Public earthquake early warning systems have the potential to reduce individual risk by warning people of an incoming tremor but their development has been hampered by costly infrastructure. Furthermore, users' understanding of such a service and their reactions to warnings remains poorly studied. The smartphone app of the Earthquake Network initiative turns users' smartphones into motion detectors and provides the first example of purely smartphone-based earthquake early warnings, without the need for dedicated seismic station infrastructure and operating in multiple countries. We demonstrate here that early warnings have been emitted in multiple countries even for damaging shaking levels and so this offers an alternative in the many regions unlikely to be covered by conventional early warning systems in the foreseeable future. We also show that although warnings are understood and appreciated by users, notably to get psychologically prepared, only a fraction take protective actions such as "drop, cover and hold".

翻译：公共地震预警系统通过警告人们发生地震,有可能降低个人风险,因为震震发生后警告人们发生地震,但其发展受到昂贵的基础设施的阻碍;此外,用户对此类服务的理解及其对警报的反应仍然没有得到很好的研究;地震网络倡议的智能手机应用将用户的智能手机变成运动探测器,提供了纯粹智能手机地震预警的第一个例子,而不需要专门的地震站基础设施和在多个国家运作;我们在这里表明,许多国家已经发出预警,即使是因为震动水平受损,因此,这为许多在可预见的将来不可能被常规预警系统覆盖的区域提供了替代方法;我们还表明,虽然用户理解和赞赏警报,特别是为了做好心理准备,但只有一小部分人采取“投放、掩护和搁置”等保护性行动。