National Oceanic and Atmospheric Administration (NOAA) uses Second Life to present interactive educational demonstrations about oceans, climate, weather, etc. Some of the examples are tsunami, submarine ride, hurricane, and melting glacier. I watched the tsunami simulation. It was both amazing and scary. I think using SL as an educational tool for this type of topics (which cannot be experience or cannot be taught in real classroom environment )is great for both students and adults.
The NOAA's sim is called Meteroa. I teleported there, I could not find anybody to talk.