Bulletin of the Seismological Society of America; December 2005; v. 95; no. 6;
p. 2539-2542; DOI: 10.1785/0120050092
© 2005 Seismological Society of America
Reply to "Comment on Lisbon 1755: A Case of Triggered Onshore Rupture? by Susana P. Vilanova, Catarina F. Nunes, and Joao F. B. D. Fonseca," by L. Matias, A. Ribeiro, M. A. Baptista, N. Zitellini, J. Cabral, P. Terrinha, P. Teves-Costa, and J. M. Miranda
Joao F. B. D. Fonseca1 and
Susana P. Vilanova1
1 Division of Earthquake Engineering
and Seismology
ICIST, Instituto Superior Tecnico
Av. Rovisco Pais, 1
1049-001 Lisboa, Portugal
jfonseca@ist.utl.pt
| The first 300 words of the full text of this article appear below. |
In Vilanova et al. (2003),
referred to in the sequence as "the article," we suggested that
several observations pertaining to the historical accounts of the 1755 Lisbon
earthquake are better explained assuming the occurrence of a triggered onshore
rupture near Lisbon, a few minutes after the main earthquake. Such observations
include the distribution of intensities and the high values in and around
Lisbon, the occurrence of an early tsunami-like wave inside the Tagus lagoon
prior to the arrival of the external tsunami, a report of ground deformation
near Lisbon, cartographic evidence of changes in the course of the Tagus river,
and the distribution of destructive aftershocks. The proposed location of the
triggered rupture is the well-established seismogenic Lower Tagus Valley
(LTV) fault
(Cabral, 1995). There is
reasonable consensus that the Lisbon earthquake was composed of three shocks in
quick succession (Reid, 1914).
The main innovation introduced in the article is the thesis that the location of
one of the subevents was close to Lisbon, at a significant distance from the
first shock. The distance between the classical Gorringe Bank epicenter
(Machado, 1966) and the
LTV fault is about 350 km, but this value can be significantly
reduced by taking into account the finite length of the offshore rupture or by
adopting a source closer to the coast as proposed in recent literature
(Zitellini et al., 1999).
In view of the progress in the understanding of fault interaction through
dynamic or static stress changes, we believe that our hypothesis is plausible,
besides it is effective as a way of explaining the observations.
L. Matias and colleagues, next referred to as "the comment,"
claim that our conclusion is speculative and unsubstantiated, arguing that each
anomalous observation reported in the article . . . [Full Text of this Article]
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Macroseismic Evidence
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Ground Deformation and Changes in the Tagus River
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Tsunami Travel Times
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Seismic Recurrence
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Implications for Seismic Hazard Assessment
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Related articles in Bulletin of the Seismological Society of America:
- Lisbon 1755: A Case of Triggered Onshore Rupture?
- Susana P. Vilanova, Catarina F. Nunes, and Joao F. B. D. Fonseca
Bulletin of the Seismological Society of America 2003 93: 2056-2068.
[Abstract]
[Full Text]
Copyright © 2005 by the Seismological Society of America.