Empirical Analysis of Global-Scale Natural Data and Analogue Seismotectonic Modelling Data to Unravel the Seismic Behaviour of the Subduction Megathrust

Subduction megathrusts host the Earth’s greatest earthquakes as the 1960 Valdivia (Mw
9.5, Chile), the largest earthquake instrumentally recorded, and the recent 2004 Sumatra-
Andaman (Mw 9.2, Indonesia), 2010 Maule (Mw 8.8, Chile), and 2011 Tohoku-Oki (Mw 9.1,
Japan) earthquakes triggering devastating tsunamis and representing a major hazard to
society. Unravelling the spatio-temporal pattern of these events is thus a key for seismic
hazard assessment of subduction zones. This paper reviews the current state of
knowledge of two research areas–empirical analysis of global-scale natural data and
experimental data from an analogue seismotectonic modelling—devoted to study causeeffect
relationships between subduction zone parameters and the megathrust
seismogenic behavior. The combination of the two approaches overcomes the
observational bias and inherent sampling limitations of geological processes
(i.e., shortness of instrumental and historical data, decreasing completeness and
resolution with time into the past) and allows drawing appropriately from multiple
disciplines with the aim of highlighting the geodynamic conditions that may favor the
occurrence of giant megathrust earthquakes.