Denise Harrington: The Best Day Ever, April 30, 2014

NOAA Teacher at Sea
Denise Harrington
Aboard NOAA Ship Rainier
April 20 – May 3, 2014

Mission: Hydrographic Survey

Geographical Area of Cruise: North Coast Kodiak Island

Date:  April 30, 2014, 11:44 a.m.

Location: 58 03.175’ N  127o 153.27.44’ W

Weather from the Bridge: 6.3C (dry bulb), Wind 5 knots @ 250o, clear, 1-2′ swell.

Our current location and weather can also be seen at NOAA Shiptracker: http://shiptracker.noaa.gov/Home/Map

Science and Technology Log

The last couple of days have been the best ever: beautiful weather, hard work, deep science. We acquired data along the continental shelf and found a cool sea floor canyon and then set benchmarks and tidal gauges.

In hydrography, we gather data in seven steps, by determining: our position on Earth, depth of water, sound speed, tides, attitude (what the boat is doing), imagery and features.  Step 1 is to determine where we are.

In this picture you can see a GOES satellite antenna and a GPS antenna that helps us determine our precise location.
In this picture you can see a GOES satellite antenna (square white one) that is used to transmit tide data ashore and a GPS antenna (the small white eggs shaped one) that provides the tide gauge with both position and UTC time. Photo by Barry Jackson
In this picture  Brandy Geiger, Senior Survey Technician, uses the GOES from various locations to determine the exact location of the tide gauge.
In this picture Brandy Geiger, Senior Survey Technician, uses GPS to record the positions of the benchmarks we have just set for the tide gauge. Photo by Barry Jackson
tide gauge install 023
Where we are happens to be the most beautiful place on earth. Photo by Barry Jackson

 

In Step 2, we determine the depth of the water below us.

Bathymetry is a cool word that means the study of how deep the water is.  Think “bath” water and metry “measure.”  When your mom tells you to get out of the tub, tell her to wait because you’re doing bathymetry.

As I explained in my first blog, we measure depth by sending out a swath of sound, or “pings,” and count how long it takes for the pings to return to the sonar, which sits beneath the ship or smaller boat.

Yesterday we used the multi-beam sonar to scan the sea floor.  Here is a screen shot of the data we collected.  It looks like a deep canyon, because it is!

Here is the image of the trench Starla Robinson, a Senior Survey Technician, and I discovered.  We decided it should be named Denla Canyon, after us.
Here is the image of the sea floor canyon Starla Robinson, a Senior Survey Technician, and I discovered. We decided it should be named Denla Canyon, after the two scientists who discovered it.

Here I am, gathering pings.

Here I am talking with "the bridge,"  the team responsible for navigating the ship while surveyors collect data.
While collecting data, I kept in contact with “the bridge,” the team responsible for navigating the ship, by radio to ensure the ship’s safety and maximum, quality data acquisition.     Photo by Starla Robinson

 

Step 3, we take into consideration the tide’s effect on the depth of the water.  Tides are one predictable influence on water depth. There are over 38 factors or “constituents” that influence the tides.  The gravitational pull of the sun and the moon at various times of the day, the tilt of the earth, the topography, and many other factors cause water to predictably bulge in different places on earth at different times. The Rainier crew works 24 hours a day and 7 days a week, so they must find a way to measure depth throughout the days and month, by taking into account the tide. Arthur Doodson, who was profoundly deaf, invented the Doodson Numbers a system taking into account the factors influencing tide in 1921. Flash forward to the 21st century, our Commanding Officer, Commander Rick Brennan worked with a team of NOAA scientists to develop a software program called TCARI, as an alternate method to do tide adjustments, taking into account 38 factors, even the moon’s wobble. Inventions abound at NOAA.

The Rainier crew worked for 14 hours today to set up a tide gauge station, an in depth study of how the tide affects our survey area.  On this map, there is a Red X for each tide gauge we will install.  This process only happens at the beginning of the season, and I feel fortunate to have been here–the work we did was….amazing.

 

Each Red X is approximately where a tide gauge will be installed.  The one we installed today in Diver's Bay is in the north west corner of the sheet map.
Each Red X is approximately where a tide gauge will be installed. The one we installed today in Driver Bay is in the north west corner of the sheet map.

