Mexico

	Earthquake

Mexico Earthquake

Seismic activity occurs in many areas of Mexico, but it is of greatest concern along the active subduction zone on Mexico’s southwestern coast. This zone along the Middle America Trench creates repeating large magnitude events with a frequency higher than any other subduction zone in the world. It accounts for the majority of the large, damaging earthquakes in Mexico.

One critical attribute of these events is their ability to cause substantial damage in Mexico City, due to a phenomenon known as the "Mexico City effect." Long-period seismic energy is amplified 5-20 times by Mexico City soil, which consists mostly of reclaimed, water-saturated lakebed deposits. This effect, coupled with the extraordinarily high concentration of exposure in Mexico City, raises earthquakes of this profile to the top of the list for catastrophe risk in Mexico.

The Central Guerrero segment, part of the Cocos plate boundary along this subduction zone, currently poses the highest potential threat to Mexico City due to its proximity and lack of major activity since 1916. Because of its quiescence, this segment is commonly referred to as the "Guerrero Gap." Historically, this plate boundary produced the destructive 1985 Michoacan Earthquake M8.1, the most damaging in Mexico City’s history causing losses of US$4 billion. Other such events over the last few decades have reached M7.8.

The RMS® Mexico Earthquake Model contains special geocoding, hazard, and vulnerability features to capture the most complete view of risk for earthquakes impacting the Mexico City area. Since 1996 insurers and reinsurers have used the model to manage earthquake catastrophe risk in Mexico.

Model Highlights

	Differentiates between 12 distinct source segments along the Middle America Trench subduction zone
	Soil hazard data for the entire country, with high resolution soil and liquefaction data for Mexico City
	Special amplification parameters to account for long-period effect for sites on old lake deposits in Mexico City
	Building vulnerability curves developed using local expert opinion and RMS research
	Accounts for local/regional construction differences, building code changes

Geographic Scope

All of Mexico

Exposure Data Resolution

Data input supported at the following levels of resolution: latitude-longitude, postal code, colonia (city district equivalent, for Mexico City and Acapulco), city, municipio (county equivalent), and CRESTA zone