Scientists find evidence that structural damage to the Alhambra is due to seismic activity

The Granada Basin, home to the Alhambra, is located in one of the most seismically active zones in the Iberian Peninsula. Historical evidence shows that the last major earthquake occurred there in 1431. New evidence indicates, however, that the topographical features of the area surrounding the Alhambra reflect recent and recurrent, though moderate, seismic activity. The research is published this week in Journal of Quaternary Science.

The Alhambra, one of the most visited monuments in Europe and a world heritage site, was the focus of research carried out by scientists in Granada. They studied the cracks and other damage to the structure of the monument, small-scale faults affecting the substratum, topographic steps, and seismic focal mechanisms, which evidence seismic activity produced by normal faults nearby the Alhambra.

Although the structural damage displayed by the Alhambra is far from significant, the cracks were able to be related with underlying faults that are possibly seismically active. Some of the cracks showed a geometrical continuity with fault planes in the underlying conglomerates, while collapsed segments of a wall surrounding the Alhambra coincide with underlying faults that cut Quaternary soil levels. Thus the structural damage and topographical steps in the neighbourhood of the Alhambra are shown to be caused by repeated earthquakes over the last 800 ka.

Based on their observations of the Alhambra Formation and the surrounding geomorphological evidence, the researchers have described the seismic risk associated with the faults of the Alhambra and surrounding areas as moderate.

About the Journal

The Journal of Quaternary Science publishes original papers on any field of Quaternary research, and aims to promote a wider appreciation and deeper understanding of the earth’s history during the last two million years. Papers from a wide range of disciplines appear in JQS including, for example, Archaeology, Botany, Climatology, Geochemistry, Geochronology, Geology, Geomorphology, Geophysics, Glaciology, Limnology, Oceanography, Palaeoceanography, Palaeoclimatology, Palaeoecology, Palaeontology, Soil Science and Zoology.