If you know there are leaks after an earthquake, you can shut off all the water in your house with this valve. You may wish to paint the valve so it is easy to find in an emergency. Open the cover with a long screwdriver or specialty tool. The valve can be operated by a special tool or with a crescent wrench. If this box is inaccessible or you cannot find it, call your water department.
Many variations are available at hardware stores.
Place heavy objects on lower shelves. Close the hooks used for hanging pictures and mirrors to prevent the objects from falling.