The Red Cross and FEMA jointly operate the National Shelter System, a comprehensive database of over 54,000 emergency shelters across the United States. When shelters are activated during an emergency, this system is used to monitor locations, capacities, and other shelter information. In addition to Red Cross and FEMA staff and volunteers, many state and local organizations use this information as well.
The Ushahidi online mapping platform, first created and used in 2008 to track election-related violence in Kenya, has recently been pressed into service as a disaster response information platform for the Haiti earthquake response. The platform allows for the collection, mapping, and reporting of incidents of various types, via both SMS (text messaging) and the Web. Instead of mapping incidents of violence as in Nairobi, the platform is now being used in Haiti to track emergency reports of various types as well as the humanitarian response.
This is an interesting writeup of a disaster preparedness exercise in Portland where a team of volunteer geographers created an interactive up-to-date Google Map/Google Earth map of infrastructure status updates (collapsed bridges, functional hospitals, etc.) while working alongside the local emergency management authorities. Apparently local status reports were sent via Internet to online mappers outside the affected area - these volunteers created maps which were then communicated back to local responders. Assuming your hypothetical 9.0 earthquake and resulting tsunami don't cut off all of your communications, this is a pretty interesting idea (the project was apparently using portable satellite connections to compensate for this?).