Preparation of subduction Earthquakes : Slow, Deep, Large-scale trigger. DeepTrigger is a project funded by the European Research Council. The aim of the project is to study the preparation of subduction earthquakes in the Chile/Peru subduction area. The seismological network deployed in Peru (6B network) is composed of 24 stations (13 broad-band velocimeters (Nanometrics T120-QA) and 11 medium-band velocimeter (Nanometrics TC20-PH). Those 24 stations will be deployed during ~3 years in southern Peru (network code 6B) from March 2022 to March 2025. The targeted area in South Peru (13°S-17°S) has been partly affected by the 2001 Mw8.4 Arequipa earthquake, and has been loaded at both extremities by the Mw8 Pisco earthquake in 2007 in the area of the Nazca ridge, and by the 2014 Mw 8.3 Iquique earthquake in North Chile. It is an area characterized by important intraslab seismicity. The megathrust is characterized by lateral variations of coupling, notably the Nazca Ridge is an intersegment area, characterized by a low coupling value, and therefore prone to host slow slip events. This area appears as an excellent target to hunt for deep – shallow interactions, large-scale transients (the effect of 2014 Iquique earthquake should be investigated), and slow slip events in low coupling areas, notably in the area of the Nazca ridge. The installed seismological network will provide key data to investigate these questions. Precise catalogues of seismicity will be generated, in which swarm, repeaters and clusters will be identified and analysed. LFEs and tremors will also be systematically scanned, catalogued and analysed.