Sand: Sword Beach, France

Some really cool sand that my friend Claudia brought back from France. I especially like the purple shell fragments. This image is magnified 40x from the actual size. If anyone else goes to the beach on holiday, please bring me back some sand!

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Sword Beach is located on the coast of Normandy in northern France, and is also where the British landed on D-Day in World War II.

An Ode to the LISST

This is a poem about the Laser In-Situ Scattering and Transmissometry or LISST instrument, which we use for measuring sand and mud floating through the water.  I wrote it in response to a challenge to rap about what we learned during a workshop on estuaries last summer.  I had some fun with it so I thought I’d share…

And now a poem about the LISST
It is a great solution
To measure stuff that’s floating
And its grain size distribution

When processing your measurements
You must beware the floc!
Since if you don’t account for it
You’re in for quite a shock

If there seems like too much mud
We should have some suspicion
Before all else, we have to check
The optical transmission

“We have an awful lot of sand!”
Is this hallucination?
First thing’s first: we should have checked
Our background concentration

We sometimes see before our eyes
Large particles appearin’
When gradients of salt are high
It is the fault of Schlieren

So from the depths of Ameland,
A lesson that does matter:
When working with a fancy LISST
Don’t blindly trust your data!

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The mighty LISST: a Laser In-Situ Scattering and Transmissometry instrument, which shines a small laser through the water.  When the beam hits a particle floating by, it scatters and makes a unique pattern of light and shadow, depending on how large the particle is.  We can then interpret these patterns to estimate the size of the sand or mud that are floating through the water.