Earthquake early warning as a socio-technical system: a cross-country systematic literature review

Earthquake Early Warning systems have expanded, yet their effectiveness depends on technical performance and whether warnings prompt timely protective action. This systematic review examines interactions among technical, institutional, and behavioural dimensions across EEW contexts. Following PRISMA 2020, literature published between 1975 and August 2026 was searched using Scopus and Massey University Library Discover. Of 1,202 records, 62 studies met the inclusion criteria. Evidence was synthesised across eight jurisdictions: Japan, Mexico, Taiwan, the United States, Aotearoa New Zealand, Switzerland, China, and Israel. Comparisons considered system maturity, technical architecture, public exposure, and differences among retrospective reports of alert responses, experiment, and stated intentions. EEW was generally perceived as valuable for situational awareness and psychological preparedness, but immediate protective action remained inconsistent. System maturity, alert thresholds, governance, risk communication, public knowledge, and preparedness practices were associated with variation in the warning-to-action pathway. Familiarity with established systems did not necessarily translate into protective action, highlighting the importance of context-specific guidance, institutional clarity, preparedness training, and accessible communication. The findings frame EEW as a socio-technical system in which technical capability creates the opportunity for protective action, while institutional, social, and behavioural conditions influence how that opportunity is used and may contribute to risk reduction.