Seismic attenuation structure of the lower crust upper mantle under El Hierro island (Spain)

The origin of the Canary Islands has been under debate for the last decades. The hotspot hypothesis as the origin of the islands was abandoned long ago, however, there are still theories that partially incorporate this idea. The scientific community widely accepts none of these models and the recent volcanic eruptions of El Hierro and La Palma once again question these theories. 

In order to confirm the structure and to explain the diversity of the eruptive processes observed in the Canarian archipelago, we return to El Hierro island to obtain a high-resolution seismic attenuation tomography, as it has proven to be more sensitive to the presence of magma as shown in Mt. Etna (Castro-melgar et al., 2021). Thus, we have analyzed the same database that García-Yeguas et al. (2014) used in the velocity tomography and we have obtained a new tomographic model of El Hierro island that confirms the existence of an intermediate chamber as observed in Tenerife and La Palma which could feed the 2011 eruption.

The lack of high attenuation anomalies in the central part of the island is already observed in the velocity tomography results obtained by García-Yeguas et al. (2014). In addition, Montesinos et al. (2005) identified high-density anomalies in the same zone, where Sainz-Maza et al. (2017) also observed high gravity values. These results could demonstrate the existence of a dense core in the center of the island related to the oldest volcanism of El Hierro and diverting the magma intrusions to the outer zone of the island as the 2011 Tagoro eruption.