Month: May 2013

Argg Matey’s,

Thanks for tuning back into the adventures aboard the R/V Marcus Langseth. This week has been full of surprises. From blue whales to hydraulic malfunctions; join me as I retell last week’s adventure.

First our OBS (Pictured) recovery hit a few snags. We had one that was unable to communicate with the ship and couldn’t be recovered (we will try again next week). Another OBS had an O-ring fail which caused the logger compartment to flood and react with the lithium battery. This caused an explosion/melting of the logger and part of the containment structure. The data for this OBS was lost. After the recoveries we deployed the streamer which is a 8km array of hydrophones spaced 25 meters apart. We control the depth of this streamer (between 11-13 meters) with 29 “birds” or radio operated diving modules. They are equipped with “wings” or flukes which can be changed for the desired depth. Each “bird” has a pressure transducer used to measure its depth below the sea surface. We simply tell the birds to dive to 12 meters and they adjust their flukes till they are there and then level out. We also mounted acoustics on the streamer one at the beginning and one at the end to give us range and bearing of the streamer.

After we finished with the streamer I hoped down to the gun deck put on my harness and we deployed the guns (which requires hanging over the back of the ship getting soaked by waves running up the slip way and it always seems to be raining when we put the guns out).

The idea behind the streamer and gun array is to measure the two way travel time (streamer) of the reflected/refracted sound waves (guns).

But nothing ever goes as planned. While deploying the streamer we blew a hydraulic line. After quickly dealing with the leak and isolating the line, we came up with some clever ways of using winches on other hydraulic systems to finish deploying the streamer. Seeing and being part of a crew who can work together so quickly and efficiently to overcome un-foreseen problems was inspiring.

One thing about science/ship life is it gets very hectic and busy then….nothing. You just sit around for 12 hours doing your logs and monitoring instruments. Maybe some ship maintance like cutting angle iron for building shelving or re-greasing machinery. This is how it’s been the past three days. Except for a few blue whale sightings that we are required to shut down the guns for, it has been quiet. This is good for science but boring for us lol.

I am sure things will get more interesting soon they always do!

Till next time

–          C

Sometimes science is best not learned in a laboratory or in a class room. Not everyone can memorize and regurgitate information, and a lot of times let’s face it that information for information’s sake seems mostly useless in the scope of thing. Out in the middle of the ocean I have started learning thing about salinity gradients and how fish migrate diurnally to avoid predation. These are thing I learned before in oceanography courses. Out here though I get to see how the salinity gradient changes over the course of a day, where the oxygen minimum zone shifts as night fall progresses. Through doing countless CTD casts I have seen these plots, time and time again, and now I have begun to grasp the relevance of fresh water input through rain events in a saline environment.

On this portion of the long term experiment in the Gulf of Mexico off the coast of Panama City Beach we have scientist looking at several types of acoustic data. Most have been interested in the data in horizontal planes in relation to the sea floor, and looking at reverberation effects due to various environmental factors. However we now have a group that are looking perpendicularly through the water column and seeing the type of life using acoustic technology. This has allowed me to see first-hand a phase shift in ambient noise, and what they believe to be caused by vertical migration of various animals. This is not the first time it has been noticed evidently, but it is still really cool none the less.

Since this experiment is being done in relatively shallow water, 20m being about the maximum depth at times all the engines need to be shut off for different reasons, and we are set adrift at the mercy of the current and waves. While being adrift for a short period of time is not too bad, once it has gone on for hours and you are caught in a trough of 7 to 10 foot waves, things start to get a little uncomfortable. Swivel chairs turn into fun time rides for about 30 seconds, until you are forced to lock your legs under a desk just so you can conduct some form of normal business. The AC units have to be turned off at some points because their cooling outlet drains right on top of the down facing sonar and causes data to be lost, so it often can get a little warm inside the ship. This unfortunately means a lot of down time for the crew, which can be a good thing and bad. About half way through the first week everyone starts getting kind of bored and cranky.

Well guys, we’re back in Seattle for a couple of weeks. Since my last post, we finished our survey for internal waves with SWIMS the towfish off the Washington coast with the group of scientists called “The Wave Chasers.” We got back to Lake Union, where the University of Washingtons’ dock is located, last Friday. Lucky enough for me I have family in the area, so on my off time I have received the grand tour of the state of Washington. 

So after the weekend off, I reported for duty on Monday morning. We started off by tracing some Cat-5 cable (Cat-5 is commonly used for internet connections and linking different computers together) because of some networking issues. Once we had traced our wires out, I was tasked with clearing the dock of some junk that was no longer being used, a fun task indeed!

After cleaning the dock, I found out that the machine shop guys were trying to get their shop repainted after an electrical upfit. Needing to have it repainted before Thursday, I offered my services. Painting is what I have been doing for the last few days, breaking for a few hours for a Mar Tech staff meeting to discuss things to get done while in port. Once I am done writing this, I will be replacing all the lanyards on the Niskin water sample bottles that are mounted on our rosette. Well until next time, Brophy out!