Box Cores

(click on any photos in this post, or others, to see an larger view)

The crowd gathers to watch an early box core deployment -- leaning over the starboard side (and over the long core).

Box coring allows us to recover a large block of sediment from the sea floor, hence to examine near-surface sediments, sedimentary structures, and biology (worms, bivalves, sea stars, corals, and more have been found in the cores from this cruise). Box cores also allow us to collect large samples with which we will examine the biology and chemistry.

The box corer.

The box core is a relatively simple device. This is a good thing -- especially in difficult-to-core sediments.







Sci2 really gets into his box cores. His technique is muddy and messy, but it works. Here's how it goes:

First, push 4" and 6" tubes into the core and take samples of the surface sediments for microbial analysis.

Next, use ropes to lift the box away from the sediment.

Once the top is removed, the oxidized top portion of the sediment is easy to see.

Here's a close-up of the contact between the oxidized and reduced zones in the box core sediment.

After admiring the cross section of near-surface sediment, remove the excess sediment from around the sample tubes.

Once they are clear of sediment, the tubes can be removed . . .

. . . and capped.

The tubes of sediment are put aside for later use. Some will be archived and others will be sub-sampled for organic and foram analysis. But first, there is cleaning up to be done. (Sci2's students are very good at this!)

Big Fish

Maha Mahi (a.k.a Dolphin Fish or Dorado)caught off the starboard this afternoon. Dinner should be good!

(If you want to see more pictures, visit the USF Blog site.)

Life Aboard the Knorr (part 2)

The crew and scientists are working hard on this cruise to make sure we get home with lots of mud, lots of water, and lots of data. But hard work requires fuel, and that means food and sleep. The R/V Knorr is not a luxury vehicle, but it is well set up to handle the demands of tired and hungry workers.

The Knorr was built in 1969, had a "mid-life overhaul" (if only we could all have one of those!) in 1989-1991, and was retrofitted for the long coring system in 2007. The ship is 279 feet (85 m) long and has a beam of 46 feet (14 m), and a draft of 16.5 feet (5 m) -- this goes up to 23 ft (7 m) with the bow thruster lowered. It holds 160,500 gallons of fuel, has a range of 12,000 nautical miles, a cruising speed of 11.o knots, and can stay at sea for up to 60 days at a time with a complement of 22 crew, 32 scientists, and 2 technicians.

Here's a cut-away diagram of the ship:

Cross sectional schematic of the R/V Knorr.

(If you want to see more details about the ship's layout, visit the ship's website at WHOI.)

The main science/core lab is on the Main Deck. Most of the crew and scientist sleeping quarters (berths) are on the 2nd Deck -- just below the Main Deck and right at waterline, where there is not as much rocking and rolling in rough seas as there is higher in the ship. Most of the berths are 2-person rooms with shared (2 adjacent rooms share a single bathroom). There is actually a gym the 2nd Deck too -- just in case you feel the urge to get some exercise sometime in your 3 week cruise!

Below left: Lucky Gary! He's alone in a 2-person room (the second berth is closed). Below Right: "Boy's town" -- a 4-person room shared by Andy, Enrique, and Trevor. (Desks are folded closed.)

Above: The Chief Scientist's "stateroom," complete with private bath, office space, and a door with a porthole.

The Chief Scientist's "stateroom" is on the 02 Deck -- right next to the Captain's stateroom and just below the bridge. I guess this means that if you want to be a Chief Scientist you'd better be able to take the rocking and rolling that comes with the "high" position on the ship! Thanks to Dave for giving up his 1/2 of the stateroom for Catherine. But, don't feel sorry for Dave. He got a private room (with a private bathroom!) in the exchange!

Sounds pretty good right? Well, as a matter of fact it is not bad at all. We are all pretty comfortable in our quarters and it seems that everyone is sleeping well. (Unless, of course there happens to be a needle gun in operation on the bulkhead opposite your bunk. But, that's another story, for another time.)

The galley is small, but amazingly comfortable. The food is great. Thanks Bobbie and Erskine! And there is way more than enough to go around: three meals a day plus snacks -- and free access to the coffee machine, the microwave, and whatever happens to be in the 2 below-counter refrigerators in the coffee area. We are not in danger of going hungry; in fact, maybe I should head to the gym now . . .

Below: The galley between meals -- ready and waiting . . .

Above left: Our smiling cooks -- Chief Steward Bobbie and Cook Erskine. Right: Happy eating!

CDH?

