“It took two hours for the waves generated by the earthquake to hit the shores of Thailand. In those two hours many lives of children and babies could have been saved”.
These words were spoken by Petra Nemcova, a tsunami survivor and campaigner, at the ‘Multi-Hazard Early Warning Conference’, held on 23 May 2017. While the 2004 Indian Ocean Tsunami is one of the deadliest natural disasters to hit our planet, it definitely isn’t the last one, and Nemcova’s words highlight the need for smart public alarm systems. Times have changed and these days disruptive digital technologies like the Internet of Things have improved public alarm systems as a whole.
This blog discusses the current state of adoption of smart public alarm systems and explores how IoT plays a crucial role in this. If you are interested to learn more about public alarms (including an in-depth analysis of gunshot detection systems), please read this report: Public Alarms & Monitors: 2.8 million connected devices by 2034 for providing timely emergency aid to citizens.
Public alarm systems include IoT sensors and devices that can detect and warn of gunshots or other public dangers. These systems have existed for quite some time now, for instance, back in 2007, Japan deployed an Earthquake Early Warning system which could warn people about the probable arrival of earthquake tremors. However, the time between the warning and the arrival of the tremors can be short, which reduces the effectiveness of the system as a whole. In fact, this system in Japan can warn only 5 seconds in advance in areas closer to the epicentre and 50 seconds in advance in more distant areas. Besides, this technology relies on data from seismographs which can result in false alarms.
In 2024, China unveiled its National Earthquake Intensity Rapid Reporting and Early Warning Project, which was initiated in 2018, in Yunnan, Sichuan, Fujian, Beijing, Tianjin, and Hebei regions, and began offering trial services to the public in 2021. It now covers the entire country and enables people in populous and quake-prone areas to receive warnings in an average of just seven seconds, while earlier, the people of China mostly relied on the CENC's rapid earthquake reports, which usually took two to three minutes to be released after an earthquake occurred. These improvements in early warning capabilities are supported by a network of 15,899 monitoring stations across the country.
In case of tsunamis in particular, the National Oceanic and Atmospheric Administration (NOAA) in the U.S. operates the NOAA Tsunami Program, including observation systems to rapidly detect potentially tsunami generating earthquakes and tsunamis, models to forecast tsunami impacts, and processes for timely messaging. The solution draws information from the U.S. Geological Survey’s Advanced National Seismic System and the Global Seismographic Network, supplemented by a network of Deep-Ocean Assessment and Reporting of Tsunami (DART) systems that provide real time reporting of tsunamis in the open ocean.
In addition to warning the public about natural disasters like earthquake and floods, public alarm systems, integrated with broader disaster response frameworks, increasingly leverage IoT to trigger various kinds of life-saving actions, like slowing trains, activating road alerts, stopping elevators, and halting factory lines. These measures not only protect lives but also reduce economic disruption by minimising production damage and maintaining supply chain continuity. There are other kinds of IoT solutions like, for example, billboards and digital signage in Mexico, that are used to warn public of potential hazards. Moreover, the numbers of connected devices in public areas are growing, which may also be used to alert people.
In her speech, Nemcova said, “Natural disasters can happen anywhere. The difference between 2004 and today is mobile phone technology”. True, smartphones offer a valuable channel for delivering hazard alerts, with Cell Broadcasting emerging as a key technology used by governments to send warnings across cellular networks. For instance, in India, C-DoT (the Centre for the Development of Telematics) has implemented a nationwide disaster alert system using 4G and 5G, delivering 3.4 billion localised messages on threats like earthquakes, floods, and heavy rain. Compared to public alarms, Cell Broadcasting is more cost-effective, especially in rural areas with low population density. Another example of smartphones enhancing the quality of service would be the deployment of MyShake App in California. It is a free earthquake early warning tool, which sends a warning to smartphone users that have installed the app in the vicinity of an earthquake as soon as ground sensors detect significant shaking. Disaster Alert, which has been developed by the Pacific Disaster Center (PDC) and can be used across the globe, also offers similar services through smartphones. Users can download the Disaster Alert mobile app and web platform for free and gain access to near real-time updates on 18 different types of hazards, which includes earthquake, drought, cyclone, tsunami, earthquake, volcano, wildfire, flood, high surf, high wind, marine, storm, high wind, volcano, landslide, wildfire, biomedical, man-made hazards and more.
Public alarm systems, enhanced by IoT and network technologies, are becoming faster, smarter, and more responsive. From earthquake alerts to real-time hazard warnings, these innovations improve public safety, reduce damage, and support quicker responses.
