Category: Columbia University, Lamont-Doherty Earth Observatory Page 8 of 10

This post is certainly later than intended, but we’ve been in open-ocean since Thursday morning. Our first two days on shore were spend drilling new holes in the mounting plates for our winch. We used two methods, one of which was a magnetic drill, the other was using a drill press. We were tossed around quite a bit Friday night due to an on shore storm sending some wind our way. At first you don’t think you’ll do so well with the waves and boat motion but your body adapts and you get there. 

The goal of our trip is to use electromagnetic waves to detect freshwater reserves that may be under the oceans crust. We will cover two main plots, one of which has been drilled and fresh water already found. The other is thought likely to have fresh water present. The main steps for detection are to launch Ocean Bottom ElectroMagnetometer (OBEM) stations that will receive data from a long and short towed antenna (called a source) rigged to the aft of the vessel. We will also tow an array of 4 receivers off the aft as well. This way we can identify the most efficient way to detect fresh water reserves under the ocean crust. We are currently off the coast of New Jersey where we have already deployed the OBEM’s and are towing antenna’s above them

The main steps: 

1.) Deploy OBEM’s

2.) Deploy towed array

3.)Deploy the long antenna

4.)Deploy the short antenna

5.)Drive back over the OBEM’s with the vessel at a slow rate to send out signals that can be captured by data loggers.

6.) Retract the antennas, and the array

7.) Retrieve the OBEM’s from the ocean bottom.

After all this is done, we will then travel back north to south of Martha’s Vineyard and repeat.

The crew (Science and Technical) works in rotating shifts, 12 hours each, to make sure data is being sent and any significant occurrences are logged in a daily agenda. They have been a pleasure and quite kind and certainly make such a new experience easier for a new comer such as myself. There’s certainly more to come, and pictures as well when we get closer to shore with a good data connection.

Signing out,

Kate

Well, it is all coming to an end now. We have started the thirty-hour hike back to the port. We have successfully mapped everything the chief scientist wanted and that has been a lot of ground. So far so good on the travel back as the waves are finally somewhat calm versus how they were yesterday.

Everything that we mapped has been processed and stored away but it does not just end there. This data will be used as evidence to help persuade a point. That point being that we should be allowed to extend our shelf out to the 350 nautical mile mark. Although it may sound unlikely, it is possible through intense and strategic negotiation. The data we collected will also be used for geologists who will have a field day with it due to the significant patterns on the ocean floor.

Of course we are still going to be mapping all the way till were back, or to about 500 meters deep (1,640ft).  It makes sense to just leave the multibeam running because you may be collecting data that hasn’t been collected before. You would much rather collect the data and have to throw it away because it has already been recorded than not collect it at all and miss out. We started mapping from the very second we left the dock and we will continue to do so until we reach the port.

This journey has been a long one but I can say that it has definitely been worth it. I’ve never had the chance to experience anything like this before and I am very thankful as well as grateful for the MATE program to provide me with this amazing opportunity!

Hello Internet, Kate here! I’m about to embark on my first internship at sea in the coming week, joining the crew of the R/V Langseth. I’ll depart on September 1^st from Woods Hole, a town near and dear to me. I’m so stoked! Growing up I would look over to the WHOI dock from one of the many Steamship Authority ferries as I headed to Martha’s Vineyard each year, thinking I want to be on one of those vessels one day. That day is here, well, almost!

R/V Langseth is part of the Lamont Doherty Earth Observatory, I first encountered the ship this past winter during an MTS meeting where we explored one of the WHOI facilities and the Langseth was parked on the dock, featured in the image I posted.

I’ve been prepping for my internship by reading about various equipment on board, getting things all set for the start of my school semester, and communicating with some of Langseth’s technical staff. Oh! and you can’t forget fighting off the minor bits of anxiety that come with an adventure such as this!

In the meantime, I’m enjoying my last week of summer vacation visiting Martha’s Vineyard. Stay tuned for my coming adventure!

It is the third week into the cruise! So far it has been twenty-one days out at sea, we have traveled a combined distance of 4,941 nautical miles, and are sitting in roughly 3 miles deep of water (16,404 ft.). It has been a smooth journey thus far with the exception of a detour, which I will talk about later in this blog.

We have been making a lot of progress towards our goal of redefining the continental shelf. The south side had been finished in a good amount of time. We even saved a couple of days worth of work by cutting the last two lines off because we predicted that there wasn’t going to be any data worth our time in those areas. Then, we did our cross line to move over to the north side. When I say “cross line” you may be thinking of the boat traversing perpendicular to its original lines, which is right. What is the purpose of that? Well, by preforming a cross line we are not only moving perpendicular across our planned route but we are also using that line to continue collecting data that we need to help refine the data we have already collected. In other words, when we do a cross line we are crossing over the lines we have already done. This allows us to confirm those lines because the parallel lines have a slight overlay with each line. The cross line eliminates those overlay lines and clears up the data.