You can see an animation here that shows the combined effect of two sine waves that produce a signal like our tide data.  Just imagine what it looks like when you factor in 38 different variables.

The earth goes around the sun in 24 hours and moon goes around the earth in a little more than 12 hours, much like these two gray sine waves. Interestingly, when you add two different waves, you get the wonky blue sine wave, with ups and downs. This combined effect of the sun and the moon (two dots) causes the ups and downs of the tide (blue wave). Graph taken from Russell, D. Acoustics and Vibration Animation, PSU, http://www.acs.psu.edu/drussell/demos/superposition/superposition.html.

 

Low tide is the best time to see sea stars, mussels and barnacles, but it is also a more hazardous time in the tidal cycle for mariners to travel. Therefore, navigational charts use the mean lower low water level, low tide, for the soundings, or depth measurements on a chart.  The black numbers seen on a nautical chart, or soundings, represent depth measurements relative to mean lower low tide. Driver Bay, the area on the chart where we installed the tide gauge today, is the crescent shaped bay at the northwest end of Raspberry Island.

This is a nautical chart used to help mariners navigate safely.
This is a nautical chart used to help mariners navigate safely.

Installing Tide Gauge Stations

Before gathering sonar data, ground and boat crews install a tide gauge to measure changes in water level and to determine the mean lower low water level datum. A tide gauge is a neat device that has air pumped into it, and uses air pressure, to determine how deep the water is.   The tide gauge uses a formula of (density of sea water)(gravity)(height) = pressure.  The gauge measures pressure, and we apply factors for gravity and sea water.  The only missing factor is height, which is what we learn as the gauge collects data.  This formula and nuances for particular locations is a fascinating topic for a blog or master’s thesis.  Scientists are looking for tidal fluctuations and other location specific variances. Then, by computer they determine the mean lower low tide depth, factoring in the tidal fluctuations.

There are permanent tide gauge stations all over the world.  The nearest permanent tide gauge station to our study area is in Kodiak and Seldovia.  These permanent gauges take into account many factors that affect tides over a 19 year period of time, not just the gravitational pull of the moon.

The tide gauge stays in place for at least 28 days (one full tidal cycle).  During the month, data of the tides is collected and can be compared to the other tide gauges we install.

Installing the Tide Gauges and Benchmarks

Excitement built as the crew prepared for the “Tide Party,” packing suitcases full of gear and readying the launches.  Installing Tide Gauges signals the beginning of the season and is one of the few times crew gets paid to go on shore.

 

Why Bench Mark?

There are three reasons I have figured out after many discussions with patient NOAA crew as to why we put in bench marks.

 

I installed this benchmark by having a hole drilled in bedrock and affixing the benchmark with concrete if anyone ever returns and needs to know their exact location.
I installed this benchmark in Driver Cove by having a hole drilled in bedrock and affixing the benchmark with concrete if anyone ever returns and needs to know their exact location. Photo by Barry Jackson

The first reason we install benchmarks is to provide a reference framework to ensure both our tide staff and the tide gauge orifice are stable and not moving relative to land.  The second reason is if we ever come back here again to gather or compare data to previous years, we will know the elevation of the tidal datum at this location relative to these benchmarks and can easily install a new tide gauge.  The third reason is that the earth and ocean floor changes constantly.  As scientists, we need to make sure the survey area is “geologically stable.”  We acquire several hours of GPS measurements on the primary benchmark to measure both its horizontal and vertical position relative to the earth’s  reference frame.  Should there ever be an earthquake here, we can come back afterwards and measure that benchmark again and see how much the position of the Earth’s crust has changed.  After the last big earthquake in Alaska, benchmarks were found to move in excess of a meter in some locations!

Teacher on Land Polishing Her Benchmark Photo by Brandy Geiger
Teacher on Land
Polishing Her Benchmark
Photo by Brandy Geiger

Installing the Benchmark

Today, our beach party broke into two groups.  We located stable places, at about 200 foot intervals along the coastline.  We drilled 5 holes on land and filled them with concrete.  A benchmark is a permanent marker you may have seen at landmarks such as a mountain peak or jetty that will remain in place for 100 years or more.  We stamped the benchmark by hand with a hammer and letter stamps with our station identification.   If we chose a good stable spot, the benchmark should remain in the same location as it is now.

