The night before a deadly magnitude 7.1 earthquake rocked central Mexico and killed hundreds, a much milder magnitude 3.6 temblor rattled nerves around Los Angeles -- reminders big and small that home owners and renters everywhere should know if their property insurance covers damage from earthquakes. Here are 5 facts to know about earthquakes and insurance:
1. Home insurance doesn't cover earthquakes
Standard homeowners insurance won't pay to replace your house or belongings after an earthquake.
In California, home insurers are required to offer supplemental earthquake coverage, for an added price. But if you live elsewhere, you might need to shop for a separate policy dedicated to these disasters.
Ask your home insurer for help finding companies in your area that sell stand-alone earthquake coverage or visit your state's Department of Insurance website. While you're at it, see if the rest of your current homeowners insurance is as good as it can be.
2. Earthquakes can happen in every state
Contrary to popular belief, there's no such thing as an earthquake-free zone. They can happen anywhere.
California grabs most of the headlines when it comes to earthquakes, and understandably so, given the state's frequent seismic activity. But no state is immune from earthquake damage.
Indeed, the U.S. Geological Survey -- using data going back to 1900 -- says there more than 14,000 earthquakes of magnitude 4.0 or great every year, or an average of about 40 per day if they were equally distributed across a calendar.
3. Aftershocks can be more destructive than earthquakes
It's fairly common for large earthquakes to trigger a series of smaller earthquakes, called aftershocks. These tremors, usually relatively mild, are the result of the earth realigning after the initial quake.
Occasionally, however, an aftershock is so intense that it overshadows the initial event. In California, for instance, between 5% and 10% of earthquakes produce an even more powerful earthquake within a week, according to the U.S. Geological Survey.
4. Insurers won't sell coverage immediately after severe earthquakes
If you don't have insurance once an earthquake hits, buying a policy ahead of its aftershocks could prove difficult. Insurers typically suspend sales of earthquake insurance after a severe quake occurs. They won't offer coverage again until a certain amount of time has passed and any earth-shaking encores have subsided.
These moratorium periods typically kick in after earthquakes of 4.5 to 5.0 magnitude or greater, and they generally last for one to two months. Specifics vary by insurer.
Make sure to solidify your earthquake insurance purchase before the next big disaster — or you might wind up paying the price for multiple tremors.
5. We can't predict how strong earthquakes will be
Unlike with tornadoes and hurricanes, it's impossible to pinpoint when or where an earthquake will occur or to predict its potential for severe damage.
The Richter scale measures an earthquake's size in terms of how much energy is released. The "intensity" of the quake refers to its possible effects on people, property and natural environments.
Scientists can make long-term estimates regarding the likelihood of severe earthquakes. But predicting how strong the next tremor will be isn't yet possible.
That's why it's crucial to stay ready for major earthquakes all year round, which includes maintaining your earthquake insurance. There's no "right" time of year to buy a policy or increase your limits.
More about earthquakes from NerdWallet:
How to prep for an earthquake and its insurance claims
How to make insurance claims after an earthquake
Complete guide to buying earthquake insurance