Nivelación de alta precisión a lo largo de la costa entre La Marina y Torrevieja (Alicante) para controlar movimientos tectónicos verticales

Abstract

The low seismic activity of the Guardamar-Torrevieja zone can be associated with NW-SE dextral faults together with E-W reverse blind faults. To monitor the vertical displacement of those active faults, a high precision levelling profile along 30 km was set up and levelled in 1997. This profile went parallel to an ancient high precision levelling line included in the Spanish first order levelling network measured by the Instituto Geográfico Nacional (IGN) in two different campaign (1934 and 1976). In 2003, the 1997 line was relevelled; and 10 new bench marks were set up to increase the bench mark density and also to restore some of the 1997 ones that have been destroyed. The 1976-2003 RVM (recent vertical movements) indicate that the vertical movements are very small, nearly equal to the error bars. Only a 0.2 mm /year rise of the Guardamar city, and a 0.15 mm /year subsidence of the southern part of the profile (Punta Prima) respect to Torrevieja town can be mentioned. These movements could be respectively related to the Bajo Segura and the San Miguel de Salinas faults.