In search of the seismogenic fault of the March 23rd 2018 earthquake (Mw 3.7) near Brindisi (Puglia, Southern Italy)

T The portion of the southern Adriatic Sea, adjacent to the Murge area (Apulian Foreland, Southern Italy), is considered mainly aseismic. The recent March 23rd 2018 earthquake (Mw 3.7), occurred near Brindisi (Puglia Region), giving us occasion to reconsider data coming from different sources (instrumentally-recorded, historically-documented and palaeoseismologically-interpreted earthquakes), that suggest some moderate seismic shocks in this portion of the Adriatic Sea. The present study, based on the re-interpretation of public domain seismic profiles and exploration well logs available in the ViDEPI Project, has been focused on the recognition of faults with Quaternary activity in the epicentral area. A S-dipping fault, with a main dip-slip component of movement, is suggested to be the seismogenic source. Its geometry is consistent with the fault plane solution and the depth of the hypocenter calculated by the INGV (Istituto Nazionale di Geofisica e Vulcanologia).  </div

The Status of \u3ci\u3ePosidonia oceanica\u3c/i\u3e at Tremiti Islands Marine Protected Area (Adriatic Sea)

Simple Summary: The seagrass Posidonia oceanica is the most important marine phanerogam of the Mediterranean Sea due to its meadows’ complexity, persistence, and extension. These habitats provide a suite of ecosystem goods and services, being of primary importance in marine conservation. Despite their central role in the coastal ecology, P. oceanica meadows are undergoing overall deterioration and fragmentation in the basin mostly due to anthropogenic impacts at local to global scales. In the last decades, several management measures have been proposed aiming to improve the meadow health conditions, while the periodic monitoring of P. oceanica meadows allows for verifying their effectiveness. Here, we report the results of the monitoring of P. oceanica at Tremiti Islands Marine Protected Area (Adriatic Sea, Italy) carried out in 2003, 2015, and 2020. A general worsening was observed, particularly enhanced by direct anthropogenic impacts mostly related to anchoring practices, as well as by a certain level of sedimentation possibly deriving from coastal development. However, the identification of these impacts and the correct management of human activities to mitigate them produced positive results in a relatively short time span. Abstract: Posidonia oceanica meadows are Mediterranean coastal habitats of great conservation importance. This study is focused on a meadow located at Tremiti Islands Marine Protected Area (Adriatic Sea, Italy), which was monitored in 2003, 2015, and 2020 to evaluate its health state over time in relation to coastal human activities, which have been highly affecting this MPA for the last 20 years. To assess any change in the physiognomy of the meadow, rhizome density, percentage coverage, and lower limit progressions and/or regression over time were evaluated by scuba diving, while the distribution and extension of the meadow were assessed through habitat mapping using a side-scan sonar. Moreover, phenological and lepidochronological analyses were performed on the collected rhizomes to assess the leaf area index (LAI, m2m2) and the rhizome age (lepidochronological years). Our study showed a general deterioration of P. oceanica meadow from 2003 to 2020, with a significant reduction of its absolute and relative rhizome density and LAI at almost all sampling stations, absence of renovation of the meadow, and lower limit regression and overall worsening of the main conservation status indicators. However, appropriate management actions, such as the establishment of mooring buoy fields, supported the improvement of the P. oceanica status at the local scale with a significant increase in density and LAI and the presence of active stolonization processes, suggesting that mitigation actions can play a crucial role in the conservation of this habitat. On the contrary, local anthropogenic impacts, especially anchoring and coastal development, markedly affect the resilience of P. oceanica meadows to global stressors, such as climate change

Experimental determination of the friction coefficient for estimating sea storm induced megaboulders movements.

The presence of numerous boulders on rocky coast is linked to phenomena of detachment and deposit due to the occur-rence of sea storms. Currently, several hydrodynamic equations are known in the bibliography to estimate the wave height able to dis-place them, applying geometric parameters and hydrodynamic coefficients. A new methodological approach intends to consider the minimum energy required for the linear movement of a boulder along a weakly sloping rocky surface as a function of the friction coefficient

Rhodolith Beds Heterogeneity along the Apulian Continental Shelf (Mediterranean Sea)

Rhodolith beds represent a key habitat worldwide, from tropical to polar ecosystems. Despite this habitat is considered a hotspot of biodiversity, providing a suite of ecosystem goods and services, still scarce quantitative information is available thus far about rhodolith beds occurrence and ecological role, especially in the Mediterranean Sea. This study reports the composition and patterns of distribution of rhodolith assemblages found in four study areas along ca. 860 km of coast in the Central Mediterranean Sea. These rhodolith beds were studied for the first time and significant differences at all spatial scales have been highlighted, documenting the high variability of this habitat. Rhodolith species composition, morphology and distribution have been discussed considering the potential role of environmental factors in driving these patterns. The need for improving their protection is discussed to complement present conservation and management initiatives, particularly in the frame of the EU Marine Strategy Framework Directive

Basic data visualization in vintage seismic profiles: indications for the interpretation of the ViDEPI database (offshore Puglia, southern Italy)

The Visibility of Petroleum Exploration Data in Italy (ViDEPI) project represents a freely accessible valuable resource for the research community. However, seismic profiles available from this project present several limitations because information such as the basic shape of the seismic wavelets and the seismic polarity are not available. In this study, using subsurface (i.e., 2D seismic profiles) data related to the Marine Zones B, D and F (offshore Puglia) a review of the basic pulse shape and polarity of seismic wavelets, as well as the shape and polarity of principal reflectors has been addressed. Moreover, borehole data (i.e., lithology and sonic logs) have been used to identify abrupt average velocity changes linked to different lithostratigraphic successions recorded as dominant high-amplitude reflectors

Energy balance to transport massive boulders on rocky coast area.

