 meters

3) distance of 64 meters to shore

Whichever of these is reached first by the skiff will be the navigational area limit line for the launches. Here in the Shumagins, kelp beds and rocks have been the boundary line determinant and often these hazards are in water that is deeper than 4 meters because we have been encountering these before we get within 64 meters of the shoreline.

While scientists are determining the NALL, they are also verifying if certain features portrayed on older charts are in fact present and in the correct location. Using navigational software on a waterproof Panasonic Toughbook, they bring up a digitized version of the old chart of a specific survey area. This chart depicts features using various symbols (asterisk=rock above water, small circle=islet). This software also overlays the boat’s movement on top of the old chart, allowing the boat to navigate directly to or above the feature in question.

Shoreline map 1 — Shoreline map showing course of skiff, shoreline buffer, and feature for examination.

Shoreline map 2 — Shoreline map showing charted location of islet and the actual location of islet determined by the skiff.

If the feature is not visually seen by the human eye or the single beam sonar on the skiff, it will be “disproved” and a picture and depth measurement will be taken of the “blank” location. If the feature IS seen, more data will be recorded (height of feature above the water, time of day observed, picture) to document its existence. This same verification procedure is used for newfound features that are not present on the old charts. All of this data is written on a paper copy of the chart and then back in the “dry lab”(computer lab), these hand-written notes are transferred to a digital copy of the chart.

Section of shoreline showing data and notes about specific features in question

Digitized version of notes and data taken at field site Note: Kelp buffer are the large shaded red areas and the smaller red circle is the actual position of the islet — Digitized version of notes and data taken at field site. The black box corresponds to the area from the previous picture above.
Note: Kelp buffers are the large shaded red areas and the smaller red circle is the actual position of the islet. The three southernmost rocks (marked by red asterisks) inside the black box were disproved.

On the two shoreline verification adventures I went on, many rocks and islets were disproved and several new features were found. Most of the new features were rocks, islets or large kelp beds. It is important to note that if scientists find a new feature which is a serious present navigational hazard (ex. Shipwreck, huge jutting rock or shoal far offshore) it will be marked a DTON (Danger to Navigation) and communicated to mariners within a short time frame. Other less significant features take 1-2 years to appear on updated nautical charts.

For some survey areas, the Rainier uses aircraft-acquired LiDAR (Light Detection And Ranging) to get an initial idea of various features and water depths of a shoreline area. (This is a service that is contracted out by NOAA.) LiDAR data is obtained by a plane flying over an area at 120 mph, emitting laser beams to the water below. Like SONAR, LiDAR measures the time it takes for the laser beam to return to its starting point. Using this measured time and the speed of light, the distance the light traveled can be obtained, using the equation distance = speed*time, accounting for the fact that it travels through air and then water. Because light travels much faster than sound, the plane can travel significantly faster than a boat and a large area can be surveyed faster. Unfortunately LiDAR can only be used in clear, calm water because light is easily reflected by various solids (silt in the water, floating wood), specific color wavelengths (ex. White foam on ocean surface) and absorbed by biological specimens for photosynthesis (ex. Surface bull kelp). LiDAR surveys do reduce the time hydrographers spend at a shoreline site thus increasing the safety and efficiency of an operation. As with any data acquisition method, it must be cross-checked by another method and in this case because of the obvious downsides, it is used as a guide to shoreline verification.

Map of island showing LIDAR data. — Map of island showing LiDAR data. The skiff does shoreline verification outside the orange line that outlines the island. Everything inside this orange island was surveyed by the LIDAR airplane. The three orange features circled in red on the southeast section of the island, need to be re-surveyed by the skiff. Different colors show various depths. (Green is more shallow than light blue.)

After spending several days “disproving” a lot of rocks and islets that were clearly not present in their identified location, we started to wonder why someone would have thought there was a specific feature there. One possibility is that it was just an ink blot on the original chart, made by accident (from a fountain pen), and then interpreted as a rock or islet in the process of digitizing the chart. It’s better to be safe than shipwrecked! Another possibility is that these features were “eyeballed” in their documented location, and thus were present but just in the wrong spot. Lastly because of limitations previously mentioned, LiDAR occasionally mis-reports features that are not present. Fortunately, our current survey methods use sophisticated navigational technology and several cross-checks to minimize data errors.

