Bulletin of the Seismological Society of America; December 2006; v. 96; no. 6;
p. 2040-2049; DOI: 10.1785/0120050139
© 2006 Seismological Society of America
Probabilistic Seismic-Hazard Assessment of the Canary Islands
Luis I. González de Vallejo1,
Julián García-Mayordomo2 and
Juan M. Insua1
1 Department of Geodynamics
Faculty
of Geology
Complutense University of Madrid
Ciudad Universitaria 28040
Madrid,
Spain
vallejo{at}geo.ucm.es
insuarev{at}geo.ucm.es
(L.L.G.V.,
J.M.I.)
2 Geotechnical Laboratory
Center for
Studies and Experimentation on Public Works (CEDEX)
28014 Madrid,
Spain
julian.g.mayordomo{at}cedex.es
(J.G.-M.)
This article presents the first probabilistic seismic hazard assessment of
the Canary Islands. The Canary Islands form a volcanic archipelago located on
the
passive margin of the African plate, 100 km off West Africa. Active volcanism
has
taken place on the islands in historical times, commonly together with the
occurrence
of volcanic-related seismic sequences, some of them felt as high as
IMSK = X. In
1989 a notorious seismic sequence (mbLg 5.2) took place
along a submarine fault
located between the islands of Gran Canaria and Tenerife, clearly representing
the
occurrence of tectonic seismicity in the archipelago as well. In this article we
review
the geology and tectonics of the islands as well as recent paleoseismological
findings
on south Tenerife. We also revise, complete, and decluster the historical and
instrumental
seismic catalog of the islands. Seismic-hazard analysis is then performed
following the standard
Cornell (1968) method, defining
three seismogenic sources
and selecting an appropriate ground-motion attenuation relationship from
Hawaiian
data. Two hazard maps of the archipelago have been developed for return periods
of
475 and 950 yr, as well as hazard curves for the capital cities. Calculated peak
ground
acceleration values at Santa Cruz de Tenerife and Las Palmas de Gran Canaria are
0.06 and 0.08g, and 0.05 and 0.07g, for the 475- and 950-yr
return periods, respectively.
Finally, we analyze the impact on hazard resulting from uncertainties associated
with the seismogenic source model and the ground-motion attenuation
relationship.
Copyright © 2009 by Seismological Society of America