China cabinets, wardrobes, and bookshelves can be prone to falling into a room in an earthquake because they are often quite tall and heavy; furniture-securing items are available at your local home improvement store. Other items that need securing are appliances like hot water tanks and fridges; products designed for securing these types of appliances are also available at home improvement stores.
Hang heavy items, pictures, mirrors, etc. away from beds and couches and brace overhead lighting and fans. Make sure all flammable liquids and dangerous chemicals are stored in a secure location. Ensure electrical and gas connections are in good condition and inspect for deep cracks in ceilings and foundations.
One way to help protect your family is to use nightlights in the hallways so that tired family members don’t have a tumble if they get up in the night. Many of us work by instinct when we wake up in the middle of the night and it might take some time for everyone to get used to the new floor-plan.
The level of home security that will feel comfortable to you will have a lot to do with how you feel about your new environment and how vulnerable you might feel in general. If you live alone, you might need a higher level of security to feel comfortable in a new neighborhood where you are unused to the sounds and activity outside especially at night.
While the technology to construct earthquake-resistant buildings has existed for many years, tsunami-proof housing is very much in its infancy. Evacuation to higher, safer, ground is pretty much the best option, but if your home is hit by a significant wave, the amount of damage that it could cause could be astronomical.
Smoke alarms can work in a few different ways; the most common are optical, ionization, and air sampling detectors. Optical detectors are generally the best for not going off over minor issues like smoke from cooking; ionization alarms are cheaper but so sensitive that they are prone to nuisance alarms from minor smoke from cooking and toasting food.