Latest Risk Insights for Central and South American Earthquakes
Laura BarksbyMay 09, 2022
The updated Version 22 RMS® Central and South America Earthquake Models provides the most up-to-date view of earthquake risk in 15 countries, which have a combined population of around 450 million people.
Over the last 20 years, we have witnessed some of the biggest earthquakes in recorded history. South America holds the record for the largest-ever earthquake; the 1960 M9.5 Valdivia Earthquake ruptured an entire segment of the Nazca subduction zone offshore of Chile. This zone extends for thousands of kilometers from Colombia to the tip of South America and dominates earthquake risk in the region.
At the boundary with Central America, the seismicity transitions to two subduction zones: the Middle America Trench and the North Panama Deformed Belt. As a result of the plate tectonics, the highest earthquake risk across Central and South America broadly tracks the boundaries of the subduction zones, primarily along the western coast of both regions.
While there is potential for large magnitude events on the subduction interface in both Central and South America, there have not been any M8 or greater earthquakes in Central America in the last 500–550 years. In contrast, South America has seen nine events of at least M8 in the last century. These earthquakes have ruptured various segments along the Nazca subduction zone and include the 2010 M8.8 Maule Earthquake in Chile.
Covering a Wide Region
The updated RMS models provide extensive coverage across all of Central America and most of South America, including Argentina, Belize, Bolivia, Brazil, Chile, Colombia, Costa Rica, Ecuador, El Salvador, Guatemala, Honduras, Nicaragua, Panama, Peru, and Venezuela (Figure 1). This comprehensive model solution provides a consistent and correlated view of earthquake risk for the damage from ground shaking, landslides, liquefaction, and tsunami accumulations.
Figure 1: Countries covered by the RMS Central and South America Earthquake Models
The rebuilt models capture the latest view of risk, combining the most recent scientific and engineering research with current modeling methodologies and data for the region. The models were developed in collaboration with local and global industries, including the insurance, scientific, and engineering sectors, and the model components were reviewed by independent, external experts. The changes across our stochastic event set, hazard modules, vulnerability model, and modeling approach help (re)insurers better price and manage risk across the region.
Presenting the Latest View of Seismic Hazard
Version 22 integrates the latest scientific understanding of seismic hazard in Central and South America. The models include an updated, comprehensive view of the subduction interface, which drives seismic risk for South America. The updated model also adds a comprehensive database of new faults, as well as introducing both sub- and multifault ruptures. For seismicity not associated with known faults, Version 22 implements a new methodology for crustal and inslab background events.
RMS built our event footprints based on a combination of the local and global ground motion prediction equations (GMPEs), considering the wealth of new ground motion recordings and improved methodology for GMPE selection and weighting. Version 22 also incorporates basin effects models to help explain the extent of potential site amplification in key exposure areas. Detailed site data is used to inform the location and severity of liquefaction and landslides, the latter of which is a new, regionwide model.
Enhancing Vulnerability
Within Version 22, all aspects of the vulnerability models across all of the modeled countries in Central and South America have been updated. It updates and adds new vulnerability areas to reflect regional differences in building code provisions and construction practices and reassesses vulnerability relativities across the different countries.
For exposure with unknown primary characteristics, the building inventory regions and distributions have been updated to reflect the current building stock. In addition, updates to the post-event loss amplification (PLA) model account for the expected economic demand surge, claims inflation, and super cat effects in each country, based on the modeled earthquake losses and the country's ability to absorb them.
For business interruption coverages, Version 22 better represents the expected downtimes and associated loss of revenue to commercial and industrial risks, plus the additional living expenses incurred by residential properties. For specialty lines, Version 22 adds RMS Builders Risk Model vulnerability functions for all countries and updates the vulnerability curves for the RMS Industrial Facilities Model and the RMS Marine Cargo Model.
Understanding Tsunami Accumulations
Version 22 also includes a separate model for earthquake-induced tsunamis, to help users understand their accumulations at risk of some of the most potentially devastating events that could impact the region. The tsunami model captures the full life cycle of the tsunami and is linked to the stochastic event set to provide a complete assessment of earthquake risk per seismic event.
Overall, RMS delivers an entirely rebuilt, comprehensive solution for understanding earthquake risk in Central and South America based on a consistent underlying methodology, the latest data and research, and current modeling approaches.
Laura joined Moody's RMS in 2014 and is an Assistant Director - Product Manager within the global earthquake product management team, based in London. She is responsible for the Moody's RMS New Zealand Earthquake HD Model, as well as the Australia earthquake, and Europe earthquake models.
Laura is a Certified Catastrophe Risk Analyst and holds a bachelor’s degree in Geography, and a master’s degree in Risk and Environmental Hazard both from Durham University.