As soon as we finished the first two lines of the north side, a crewmember claimed that they were having chest pains. So, without any hesitation, the captain turned the boat around and we headed to shore. Once we were about a mile off shore, we deployed our rescue boat off the side of the ship and put the crewmember on it. They drove out to meet up with another small boat that was going to bring him to shore and then to a hospital. Our rescue boat came back to the ship and was hoisted back on. This whole transfer took a matter of twenty minutes. I was shocked at how fast it was over.

This journey has been very interesting thus far! I can’t wait till the last week when we complete out mission!

Last week I talked about the general objective of this mission. This week I want to speak more about one of the pieces of equipment that we are deploying frequently and every six hours, an expendable bathythermograph (XBT).

Try to picture a football but one that is overall about three times smaller. That is about the size and shape of this probe. There is a small divot in the nose of the probe, which has a small sensor in it. The probe is housed safely in a plastic tube that is secured with a pin to hold it in place and a plastic end cap to ensure it will not fall out while being transported. These probes are stored in the Bird Lab onboard in cardboard boxes until we are ready to deploy one.

When ready, we then take the plastic tube out to the streamer deck where there is a so-called “gun” that is used to launch it. This gun is made of plastic and metal brackets that are formed in the shape of a gun, hence the name. Attached to it is a wire that runs back and into a deck unit, which looks like a wall outlet in a box. This deck unit is used to bridge a connection between the probe and the main lab, which is three decks below. The probe is connected to the gun via thin copper wire that runs through the plastic tube. This wire is probably two times thicker then hair. It is wound around the end of the probe as well as the end of the plastic tube so that when we drop the probe into the water, they both unravel without any tension because it will break. When the probe is dropped from the ship into the water, it measures the temperature of the water as it travel to its depth of 700 meters where we then break the line.

Measuring the temperature of the water will provide us with more information then just how cold the water might be. Temperature shares an inverted relationship to density because as the temperature increases, the density decreases. Measuring the density will give us the data that we need tied with the salinity and depth of the water. All of these variables are used to determine how sound is affected in the water. Why do we care? Simply put, because we need to determine how the sound is being refracted throughout the water columns as it travels from the ship to the ocean floor. If we did not do these measurements then we would not be able to correctly calibrate the multibeam system that is shooting sound waves to make an image of the sea floor.

More information to come next week!

The image above is a picture of myself  (far left) and a few other people onboard. In this picture I am in a harness just after we brought the seismic source up the slip.

            So tomorrow my last day onboard the RV Langseth and I head back home. The past 6 weeks have been a very challenging and life changing experience for me. We encountered both smooth and rough seas while off the coast of New Jersey. I’ve learned everything from spicing rope and air gun mechanics to p-cable operations, seismic operations, and life long people skills. I met people aboard that are now lifelong friends and people that I hope to work with in the future. The technicians and navigators on board helped to make me feel right at home and welcomed me into their family without question.

            The past week of operating was very hectic and busy. We were able to successfully be in production for several days straight. Even though the entire prospect was not filled in, we were able to complete over 90% of it. This is a miracle considering the difficulties the Langseth faced a year ago trying to complete the same project.  Once we made it to port we had to pack up everything to be sent back to Geometrics and NCS Subsea. The two days at the dock were filled with crane operations and preparations for the next cruise.  Even though I will not be joining them on the next cruise I wish them smooth seas and safe travels.

            This is the last blog I will be writing, if anyone would like to know more information about my cruise and my experience feel free to email me at thackett2012@my.fit.edu

            The image above is me helping to deploy the head float for the cross cable. This is done just prior to the cross cable and GeoEels being put in the water. 

            This past week has been very busy and a lot of hard work. At the beginning of the week we noticed we were having some issues with the P-cable. The decision was made to pull everything in and finish the survey without the 3 Kilometer 2D streamer. We spent all day Monday on the back deck trying to repair the p-cable, which we were unable to do. Several attempts were made to replace parts on the cross cable but a decision was made to pull everything and run in towards the Manasquan inlet to pick up a Geometrics employee.

            Tuesday morning we were close enough to shore that I was able to make a few calls. Once it was time for my shift to start I walked outside and found that we were replacing the entire signal cable. Finishing the signal cable and deploying the entire p-cable took most of the day but we were able to start shooting around 8pm that night. Ever since then we have been shooting and filling in the prospect. Like I have said before, boring seismic is good seismic. I also sat down with Dan from Geometrics and we started to design and draw up a few brackets that would fix several problems on the p-cable It has been decided that we will pick up the p-cable and head back to port on Monday. Next week will be my last blog post during my internship.

