Here goes...
- Plot the counties in California
- Use another projection
- Use California state plane coordinates
- Instead of counties, plot the last week's worth of earthquakes
- Turn the earthquakes red
- Turn an earthquake yellow when you mouse over it
- Turn an earthquake back to red when you move your mouse away from it
- When mousing over an earthquake, indicate the "place" and "magnitude" with the tooltip
- Make the ocean blue
- Make the land green
By the way, you might need this:
California state plane: Conic Conformal
Latitude of origin: 36 deg 30' N
Central Meridian: - 120 deg 30' E
Standard Parallel #1: 38 deg 26' N
Standard Parallel #2: 37 deg 4' N