A 6.7-magnitude strong earthquake shook the Philippines on Saturday, July 24th. Some people in Central Luzon said on Twitter that they received an alert on their Android smartphones about an "incoming earthquake" which apparently made them confused.

In 2020, Google released its first versions of the "Android Earthquake Alert System" — a free feature that detects earthquakes around the world and alerts Android users — announcing its existence in a blog post.

According to the article's author, Marc Stogaitis, they collaborated with the United States Geological Survey (USGS) and other state authorities including emergency organizations to send earthquake alerts powered by the earthquake early warning (EEW) system, "ShakeAlert."

In June 2021, Google Philippines deployed the early warning system its the country.

The system alerts people in two ways — via a search engine and directly on an Android mobile device.

It provides near-instant information via Google Search. When people look up “earthquake” or “earthquake near me”, they will find relevant results, along with helpful resources on what to do after an earthquake.

The Android device notification, on the other hand, provides an early warning alert when accelerometers detect an earthquake in an area.

It sends a signal to Google’s earthquake detection server, along with a coarse location of where the shaking occurred.

The server then takes this information from smartphones to analyze if an earthquake is happening, where, and its corresponding magnitude.

The feature can also be turned off in the device’s settings if users do not wish to receive such alerts.

On mobile devices, the Android Earthquake Alerts System displays two types of alerts, depending on the magnitude and intensity of the earthquake.

"Our country, being located in the Pacific Ring of Fire, is prone to natural calamities and this update will play an important role in disaster preparedness and risk reduction," Google Philippines country director Bernadette Nacario said in a virtual briefing on Thursday.

“Our smartphones are indispensable in moments of crisis. We believe Android devices can help people be prepared and stay connected in times of need. We will continue to partner with the government, public safety officials, and leading crisis response experts to better surface relevant information in times of adversities,” she added.

A Be Aware system likewise sends alerts when earthquakes with a magnitude of 4.5 occur, or an intensity level of 3 or 4 on the MMI (modified Mercalli intensity) scale, used for measuring the intensity of shaking produced by an earthquake.

Take Action, meanwhile, is a full-screen alert for earthquakes with a magnitude higher than 4.5, or an intensity level of 5 and above on the MMI.

To help people prepare for potential heavy shaking, full-screen instructions are shown and the phone plays a loud sound.

Google said the Android Earthquake Alerts System was first introduced in New Zealand and Greece.

Aside from the Philippines, it is also accessible in Kazakhstan, Kyrgyz Republic, Philippines, Tajikistan, Turkey, Turkmenistan, and Uzbekistan.