Posted by: adorsk | August 7, 2007

Jersey Mud

Right now the ship is off the coast of New Jersey with about 35 m of water.. It’s a foggy, hot, humid day. When I step out on deck my glasses fog up right away. Every few minutes the ship’s fog horn sounds off.

A Dirty Job

You might think that dirty jobs near Jersey involve cement shoes and burlap sacks, but the one we’re working on is only concerned with mud. We’re trying to get long cores (10-20ft) of mud from the bottom.

I’ve been learning a lot about Jersey mud. For starters, it’s quite thick. We haven’t had much success getting cores, even with the vibracorer. After 15-20 deployments we’ve only gotten a couple 4-6 foot cores.

However, those cores have told us a lot. B, one of the scientists on board, told me about how sedimentologists analyze cores. It’s kind of a detective puzzle.  I can imagine it as a film Noir, “Rocky Shore, Geological Detective.  The answers are always muddy”

B tells me that a lot of the work is visual inspection: looking for layers, pockets of sand, fossils, shells. I think that what people can figure out from just the visual clues is impressive. The type and color of the sand can tell you about rivers which flowed through an area thousands of years ago. For example, if you’ve got very fine clay-like sediment, then there probably weren’t any fast-moving rivers; it takes a long time for clay to settle. If you’ve got pockets of gravelly sand, then there probably was a river, or a storm, or something which moved a lot of dirt in a hurry. I think that’s pretty good for just looking at mud. It reminds me of what my dad says about doctoring: that a lot can be determined from a good history & checkup.

Scientists do other stuff with the cores besides look at them. They test how sound and radiation travel through the cores. After we get back on shore they’ll do carbon-14 dating to get accurate dates.

Here’s what one of our core samples looks like:

core_sample

Megafauna

Dolphins have been coming by the boat frequently over the past few days. They’re fun to watch. They usually come in a group of 4-8 and leap out of the water in pairs.

Sand sharks come up at night when we’re deploying the vibracorer. They’re probably wondering what all the noise is about. The ship is constantly running our echo sounders and sonar. It’s probably like finding a speaker hanging from the sky in your backyard which constantly broadcasts “Hey! Hey! Hey! Hey!…” at peak volume.

Halfway Through

This cruise is a short one. We’re about halfway through, due to get back to WHOI on the 13th. Until then we’ll keep coring. Hopefully we’ll have better luck and get some long ones. Thanks for reading.

I haven’t been shooting as much this week, but here are a few shots from around the ship.

core_sleeves arrow work_gear sunset

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Responses

  1. Hi there Alex, hope you are enjoying yourself. Your photos are really stunning. I hope it’s okay if I show my freshmen your blog, since we’re going to attempt some of our own blogging. stay cool! and all the best, Christina

  2. mmmmm…Jersey mud….


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