Shoreline arch. — Arch carved in shoreline by gradual erosion from waves.

After shoreline verification has been completed, launches can survey the ocean floor (using SONAR) outside the boundary (NALL) that was established by the skiff. Each launch will be in charge of surveying specific polygons (labeled by letters and names). The picture above shows the polygon areas which are outlined in light orange (most are rectangles). I will talk more about SONAR and surveying on the launch in my next post. 🙂

Personal log:

During a rare break from the hustle and bustle of work and ship life, I joined several other people on an expedition to the beach to do some exploring and beach-combing on Bird Island. We initially tried to hike up and over one of the saddles on the island to reach a beach on the other side that was more exposed and thus might have had more items washed up, but after 30 minutes of hiking, we had only just reached the top of the saddle, which included a lake with a noisy flock of white birds on it, mostly hidden in the fog. Although it was a bit disappointing not to reach the other side, hiking on the tundra was a fascinating experience. Aside from the mist-shroud, which has been with us for the past few days, walking on the tundra itself was unlike anything else I have experienced. The spring bed of mosses, shrubs, and small flowers make every step feel like two, but should you chance to fall down, it is an incredibly comfortable landing. An ideal place for a nap, as long as it is not wet. Overall, between my less-than-graceful shoreline-to-skiff entrance, scrambling uphill through waste-high damp grass, exploring the coastline, which really looked more like a sea urchin graveyard, and getting to know some of my fellow shipmates better, it was a truly delightful outing.

Tundra wildflowers — Some of the flowers we saw on our hike on the tundra.

Aside from occasional excursions like this, we are generally on the ship or a launch 24 hours a day, which means that crew members have to be creative about getting exercise. Underneath the “fantail” (the outside deck at the stern of the ship), there is a small space that has been converted into a workout room, complete with treadmill, elliptical, exercise bike, and a sizable collection of weights. There is a group of crew members who have a sort of weight-lifting club, under the guidance of the third mate; one crew member likes to jump rope on the fantail so she has a good view for her exercise, and a number of people are intrepid enough to use the treadmill. I have now experimented with running a few times, and can only say that running on a treadmill on a rocking ship, even an ever-so-gently-rocking one, adds a new and exciting element to the treadmill that is sadly lacking in your typical gym.

Did you know?

The ship can rock in two different directions with the seas. When it is rocking forward and backward, it’s called pitch. When it’s rocking side-to-side, it’s called roll. The whole treadmill experience is quite different depending on whether the ship is pitching or rolling, but I always keep one hand on the bar for extra stability.

July 15, 2013August 13, 2021

Rosalind Echols: Ebbs and Flows, July 11, 2013

NOAA Teacher at Sea
Rosalind Echols
Aboard NOAA Ship Rainier
July 8 — 25, 2013

Mission: Hydrographic Survey
Geographical Area of Cruise: Shumagin Islands, Alaska
Date: July 11, 2013

Current Location: 54° 49.6 N, 159° 46.6 W

Weather data from bridge: 8.7°C, good visibility (6-8 miles), light and variable wind, overcast

View of cove — View of our anchorage from the installation point in a sunny moment.

Science and Technology Log:

Today, Avery and I were scientists in the field, helping the ship’s crew install tidal equipment in preparation for ocean floor survey work. This was a complex process, so we decided to walk you through it in a step-by-step question format.

What does a navigation chart show you?

The image below shows a chart of the area that we are in right now. Our first anchor point was off the north coast of Bird Island in a cove. On the chart, you can see many tiny numbers in the water areas, which represent various depths. These depths are measured in fathoms (1 fathom=6 feet). This depth information helps mariners stay in safe areas that are not too shallow. The charts also show known hazards such as sub-surface rocks and ship-wrecks. This chart clearly has a lot of white space, signifying many areas were never surveyed.