Tide Gauge

As one group sets up benchmarks, another group installed the tide gauge.

 

Here, Chief Jim Jacobson, Lead Survey Technician, sets up a staff, or meter stick, I used to measure the change in water depth and others used for leveling.
Here, Chief Jim Jacobson, Lead Survey Technician, sets up a staff, or meter stick, I used to measure the change in water depth and others used for leveling.  Photo by Barry Jackson

To install the tide gauge, you must have at least three approved divers who install the sensor in deep water so that it is always covered by water.  Because there were only two crew on board trained to dive, Lieutenant Bart Buesseler, who is a dive master, was called in to assist the team.   The dive team secured a sensor below the water.  The sensor measures the water depth with an air pressure valve for at least 28 days.  During this time there is a pump on shore that keeps the tube to the orifice pressurized and a pressure sensor in the gauge that records the pressure. The pressure is equal to the number of feet of sea water vertically above the gauge’s orifice. An on-board data logger records this data and will transmit the data to shore through a satellite antenna.

Divers install the tide gauge, and spent most of the day in the cold Alaska waters.  Good thing they were wearing dive suits!  Photo by Barry Jackson
Divers install the tide gauge, and spent most of the day in the cold Alaska waters. Good thing they were wearing dive suits! Photo by Barry Jackson

Leveling Run

After the gauge and benchmarks are in place, a group does a leveling run to measure the benchmark’s height relative to the staff or meter stick.  One person reads the height difference between 5 different benchmarks and the gauge. Then they go back and measure the height difference a second time to “close” the deal.  They will do the same measurements again at the end of the survey in the fall to make sure the survey area has not changed geographically more than ½ a millimeter in height!  Putting the bubble in the middle of the circle and holding it steady, leveling, was a highlight of my day.

Observation

Finally, a person–me– watches the staff (big meter stick above the sensor) and takes measurements of the water level with their eyes every six minutes for three hours.  Meanwhile, the sensor, secured at the orifice to the ocean floor by divers, is also measuring the water level by pressure. The difference between these two numbers is used to determine how far below the water’s surface the orifice has been installed and to relate that distance to the benchmarks we have just leveled to.  If the numbers are consistent, then we know we have reliable measurements.  I won’t find out if they match until tomorrow, but hope they do.  If they don’t match, I’ll have to go back to Driver Bay and try again.

As we finished up the observations, we had a very exciting sunset exit from Raspberry Island.  I was sad to leave such a beautiful place, but glad to have the memories.

Last minute update: word just came back from my supervisor, Ensign J.C. Clark, that my tidal data matches the gauge’s tidal data, which he says is “proof of my awesomeness.” Anyone who can swim with a car battery in tow is pretty awesome in my book too.

The data Starla Robinson and I collected is represented by the red line and the data the gauge collected is represented by the blue line.  The exact measurements we collected are on the table.
The data Starla Robinson and I collected is represented by the red line and the data the gauge collected is represented by the blue line. The exact measurements we collected are on the table.

Spotlight on a Scientist

Lieutenant Bart Buesseler came to us straight from his family home in the Netherlands, and before that from his research vessel, Bay Hydro II.  The main reason our CO asked him to leave his crew in Chesapeake Bay, Maryland, and join us on the Rainier is because he is a dive master, capable of installing our sensors under water, and gifted at training junior officers.

 

Lieutenant Beusseler knows he needs to be particularly nice to  Floyd Pounds, an amazing cook from the south who cooks food from every corner of our ocean planet.
Lieutenant Beusseler knows he needs to be particularly nice to the amazing chefs aboard Rainier, including Floyd Pounds, who cooks food from every corner of our ocean planet with a hint of a southern accent.

During his few years of service, LTJG Buesseler adventured through the Panama Canal, along both coasts of North America, and has done everything from repairing gear to navigating the largest and smallest of NOAA vessels through very narrow straits.  He loves the variety: “if I get tired of one task, I rotate on to another to keep engaged and keep my mind sharp.”  He explains that on a ship, each person is trained to do most tasks.  For example, he says, “during our fast rescue boat training today, Cal led several rotations. But what if he is gone? Everyone needs to be ready to help in a rescue.”  Bart says at NOAA people educate each other, regardless of their assignments, “cultivating information” among themselves. Everyone is skilled at everything aboard Rainier.
In the end, he says that all the things the crew does are with an end goal of making a chart.   His motto? Do what you love to do and that is what he’s doing.

