Canary Islands
Flexure of the Canary Islands
![Tracks](/media/migration/faculty-of-engineering/tracks--tojpeg_1524478040320_x1.jpg)
A controlled-source seismic reflection and wide-angle refraction (OBS and landstations) experiment was conducted around the central Canary Islands (Fig.1). The results showed the oceanic basement to be flexed downwards beneath the volcanic loads, forming a moat infilled by 2-3 km of sediments (Fig.2). This flexure, which has been verified by gravity modelling, can be explained by a model in which Tenerife and adjacent islands have loaded a lithosphere with a long-term (> 106 yr) elastic thickness of approximately 20 km. No significant volume of volcanically underplated material was detected beneath the crust of Tenerife.
![Graph](/media/migration/faculty-of-engineering/65179699--tojpeg_1524395734728_x2.jpg)
![Progressive age loading](/media/migration/faculty-of-engineering/65179698--tojpeg_1523985737530_x2.jpg)
It has been much debated whether the Canary Islands form a time-progressive chain, as would be expected for a classic hotspot origin. Dating of samples from the islands themselves show much age-overlap. We therefore conducted a detailed analysis of the seismic stratigraphy of the sediments deposited in the moat around the islands. By comparing the patterns observed with forward-modelled flexure predictions (Fig.3) we showed progressive loading of the crust from east to west (see diagram below). Hence this work gives support to a hotspot origin for the island chain.
Publications
- "A seismic study of lithospheric flexure in the vicinity of Tenerife, Canary Islands" (1997) A.B. Watts, C. Peirce, J S Collier, R. Dalwood, J.P. Canales, T.J. Henstock. Earth. Planet. Sci. Lett., Vol.146, No.3-4, pp.431-447 A seismic study of lithospheric flexure (pdf)
- "Lithospheric response to volcanic loading by the Canary Islands" (2001) J S Collier, A.B. Watts. Geophys. J. Int., 147, 660-676 Lithospheric response to volcanic loading (pdf)
People
- Rupert Dalwood (PhD student)
- Tony Watts (Oxford)
- Chris Peirce (Durham)