Earthquake Scaling Equations Under Small Strain, Steady Moment
Release-Rate Conditions in Southern Andes from 2015 to 2017
Abstract
In the South Andes western edge, a very active seismic contact, with
earthquakes up to magnitude $9.5$ and ca.
$4000\thinspace\textnormal{km}$
extension threatens cities and very large populations. The existence of
modern seismological networks along the contact allowed the observation
of unprecedented earthquake cycle characteristics, which can improve our
ability to estimate earthquake hazard, a main objective of seismology.
Using dimensional and similarity analysis techniques, we show precise
mechanical conditions under which the earthquake generation process
unfolds, and derive a set of scaling equations linking renormalized
variables. Later on, we test our theoretical results using a curated
earthquake point-catalog by using gridding, box-counting, statistical
bootstrap and fixed-point iteration collapse techniques. We found
non-trivial scaling laws valid across multiple orders of magnitude
capable of describing a complex interplay between renormalized
earthquake occurrence and renormalized moment release rate. We discuss
finite-strain and seismic-moment release-rate conditions; declustering,
foreshock, mainshock, aftershock notions; cutoff magnitudes, earthquake
hazard implications and a possible large-scale tectonic energy transfer
mechanism.