Shumagin survey area — Part of our survey area. Notice the white spaces around Bird and Chernabura Islands!

But wait, why are the depth numbers “fixed” on the charts? Doesn’t the water level change with the tides?

Yes! It sounds easy to say, “the water is 10 fathoms deep at this point”. However, water is subject to the gravitational pull of the moon and sun, resulting in various water levels or tides throughout the day. So the water will not always be “10 fathoms deep at this point.” For navigational purposes, the most hazardous water level is the lowest one, so nautical charts show the depth at the low tide water level. Depending on the location, some places have two high tides and two low tides per day (semi-diurnal) and some places have one high tide and one low tide per day (diurnal). Here in the Shumagin Islands we are on a semi-diurnal mixed tide schedule (meaning that the two highs and two lows are not the same height).

What are your experiences with high and low tides? What do you notice when you go to the beach? Leave me a comment!

How do you measure the tides each day?

shumagin_tide_zone — Map of the Shumagin Island-Sand Point Tide Zones. Notice how the eastern Shumagin Islands are 6 minutes ahead of Sand Point.

There are permanent tide measuring stations all over the globe that provide information on how to “correct for” and figure out your local tide conditions. For our case, there is a tide station at Sand Point on Popof Island, which is west from our survey area. Our survey area is in two zones, one which is in the same zone as Sand Point and the other which is in a different zone. Therefore, we installed a tide gauge in the latter to verify that the tidal times and heights of this zone are accurately predicted by the Sand Point values. According to the current information, it says that in the different zone the tides should occur 6 minutes before the tides in Sand Point and to multiply the heights by 0.98.

A tide gauge is a pretty cool device that works by the laws of physics. It is installed (by divers) on the sea floor near a coast-line, in relatively deep water, so that it will always be covered with water. The tide gauge uses the water pressure above to determine the depth of the water column (density of water and gravity are the important factors in making this calculation). The tide gauge stays in place for at least 28 days (one full tidal cycle), after which there is a record of the water level throughout that time period (as we were gathering data), as well as a rough idea of the tidal cycle each month, ready for comparison to the Sand Point data.

How do you know if the tide gauge is working?

To verify that the tide gauge is working, humans (i.e.: Avery and I), take water level measurements (in an area close to the tide gauge) using a giant meter stick or “staff”. In our case, we recorded the average water level height every 6 minutes for 3 consecutive hours. This 3-hour data set can then be compared to the tide gauge data set for that same time period, and hopefully they will show similar trends.

Tide staff — This is the tide staff we used to gather water level data for comparison to the tide gauge.

Map of the Shumagin Island-Sand Point Tide Zones. Notice how the eastern Shumagin Islands are 6 minutes ahead of Sand Point. — Graph showing the water height measurements from the tide staff and the tide gauge. Notice how they appear to be increasing at the same rate! That’s good.

What happens if the survey terrain changes over time? Will that affect the water depth?

The ocean floor is above a liquid mantle, so it is possible for there to be terrain changes and this would affect depth measurements. Thus, as scientists, we must make sure where our survey area is “geologically stable”. To do this, we installed “benchmarks”. If you’ve ever been to the highest point on a mountain in the United States, you might have already seen something like this: they are bronze disks that mark important places, used by NOAA as well as other agencies. We stamped our benchmarks with the year and our station data, letter A-E (by hand! with a hammer and letter stamps!), and installed them at roughly 200-foot intervals along the coastline in what we hope is bedrock. Once they were cemented in place, we determined each benchmark’s relative height in relation to the staff using a survey instrument called an optical level – this process is also called “leveling.” At the end of the survey season, the ship will come back and re-level them. If the area is geologically stable, the benchmarks should all be at the same relative heights to one another as they were when they were initially installed. More so, the scientists will also be very pleased because their depth measurements will be reliable going forward in time.

Benchmark gear — This is the benchmark-stamping set-up.

Rosalind chiseling away at the rock to ready it for benchmark installation.

