Details

Autor(en) / Beteiligte

• Jara, Jorge
• Socquet, Anne
• Marsan, David
• Bouchon, Michel

Titel

Long‐Term Interactions Between Intermediate Depth and Shallow Seismicity in North Chile Subduction Zone

Ist Teil von

• Geophysical research letters, 2017-09, Vol.44 (18), p.9283-9292

Ort / Verlag

Washington: John Wiley & Sons, Inc

Erscheinungsjahr

2017

Quelle

Wiley-Blackwell Journals

Beschreibungen/Notizen

• We document interactions between intermediate depth and interplate seismicity in the North Chile subduction zone, over a 25 year period (1990–2015). We show that the 2005 Mw 7.8 Tarapaca slab‐pull earthquake was followed by 9 years of enhanced deep and shallow seismicity, together with the decrease of eastward average GPS velocities and associated interplate coupling, eventually leading to the 2014 Mw 8.1 Iquique megathrust earthquake. In contrast, megathrust ruptures (e.g., Mw 8.0 Antofagasta in 1995, or Mw 8.1 Iquique in 2014) initiate several years of silent background seismicity in the studied area, both at shallow and intermediate depths. The plunge of a rigid slab into a viscous asthenospheric mantle could explain the observed synchronization between deep and shallow seismicity and their long‐term interactions. Key Points The 2005 slab‐pull earthquake triggered 9 years of deep‐shallow seismicity interactions, while megathrust ruptures initiate a seismic quiescence Post slab‐pull increased background seismicity is associated with a decrease in GPS eastward velocity, interpreted as interplate decoupling Bursts of deep and shallow seismicity are correlated in time, suggesting a lasting physical link between intraslab and interplate ruptures