Living on a Fault Line

California is home to one of the most renowned fault lines in the world, namely the San Andreas fault. This fault is far from being the only one crossing the State, but it is expected to produce the next “Big One” – i.e. an earthquake of magnitude 7.8 or stronger. Seismologists cannot estimate precisely when such an earthquake would occur, but they know that the fault has reached a sufficient stress level for it to occur in the following years. They also expect it to happen on the southern part of the fault that runs along the northern base of the San Gabriel mountains to the Salton Sea, as the last two major earthquakes (estimated magnitude: 7.9) it produced were located in the central part (Fort Tejon, 1857) and the northern part (San Francisco, 1906). Though the San Andreas fault does not lie under the Los Angeles area, it is expected to be strongly felt across the region, and may cause major damages to infrastructures.

In view of these facts, Californians have learned at an early age how to behave in case of such an event. As the Ridgecrest earthquakes reminded us last summer, living in Los Angeles literally means living on a fault line, or more exactly on a bunch of fault lines, and anyone coming here should be prepared. Because, even if “The Big One” might not occur as early as predicted, you will most likely feel at least one earthquake if you stay a few months here. Hopefully, it won’t be too strong, but it’s better to be safe than sorry, so let me share with you a few tips I received during a training at work.

Before an Earthquake: Prepare Yourself

In the event of a major earthquake, roads and highways may collapse – as we have seen during the 1994 Northridge earthquake – and there might be failure across the water system or electrical power infrastructure. In other words, the impacted area may be cut off from the rest of the country for several days. Hence the suggestion of keeping enough supply for 10 days (the estimated time for services to be restored). But other things can be done in order to be prepared:

1. Check for potential hazards in your home:

• Anchor bookshelves to walls
• Remove heavy items from the top of cabinets and place them on the lower shelves
• Hang heavy items such as pictures and mirrors away from where people sit/sleep
• Identify the bearing walls in your apartment
• …

2. Create your disaster plan:

• Take first aid and CPR courses
• Identify your household’s special requirements (medication, …)
• Make sure everyone in your house knows where the utility shut-offs are (gas/electricity)
• Prepare an evacuation plan (primary and secondary escape path) and identify a safe meeting area where you can go once the tremor has stopped
• Establish a single out-of-area point of contact who will be in charge of distributing information to others when service is overwhelmed
• If you have kids, be familiar with the school procedures
• …

3. Store supply for 10 days:

• 3 to 4 liters of water per person and per day
• Non-perishable food (cans, bars) that can be easily prepared
• If you have pets, don’t forget to store food for them as well

4. Prepare an emergency “Go-Kit” that can last for 10 days and contains:

• Snack food (high in calories)
• Water
• A first aid kit
• A list of emergency contacts
• A copy of your personal ID (driver’s license, passport, VISA, etc.)
• Any medication that your household needs & medical card copies/your doctor’s info
• Spare eyeglasses/contact lenses & cleaning solution
• A whistle
• A flash light with extra batteries
• A dust mask
• Sturdy shoes (to protect your feet from debris that cover the floor)
• Hygiene supplies
• Emergency cash

During an Earthquake

Seismologists can predict an earthquake a few seconds before it happens, so you might hear an alarm drill or receive an alert on your smartphone. Nevertheless, as the recent Ridgecrest earthquakes showed it, some faults are yet to be identified, and their rupture will therefore be unexpected. In any cases, you should protect yourself. In the case of an alarm, you may evacuate to an area with less hazards ONLY IF it is safe for you to do so and you have enough time (remember, you will receive the alert a few seconds before). As soon as the quake hits, stop anything that you are doing and follow those three words: DROP, COVER, HOLD ON.

1. Drop

When the ground starts moving, the safest thing to do is to drop before you fall. Especially, do not run because that’s when you are more likely to injure yourself.

2. Cover

Protect your neck and head with one of your hands and bend yourself so as to protect your vital organs, and then crawl under a table or something that can protect you from all the objects that will be flying and falling on the ground.

If there is no place where you can take cover, go next to an interior bearing wall, away from windows and doorways.

3. Hold on

In order to stay where you are, hold on firmly to the table’s leg or anything sturdy.

After an Earthquake

Once the ground stops shaking, you will want to evacuate in order to be in a safer place or look for assistance if needed. Always keep in mind, though, that an earthquake is always followed by aftershocks, and there is a small percent of chances that a stronger one may happen in the following minutes, days, months, or even years. To illustrate that, let’s take a look at the Ridgecrest earthquakes that occurred on July 4 and 5, 2019:

Date	Time	Magnitude Mw	Intensity
July 4	10:30 am	6.4	VIII
July 5	4:07 am	5.4	VII
July 5	8:16 pm	5.0	VII
July 5	8:19 pm	7.1	IX
July 5	8:22 pm	5.0	VI
July 5	8:23 pm	5.4	VII
July 5	8:25 pm	5.0	VI
July 5	8:47 pm	5.5	V
July 5	9:18 pm	5.4	VII

This table actually only contains the earthquakes with a magnitude greater than 5. To give you an idea of how the ground is unstable, bear in mind that more than 3,000 aftershocks were registered between July 4 and July 7. So, here are some rules of thumbs that you should keep in mind when moving around:

1. First things first, make sure that you are not injured.
2. Look for others who may need assistance.
3. If you are not alone, always evacuate together (extra pairs of eyes are invaluable in such scenarios).
4. Watch for electrical and fire hazards: power lines may have fallen on the ground, or leaking gas pipes may have broken during the earthquake.
5. Watch for falling hazards and debris.
6. If you want to evacuate the region, check the conditions and instructions on the radio.
7. Only use telephones to report life-threatening emergencies.

If you want to know more about earthquake safety, you can visit the Department of Homeland Security or the American Red Cross websites.