%0 Journal Article %T Extended Nucleation of the 1999 Mw 7.6 Izmit Earthquake %+ Mécanique des failles %+ Kandilli Observatory and Earthquake Research Institute (KOERI) %+ Earth and Marine Sciences Research Institute [Gebze] %+ Sismologie (IPGS) (IPGS-Sismologie) %+ Observatoire Volcanologique de Guadeloupe %A Bouchon, Michel %A Karabulut, Hayrullah %A Aktar, Mustafa %A Özalaybey, Serdar %A Schmittbuhl, Jean %A Bouin, Marie-Paule %< avec comité de lecture %@ 0036-8075 %J Science %I American Association for the Advancement of Science (AAAS) %V 331 %N 6019 %P pp.877-880 %8 2011 %D 2011 %R 10.1126/science.1197341 %K Nucleation %K seismology %K geology %K faults %K Izmit %K Turkey %Z Sciences of the Universe [physics]/Earth Sciences/GeomorphologyJournal articles %X Laboratory and theoretical studies suggest that earthquakes are preceded by a phase of developing slip instability in which the fault slips slowly before accelerating to dynamic rupture. We report here that one of the best-recorded large earthquakes to date, the 1999 moment magnitude (Mw) 7.6 Izmit (Turkey) earthquake, was preceded by a seismic signal of long duration that originated from the hypocenter. The signal consisted of a succession of repetitive seismic bursts, accelerating with time, and increased low-frequency seismic noise. These observations show that the earthquake was preceded for 44 minutes by a phase of slow slip occurring at the base of the brittle crust. This slip accelerated slowly initially, and then rapidly accelerated in the 2 minutes preceding the earthquake. [ABSTRACT FROM AUTHOR] %G English %L insu-00679411 %U https://insu.hal.science/insu-00679411 %~ INSU %~ UNIV-SAVOIE %~ UGA %~ CNRS %~ UNIV-GRENOBLE1 %~ OSUG %~ UNIV-STRASBG %~ GIP-BE %~ ISTERRE %~ SITE-ALSACE %~ USMB-COMUE