HONOLULU (KHON) — Hawaii, Alaska and the West Coast faced strong waves and lingering warnings Wednesday following a 8.8 magnitude earthquake that shook eastern Russia and sent aftershocks across the Pacific. Many warnings that were in place have since faded.

Here’s a guide of how to prepare for a tsunami threat:

1. Water supply

After a tsunami, clean water is often not available. You will need at least two weeks of drinking water for each person stored before disaster strikes.

Saltwater floods can ruin freshwater aquifers, wells can break, and sometimes, underground water moves or dries up. This allows salt to seep into the soil and ruin the water for years.

Keep your water in sealed containers and use purification tablets if needed.

2. Food stockpile

Store at least two weeks of food for each person. Get items that will not spoil, such as canned foods, dried fruits and vegetables and rice.

Keep everything in a cool, dry place, and don’t forget that you will need a manual can opener, propane or butane fuel, a small stove or oven and eating tools.

Do not count on grocery stores to be open or restocked for the first couple of weeks after the tsunami hits.

3. First aid and medical kit

Hospitals may be damaged or overcrowded. Be ready to handle cuts, burns and illness at home. Stock up on gauze, bandages, antiseptic wipes, hydrogen peroxide, gloves, tweezers and basic medications.

In your stockpiles, be sure to include 14-day supplies of prescriptions and treatments for chronic conditions. A first aid manual helps when you need to act fast.

4. Backup power and lighting

Power lines often fail, so, be ready to charge devices with charging boxes and have extra external batteries on hand. Stock up on flashlights, headlamps, lanterns and glow sticks.

Keep batteries in different sizes. Use solar panels, crank generators or power banks. A gas or solar generator can be helpful, but store fuel safely. Use extension cords and waterproof cases for everything.

5. Shelter and housing

If your home is destroyed, know where to go. If you shelter in place, sandbags and tarps can help protect your space.

Have extra blankets, pillows, sleeping bags, clothes, shoes and socks. Make a plan to reunite with family if you are separated and practice your evacuation route ahead of time.

6. Communication plan

Cell phones, internet and landlines may all go down when a tsunami hits. Choose a meeting spot your family can reach without help. Everyone needs to carry a portable radio or HAM radio and practice how to use them.

7. Mental health tools

Fear, anxiety, depression and stress are common during disasters. Bring games, books or hobbies to help people stay calm.

A support network can also help. It’s important to practice calming routines ahead of time. These techniques can help children and adults stay grounded.

8. Documents and cash

ATMs and credit card machines will not work without power. Save cash in small bills to pay for things or services you and your family may need.

Store important documents in a waterproof, portable case. You will need to include ID, insurance papers and copies of medical records. Keep digital backups on a USB drive or hard drive, just in case.

9. Multipurpose tools

You will need more than flashlights and radios, so pack a survival knife, shovel, hammer and crowbar. Use a wrench to shut off gas or water lines. Have tarps, duct tape, gloves and masks readily available and in abundance.

You can use crowbars, or pry bars, to open jammed doors or for lifting heavy debris. Be sure to utilize a checklist and bring a compass, whistle and map in case local signs are gone.

10. Security and defense

A tsunami can cause chaos, meaning first responders, medical and police may be overwhelmed. Remain calm and levelheaded. Everyone else around you is in the same situation you are in.

One source suggested that families need to take self-defense classes together. The more prepared you are, the more secure you will be in situations where society has broken down.

The time to prepare is now. Train your family. Practice your plans. What you do today may save lives tomorrow.