Name This Pulley?

http://i62.tinypic.com/20itj61.jpg

Last night my serpentine belt started squealing. Got up today and it had snapped; it'd been a while so I figured the Oklahoma temps had gotten to it. Grabbed a new one and installed it no problems, but when I turned the car on, same noise.

Upon further inspection, I realized one of the pulleys was no longer turning. Could someone tell me the actual name for this specific part, and if possible, some suggestions as to what the problem may be?

Thanks.

That is your water pump pulley. Bolted to the water pump. If it does not turn, the water pump is seized. Not really common without a bad leak.

Seen it before on 3.1liter engines- water pump is seized- autozone has them for about $15 - just about the easiest WP ever to change...

BTW- I've seen a 3.1 come to me with belt wrapped over this pulley! WP turns wrong way but it never got hot!

Never seen a w/p pulley seize on a 3.1.......seen them leak, but never seize......as stated, one of the easiest w/p's to replace....