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Publication
Improving the seismic hazard evaluation of the Lisbon and Lower Tagus Valley area
Advisor(s)
Abstract(s)
The Lisbon and surrounding area of the Lower Tagus Valley has experienced in the past the effects of
several moderate sized earthquakes that caused significant damage and destruction. They have been
attributed to local sources, though in some cases the source remains to be located. The lack of outcrops in
the flat lying Quaternary terrains, the low slip-rates of the area in connection with sedimentation and
erosion rates that erase surface ruptures are among the causes of a poor association between faults and
seismicty, which has opened way to geophysical studies. Seismic, potential-field and seismicity data have
been recently used to improve the seismic hazard evaluation of the area. In this work we complement these
studies with DTM and PSInSAR data with the purpose of obtaining an accurate evaluation of the seismic
hazard of the study area. The correlation of improved epicentre locations with major fault zones located
from the above mentioned data shows that we have progressed in the understanding of the earthquake
sources in the region. Some structures show no apparent relationship with present-day seismicity but some
are known to be active into the Quaternary. Further geophysical and geological studies are required to
understand the causes.
Description
Keywords
Risco sísmico Avaliação de riscos Vale do Rio Tejo (Portugal) Lisboa (Portugal)
Citation
Carvalho, João P. F.; Pinto, Carlos C.; Costa, M.; Heleno, S.; Silva, M.; Rabeh, Taha; Cooksley, G.; Carrilho, F. - Improving the seismic hazard evaluation of the Lisbon and Lower Tagus Valley area. Comunicação apresentada no Near Surface 2008 - 14th European Meeting of Environmental and Engineering Geophysics, 15-17 September 2008.