Personal Log

Today was a special day for me for many reasons.  It is majestic here: the stark Alaskan peninsula white against the changing color of the sky, Raspberry Island with its brown, golden, crimson and forest green vegetation, waterfalls and rocky outcroppings.  I’m seeing whales, Puffins, Harlequin Ducks and got up close with the biggest red fox ever.  Most importantly, I felt useful and simultaneously centered myself by doing tide observations, leveling and hiking.  I almost dove through the surf to make it “home” to the ship just in time for a hot shower. Lieutenant Buesseler’s reference to “cultivating information” rings very true to me.  In writing these blogs, there is virtually nothing I came up with independently.  All that I have written is a product of the patient instruction of Rainier crew, especially Commander Brennan. Each day I feel more like I am a member of the NOAA crew here in Alaska.

 

Stephen Bunker: Science Experiments on the R/V Walton Smith, 20 October 2011

NOAA Teacher at Sea
Stephen Bunker
Aboard R/V Walton Smith
October 20 — 24, 2011

Mission: South Florida Bimonthly Regional Survey
Geographical Area: South Florida Coast and Gulf of Mexico
Date: 20 October 2011

Weather Data from the Bridge

Time: 11:39 AM
Wind direction: North-northwest
Wind velocity: 4.5 m/s
Air Temperature: 23 °C (75° F)
Clouds: Alto cumulus

Science and Technology Log

We left port today at about 6:30 AM, before the sun had even come up. We are  headed out to the Florida Keys. The rain has stopped as well as the wind. We left Miami Harbor as the sun was coming up.

Our scientific research will take place along the Florida Keys, a chain of low-lying  Islands that arc around the southern tip of Florida. The R/V Walton Smith will stop at predetermined stops and take measurements.

There are many science experiments happening on board. In each post, I will try to highlight a different experiment. I’ll start off with the CTD  because it is the experiment that drives our schedule throughout our cruise.

The Conductivity, Temperature, & Depth Instrument. Everyone on board calls it the CTD for short. The CTD schedule is our game plan. At about every 3 -5 hours — night and day —  we’ll cycle through a series 3-4 CTD drops.

Lower CDT
These are the instruments on the lower part of the CTD.

On the bottom of the CTD are a number of instruments that give real-time data to a scientist on board the boat. The conductivity part of the instrument measures how much electricity passes through the sea water. Using a mathematical algorithm that takes in account temperature and how much current passes through the water, we can determine the density (salinity) of the water.

Full CDT
The CTD on deck. The grey tubes fill with water.

The top part of the CTD has 12 cylinders that can trap water. Those are the grey tubes you see in the picture to the left. There are lids on the top and bottom of each tube that can be closed with a remote control from inside the boat. In this way the scientists can take water samples from any depth of water.

So, when we arrive at one of these predetermined location we’ll lower the CTD.

Once the CTD is just below the surface of the water and everything checks out, the scientist will radio to the crane operator to lower the CTD to within a meter of the bottom of the ocean. That can be anywhere from 5 meters to over 100 down. As the CTD lowers, the scientist monitors the CTD instrument real-time readouts. Using a graph of the data, he or she will decide at which locations to close the cylinders on its return trip to the surface.

CDT Control Center
Nelson monitors the CTD data as it is collected.
Water sample processing
Cheryl is processing water samples from the CTD.

Once it surfaces, we’ll  assist in placing the CTD back on the deck and securing it. We’ll then take water samples from the grey tubes. Those water samples will be analyzed in one of the laboratories on the boat. The water samples will show us chemical properties of the water.

Personal Log

Teamwork works! It takes a lot of teamwork to make things happen on board. Guiding the boat to the precise locations is the easy part for the crew. They have a GPS to help them do it. After they get there they have to maintain the location. That’s hard when currents, wind and waves, move the boat which is the size of a house. Then they delicately raise and lower the CTD.

Dave Diving
Crew member Dave preparing to dive in order to remove ropes caught in the ship propeller.

