Geology

[equalsmcsquared.livejournal.com]

*In Geology today the students will be learning about plate tectonics.*

Good morning, *Sara says, looking around the class.* I trust you all had either a restful or eventful weekend. Hangover remedy is on the counter by the door, along with energy bars. Please sign the roll sheet before you leave.

Today, we will be discussing plate tectonics. If you will open the handouts I've passed around.

The plates consist of an outer layer of the Earth, the lithosphere, which is cool enough to behave as a more or less rigid shell. Occasionally the hot asthenosphere of the Earth finds a weak place in the lithosphere to rise buoyantly as a plume, or hotspot.
Only lithosphere has the strength and the brittle behavior to fracture in an earthquake.

The map below locates earthquakes around the globe. They are not evenly distributed; the boundaries between the plates grind against each other, producing most earthquakes. So the lines of earthquakes help define the plates...

Comments

[chasingangela]

*arrives in class, signs roll sheet. Does not look like she's paying attention.*

[equalsmcsquared.livejournal.com]

Something wrong, Angela? *Sara has paused the lecture while the other students dig through their notes to answer a question.

[chasingangela]

Angela looks down at her desk and shakes her head slightly.

"I just didn't get much sleep last night. It's nothing."

[equalsmcsquared.livejournal.com]

As long as you're sure. *A brief smile before resuming her talk.*

[sensethevisions]

Phoebe looks at her partner and friend in concern, but figures that she'll tell her what's going on if she wants to talk.

[chasingangela]

Angela flashes a shy smile at Phoebe. "It's nothing."

[sensethevisions]

Phoebe looks concerned. "I won't pry, but I'm here if you need to talk."

[chasingangela]

Angela nods. "I really appreciate that."