Ground-motion prediction for subduction-zone earthquakes: insights from South and Central American data
Author(s)
Arango-Gaviria, Maria Cristina
Type
Thesis
Abstract
Models to predict the ground motion for earthquakes that occur in subduction
zones are of great importance for earthquake risk reduction and mitigation in many
parts of the world where there is a significant hazard from large earthquakes along
the subduction interface and from earthquakes within the subducting slab. Most
existing ground-motion predictive equations for subduction-zone events are
primarily based on strong-motion recordings from Japan, Cascadia, Mexico, Alaska
and New Zealand. In contrast, few records from South and Central America have
been included in global predictive equations to date, although a major proportion of
the seismicity of these regions is related to subduction-zone processes. The
development of a strong-motion database from subduction-type events in South and
Central America is therefore an important and essential step for ground-motion
prediction in these regions as well as other subduction zones in the world.
In this project two databases of strong-motion records from subduction-zone
events along the Peruvian-Chilean and the Central American subduction zones have
been developed. The Central American database compiled during this study consists
of 554 triaxial ground-motion recordings from both interface and intraslab-type
events of magnitudes between 5.0≤MW≤7.7. The database compiled for South
America consists of 98 triaxial ground-motion recordings from 15 subduction-type
events of magnitudes 6.3≤MW≤8.4, recorded at 55 different sites in Peru and Chile,
between 1966 and 2007. These datasets have then been used to investigate the extent
to which global and regional models for subduction regimes could be applied for the
prediction of ground motions from the subduction events in these regions, following
a maximum-likelihood approach. Regional differences in the ground-motion
amplitudes amongst the South and Central America subduction zones are examined
and preliminary adjustments to existing equations are made in order to resolve the
differences between observed ground motions and predictions from these equations.
This has led to suggestions for the prediction of ground motions from subductionzone
earthquakes in the South and Central American regions.
zones are of great importance for earthquake risk reduction and mitigation in many
parts of the world where there is a significant hazard from large earthquakes along
the subduction interface and from earthquakes within the subducting slab. Most
existing ground-motion predictive equations for subduction-zone events are
primarily based on strong-motion recordings from Japan, Cascadia, Mexico, Alaska
and New Zealand. In contrast, few records from South and Central America have
been included in global predictive equations to date, although a major proportion of
the seismicity of these regions is related to subduction-zone processes. The
development of a strong-motion database from subduction-type events in South and
Central America is therefore an important and essential step for ground-motion
prediction in these regions as well as other subduction zones in the world.
In this project two databases of strong-motion records from subduction-zone
events along the Peruvian-Chilean and the Central American subduction zones have
been developed. The Central American database compiled during this study consists
of 554 triaxial ground-motion recordings from both interface and intraslab-type
events of magnitudes between 5.0≤MW≤7.7. The database compiled for South
America consists of 98 triaxial ground-motion recordings from 15 subduction-type
events of magnitudes 6.3≤MW≤8.4, recorded at 55 different sites in Peru and Chile,
between 1966 and 2007. These datasets have then been used to investigate the extent
to which global and regional models for subduction regimes could be applied for the
prediction of ground motions from the subduction events in these regions, following
a maximum-likelihood approach. Regional differences in the ground-motion
amplitudes amongst the South and Central America subduction zones are examined
and preliminary adjustments to existing equations are made in order to resolve the
differences between observed ground motions and predictions from these equations.
This has led to suggestions for the prediction of ground motions from subductionzone
earthquakes in the South and Central American regions.
Date Issued
2010-01
Date Awarded
2010-03
Copyright Statement
Attribution NoDerivatives 4.0 International Licence (CC BY-ND)
Advisor
Strasser, Fleur
Sponsor
Alban programme
Creator
Arango-Gaviria, Maria Cristina
Grant Number
E05D053967CO
Publisher Department
Civil and Environmental Engineering
Publisher Institution
Imperial College London
Qualification Level
Doctoral
Qualification Name
Doctor of Philosophy (PhD)