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 I MSK ‫ס‬ X. In 1989 a notorious seismic sequence (m bLg 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.

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On Tenerife, one of the Canary Islands, a series of clastic dikes and tubular vents is attributed to liquefaction of sediments during a high-intensity paleoeatihquake. Geotechnical, geological, tectonic, and mineralogical investigations have been can-ied out to identifY the soil composition and structure, as well as the geological processes operating in the area. Geochronological analysis has indicated an age ranging from 10,081 ±933 to 3490±473 years BP for the liquefaction features. The area in which these liquefaction features are found has undergone tectonic uplift and is affected by two faults. One of these faults was responsible for displacing the Holocene matet-ials. The paleoeatihquake responsible for this liquefaction has been analysed in terms of its peak ground acceleration (pga) and magnitude by back calculation analysis based on the cyclic stress and Ishihara methods. A range of 0.22-0.35g was obtained for the pga, with the value of 0.30g being selected as most representative. From this, an earthquake-modified Mercalli intensity of IMM = IX was estimated for the liquefaction site. The magnitude-bound method and energy-based approaches were used to determine the magnitude of the paleoearthquake, providing a moment magnitude Min the range of 6.4-7.2; M=6.8 is taken as the representative figure.