Category: Vessel/Laboratory Page 76 of 89

We’re approaching the final day of our trip. I’ve spent countless hours in the Main Lab proctoring communications with the Bridge and our Science team, logging events, and keeping our monitoring systems somewhat in check. We’ve deployed and recovered OBEM’s almost 25 times over the past two weeks, along with having taken our antenna’s in and out several times due to some hazardous water encounters. We actually lost all activity from our porpoise array on their final tow due to fishing gear and long lines in the water. 3 out of the 4 had their electrodes destroyed. You can see where each one was lost when you go back through their incomplete data sets.

Today specifically, we will haul in our remaining Scripps OBEM’s from south of Martha’s Vineyard. As each is brought aboard, it gets somewhat disassembled, removing electrodes and data loggers and then the data is collected from the compact flash cards that the data loggers recorded to. We have left 5 OBEM’s at the bottom of the ocean that will remain for the next year. They were created by WHOI, they sit off the edge of the continental slope in deep water. They will monitor electromagnetic activity they encounter for use upon their collection in the following year.

I’ve learned about launching XBT’s and how the WinMK21 software works. I have played with the different phases, gain, and shadow reduction to get accurate depths on the Knudsen 3.5 Hz Sub-bottom Profiler. I also got some time into the Spectra Robtrack Interface, getting time estimates and seeing our plotted course. Furthermore, I’ve met a great group of people who will continue to contribute knowledge and ability in the future of the marine science industry.

Tomorrow, we will wait for our Pilot boat to bring us to our dock in the morning, probably right before breakfast time. We will begin our demobilization of the ship, collecting our equipment and things all together, and transport them off boat via cranes. 

All I can say is.. what a great experience I’ve had the pleasure of partaking in. I can’t wait to pursue my future opportunities!

~Kate

 It has been such an incredible opportunity to work with scientists from Woods Hole and Scripps Institute in sending down instruments which have never been used for our purpose in mapping freshwater deposits under the seafloor. Working in 12 hour shifts from midnight to noon I have helped to assemble the Ocean Bottom Electromagnetic instruments and outfit them with batteries, hydrophones, and fluxgate magnetometers along with other instruments that will be recording the changes in frequency of electromagnetic waves as they travel through the ocean floor. We deployed those at specific intervals on the ocean bottom off the coast of NJ and then towed a dipole behind the boat that sent current through the water and generated a complex wave form which was then recorded by the OBEMs and also recievers also towed behind the boat. I have also participated in logging every deployment and recovery including Latitude and Longitude, boat and wind speed, course, depth, and have taken readings from echosounders, GPS recievers, Direct Positioning systems, and other complex multibeam sonar. The geophysics is a little over my head, but I get mini lectures from the enthusiastic scientists on board while we sit and tow our array for days, monitoring all systems on computer screens. I’ve also had tours of the bridge and engine room by the excellent crew. I’m loving it so far. We have now picked up the OBEMs after towing for a few days and are now en route to the continental shelf below Martha’s Vineyard, where we will deploy another kind of Ocean Bottom System which will sit below for 8 weeks and again deploy the OBEMs and tow our array before picking them up and heading back to Woods Hole on the 14th.

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!