Exploration Geophysics for Rock Farmers · 9:53pm Apr 12th, 2014
I smiled at Maud Pie, wanting to start a conversation and make friends. “So... what is it that you do exactly, on your rock science research trips?”
Maud thought over the question before answering accurately. “We drill holes in the ground, and extract a core sample.”
“That sounds interesting...”
“It's boring.”
Pinkie Pie bounded over to provide further clarification. “Digging boreholes is time consuming, expensive, and it messes up your hair. That's why every rock farmer knows before you dig, you do a proper survey of the site to learn what's under the ground.”
“But won't you find rocks wherever you dig?”
“But they might be the wrong sort of rocks.”
There was clearly a lot I still had to learn about the way of life of earth ponies.
“How can you find out what's under the ground without digging?”
“Allow me to demonstrate... Put your ear to the ground.”
Pinkie push my head downwards until my ear was firmly embedded in the dirt. She then jumped up and down repeatedly.
“What do you hear?”
“You stomping on the ground.”
“Okay... Now try here.”
She lead me a few metres to one side, then push my head back onto the ground and repeated the stomping exercise.
“Sounds sort of hollow... Is there an underground room there?”
“Actually it's our septic tank. You see how you can learn what's under the ground by listening to it.”
“Sort of,” I said. “But you can't tell what sort of rocks are underground that way...”
“You can if you make a loud enough noise and listen very carefully.”
Pinkie proceeded to explain the principle of reflection seismology.
“First we lay a long line of geophones across the rock field. Then we bury sticks of dynamite at selected points. Playing with high power explosives is great fun – but you have to be very careful or somepony could get hurt. When we detonate the charge, the shock wave goes down under the ground, and bounces off the rocks and anything else. The geophones record the echoes. From the time the sound reaches different points, we can tell how deep the rocks are, and the speed of sound in the rock – from which we can tell what sort of rock it is.”
“How do you know all this?”
“I grew up on a rock farm Twilight. I did my first seismic sounding before I could walk. Then I learnt to fly a helicopter, in order to do airborne survey with ground penetrating radar and time domain electromagnetics.”
“What?”
“I'll tell you another time.”
Now I want to see one of the other Pies pull off the hair drill. I could maybe see Pinkie's mother managing it, but the rest? I don't think they use the right conditioner.
In any case, loved this short.
Wait, so Pinkie Pie knows how to fly a helicopter because she used to work on a rock farm?
... Ok, headcanon accepted!
Once again, I wish I could add blog posts to favorites, because I want to remember this, but I know I won't, so I'll copy-paste this blog on Word, save it, and consider how my personal headcanon could benefit from this.