            The image above is me helping to deploy the head float for the cross cable. This is done just prior to the cross cable and GeoEels being put in the water. 

            This past week has been very busy and a lot of hard work. At the beginning of the week we noticed we were having some issues with the P-cable. The decision was made to pull everything in and finish the survey without the 3 Kilometer 2D streamer. We spent all day Monday on the back deck trying to repair the p-cable, which we were unable to do. Several attempts were made to replace parts on the cross cable but a decision was made to pull everything and run in towards the Manasquan inlet to pick up a Geometrics employee.

            Tuesday morning we were close enough to shore that I was able to make a few calls. Once it was time for my shift to start I walked outside and found that we were replacing the entire signal cable. Finishing the signal cable and deploying the entire p-cable took most of the day but we were able to start shooting around 8pm that night. Ever since then we have been shooting and filling in the prospect. Like I have said before, boring seismic is good seismic. I also sat down with Dan from Geometrics and we started to design and draw up a few brackets that would fix several problems on the p-cable It has been decided that we will pick up the p-cable and head back to port on Monday. Next week will be my last blog post during my internship.

The picture above is an example of a seismic air gun going off underwater and how it produces the sound wave that reflects off of geology well beneath the sea floor.

            Today we calculated that with the area we have covered we would be able to go around the world twice. We have been constantly shooting and recording data. Almost immediately after I posted my last blog we had to pick up the gear again because there was an issue. We noticed that there was a shark bite on one of the cables but that was not the issue. The true issue was that one of the GeoEels was missing. After further investigation we believe that a shark grabbed it and ripped it off. During the process of bringing in the P-cable I was in charge of the spares reel, a 12ft diameter reel that holds all of the eel cables.

            Besides that instance we have had a very relaxed time. The rest of the weekend and beginning of the week went well until today. Today around 4pm we lost communications and data with another eel. With the time constraints we are under the party chief decided that we would keep shooting without one of the eels. We believe that this is partially due to the fishing gear that was caught on our signal cable, bt we can not be sure until we bring the gear up. We also heard that this weekend is going got get rough and we may be picking everything up and heading to port but no one is sure yet. I will try and keep updating.

I have been very busy this past week learning more and more each day. We are now half way through the cruise and mowing away at the prospect area. My job as an observer is to monitor the guns, streamer, and p-cable. This means that I have to look at 8 different screens to make sure that everything is in working order. When the PSO (protected species observers) spot an animal that we have to power down or shut down for, it is my job to quickly turn the guns off and activate the mitigation gun. This is so we do not have to do a ramp up (gradual increase in noise level) and we can start right back up once the animal leaves the area. This past week I have gotten a lot of practice on turning the guns off and activating them in a timely manner.

            This week we also had and emergency where we had to pull the air-gun string in and do some maintenance. Since it was late at night and people were sleeping I was chosen to suit up and get in the gun slip. The slip is pictured above and while the guns are being pulled in the green safety net is not there. I did however have to wear a plethora of safety equipment, including a 4-point safety harness, work life vest, hardhat, steel-toe boots, and gloves. When the guns are coming in, everyone has to be focused and there has to be clear communication otherwise someone will get hurt. Needless to say we accomplished the maintenance without any issues and we were able to keep shooting soon after.

This week has been a difficult learning experience. Working 12 hour shifts can be very difficult and hard on the mind. At this point I thought that we would have been up and running without any interruptions, but it has been full of small issues and quick problem solving. Over the past week we have had 3 separate times when we had to power down due to a protected species in our area. All of these instances involved turtles being in the area.  During this time we are required to only fire the 40 in3 mitigation gun. This allows us to stay online without hurting the animals or having us completely shut down. We also had other problems with the P-cable not recording data properly and one of the EELs (p-cable streamer) on the  cross cable not functioning. These errors were generally fixed within several hours of them being present. Even with all of these issues, about 15% of the prospect area has been successfully completed.

             At this point I could safely and efficiently perform the duties of an observer after spending over 75 hours watching and training. I also spent time working with the gun mechanics this week. I got my first try at welding while on a boat. As you can imagine it is much more difficult than welding on land because you must move with every pitch and roll of the ship. I have also found my regular spot for recovery and deployment of the gear. When deploying or recovering the doors my job is controlling the wide tow winch and helping to handle the lift lines.  I have started to get an understanding of why we are out here doing this survey and how everything works. Everyone on board that I interact with has been very helpful and welcoming even though I am new to the vessel. One of the largest morale boosters is the food! Every night we have had some type of meat and fish along with vegetables and dessert of course.  My next few weeks will be focused on learning the navigation and data processing side of the operation.