Google earthquake alert failure up to 35 seconds warning to 10 million not warned within 98 miles (160km) of the epicenter to find safety, was not sent.

Only 469 users were sent the much lower-level “Take Action” warning during the first 7.8 magnitude earthquake.

“We had approximately 500,000 users that were sent a “Be Aware” alert,” a Google spokesperson told the BBC.

The notification is a “low priority” warning for light tremors that is designed not to be disruptive to users.

The company’s previous statement to the BBC said the system had “performed well.”

“Development of these improvements was informed by our experience with the Turkey earthquake 2025,” the Google spokesperson added.

How it works

Google's warning system, which is called Android Earthquake Alerts (AEA), can detect shaking using data from the large numbers of mobile phones with its Android operating system.

Earthquake warning systems are possible because seismic waves move at a moderate speed through the earth, allowing for a warning before the shaking arrives.

Google’s most serious warning is called “Take Action”. It turns on a loud alarm on a user’s phone (even if the device is on “Do Not Disturb”), and covers their screen.

AEA also issues a less urgent “Be Aware” alert that is meant to let users know there’s a possibility of light shaking. This alert doesn’t silence a phone’s “Do Not Disturb” mode.

Google's emergency alert system was particularly important for Turkey’s quake due to the catastrophic shaking and the fact the first earthquake struck at 04: 17, when many users are likely to have been asleep.

‘Limitations’

Google researchers wrote in the journal Turkey seismic activity about what went wrong, listing “limitations to the detection algorithms” as the cause.

The system estimated shaking for the first quake to be between 4.5 and 4.9 on the moment magnitude scale (MMS) when it was actually 7.8.

AEA also underestimated the second large earthquake that day but this time did send Take Action alerts to 8,158 phones and Be Aware alerts to just under four million users.