Google has acknowledged that its earthquake early warning system failed to send the highest-level warning to millions of people during the deadly 2023 disaster in Turkey.
The Android Earthquake Alerts sent the highest-level warning – “Take Action – to only 469 people despite over 10 million people being within 98 miles of the epicentre of the initial 7.8-magnitude quake.
Around half a million people received a lower-level alert – “Be Aware” – meant for light shaking that is not as noticeable or urgent. This alert cannot override Android phone settings like Do Not Disturb and would likely have gone unnoticed when the earthquake struck at 4.17am local time.
Days after claiming its systems “performed well”, Google has now told the BBC that nearly 500,000 people in Turkey did not receive the correct alert on their phones as its warning system underestimated the earthquake.
Launched in August 2020 in collaboration with the US Geological Survey, the Android Earthquake Alerts System uses phone sensors to detect earthquakes.
When many devices in an area sense shaking, the system verifies the data and sends alerts, sometimes seconds before the quake hits. It issues high-level warnings for strong tremors and lower-level ones for mild shaking, helping users take quick action even in regions without official alert systems.
Two powerful earthquakes, measuring magnitude 7.8 and 7.5, struck Turkey at 4.17am and 1.24pm local time on 6 February, killing more than 55,000 people, injuring over 100,000, and destroying scores of buildings and roads across 11 of Turkey’s southern and southeastern provinces. The earthquakes also killed 6,000 people in neighbouring Syria.
The quake was the largest to hit Turkey since 1999 and the deadliest worldwide since the 2004 Boxing Day tsunami off Indonesia, which killed around 228,000 people.
An internal investigation revealed that Google’s warning system significantly underestimated the earthquake’s strength, initially rating it a magnitude of between 4.5 and 4.9.
The second tremor later in the day also triggered inaccurate readings. During this event, AEA issued 8,158 “Take Action” alerts and nearly four million “Be Aware” notifications. This response still fell short of expectations given the scale of the disaster.
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“We continue to improve the system based on what we learn in each earthquake”, a Google spokesperson told the BBC.
In a blog post about the alert system, Google acknowledged the challenges of maintaining a balance between speed and accuracy.
“One of the trickiest parts of an EEW system is estimating the magnitude of an earthquake in real-time. The magnitude tells us how big the earthquake is, which in turn determines how far the shaking will travel and who needs to be alerted,” it said.
“Getting this right is crucial – underestimate, and you might not warn people in danger; overestimate, and you risk sending out false alarms that erode public trust.”
The Independent has reached out to Google for comment.
