"The National Oceanic & Atmospheric Administration has a West Coast And Alaska Tsunami Warning Center. This is the “preliminary forecast model energy map” they generated showing possible routes of possible tsunami waves that might result from the 8.8 magnitude quake in Chile. CNN reminds us that tsunamis travel at approximately 500 miles per hour, and can travel unimpeded in the vast - and relatively land-empty - Pacific Ocean."
The Nation has a small round up of ways you can help.