Long coring was abandoned in the US in the mid-1980s, but the WHOI Long Core system that we are using on this cruise – which took 5 years to develop and was tested for the first time in 2007 – brings it back.

This new system is capable of collecting cores up to 45 meters (150 feet) long. This is almost twice as long as the previously possible on an UNOLS vessel. You can read about the Long Core system (how it works, how the 287’ Knorr was retrofitted to be able to handle a system that can pull up cores that weight up to 30,000 pounds, etc.) and even watch a video of the coring operation at WHOI’s Long Core website (http://www.whoi.edu/page.do?pid=19095).

One of the mysteries of the long core – at least to the uninitiated – is its name. You may have noticed that there are a lot of abbreviations around here: GGC (giant gravity core), POD (plan of the day), BC (box core), UNOLS (University-National Oceanographic Laboratory System), WHOI (Woods Hole Oceanographic Institution), and many more. Most of the abbreviations are easy to understand. But, all of the long cores are labeled CDH. What's up with that?

Jim Broda, who has worked designing and engineering corers at WHOI since 1980 and was one of the principles in the project that resulted in the WHOI Long Core, told us that CDH stands for Charles David Hollister.

Charles David Hollister was a well-known marine geologist. While at WHOI in the 1970s, Hollister (yes, think Santa Barbara county’s Hollister Ranch) started the development of a giant piston coring system. In the 1970s he collected a 100-foot-long core that was dubbed the “Super Straw." That core documented what was, at the time, the longest continuous record of ocean history.

The cores that are recovered using the new WHOI Long Core system are labeled in Hollister’s honor.

Life Aboard the Knorr (part 1)

Today is mostly a transit day (subject to change at any moment, of course). After a couple of days of all-out coring and water sampling, folks are getting some much-need R&R.

The scientists are variously sunning, reading in a shady corner on the deck, napping in their bunks, staring at their computer screens (working? playing? who knows?), or just plain MIA.

So, it seems like a good time to show a few candid pictures of the relaxed life aboard a scientific research vessel.

P.S. The ship's crew, of course, is still hard at work (3rd Mate Allison has been washing life vests), Cleverson is ever vigilant at the seabeam station, and Gary is still logging core . . .

Wildlife of the Day

Look what showed up in one of today's BCs (box cores):

Does anyone know what this is??

Whatever it is, it was enjoyed by all . . .

Marking core

Here are the Duke guys (sci1, Trevor, and Andy) marking core -- a GGC (giant gravity core, if you remember our last post) to be precise:

Don't they look like they know what they are doing? Here are a couple of questions: Is section #1 on the bottom or on the top? Which of the 150 cm sections should be marked 0-150? Which one of theses guys should we ask?!

Okay, you guessed it, we've had some core labeling issues in the last 24 hours. Yes, I've made a mistake or two myself. But, it became very funny last night and this morning -- at about the time we were all pretty exhausted. Why were we exhausted?

Perhaps it had something to do with this POD (plan of the "day"):

We're on deployment 28 right now. So, as crazy as it looks, it (or at least some close variation on this plan) IS possible . . .

By the way, for you guys who may be wondering what the mud in this part of the world looks like, here is a photo of the top portion of a GGC we took yesterday:

We're not splitting most of the cores on board ship, but we couldn't resist a peek.

With most of the cores, we simply mark them, cut them, and log them with the Geotek logger. Here's a portion of last night's pile of to-be-logged cores (and Gary drilling gas-release holes in cores -- a must do for these sediments):

Not bad for a day's coring!

The "Full Monty"

Yesterday we got our first full Monty (as Paul likes to call it). On this cruise a full Monty means a full set of deployments, usually in this order:

CTD (conductivity, temperature, depth):

WTS (water transfer system -- the McLane pumps):

BC (box core):

GGC (giant gravity core):

CDH (long core -- named after Charles Davis Hollister, hence the CDH):

and the MC (multicore):

The entire full Monty took us just at 12 hours -- not bad at all.

Of course, this is just the start. We also have to subsample the box core and multicores, squeeze pore waters from the gravity core, filter a lot of water samples, and log the cores (using the Geotek logger).

Last night, we after we completed the full Monty we (of course) decided we needed a little more. So, we took a couple of gravity cores at some interesting (based on the seabeam survey) spots nearby. We got 2 short, but sweet, sections before the coring crew got to rest.

I think we'll have to be very careful in our planning so that the coring crew (and the rest of us!) actually get to rest between sites! Too bad I missed the photo of the crew napping on the lab benches between cores last night -- it was quite a sight! No worries, I'll get it next time!