After a major quake, remember that opening your refrigerator and freezer can be a judgment call if you have no electricity. If indications are that power will be restored within a day or so, most foods will be fine as long as you don't open freezer or refrigerator doors. If you think it's going to be a long emergency, however, you might as well consume foods while they last. Watch for spoilage, and toss anything that's suspect. Here are some suggestions for basic sustenance to see you through the first few days after a disaster.
Shelf life is indicated in parentheses.
If water is shut off, ladle out the water from toilet tanks and hot-water heaters. Water purification tablets are available at sports and camping stores. If you have ice cream melting in the freezer, pour it on the cereal. Even if you generally don't use much canned food, it is invaluable in an emergency. Just be sure you've got a manual can opener.