Rosalind and Avery with cement — Rosalind and Avery cementing a benchmark in place for posterity.

Cemented benchmark — A benchmark firmly cemented in place.

Rosalind holding stick — Rosalind holding the level rod for the benchmark leveling process. It turns out that it is incredibly difficult to hold 12 feet of leveling rod level.

So what next?

Now that we have completed all necessary pre-survey measurements and research, we are ready to begin surveying the coastline and ocean floor. Happy Hydro!

Personal log

One of my favorite parts about this particular activity was exploring the coastal wildlife along the way. A Harbor Seal spent a good portion of the day swimming near by and keeping an eye on what we were doing. Unfortunately, every time I tried to get closer for a picture he ducked under water. He was clearly very curious, though. No doubt the installation of the equipment seemed rather bizarre.

Installation point — This is a view of the installation point we used for the tide gauge. You can tell that the tide is low because of all the exposed animal and plant life at the base of the rocks.

Being on the rocky outcropping where we installed the tidal gauge and the beach nearby reminded me a great deal of my childhood. From the washed up bull kelp still clinging to a barnacle (sometimes still alive) to the hermit crabs scurrying away from my hand in tide pools to the brightly colored sea anemones untucking as the tide came in, it brought back a lot of fond memories and definitely re-inspired my childhood enthusiasm for exploring nature and learning about biology by experiencing it. It also brought back that sense of heightened physical awareness as I scrambled from barnacle-covered rock to barnacle-covered rock, trying to avoid the slippery foot placements that would inevitably lead to lengthy gashes on my hands. All is well. I returned from my beach adventure in one very intact piece, slightly rosy-cheeked despite the overcast conditions.

Sea anemone! — An open sea anemone. They also come in red, orange, pink, and purple!

Wildlife! — Sea Anemones, barnacles, and other rock-dwelling critters exposed at low tide.

Aside from that, as someone who loves food and eating, the Rainier has treated me very well so far. We have some wonderful stewards and cooks, who do a far better job feeding 50+ people than I do feeding one or two. Every meal includes several gourmet options, including stuffed peppers, chicken or tofu stir fry, braised beef, and countless other delicious things. And there is dessert at every meal. And a freezer full of ice cream. No wonder the crew on the Rainier seems so happy!

July 11, 2013August 13, 2021

Rosalind Echols: Discovering Ship Life En Route to the Shumagin Islands, July 9, 2013

NOAA Teacher at Sea
Rosalind Echols
Aboard NOAA Ship Rainier
July 8–25, 2013

Mission: Hydrographic Survey
Geographical Area of Cruise: Shumagin Islands, Alaska
Date: July 9, 2013

Current Location: 54° 49.6 N, 159° 46.6 W

Weather data from bridge: Broken clouds, no wind, 12° C

Orientation to Ship Life: NOAA Ship Rainier motto: “Teamwork, safety first.”

Rosalind talking to the XO about ship operations.

Science and Technology Log

Greetings from the NOAA Ship Rainier! It has been a whirlwind two days since we departed from our docking station at the Coast Guard base in Kodiak, AK and Philadelphia seems a world away here in the remote Shumagin Islands. The trip over took roughly 32 hours and during this time we had the chance to see the many facets of ship life. The crew on board the Rainier have been incredibly welcoming, enthusiastically answering even the most basic questions (of which we Teachers at Sea have many), and have made both myself and the other Teacher at Sea onboard, Avery Marvin, feel very comfortable.

In this blog post, I’d like to talk about getting acquainted with life on a ship. The Rainier is a complex operation, and each person on the ship wears many hats (which is very much like being a teacher) depending on what is happening on the ship each day. One person might man the bridge (front command center of the ship) in the morning, be part of the dive team in the afternoon, and at night, take the role of the on-call medical officer.

Our course leaving our docking point in Kodiak

Avery and I have both spent considerable time on the bridge in the last two days, watching the navigation process, from “threading the needle” between the red and green buoys in Woman’s Bay where our ship was docked to plotting out the course many hours ahead. We both noticed how important communication is in this process, specifically making sure that everyone is on the same page all the time. Thus there is specific ship language that is used and repeated for every activity. For example: when acknowledging a change of duty, everyone on the bridge responds with “Aye.”

