In this last year, in Portugal and in the world, much of the attention, both from the political powers and from society in general, has been focused on the pandemic, on its fight and on its various consequences.
Our planet, however, is immune to the concerns of human civilization and continues... it continues to walk in its orbit around the Sun, continues with its internal and external geodynamics, ignoring that one of the species that inhabit it is passing through one of the greatest tests of their collective resilience in the modern era.
This could lead us to reflections on the importance and impact of human beings for the Earth, but that is not the topic of today… today we are going to talk about earthquakes.
Returning to the geodynamics of our planet, they are responsible for earthquakes occurring every day, most of which are not felt by the populations, nor do they cause any kind of damage, but are registered by the seismic stations existing in different places on Earth.
However, until about two centuries ago, it was only known of the existence of telluric events that were felt, since, until then, there was no equipment capable of making the instrumental recording of the seismic vibrations that propagate through the different layers of the Earth and that shake the crust.
This does not imply that there were no earthquakes, some of which, as today, devastating and destroying cities, towns or places, with fatalities and triggers of other equally devastating events, such as tsunamis, landslides and volcanic eruptions.
One of the most studied earthquakes worldwide and which was the forerunner of the scientific study of this type of phenomenon was the event that occurred on November 1, 1755, which destroyed it, together with the tsunami that triggered it and the fires that followed , one of the most important and cosmopolitan capitals of the time, Lisbon.
This earthquake caused a stir of conscience and helped, and potentiated, the paradigm shift of how to view these types of natural events.
In recent weeks, the news has reported several seismic events with high magnitude all over the globe, that is, with high energy released when the disruption caused the formation of the various seismic waves.
Portugal, due to its complex geodynamic location, both continental and insular territory, is the scene of several geological risks, especially seismic events.
Considering only the 4th century and seismic events that have caused significant damage, our country was shaken XNUMX times, causing fatalities and considerable damage. Two telluric events affected mainland Portugal and the other two caused victims in the Azores archipelago.
Even before the end of the first decade of the century. In the 23th century, the Ribatejo areas of Benavente, Samora Correia and Santo Estêvão were practically all destroyed due to the earthquake that occurred on April 1909, 1. devastated Terceira island in the Azores, on January 1980, XNUMX, had the highest number of fatalities.
Did, last February 28, 52 years since the last major earthquake which affected mainland Portugal. This event had a significant impact, both in terms of bringing to debate the seismic risk in Portugal and the need to have a comprehensive seismic network in the country, as well as in society.
The earthquake that had happened just before the end of the first decade of the century. XX was already practically erased from the collective memory, due to the time that had elapsed and the pandemic that, however, had emerged and affected the country in 1918.
For the population of the second half of the century. XX, the 1969 earthquake was an unavoidable milestone. The 1969 earthquake, despite having been the event with the highest magnitude to shake Portugal in the century. XX, due to its location, fortunately, had a relatively low impact with respect to victims and damages.
However, the fact that this geological event has meaning throughout the national territory significantly marked an entire generation that experienced it. If it is true that, in 1969, the country was not prepared to face a seismic event, is it now?
Although it is not yet possible to make a seismic forecast, that is, scientists are still unable to predict where, when and with what magnitude the next earthquake will occur, it is certain that with each passing day we are getting closer to the next big earthquake.
This brings us to the question: "Are we prepared for the next big earthquake?"
This question, which may seem simple, encompasses an enormous panoply of issues and actors. The first would be related to the “next great earthquake”, which takes us to “Where? When? Like?".
As already mentioned, these are questions to which we still do not have the capacity to answer so that an alert can be made to the population. We know that there are zones that, due to their geological environments, the type of faults and the acting geodynamic forces, are more likely to generate a new rupture in the earth's crust and, consequently, a new earthquake. However, “what is the extent of such a break? “when will this break take place?”. This is not yet possible to predict.
Thus, from the question we had initially asked, namely, “Are we prepared for the next big earthquake?”, we are left with only the first two words.
When we talk about “We are”, it is necessary to define who “We are”. In this case, “Estamos” encompasses the entire society, either as a whole or individually.
We, each of us as a person, citizens, are our first aid in the event of a disaster, we are our “Civil Protection”, and we must be informed and prepared for what may happen.
This leads us to a new question: “How prepared?”. We can only be prepared if we are properly and correctly informed, knowing how to act, whether before the event happens or during and after the catastrophe.
Only in this way do we achieve personal resilience, which culminates in collective resilience. This does not cause the competent authorities and government to resign from their responsibilities, quite the contrary. Having an informed, active and resilient society in the face of a certain danger leads to greater responsibility and accountability from the competent authorities, which, consequently, implies a better and greater preparation and programming of these entities.
Author: Ana Gomes, graduated in Geology from the Faculty of Science and Technology of the University of Coimbra, Master in Volcanology and Geological Hazards and Ph.D. in Geology (specialty in Vulcanology) from the University of Azores.
Since the conclusion of her degree and until the end of 2013, she was a researcher at the Center for Volcanology and Geological Risks at the University of the Azores, where she was involved in seismovolcanic monitoring, science dissemination and was part of several national, regional and European projects . She is the author of several scientific articles and has participated in several scientific meetings over the years.
Currently, she is a researcher at the Earth and Space Research Center of the University of Coimbra, where she develops research in the field of seismic data analysis from the COI seismic station of the UC Geophysical and Astronomical Observatory and develops science dissemination actions.
She is co-coordinator of the “Associated Schools” project of the Department of Earth Sciences at UC.
Comments