Bletery Quentin auteur aut IRD Nocquet Jean-Mathieu auteur aut IRD text journalArticle eng text/pdf born digital access The existence of an observable precursory phase of slip on the fault before large earthquakes has been debated for decades. Although observations preceding several large earthquakes have been proposed as possible indicators of precursory slip, these observations do not directly precede earthquakes, are not seen before most events, and are also commonly observed without being followed by earthquakes. We conducted a global search for short-term precursory slip in GPS data. We summed the displacements measured by 3026 high-rate GPS time series-projected onto the directions expected from precursory slip at the hypocenter-during 48 hours before 90 (moment magnitude >= 7) earthquakes. Our approach reveals a approximate to 2-hour-long exponential acceleration of slip before the ruptures, suggesting that large earthquakes start with a precursory phase of slip, which improvements in measurement precision and density could more effectively detect and possibly monitor. specialized 066 064 020 381 6655 297-301 2023 0036-8075 https://www.documentation.ird.fr/hor/fdi:010090123 10.1126/science.adg2565 0036-8075 [F B010090123] https://www.documentation.ird.fr/hor/fdi:010090123 https://www.documentation.ird.fr/intranet/publi/2023-10/010090123.pdf Accès réservé (Intranet de l'IRD) IRD - Base Horizon / Pleins textes 2023-10-06 2026-06-12 fdi:010090123 fre