Active surface faulting or landsliding in the Lower Tagus Valley (Portugal)? A solved controversy concerning the Vila Chã de Ourique site

Cabral, João; Marques, Fernando; Figueiredo, Paula; Matias, L.

doi:10.1007/s10950-010-9221-8

Cited by 8 publications

(8 citation statements)

References 29 publications

(28 reference statements)

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“…In order to obviate this problem, two research projects were submitted in 1998 for studying the seismic hazard in the Lower Tagus Valley (projects TAGUS, PI J. Fonseca, and SHELT, PI J. Cabral), which comprised a significant component of paleoseismological research. Paleoseismic results on the Lower Tagus fault system were published by Fonseca et al (2000), Vilanova (2003) and Vilanova and Fonseca (2004), and these were contested and interpreted as having landslide origin by Cabral and Marques (2001) and Cabral et al (2002Cabral et al ( , 2011a, while the palesoseismic research performed by the SHELT group yielded in- que muestra esquistos Cámbricos cabalgando sobre conglomerados aluviales de probable edad Piaccenciana (NW); b -Afloramiento de la falla de Manteigas-Vilariça-Bragança cerca del río Duero (Pocinho) que muestra el granito varisco (Oeste) en contacto por falla con depósitos de terraza de probable edad pleistocena superior (200 -100 ka) (Este).…”

Section: Present and Futures Perspectivesmentioning

confidence: 99%

“…and Ph.D. theses, have largely increased the knowledge on the active structures in the Portuguese mainland. Many examples may be given, such as for the Penacova-Régua-Verin fault (Baptista, 1998), the PortoCoimbra-Tomar fault zone (Dinis, 2004;Dinis et al, 2007;Gomes, 2008), the Lower Tagus Valley fault system (Vilanova, 2003;Vilanova and Fonseca, 2004;Cabral et al, , 2004Cabral et al, , 2011aBesana-Ostman et al, 2012;Carvalho et al, 2006Carvalho et al, , 2008Martins et al, 2009), the Vidigueira-Moura and Alqueva faults (Brum da Silveira, 2002;Brum da Silveira et al, 2009), or faults in the Algarve (southern Portugal) (Dias, 2001;Dias and Cabral, 2002a,b).…”

Section: Vertical Movements Of the Crustmentioning

confidence: 99%

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Neotectonics of mainland Portugal: state of the art and future perspectives

Cabral¹

2012

Journal of Iberian Geology

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This paper presents a synthesis of the neotectonic studies performed in mainland Portugal that address the "recent" (post Piacenzian, ~3 Ma) tectonic evolution of the Portuguese territory as part of the West Iberian continental margin, specifically in regard to regional seismic hazard evaluation. The interaction of the Iberian microplate with the Nubia plate is identified as the source for the regional neotectonic deformations, which occur at relatively low rates in spite of significant historical seismic activity. In this context of low strain rates expressed by the presence of slow slip rate active faults, it is important to acquire paleoseismic data on the major seismogenic structures to characterize the large earthquakes that they generated in the past, because average recurrence intervals are much longer than the time span covered by the regional historical and instrumental period.Keywords: Neotectonics, Seismotectonics, Active faults, Seismic Hazard, Portugal ResumenEste artículo presenta una síntesis sobre los trabajos de neotectónica que se han llevado a cabo en el Portugal continental como parte del margen continental Iberico occidental, que se centren en la evolución tectónica "reciente" (post Plasenciano, ~3 Ma), en especial aquellos que se centran en la evaluación del peligro sísmico regional. La interacción entre la microplaca Ibérica y la placa de Nubia se caracteriza por ser una fuente de deformaciones neotectónicas que ocurren a velocidades relativamente bajas a pesar de que la sismicidad histórica es significativa. En este contexto de tasas de deformación bajas, reflejadas por la presencia de fallas lentas, es importante adquirir datos paleosísmicos en las principales fallas sismogénicas para así caracterizar los terremotos catastróficos que hayan podido producir-se en dichas estructuras en el pasado. Esto es especialmente importante dado que los períodos de recurrencia de dichas fallas son mucho más largos que el periodo de tiempo cubierto por los datos sísmicos históricos o instrumentales.

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Section: Present and Futures Perspectivesmentioning

confidence: 99%

Section: Vertical Movements Of the Crustmentioning

confidence: 99%

Neotectonics of mainland Portugal: state of the art and future perspectives

Cabral¹

2012

Journal of Iberian Geology

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“…Geological and morphotectonic studies indicate Quaternary slip on the fault in the range of 0.05-0.06 mm/yr (Cabral et al 2004). The southern, hidden sector of the Azambuja fault extends to the meizoseismal area of the 1909 earthquake, making this fault a likely source for the seismic event (Cabral et al 2011).…”

Section: Seismotectonic Settingmentioning

confidence: 99%

“…Search for surface faulting evidence and paleoseismic data has been performed by several teams on the Lower Tagus fault system, though the results are still scarce and controversial (Fonseca et al 2000, Vilanova 2003, Vilanova and Fonseca 2004, Cabral and Marques 2001, Cabral et al 2011, Besana-Ostman et al 2012, Canora et al 2015. Based on detailed geomorphic studies, Besana-Ostman et al (2012) argue to have recognized a major active structure extending NNE-SSW for 85 km along the western bank of the Tagus River, which they call the "Lower Tagus Valley fault zone".…”

Section: Seismotectonic Settingmentioning

confidence: 99%

“…It is for this reason that even today the 1909 earthquake remains very significant, evidencing the seismic activity in the LTV and contributing in a very important way for the regional seismic hazard and risk assessment (Fonseca and Vilanova 2010). Recently, several studies have been performed to better understand its source mechanism, as well as the seismic attenuation processes in the western part of the Iberian Peninsula (Stich et al 2005, Cabral et al 2011, Teves-Costa and Batlló 2011.…”

Section: Introductionmentioning

confidence: 99%

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Los terremotos del Bajo Valle del Tajo (Portugal): Lisboa 26 de Enero de 1531 y Benavente 23 de Abril de 1909

2017

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Abstract. The Lower Tagus Valley (LTV) has been the source of several local earthquakes that affected the region of Lisbon, in the central part of Portugal. In spite of absence of strong earthquakes during the last 100 years, past events have produced large damage in this area. We present the state of the art concerning the last two major earthquakes, which occurred in 1531 and 1909. The effects of both events are described, based on coeval reports already interpreted by several authors. The source parameters determined by different authors are also presented. The characterization of the seismogenic potential of the LTV is very important to better estimate the seismic hazard and risk of the region of Lisbon and Tagus Valley.

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