Aug
22
Filed Under (cruise blog) by Ting on 22-08-2009

CTD (Conductivity, Temperature, Density)

19 collecting the samples from the CTD

I have enjoyed a routine of assisting, Margaret, with the deployment of the CTD. The CTD holds an array of water collection bottles and several sensors that record vital information about the water into which we are sending our 3 different landers to stay overnight. We’ve gotten into the routine of sending down the CTD when the landers first go out and right before they are hauled back onto the boat. You can think of the CTD as taking the vital signs of the ocean just as your nurse takes your vital signs every time you see your doctor.

19 The CTD takes the plungeThe some of the information from the CTD comes back immediately (via a very long cable) to Wecoma’s on-board computer system. Margaret and I watch as a graph is produced that shows temperature, salt concentration, oxygen concentration, and light transmission (clarity). This information is gathered as the CTD is lowered down to about 1 meter above the sea floor. After reviewing this information we can determine from what depths we what to collect our water. While sitting at our computer station we can close a bottle, thus we can choose to collect a sample from any depth. As soon as all the samples are collected we bring the CTD back on board the boat.

Margaret has been collecting samples in search of methane. Methane is a gas that can be found along the Oregon coast, near volcanic vents, within the boundary zones of the Juan de Fuca plate. Methane is also found in smaller concentrations as a product of the decomposition of dead plants and animals. Today, Margaret was quite surprised to find an elevated level of methane show up in water collected from 120 meters. a sight off a Cape Perpetua.

My job on board is to collect water samples that will later be tested for oxygen, nutrients, and salts. I, also, collect and filter water for future pigments and particle detection and analysis.

Me collecting water samples

Me collecting water samples

Aug
20

19 ol yeller going in for the night19 ol yeller, Allen looks on Ol’ Yeller is rightly named because of the prominent bright yellow floats that cap the sophisticated group of water collectors arranged neatly within the sturdy frame. From a distance this apparatus looks extremely complicated. When you get close a close up view, the complexity quadruples. And, Ol’ Yeller really does suck; two rings of syringes are programmed to suck water from a closed system at the sea floor. (Confused? I’ll try to paint the picture)

19 ol yeller, the team sets it up

The team sets it up

19 OL yeller gets a push overboard

push it overboard

The entire thing is spring loaded as it leaves the dock and settles to the bottom. To allow for the settling of any disturbed sediment, its’ two bottomless, otherwise sealed boxes, are programmed to spring into the sea floor one hour after the device reaches the bottom. At that point the environment in each box is closed to outside influences. Now, with the box settled into the sea floor, the water in each box is injected with a tracer and the sucking begins. Samples of water are collected with the help of a series of spring-loaded syringes connected to small plastic tubing. Each syringe is programmed to suck a sample from the box at a precise time during the night. Having the two boxes programmed to take samples at the same time helps with quality control and validity of the samples. (Confused? It took me days to figure this much out.)

19 ol yeller plunge

19 hope to get it back tomorrow

Ol’ Yeller, along with the other devises on this cruise are designed to answer questions about how oxygen in its’ many forms are consumed, expelled, and transferred throughout the ocean. The question remains, is the ocean a CO2 sink, takes in more CO2 then it releases, or, is the ocean a CO2 producer, giving off more CO2 then it consumes?

The team

The team

Aug
18
Filed Under (cruise blog) by Ting on 18-08-2009

As people try to understand the dynamics of the ocean, devices are developed to gather information from ‘down there’, the mysterious depths of the ocean.

Today, Clare Reimers, chief scientist on board, with a group of graduate students and research assistants, prepare for their deployment-time this afternoon. Part of what they plan to do is take pictures at regular intervals. more detailsa careful eye
They are careful to mount the special digital camera on the tri-pod, they clean the high-powered lens, they mount the strobe light, and they program the camera. At the same time other members of the team are mounting the battery pack, programming a delicate oxygen sensor and mounting this on the tri-pod alongside the camera.

Cody with underwater camera

Cody with underwater camera

Clare, Cody, Andrea, and Kristina with tri-podAs I watch the set-up and try to understand the science I’m reminded of the Mars-Lander, built to land in an upright position and able to withstand the elements. In this case, this ‘Lander’ must withstand moving currents and salty water.

When everything is ready and the time is right, the crew and the scientists work together to lift the tri-pod off the back deck and swing it out into the ocean. going inImagine doing this with your camera, your i-pod, and your computer! You might want to make sure everything is sealed tight against the elements. In this case, everything was sealed tight and they released it attached to a long line, a metal radar ball, an orange float, and a flag. The entire set-up is out for the night, all programmed, ready to take pictures and measure oxygen.

The plan is to take a picture of an area during regular intervals while a sensor records oxygen levels almost continuously. A fin attached to the camera keeps the camera pointed into the current so that the photos taken are of the area where the sensor is takings its readings.

The information gathered is helpful in understanding more about the amount of oxygen available to living organisms that live off the coast of Oregon. Scientists, fisherman, and many others will benefit from the combined effort of many who work on finding out about this dynamic ocean by solving problems, and answering questions about our mysterious sea.

own its own

flatfish_small

We captured a picture of a flatfish on the sea floor.

Aug
17
Filed Under (cruise blog) by Ting on 17-08-2009

IMG_0034.smaller(2)

When you think of iron, do you think of the iron that great grandma used to iron the wrinkles out of clothes, or the iron rails of an ornate fence? In a science class you may have used a magnet to remove iron filings from sand. There are many things made of iron, including the Research Vessel Wecoma.

IMG_0056.smaller(2)Research Assistant, Chris Holm, is looking for iron so small that it can only be seen with specialized instruments. Just like using a microscope to see the cells that make up your body, he uses an instrument to detect or ‘see’ iron in water, except this instrument uses a chemical reaction that creates color in the presence of iron.

Chris says, “It is by measuring how much light passes through this colored solution that we can measure these low concentrations in seawater.  The concentration of iron that is routinely measured in seawater is roughly equivalent to dissolving a paper clip in 50 Olympic swimming pools.”

IMG_0076_modified

The entire structure of the boat is made of iron. So, when you collect a sample of water on an iron boat, chances are, it will include some iron. Since Chris is looking for iron in seawater, his challenge has been to collect seawater that isn’t contaminated with added iron from the boat or from human hands. Special gloves are worn when working with water samples being collected for iron detection.

The environment of Oregon’s continental shelf, where the water samples are collected, is unique. It is 150 meters deep (about 450 feet), and it’s dark. The question is, are growing organisms, such as bacteria on the ocean floor or plankton near the ocean’s surface, using iron and if so, how much iron? In other words, what’s the daily requirement of iron needed to support life in the ocean?