The Seismicity of Portugal and Its Adjacent Atlantic Region from 1300 to 2014: Maximum Observed Intensity (MOI) Map

Abstract

In this study, we considered earthquakes with a maximum observed intensity (MOI) I o ≥ V that occurred throughout the Portuguese mainland and its adjacent Atlantic region to produce the map of maximum intensities of Portugal. This map is based on a wide variety of historical and recent sources, including 175 earthquakes, over the period of 1300-2014. This MOI map allows the regions of high, medium, and low levels of seismic hazard to be highlighted. The entirety of Portugal has been affected by major seismic events, some of which have caused serious damage. In addition, offshore earthquakes have had significant impacts on the coastal cities located in the central and southern regions of the country. Because the southern region of mainland Portugal is more active than the northern region, the largest concentrations of events with I o ≥ VI are in the southern region, especially on the mainland near the city of Évora, in the Lisbon region, in the Lower Tagus Valley region, and along the Algarve coast, especially in the southwest region in Cape of São Vicente and the Gorringe Bank.

The Voice of Skogula in ‘Beasts Royal’ and a Story of the Tagus Estuary (Lisbon, Portugal) as Seen through a Whale’s-Eye View

“…In this region, several seismic events are documented over the centuries; around 175 earthquakes are documented for Portugal mainland for a period ranging from 1300 to 2014 (Ferrão et al 2016). Some of them-namely the 1344, 1356, 1531 and the 1755 earthquakes-are acknowledged as some of the largest earthquakes known and with dramatic consequences in different localities in Portugal.…”

“…Some of them-namely the 1344, 1356, 1531 and the 1755 earthquakes-are acknowledged as some of the largest earthquakes known and with dramatic consequences in different localities in Portugal. The 1531 earthquake is considered to have been very devastating-one out of three major earthquakes felt in Portugal during the 16th century: destruction of churches and about 1500 buildings in Lisbon 16 ; the agitation of the Tagus river, overtaking the margins, presenting a high seismic activity and being followed by aftershocks (Ferrão et al 2016). These happenings were so extraordinary and had such a huge impact on peoples' life that they were very well documented particularly the 1755 earthquake (Lima 2007;Lisboa 2007;Ferrão et al 2016).…”

“…The 1531 earthquake is considered to have been very devastating-one out of three major earthquakes felt in Portugal during the 16th century: destruction of churches and about 1500 buildings in Lisbon 16 ; the agitation of the Tagus river, overtaking the margins, presenting a high seismic activity and being followed by aftershocks (Ferrão et al 2016). These happenings were so extraordinary and had such a huge impact on peoples' life that they were very well documented particularly the 1755 earthquake (Lima 2007;Lisboa 2007;Ferrão et al 2016). And the earthquakes, as other natural manifestations, are to be seen through coeval narratives and accounts, yet also through multiple later publications and visual representations; they echo across time, feeding peoples' imagination and provoking different reactions (Lisboa 2007).…”

A importância da sismologia – breve evolução histórica da ciência, alguns grandes sismos e os seus impactes

“…Também Portugal continental, tem sido, ao longo da sua história, assolado por vários sismos devastadores (e.g. Custódio et al, 2015;Ferrão et al, 2016;Vilanova e Fonseca, 2007). Miranda, 1931).…”

Revisión y ampliación del catálogo sísmico del noroeste de la Península Ibérica previo a 1755 y sus implicaciones en la actividad intraplaca

“…cual puede obtenerse, entre otros medios, mediante el estudio de sus narraciones en documentos históricos (p. ej. Mallet, 1862;Martínez Solares & Mezcua, 2002;Galadini et al, 2006;Guidoboni & Ebel, 2009;Ces Fernández, 2015;Ferrão et al, 2016;González, 2017;Udías, 2017). Esta información de los efectos y daños, junto con la manera en que la población sintió el terremoto, se han utilizado en muchos casos para hacer estimaciones de parámetros del sismo como la fecha, la localización, la profundidad focal, la intensidad y la falla sismogénica.…”