Okay y’all here’s your Lunchtime #Geology class. Today I’m leaving the world of hydrogeology for #StructuralGeology, leaning toward engineering geology.

We’re gonna talk about Shear strength.

Shear strength is the strength a material has against oppositional forces. Another way to think about it, is the amount of force it would take to break it.

Note, "shear" is an important term. It's a certain KIND of force. Think of a pencil. Hold a pencil in two hands and BEND it until it breaks. That is NOT shear, that's something else (Bending moment? Something like that, I forget). Shear would be holding the pencil the same way, but don't bend it. Instead, push with your right hand and pull with your left hand. It's a LOT harder to break. It has a higher shear strength. If you DID break it, the break itself would be the "failure plane" or, ahem, "fault."

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Surprisingly, many #Geology students don’t do math, and geology programs are often extremely math light.

Often, when students get to things like #hydrogeology or #StructuralGeology, they shut down because our subfields are math-first.

Stress-strain relationships, and specifically the sheer strength equations that define stress-strain, in Structural geology are an example of this. Students shut down because there are “so many equations.

But there’s really only one, and it’s actually really simple if you step back.