Gravity analysis offshore the Canary Islands from a systematic survey

Abstract

As part of a systematic mapping program of the Hydrographic and Oceanographic Research Plan for the Spanish Exclusive Economic Zone (EEZ), gravity surveys were carried out offshore the Canary Islands. Using the gravity data collected during cruises between 1998 and 2000 aboard the RV Hesperides and satellite and land data, we construct free air and Bouguer anomaly maps and discuss the geodynamic implications.Using maps of Bouguer anomaly, free air anomaly, vertical derivative, long wavelength Bouguer anomaly and short wavelength anomaly, a detailed description of the gravity characteristics of the archipelago is presented, describing gravity anomalies from a geologic point of view. The character of the crust throughout the studied area has been defined, as well as high gradient zones that limit crustal blocks of different density. High gradient zones have been mapped for the first time and interpreted as fracture zones, taking into account geophysical and geological information. Gravity highs and lows have been studied and related to crustal, mantle and volcanic effects.

Gravity modeling of the Muertos Trough and tectonic implications (north-eastern Caribbean)

“…The offshore gravity data was linked to on-land absolute-gravity stations and integrated in a geo-referenced database with both onshore data from the Dominican Republic and satellitederived data used to extend longitudinally the gravity model . The gravity data were processed using common corrections including the seabottom terrain correction (Carbó et al 2003). Additional data to constrain the gravity models were taken from a deep seismic sounding profile also recorded during the same cruise and oriented N-S on the same track line as the gravity model (L8 in Fig.…”

S-wave envelope broadening characteristics of microearthquakes in the Canary Islands

“…In recent decades, together with local geophysical surveys, many regional marine geophysical studies have been conducted in the archipelago using seismic, gravity and magnetic data (e.g., Dañobeitia et al 1994;Ranero et al 1995;Socías and Mézcua 1996;Canales and Dañobeitia 1998;Carbó et al 2003). Canas et al (1995) and Canas et al (1998) magnitudes ranging between 2.0 and 4.1 and having hypocentral distances less than about 600 km and focal depths less than 80 km were analyzed.…”

New gravity map of the western Galicia margin: The Spanish exclusive economic zone project

“…Bouguer anomalies and sea bottom correc tion were calculated using a digital elevation model (DEM) with a 2-km grid size following the procedure of Carbo et al [2004].…”