If something happens, they also need to fix it. They can’t drive it to a repair shop. They have to fix things on the spot. During the night, some ropes from lobster traps got tangled into one of the propellers. One of the crew put on scuba gear, got in the water, and removed the ropes.

The group of scientists have been organized into a day shift from 7:00 AM to 7:00 PM and the other half is on the night shift for 7:00 PM to 7:00 AM. This can be uncomfortable to have to stay awake all night, but it also means they have to sleep during the day. The day shift will also have a heavier work load because there are additional experiments that have to be done during the sunshine.

The bridge of the SV Walton Smith
Crew member Bill at the helm of the R/V Walton Smith

Leyf Peirce, July 13, 2004

NOAA Teacher at Sea
Leyf Peirce
Onboard NOAA Ship Rainier

July 6 – 15, 2004

Mission: Hydrographic Survey
Geographical Area:
Eastern Aleutian Islands, Alaska
Date:
July 13, 2004

Time: 15:00
Latitude: N 55°17.29
Longitude: W 160°32.14
Visibility: 4 nm

Wind direction: 140
Wind speed: 6 knots
Sea wave height: 0 – 1 foot
Swell wave height: —
Sea water temperature: 10.0 °C
Sea level pressure: 1007.8 mb
Air temperature: 12.2 °C
Cloud cover: 8/8

Science and Technology Log

I awoke today to an announcement over the ships intercom saying, “Attention all hands, attention all hands, divers are in the water, please make sure all equipment is stored and locked”. I first checked to make sure it wasn’t me in the water, as exciting as that would have been, and then I raced out of bed to see what was going on. Apparently, since we have been anchored off the coast of Egg Island, we have had a very small oil leak. It was believed to have fixed itself after the first few hours of anchoring; however, yesterday many of the crew noticed that there was still a slick on the water off the port stern. To investigate, three NOAA certified divers dove down about 15 feet and inspected the hull of the ship. They saw that the oil was in fact coming from the left propeller, yet they could not directly identify the source of the problem, but speculate that there is a small leak in one of the o-rings. The only way to truly fix this problem is to dry-dock the boat. The closest dry-dock is in Seward, but we are scheduled to go to Kodiak first. Therefore, the plan is to see if the problem takes care of itself and if it is not better by the end of the stay in Kodiak, then take the boat to Seward. The amount of oil that is leaving the ship is very small and is escaping at an extremely slow rate. However, if this problem persists, it could become very serious.

I talked with ENS Lominkey about his dive this morning and about other dives he has made recently. He informed me that once you are NOAA certified, the equivalent of becoming a PADI or NAUI dive master, you will be allowed to help with dives that involve ship repair, tide gauge installation, or wreck surveying. In fact, only two weeks ago the RAINIER was performing hydrographic research and identified the fishing boat CONQUEST which sunk in 1994. ENS Lominkey and other certified divers dove the wreck to gather information about the wreck including its minimum depth which happened to be about 90 feet. To do this, they used a very sensitive depth gauge that relies on pressure changes. They would place this gauge at different locations on the wreck and record the various readings. ENS Lominkey also told me that they found another fishing boat wreck near the CONQUEST, but were unable to identify it. As I have developed my passion for diving over the past few years, I become more amazed at the opportunity to dive and explore uncharted waters knowing that the research you are conducting is contributing greatly to society. And, as technological advancements are made for both safer diving and better navigational charting, I can’t help but wonder how these will be further combined in years to come—a very interesting engineering design problem!

Personal Log

Today was mostly spent writing more lesson plans for my 6th, 7th, and 8th grade science classes as well as planning my 8th grade pre-algebra course. I also spent a lot of time talking with several officers about the amazing act of diving and how wonderful it would be to be paid to do something so adventuresome everyday. When sharing experiences, I did notice that the excitement of diving somewhat parallels the excitement of teaching; you never know what you are going to see, there are some dangers, but overall the experience is extremely rewarding. In both, you not only learn about other animals, or students as the case may be, but you also learn a lot about yourself, your goals and dreams, and your limits. While I am greatly enjoying my experience aboard the RAINIER, the more I think about my different classes and the students that I will see in the fall, the more excited I get about returning to the classroom!

Question of the Day:

How much oil would have to be in the water before it drastically starts harming marine life?