A scientific collaboration between researchers from the Trofimuk Institute of Petroleum Geology and Geophysics of Novosibirsk in Russia, the Volcanological Institute of the Canary Islands (INVOLCAN) and the University of Granada reveals the secrets of the centre of the island of Tenerife through a New seismic tomography study using microseismicity located in the interior of the island

The results of this study have recently been published in the Journal of Geophysical Research, one of the most relevant international scientific journals in the field of geophysics edited by the American Geophysical Society (AGU). These results constitute an important tool to interpret the increase in seismicity in Tenerife and the emission of carbon dioxide by the Teide volcano, which INVOLCAN has detected since the end of 2016. This activity could be related to the slow ascent of a diapir, say a “bubble” of magma, located more than 10 km below Teide. Therefore, this new knowledge will be of great use for a better interpretation of the precursor signals of a possible eruptive process in Tenerife.

The results of this study are equally astonishing because it is the first time it has been possible to visualize and characterize a “warm heart” below the island. The tomography clearly shows that, in the crust below the caldera of Las Cañadas, the presence of small magmatic reservoirs located less than 5 km are possible. These reservoirs allow basaltic magmas to cool, changing their chemical composition towards more evolved magmas such as phonolitic magmas, a potentially explosive type of magma. These magmatic reservoirs can be the source of very explosive eruptions such as the one that occurred around 2000 years ago in Montaña Blanca and has been cataloged as a sub-Plinian eruption. At the same time, the study explains why the eruptions of Tenerife that occur outside the caldera of Las Cañadas, along the NE and NW ridges, have a more effusive character, not being able to stagnate enough time to evolve towards potentially more explosive magmas.

This seismic tomography study has been possible as a result of the start-up in 2016 of the Canarian Seismic Network managed by INVOLCAN and which currently has 19 broadband seismic stations that have allowed to lower the detection and location capacity of thousands of microearthquakes in Tenerife. These data, together with those previously recorded by the National Geographic Institute (IGN), have made it possible to use seismic tomography to investigate the interior of the island up to a depth of 20 km and, even more importantly, to determine the speed of S seismic waves, which are the most sensitive to the presence of hydrothermal fluids and magma.

Prior to this recent seismic tomography study, another international scientific collaboration led by the Universidad de Gradada in 2007 managed to obtain the first three-dimensional model of the island of Tenerife in 2012 (García-Yeguas et el., 2012; https://agupubs.onlinelibrary.wiley.com/…/2011JB008970). For the execution of this work of scientific collaboration, the oceanographic vessel R/V Hespérides that made 6459 shots registered by a network composed of 125 seismic stations. This active seismic experiment helped investigate the interior of the island up to a depth of 10 km and due to the nature of the artificial seismic source, it was only possible to obtain a velocity model of the P seismic waves.

The results of this new work of international scientific collaboration published in 2023 has been possible thanks to the VOLRISKMAC II projects (MAC2/3.5b/328), co-financed by the European Commission through the Territorial Cooperation Program INTERREG MAC 2014-2020, TFvolcano, funded by ITER and the Cabildo Insular de Tenerife, FEMALE (PID2019-106260GB-I00) and PROOF-FOREVER as well as the projects of the Russian Science Foundation (Grant No. 20-17-00075 and Project FWZZ-2022-0017).

Article reference:

  • Ivan Koulakov, Luca D’Auria, Janire Prudencio, Iván Cabrera-Pérez, José Barrancos, Germán D. Padilla, Nemesio M. Pérez, Jesús M. Ibáñez. Local earthquake seismic tomography reveals the link between crustal structure and volcanism in Tenerife (Canary Islands). Journal of Geophysical Research-Solid Earth, https://doi.org/10.1029/2022JB025798