Being a newcomer on a ship can be daunting. My first day on the ship, before we set sail, the only thing I could reliably find was my own stateroom (which has our bunkbed, or “rack”, and bathroom, or “head”). One of the many things the Rainier crew has done for us is to take us on a very thorough tour of the ship, showing us everything from the engine room to the flying bridge (the highest point on the ship outside of the mast, which offers a great view of what is going on). It is important to know how to get around in case of an emergency, so you can get to your assigned “muster” point quickly, and take an alternate route if necessary.

Survival suit — Rosalind in her survival suit during our abandon ship drill.

This actually came up not long after we got underway! In the spirit of safety, the whole ship regularly does emergency drills, so once we were in open water, we had a fire drill which was signaled by one loud long horn. Since we’re on a ship, this isn’t like a school fire drill where everyone leaves the building as fast as possible and waits for the experts to show up. The ship is a self-contained community and it is in everyone’s best interest to keep the ship afloat and functional. Therefore, when the fire drill sounds, everyone heads to their muster station, is checked in (to make sure you are not trapped in the fire!), and then either carries out or is assigned a fire fighting duty such as: attending to the injured, manning the fire hose, preparing to mop up the water, “de-smoking” the area etc. Shortly after the fire drill, we had an abandon ship drill, which again involved us meeting at a specific “muster” station. In this case, we were preparing to abandon ship, so we quickly slipped into our bulky, waterproof, self-inflating “immersion” or “survival” suits and then prepared to exit the ship. We didn’t actually exit the ship but envisioned such a next step. After the two drills, the crew met in the “galley” (eating area) for a debrief of the two drills led by the XO (Executive Officer) where we discussed what had gone well, what hadn’t and what we should improve upon for next time. It made me feel like I am in very good hands here on the Rainier. In the end, this complex ship operation relies on a dedicated crew who works and communicates well as a team, keeping safety as the number one priority.

Our Geographical Area

Survey area — Part of our survey area, around Bird and Chernabura Islands

While on board, we will be working primarily as part of the Survey Team, the people taking the hydrographic measurements. I will get into much more detail about how this all works once we delve into our first project, but for today, I want to focus on why this work is important and why we are in the Shumagin Islands specifically. When navigating, ships use charts, either electronic or paper, to plot a safe course through an area. In open ocean, you typically don’t have to worry about navigational hazards (rocks, shoals, ship wrecks), but as you get closer to land, these are more and more common, and ships need to be able to avoid them.

Approaching the Shumagins — The Rainier approaches the Shumagin Islands

If you look at a chart of the Shumagins, you can see that there is a lot of “white space”: empty areas with no depth soundings. Most often, we see a string of measurements in a straight line, fairly regular but also fairly sparse. Our CO (Commanding Officer) said that these were most likely done with a lead line, where someone literally took a lead weight on the end of string and dropped it down to the seafloor over the side of the ship, and measured how deep it was in that spot. While very accurate, it is hard to collect a lot of data about one entire area, and therefore there are many blank spaces.

In deciding where to survey, NOAA creates a priority list. You can find the complete list and list of factors on the Nautical Charts site, but our CO said it comes down to three main factors: age of the last survey, commerce in the area, and recent natural disasters (like Hurricane Sandy, for those of you on the East Coast: the shoreline and sea floor look very different now). As I said earlier, the Shumagins have very sparse data, and it’s old (the most recent survey in the area we are looking at was 1969, at best). Some of the measurements could be from when the Russians surveyed the area, 100+ years ago. Because the Shumagins are en route from Asia to some North American ports, updated nautical charts are vital for safe mariner travel.

Speaking of remote, the CO said that it might have been 20 years since someone set foot on one of the Shumigan islands. That seems incredible to me! Living in a big city, there are always people around. What about you? What’s the most remote place you’ve ever been? Leave me a comment below to let me know.

