Geology

[equalsmcsquared.livejournal.com]

*She is remarkably cheerful for someone who had spent the better part of last week testifying over a rather grisly set of murders, complete with suspected cannibalism.*

I trust you all remembered the papers I assigned. Please stack them next to the roll sheet as you sign in. There are coffee and doughnuts if anyone wants them.

Today, we will be discussing the Earth's magnetic field and how it relates to geology.

The geomagnetic field is generated by electric currents located in many different parts of the Earth. In the outer core the main part of the geomagnetic field is sustained by a naturally occurring dynamo. In the mantle currents can be induced by time-dependent variations in the ambient magnetic field. In the crust the field has both induced and permanent components.

And, in the ionosphere and magnetosphere electric currents are sustained through a complicated interaction with the Sun, the heliomagnetic field, and the solar wind of charged particles. The many different, and sometimes remote, sources of the Earth's magnetic field each contribute to the total field at any one particular location, with the very different physical processes in each domain giving rise to a wide variety of time-dependent geomagnetic variations.

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[chasingangela]

After handing in her paper, Angela takes a seat next to Phoebe and shoots her a sympathetic smile. "Let me know if you want to talk," she whispers.

[sensethevisions]

Phoebe smiles gratefully at Angela. "Yeah, I'd like to," she whispers back.

[chasingangela]

"Are you okay? I heard some bad stuff was going on with Paige."

[sensethevisions]

"Paige...Maia...classes...you name it, my life hates me," she whispers softly.

[chasingangela]

Angela winces. "I'm sorry. I broke up with Marty last week, so ... I think life hates me too."

[sensethevisions]

Phoebe winces in sympathy. "I wanted to say something supportive that doesn't sound lame...but I like you too much to just use any words." She smiles. "You need to talk, I'm a good listener."

[chasingangela]

"It's okay. We're ... trying to be friends," Angela whispers. "Maybe it's for the best, y'know?" She doesn't sound as though she believes this. "What's going on with you and -- do you call him Cole or Belthazor?"