I don't know of any specific name to this pattern besides a 'map' - it's not too common to see maps on the internet that don't do something similar to what you're describing (the only exceptions being 'find us' and 'our location' maps for business sites).
As for examples of this being used effectively, might I suggest looking at how Google Maps handles things? It provides both a list and map view simultaneously, auto-zooms a map when pins might be widely dispersed. Might I also suggest looking at examples from the paper / non-online world? Bus maps sometimes do interesting things with colour and size, and road maps show us a lot of ways to make signs and pins legible even on busy, densely illustrated backgrounds. All these should help get you on your way.
That being said, don't be a slave to patterns. Yes, it's good to invoke conventions from other websites, and helps make users feel they know how your application is going to act. But if your design just doesn't support the kinds of interaction and workflow your research has shown users to need, even a familiar design will create a suboptimal experience. Don't be afraid to at least experiment and put new ideas in front of users - doing usability testing first, of course!