Networks

In-situ geophysical monitoring in 2 zones of interest along the South American subduction is in progress in South Peru (13°S-17°S) and in Central-North Chile (27°S-30°S).

Existing GNSS networks in South America. Interseismic coupling is shown in yellow/red, and epicentres of large instrumental earthquakes as blue dots The 2 zones of interest where the geophysical instrumentation will be done in the frame of the project are indicated in green.
  • 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, where we can expect to detect small slow slip events and a potential future great earthquake since the last one in the area was in 1942.
    A network of 24 seismological stations and 8 GNSS stations has been installed in this area.
    Webpage of the seismological network in Peru
  • The targeted area in North-Central Chile (27°S-30°S) is located just north of the 2015 Illapel rupture. It is a recognized ‘seismic gap’, where the last earthquakes of Mw8.5+ occurred in1819 and 1922, and where a future large event is to be expected. The area is characterized by an interseismic coupling that evolves from low in the south to high in the north (Métois et al., 2018), and where deep slow slip events have been recently discovered (Klein et al., 2018). This is therefore an excellent target to study the preparation of a future large earthquake, the lateral interactions between large seismic ruptures, and the link between slow slip and the seismic response to slow slip.
    A network of 25 seismological stations and 9 GNSS stations has been installed in this area.
    Webpage of the seismological network in Chile

Updated on 3 May 2023