8350i browser panning of a .gif image

I like to use my device to check the moving doppler weather for rain:

http://images.intellicast.com/Weathe..._None_anim.gif
http://images.intellicast.com/Weathe..._None_anim.gif

That being said, when viewing in the native browser, I can hit the BB menu key and zoom in, howerver, I can't seem to find the mecahnism to allow me to use the trackball \ keys to pan. I am use the native BB web browser. If there is a list of keys and their functions (in context of using of using the browser), that would be appreciated.

My search was not fruitful, so I am hoping that someone will have this insight.