Details

Autor(en) / Beteiligte

• Mildon, Zoë K.
• Roberts, Gerald P.
• Faure Walker, Joanna P.
• Beck, Joakim
• Papanikolaou, Ioannis
• Michetti, Alessandro M.
• Toda, Shinji
• Iezzi, Francesco
• Campbell, Lucy
• McCaffrey, Kenneth J. W.
• Shanks, Richard
• Sgambato, Claudia
• Robertson, Jennifer
• Meschis, Marco
• Vittori, Eutizio

Titel

Surface faulting earthquake clustering controlled by fault and shear-zone interactions

Ist Teil von

• Nature communications, 2022-11, Vol.13 (1), p.7126-7126, Article 7126

Ort / Verlag

London: Nature Publishing Group

Erscheinungsjahr

2022

Quelle

Elektronische Zeitschriftenbibliothek - Frei zugängliche E-Journals

Beschreibungen/Notizen

• Abstract Surface faulting earthquakes are known to cluster in time from historical and palaeoseismic studies, but the mechanism(s) responsible for clustering, such as fault interaction, strain-storage, and evolving dynamic topography, are poorly quantified, and hence not well understood. We present a quantified replication of observed earthquake clustering in central Italy. Six active normal faults are studied using 36 Cl cosmogenic dating, revealing out-of-phase periods of high or low surface slip-rate on neighboring structures that we interpret as earthquake clusters and anticlusters. Our calculations link stress transfer caused by slip averaged over clusters and anti-clusters on coupled fault/shear-zone structures to viscous flow laws. We show that (1) differential stress fluctuates during fault/shear-zone interactions, and (2) these fluctuations are of sufficient magnitude to produce changes in strain-rate on viscous shear zones that explain slip-rate changes on their overlying brittle faults. These results suggest that fault/shear-zone interactions are a plausible explanation for clustering, opening the path towards process-led seismic hazard assessments.