I recently re-read Scott McCloud‘s awesome 1993 treatise on comics Understanding Comics: The Invisible Art. This book, along with McCloud’s subsequent comics volumes, is really the best resource for exploring comic book vocabulary – ie: how comics do what comics do.
McCloud’s chapter 4, on Time Frames, touches on what I’ve been calling a “multi-panel pan sequence” (though I’ve been thinking of trimming this to a “multi-pan”) and he calls this sequence a “polyptych.”