Personal Log

Big fish — Rosalind tries to see whose mouth is bigger.

As might be expected from my introduction, I spent most of my first day thinking (and saying), “I’m so excited”. Between the tour of the ship, where we stopped into just about every major room and department on the ship, watching the ship leave the cove on Monday morning, and talking to various survey techs about what they do, I was overwhelmed by the number of new and interesting things to learn about. When I first got on board, I was a bit fidgety, because I didn’t feel like I had a specific job yet like everyone else, but now I’ve gotten a lot more comfortable just sitting down next to someone and asking about what they’re doing.

Thus far, the scariest thing about the trip was the plane ride from Anchorage to Kodiak. It wasn’t the smallest plane I’ve ever been in, but I was definitely a bit anxious. We were very fortunate on our crossing to the Shumagins in the Rainier to have very little in the way of weather and I luckily have not gotten sea sick yet (although I did worry about rolling off my top bunk as the ship was rolling last night).

One of the things that has struck me about this experience so far is how much I enjoy experiential learning. I love learning about science regardless, but learning about a ship by participating in the drills or activities, or learning about hydrographic surveys by participating in the process, incessantly asking questions as I go, takes on a whole new meaning. It has also reminded me of the importance of humility and asking questions if you don’t understand something. I can’t wait to see what I get to learn about next!

Have any questions about life at sea or the research I’ll be doing? Leave me a comment below!

June 23, 2013August 13, 2021

Rosalind Echols: Preparing for my adventures! June 23, 2013

NOAA Teacher at Sea

Rosalind Echols

Aboard NOAA Ship Rainier

July 8-25, 2013

Mission: Hydrographic Survey

Geographical area of cruise: Kodiak, Alaska

Date: June 24, 2013

Greetings from Philadelphia, almost 5,000 miles away from Kodiak, Alaska, where I will be meeting up with the NOAA ship Rainier in a few short weeks. A few years ago, one of my students made me an award that characterized my personality with the phrase, “I’m so excited!” and this is how I feel about my upcoming cruise with NOAA. Between the science, the opportunity to work with some amazing people, and the scenery, I can’t believe my good fortune in having this opportunity.

Rosalind in Alaska — Rosalind (right), NOAA Teacher at Sea during her last Alaskan adventure

My name is Rosalind Echols, and I teach students physics at the Science Leadership Academy in Philadelphia. I also coordinate our “Capstone” senior project program, and teach a ceramics elective. I like to stay busy, so in my “free time”, I coach ultimate Frisbee and cross country. One of the most exciting features of the school I teach it is that our whole curriculum is project based, meaning that all of the learning is contextualized and applicable to settings beyond the classroom. I am looking forward to being able to bring what I learn this summer on the Rainier back to my classroom in the form of new and exciting projects. Although Philadelphia is close to the now-infamous “Jersey Shore,” my students do not have a great deal of experience with the ocean, particularly in the realm of science, so I hope that this experience helps me identify ways to make oceanographic topics more relevant to their lives.

The main mission of the Rainier is a hydrographic survey, mapping the sea floor in coastal areas to support NOAA’s nautical charting program. This is particularly important because it allows chart-makers to identify areas of possible danger as well as safe shipping routes. If you are looking for more information right away, you can check out the Rainier’s homepage, but rest assured, I’ll be sharing plenty of information through this blog as I learn more about our mission! From reading about past missions, I have found that even in re-surveying areas previously charted, the ships sometimes find new features on the sea floor which, had they remained unknown, could have been dangerous to ships in the area. The Rainier does this research using a variety of sonar systems, both on board the Rainier itself and from several smaller boats it can launch.

I will be with the Rainier for 18 days, just shy of its 22-day endurance limit. During this time, we will be sailing around the Shumagin Islands and possibly other places on the Alaska Peninsula, starting and ending in Kodiak, Alaska. As a native Seattle-ite, I am particularly looking forward to the scenery and the weather in Alaska, as it should remind me of my home town. I also can’t wait to share what I see and learn with my students back in Philadelphia, most of whom have never been out in this direction.