On August 14, 2021, the earth trembled in Haiti with such violence that it caused more than 2,200 victims and the number of buildings destroyed or seriously damaged exceeded 130,000. That catastrophe was one more in a long series of large-magnitude seismic movements that have hit the Central American and Caribbean region since time immemorial. The earthquakes in Guatemala (1976), Nicaragua (1972), Mexico (2017), El Salvador and many others are of sad memory, due to their terrible consequences for the population. The region has such a complex network of encounters between tectonic plates and active faults that, if seismic movements of lesser magnitude were taken into account, we can assure that tremors are a daily occurrence for the inhabitants of the region. For those who study these natural phenomena, the active tectonics of the Central American region constitutes a unique natural laboratory for the knowledge of seismic activity and the calculations of the danger associated with it.
Our guest today in Hablando con Científicos, María Belén Benito, University Professor in the area of Mechanics of Continuous Media and Theory of Structures of ETSI Topography, Geodesy and Cartography from the Polytechnic University of Madrid (UPM) has extensive experience in the study of seismology, hazard and seismic risk in Spain, Latin America and the Caribbean. At present she participates in the project KUK THE APPEALwhich studies the structure and 4D evolution of the lithosphere in Central America and its implications in calculating the hazard and seismic risk.
Kuk Ahpán is made up of two coordinated subprojects. The first, led by Diego Córdoba, a researcher at the Complutense University of Madrid, aims to improve current knowledge of the structure of the lithosphere from the seabed to the mantle and determine the sources where earthquakes and tsunamis are generated. . The second subproject, called KUK–THE APPEAL-RS, is coordinated by María Belén Benito and its objective is to evaluate the seismic hazard and the risk it represents for the population using the most recent results provided by seismic stations on land and in space.
The project, explains María Belén Benito during the interview, makes it possible to develop models that make it possible to calculate seismic risk, that is, the degree of losses that can be expected if movements of the crust take place that have previously been estimated as dangerous. Applied to a specific place or population, it is essential to know which structures can collapse and which can resist without collapsing but which, as a consequence of the seismic movement, may be damaged to the point of being uninhabitable. Another aspect to assess is the number of victims possible there may be, etc. These risk calculations are essential to estimate what means will be necessary to respond to emergencies, for example, number of ambulances, hospital beds, resources necessary to assist people who may become homeless and the infrastructure necessary to care for them and provide them with shelter and assistance after the earthquake. Having determined in advance the most stable and least exposed areas of a city where camps can be set up to accommodate the victims, etc.
Knowing the risks allows us to measure the response and, most importantly, save lives. The protection of the population against these phenomena depends on many factors, one of them and fundamental is prevention through exercises and drills that provide the inhabitants with knowledge of how they should react to an earthquake, this preparation can provide a few vital seconds in many cases . Another aspect of risk assessment consists in detecting vulnerable structures that are susceptible to collapse in the event of an earthquake. This prior knowledge allows the development of reinforcement strategies that reduce the risk of collapse.
The establishment of early warning systems allow the population to receive warnings prior to the arrival of the seismic wave or a tsunami. Belén Benito comments that in Central America there is a project consisting of placing sensors on the faults that monitor their movement, so that if a rupture occurs, the sensor captures it and sends a warning signal. Since the electromagnetic signal travels at the speed of light (300,000 km/s) and the seismic wave is much slower (about 7 km/s), the warning can give people a few vital seconds to protect themselves and put on safe, in addition to facilitating quick orders to stop trains and vehicles, to schedule the shutdown of nuclear power plants, etc.
In the project KUK Ahpán participates institutions from Honduras, Guatemala, Nicaragua, Dominican Republic and Norway and Spain.
I invite you to listen to María Belén Benito, University Professor in the area of Mechanics of Continuous Media and Theory of Structures of ETSI Topography, Geodesy and Cartography from the Polytechnic University of Madrid (UPM).
Project KUK AHAPAN