Pafos Press 14 November 2025
In a seismically active country, early warning of an earthquake can make all the difference, giving you precious seconds to protect yourself. Modern smartphones have built-in features to alert you as soon as seismic activity is detected.
These alerts are not earthquake predictions, but detection of the first seismic waves (P-waves) that travel faster than the more destructive secondary waves (S-waves).
Here’s how to enable these vital alerts, depending on your phone’s operating system.
🤖 For Android Users (Google)
Most Android phones use Google’s Earthquake Alert System. This system uses the millions of Android phones around the world as a vast network of “mini-seismographs” via each device’s accelerometer.
How to enable it:
The path may vary slightly depending on the manufacturer (e.g. Samsung, Xiaomi, etc.), but it is usually located in one of the following places:
Main Method:
Open your device's Settings.
Select "Safety & emergency".
Tap "Earthquake alerts".
Make sure the "Earthquake alerts" switch is turned on.
You can also tap "See a demo" to see what the alert looks like.
Alternate Method (If you can't find it):
Open Settings.
Go to "Location".
Tap "Location services".
Select "Earthquake alerts" and turn on the switch.
Note: To work properly, you must have Location (GPS) and/or Wi-Fi enabled on your device.
For iOS Users (Apple iPhone)
On iPhones, earthquake alerts are usually integrated into the Government Alerts system, which works in collaboration with local authorities (such as 112 or GR-Alert in Greece).
How to check your settings:
Open your iPhone's Settings.
Tap "Notifications".
Scroll all the way down the screen.
You will find the "Government Alerts" section.
Make sure the switches for "Emergency Alerts" and/or "Threat Notifications" are turned on.
In countries with specialized systems, such as the US or Japan, there may be a separate “Earthquake Alerts” option. In Europe, these alerts usually come through the general emergency channel.
⚠️ What to Remember
It’s a Warning Tool, Not a Forecast: These alerts do not predict earthquakes. They are sent after the earthquake has already started, giving you seconds of warning before the strongest wave reaches you.
Time Depends on Distance: The closer you are to the epicenter, the less (if any) warning time you will have. The further away you are, the more seconds you gain.
Connection Required: Your device must have an internet connection (either Wi-Fi or mobile data) and location services enabled to receive the alert.
Don’t Rely on It Exclusively: This technology is an additional safety tool. You should always know the basic safety instructions during an earthquake (Drop, Cover, Hold).
Enabling these alerts is a simple move that can be life-saving. Take a minute to make sure your phone is set up correctly.
How does it work?
Here’s a complete and detailed explanation of exactly how Google’s crowdsourced earthquake alert system (Android Earthquake Alerts System) works, especially when it’s running autonomously, as we saw in the example of Turkey.
How Phones Become Seismographs: A Complete Analysis of Google’s System
The central idea behind Google’s system is simple but revolutionary: Every Android phone can act as a mini-seismograph.
With billions of Android devices active around the world, Google has created the largest, global, “live” earthquake detection network, without having to install a single ground sensor of its own.
Here’s how it works step by step:
Step 1: The Sensor You Already Have in Your Pocket
Every modern smartphone (Android and iPhone) contains a sensor called an accelerometer. Its main purpose is to detect the movement and orientation of the phone—that’s why your screen rotates when you turn it, or why it counts your steps.
This sensor is extremely sensitive. It can detect the subtle vibrations caused by the first waves of an earthquake.
Step 2: The Biggest Question: “Earthquake” or “Noise”?
This is the key to the whole system and its smartest aspect. As you rightly mentioned with the example of Turkey (the yellow dots), a phone vibrates constantly for “fake” reasons:
You put it on the table.
Someone sends you a message (vibration).
It is in a moving car.
You drop it by mistake.
Google’s algorithm has to filter out this “noise” to find the real “signal” of the earthquake.
How does it do it? By crowdsourcing.
The rule is: A single phone vibrating is “noise”. Hundreds of phones vibrating at the same time, in the same area, with the same vibration pattern, is not a coincidence. It is an earthquake.
Step 3: Confirmation and the “Race” of Waves
Here’s where the process happens at breakneck speed:
Earthquake Initiation: The earthquake begins. The first, fastest P-waves begin to travel from the epicenter. These are weak and rarely cause damage, but they are the first signal.
First Detection: Android phones closest to the epicenter (e.g., 100 phones in a city) detect the P-waves simultaneously.
Send Signal: Each of these phones immediately (and anonymously) sends a tiny data packet to Google’s servers, essentially saying, “I’m at coordinate X,Y and I just felt a Z-type tremor.”
Server Confirmation: Google’s central algorithm receives these 100+ signals within a split second. It confirms that it’s not noise.
Calculation: Using the data from these first phones (who received it first, who received it second, etc.), the system does a very fast “triangulation” to calculate:
The epicenter of the earthquake.
The magnitude (approximate).
Step 4: Sending the Alert
Now the real race begins:
The destructive S-waves, which are slower, still travel to the most distant cities.
Google’s alert, however, travels at speed (via the internet, 4G/5G).
Within seconds of the initial detection, Google's system automatically sends an alert to all Android phones in the area about to be hit by the S-waves.
The result is what we see in the simulations: People 20, 30, or 50 kilometers away from the epicenter receive the alert 5, 10, or even 30 seconds before the strong tremor reaches them, giving them critical time to take cover.
What Does It Need to Work?
To be part of this network (either to send data or to receive alerts), your phone needs three things:
Android operating system (it's a Google service).
Location enabled (so Google knows where you are and if you're in danger).
Connectivity enabled (Wi-Fi or mobile data).
Summary: Two Operating Models
As we discussed, Google’s system comes in two models:
Cooperative Model (e.g., US with ShakeAlert): Google receives the precise data from ground-based, government-owned seismographs (like the 1,675 sensors) and simply uses the Android network as a powerful notification distributor.
Crowdsourcing Model (e.g., Greece, Turkey): Where there is no formal cooperative network, Google uses Android phones themselves as both sensors AND distributors. This is the system we analyzed here.
It is, in essence, a global, collective defense system powered by the devices we all have in our pockets.