Along the Italian rocky coasts it’s possible to recognize deposits made up mainly of boulders, isolated or accumulated in fields and berms, at elevations and distances variables from the shoreline. These singular geomorphological evidences are connected to extreme marine events such as storm surge that are frequents on rocky coast of Apulia region. During a storm event, a high energy flux is produced, to allow the transport of boulders along the coast in different scenarios, like subaerial, submerged and joint bounded. Evaluating energy flux needed to move boulders respect the energy flux deriving from a storm, it’s possible quantify the number of waves needed to move the boulders. Here an example of boulders transported on rocky coast is given by Torre dell’Ovo area, 45 kilometers south-east of Taranto

The northern fault of the on shore-off shore Monte Giove re lief in the southern Adriatic Sea, Italy: implications for tectonic reactivation in the Apulian Foreland

We provide improved constraints on the timing, geometry and kinematics of the fault that may control the northern sub-merged morpho-structural relief termed Monte Giove, offshore from the town of Polignano a Mare. We have integrated onshore and offshore data, and interpreted seismic profiles from the ViDEPI project pertaining to the offshore Adriatic Sea of the Murge area, and made field observations north of Polignano a Mare. The fault has been surveyed onshore and mainly offshore along a distance of ~25 km. Generally striking E–W, it dips at high angle to the NNE in the west and to the N in the east. Active since at least the Cretaceous, this was reactivated after the Early Pleistocene with dextral oblique-slip kinematics. It borders the Monte Giove submerged relief/structural high, and continues eastwards in the Adriatic Sea into the Northern Deformation Zone/"Murge basse” graben, that in turn affected the onshore Murge area. Fault reactivation may have been related to a strain field in the outer part of the gentle buckle fold that involved the continental lithosphere of the Apulian Foreland (i.e., the areas of the Murge onshore and the Adriatic Sea offshore) since the Middle Pleistocene, as roll-back of the subducting lithosphere halted. Besides its tectonic reactivation, this fault has important implications as regards local seismic hazard, as well as the morphology influencing the present-day bioherm

The Status of <i>Posidonia oceanica</i> at Tremiti Islands Marine Protected Area (Adriatic Sea)

Posidonia oceanica meadows are Mediterranean coastal habitats of great conservation importance. This study is focused on a meadow located at Tremiti Islands Marine Protected Area (Adriatic Sea, Italy), which was monitored in 2003, 2015, and 2020 to evaluate its health state over time in relation to coastal human activities, which have been highly affecting this MPA for the last 20 years. To assess any change in the physiognomy of the meadow, rhizome density, percentage coverage, and lower limit progressions and/or regression over time were evaluated by scuba diving, while the distribution and extension of the meadow were assessed through habitat mapping using a side-scan sonar. Moreover, phenological and lepidochronological analyses were performed on the collected rhizomes to assess the leaf area index (LAI, m2m−2) and the rhizome age (lepidochronological years). Our study showed a general deterioration of P. oceanica meadow from 2003 to 2020, with a significant reduction of its absolute and relative rhizome density and LAI at almost all sampling stations, absence of renovation of the meadow, and lower limit regression and overall worsening of the main conservation status indicators. However, appropriate management actions, such as the establishment of mooring buoy fields, supported the improvement of the P. oceanica status at the local scale with a significant increase in density and LAI and the presence of active stolonization processes, suggesting that mitigation actions can play a crucial role in the conservation of this habitat. On the contrary, local anthropogenic impacts, especially anchoring and coastal development, markedly affect the resilience of P. oceanica meadows to global stressors, such as climate change

The northern fault of the onshore-offshore Monte Giove relief in the southern Adriatic Sea, Italy: implications for tectonic reactivation in the Apulian Foreland

We provide improved constraints on the timing, geometry and kinematics of the fault that may control the northern submerged morpho-structural relief termed Monte Giove, offshore from the town of Polignano a Mare. We have integrated onshore and offshore data, and interpreted seismic profiles from the ViDEPI project pertaining to the offshore Adriatic Sea of the Murge area, and made field observations north of Polignano a Mare. The fault has been surveyed onshore and mainly offshore along a distance of ~25 km. Generally striking E–W, it dips at high angle to the NNE in the west and to the N in the east. Active since at least the Cretaceous, this was reactivated after the Early Pleistocene with dextral oblique-slip kinematics. It borders the Monte Giove submerged relief/structural high, and continues eastwards in the Adriatic Sea into the Northern Deformation Zone/”Murge basse” graben, that in turn affected the onshore Murge area. Fault reactivation may have been related to a strain field in the outer part of the gentle buckle fold that involved the continental lithosphere of the Apulian Foreland (i.e., the areas of the Murge onshore and the Adriatic Sea offshore) since the Middle Pleistocene, as roll-back of the subducting lithosphere halted. Besides its tectonic reactivation, this fault has important implications as regards local seismic hazard, as well as the morphology influencing the present-day bioherm