26-08-2020 | | By Sam Brown
Google is planning to release an app that will notify users of earthquakes seconds before they happen in an attempt to give users a few extra seconds to find safety. What are earthquakes, what does the system do, and what implications does the system have?
The definition of an earthquake is the resulting movement of the earth surface when a large amount of energy stored in the lithosphere is released. While earthquakes come in different varieties (e.g. plate movement type), the only fact that matters in an earthquake is its strength. According to the National Earthquake Information Centre (NEIC), there are over 50 earthquakes a day, but most of these are far too small to be noticed. However, those that can be felt can be potentially lethal, and some earthquakes of the past have been responsible for killing up to 300,00 people in a single incident. Major earthquakes are rare, and countries that have frequent earthquakes (such as Japan), have specially designed buildings to mitigate the shifting ground, and resist damage.
Different mechanisms can cause earthquakes, but the most common mechanism is plate tectonics and the movement between tectonic plates. When tectonic plates push against each other, or slide next to each other, they are prone to getting stuck (i.e. restricted movement), and as the plate pushes on these points large amounts of elastic energy is stored. If the energy stored becomes too great, the plates can slip, releasing the stored energy, and the result is large shockwaves throughout the nearby plate. Predicting earthquakes is very tricky, and to date, no researcher has ever predicted a major earthquake. This is what makes earthquakes incredibly deadly; there’s no warning.
While earthquakes cannot be predicted, the destructive wave that travels through the ground is not instantaneous. The initial wave from an earthquake is called the P-wave, and this can be thought of as an underground sound wave. This wave travels anywhere between 1 to 14km/s, but is not necessarily destructive, if at all. The second wave, the S-wave, is the shearing wave which causes the ground to move physically, and this is what causes damage to buildings and roads. S waves are destructive and move anywhere between 1 to 8km/s depending on the ground composition. These speeds are very fast, but an earthquake 10km could, in theory, provide nearby individuals a few seconds to get into a doorway or under a table, thus saving lives.
It is these few seconds that Google is counting on, and have announced their plans to create an early warning system for earthquakes. Thanks to Android being used on more than 2.5 billion devices, Google believes that it can utilise the accelerometers in smartphones to detect earthquakes and report them when they occur. Accelerometers are used in phones to detect portrait and landscape modes, but these devices can be used for other purposes, including shake, gesture, and drop detection. The earthquake program has emerged from experiments over 4 years ago that sought to test whether accelerometers to detect crashes, tornadoes, and earthquakes; evidently which must have been successful as according to Google, historical analysis of accelerometer data during earthquakes can be isolated.
The end-plan for the system would be a background service that is installed on the user's phone. During the detection of an earthquake, a loud pinging sound would be sounded by the phone, as well as a display alert to drop and cover. The usage of many millions of phones enables for the approximate determination of the distance to the epicentre, and thus issue different warnings depending on how far away users are. The system would also be able to inform people of safety checks they should perform after the earthquake, including water, gas, and electrical. One major advantage of using smartphones is the ability to protect cities without the need for dedicated infrastructure quickly. This could bring earthquake protection to struggling countries with failing infrastructure and may be the difference between life and death.
The system would undoubtedly be able to save lives, but at what cost? One concern from such a system would be privacy; the system by Google is not an app and runs in the background. During operation, readings from the accelerometer would be obtained and operated on, but whether this data is sent back to Google or stored locally is not described. If data is streamed to a remote service, questions surrounding security need to be answered. Would a Google employee be able to view live-streamed data from accelerometer? Would the service grant access to other hardware such as microphones and cameras? Would this provide attackers with an alternative entry point into the system? These are questions that must be given serious consideration, as the industry has time and time again seen the impacts of poor security design.