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The marine gravity field derived from satellite altimetry is generally biased in coastal areas by signals back‐scattered from the adjacent land. As a result, the derived gravity anomalies are generally unreliable for geophysical and geological interpretations of near‐shore environments. We compared two different altimetry models with sea‐bottom gravity measurements acquired along the Italian coast to quantify the errors generated by reflections from onshore areas and verify the quality of the geologic models inferred from gravity data. We focused on the Gulf of Manfredonia, in the SE sector of the Adriatic Sea, where (a) two different sea‐bottom gravity surveys have been conducted over the years, (b) the bathymetry is mainly flat, and (c) seismic data has revealed a prominent carbonate ridge covered by hundreds of meters of Oligocene‐Quaternary sediments. Gravity field derivatives have been used to enhance both deep geological contacts and coastal noise. The analyses point to a ringing noise that degrades the altimeter signals up to 17 km from the coast. Differences between observations and gravity calculated from a geological model and constrained by seismic data show that all the data sets investigated register approximately the same interference patterns associated with the Gondola Fault Zone. This study shows the potential for integrating gravity anomalies from satellite altimetry with high‐resolution near‐shore data, such as that provided by sea‐bottom gravity network available around the Italian coasts. Future applications will use this technique to improve the analysis of the connections between marine and inland geology in transitional areas. Plain Language Summary: We present a comparative analysis between two types of gravity data used in geophysical studies: satellite altimeter‐derived gravity and sea‐bottom gravity. It is generally accepted that the quality of satellite altimetry data in the vicinity of the coast is impaired by signals reflected from nearby land. We show how this may affect the interpretation of gravity anomalies and how it could be solved by integrating altimetry‐derived gravity data with high‐resolution marine gravity networks in the proximity of coasts. We chose as a test area the Gulf of Manfredonia on the South Adriatic coast of Italy, which hosts a major tectonic feature, namely, the Gondola Fault Zone. The fault zone is not clearly expressed at the seafloor, which is generally flat, but it dislocates carbonate rocks located hundreds of meters below the sediments. In so doing, it creates lateral density contrasts that are detectable in the gravity data. Key Points: Comparison between sea‐bottom and satellite altimeter‐derived gravity allowed to estimate the noise effects in altimeter data, near‐shoreThe high‐resolution sea‐bottom gravity available along the Italian coasts detects effects of sources not seen by satellite altimeter dataCombined analysis of satellite altimeter and sea‐bottom gravity gives a complete view on the offshore continuation of near‐shore structures [ABSTRACT FROM AUTHOR]

The analysis of swath bathymetric data and high-resolution seismic profiles (CHIRP), combined with information from the literature, allowed the creation of an updated map of the topography of the seabed in the western part of the Sicilian Channel. This area includes the entire Adventure Plateau, the Pantelleria Graben, and the Capo Granitola- Sciacca offshore sector between the Sicilian coast, the Graham and the Terrible banks. Positive and negative bedforms (sedimentary banks, volcanoes and mud volcanoes, pockmarks) and some erosional features were recognised and analysed in the study area. The Capo Granitola-Sciacca offshore sector is a continental shelf characterised by the presence of various sand bodies that are locally cemented and interpreted as sand ridges, dunes and remnants of dune strands or barrier lagoon systems eroded by the action of bottom currents. These bodies were probably deposited during the post-LGM sea level rise, occurred from ca. 18 kyr B.P. and 6 kyr B.P. (transgressive deposits) and during the glacial phase (lowstand deposits) occurred about 20 kyr B.P., when sea level was ca. 120-130 m lower than today. In this area there are also several volcanic edifices, mud volcanoes and numerous pockmarks due to the presence of gas. The distribution of these bodies is controlled by the faults associated with the NNE-oriented active lithospheric structure called Capo Granitola-Sciacca Fault Zone, which crosses the entire western part of the Sicilian Channel. The northern margin of the rift-related Pantelleria Graben is punctuated by NW-oriented pockmarks, probably controlled by the faults bounding tectonic depression, where several scars and a broad landslide have been this also mapped. In addition, canyons were noted along the southern margin of the Adventure Plateau. [ABSTRACT FROM AUTHOR]

Two ERT (Electrical Resistivity Tomography) profiles were conducted at the eastern head of Lago Fagnano within the main deformation zone of the Magallanes-Fagnano Transform fault system (MFS) which represents the onland boundary between the South America and Scotia plates. Results from the inversion models have provided new evidence of the presence and location, at shallow depths, of some strands of the MFS. Tomographic models showed significant resistivity contrasts across the inferred fault zones in the subsurface. The combination of ERT, geomorphic and outcrop structural data allowed us to interpret the stepped, southward subsidence of Tertiary and Quaternary units within the studied area. The Holocene development and evolution of a shallow deltaic basin at the mouth of Río Turbio, the eastern tributary of Lago Fagnano, was also interpreted from electrical imaging. [ABSTRACT FROM AUTHOR]