Modern submarine canyon feeder-system and deep-sea fan growth in a tectonically active margin (northern Sicily)

Widely used sequence stratigraphic models predict that specific facies assemblages alternate in the stratigraphy of deep-sea fans, depending on the cyclic nature of sea-level variations. Our work tests this assumption through facies reconstruction of submarine fans that are growing in a small basin along the tectonically active Sicilian margin. Connected canyons have heads close to the coastline; they can be river connected or littoral cell-connected, the first receiving sediment from hyperpycnal flows, the latter intercepting shelf sediment dispersal pathways. Hyperpycnal flows directly discharge river-born sediment into the head of the river-connected canyon and originate a large turbidite fan. A drift formed by the longshore redistribution of sediment of a nearby delta introduces sediment to the head of the littoral cell-connected canyon, forming turbidity currents that flow within the canyon to reach the basin plain. However, since sediment failure and landslide processes are common in the slope part of the system, a mixed fan, consisting of both turbidites and mass-transport deposits, is formed. Disconnected canyons, with heads at the shelf edge far from the coastline, are fed by canyon head and levee-wedge failures, resulting in mass-transport or mixed fan deposition, the latter developing when the seafloor gradient or the lithology of the failed sediment allows turbidity current formation. Connected canyons form in areas with high uplift rates, where the shelf is narrow and steep and the shelf edge is at a relatively shallow depth. Disconnected canyons develop where there are lower uplift rates or subsidence, where the shelf is large and relatively gentle with a deeper shelf edge. It is deduced that the relative vertical movements of fault-bound blocks control whether canyons are connected to the coast at the present day. The role of tectonics in controlling the canyon feeding processes and the facies of submarine fan growth during highstand periods is therefore highlighted. A further view that arises from our paper is that in active margins, the slope portion of fan systems, through seafloor instability and variations in channel gradient, is a key factor in determining the final deep-sea fan facies, regardless of the distance between the coast and the canyon. The concomitant growth of turbidites, mass-transport deposits, and mixed fans demonstrates that models that predict changes in submarine fan facies on the basis of sea-level cycles do not necessarily apply to systems developed along tectonically active margins

Quaternary Evolution of Coastal Plain in Response to Sea-Level Changes: Example from South-East Sicily (Southern Italy)

During a cycle of sea-level variation, coastal environments develop in different position of the continental shelf following seaward and landward shift of the coastline. They vary widely in character, reflecting the wide range of process-regimes that are brought about during the different stages of sea-level variations. Within this scenario, the morphology of continental shelves, mainly resulting from the combined effect of tectonic activity and eustatism, plays an important role in controlling the features and the preservation of coastal environments. Coastal deposits formed along continental shelves in the past, during different stages of sea-level changes, consist of discontinuous and thin depositional bodies, thus their reconstruction can be best carried out through the interpretation of high-resolution seismic data. Such a research approach is adopted in the present study to investigate a portion of the continental shelf of the southernmost sector of SE Sicily, in the offshore of Marzamemi village (Syracuse). The interpretation of high-resolution "Sparker" profiles allowed us to reconstruct the evolution of alluvial and lagoonal environments, established on a substratum of Pliocene or more ancient marine deposits, with the detection of several seismic units and unconformity surfaces, which have been related to alternating sedimentation and erosional processes, depicting the sea-level change framework of glacial-interglacial phases, from the late Pleistocene onward

Resilient biotic response to long-term climate change in the Adriatic Sea

Preserving adaptive capacities of coastal ecosystems, which are currently facing the ongoing climate warming and a multitude of other anthropogenic impacts, requires an understanding of long-term biotic dynamics in the context of major environmental shifts prior to human disturbances. We quantified responses of nearshore mollusk assemblages to long-term climate and sea-level changes using 223 samples (similar to 71,300 specimens) retrieved from latest Quaternary sediment cores of the Adriatic coastal systems. These cores provide a rare chance to study coastal systems that existed during glacial lowstands. The fossil mollusk record indicates that nearshore assemblages of the penultimate interglacial (Late Pleistocene) shifted in their faunal composition during the subsequent ice age, and then reassembled again with the return of interglacial climate in the Holocene. These shifts point to a climate-driven habitat filtering modulated by dispersal processes. The resilient, rather than persistent or stochastic, response of the mollusk assemblages to long-term environmental changes over at least 125 thousand years highlights the historically unprecedented nature of the ongoing anthropogenic stressors (e.g., pollution, eutrophication, bottom trawling, and invasive species) that are currently shifting coastal regions into novel system states far outside the range of natural variability archived in the fossil record

How to make a 350-m-thick lowstand systems tract in 17,000 years : The Late Pleistocene Po River (Italy) lowstand wedge

Peer reviewedPublisher PD

The late Pleistocene Po River lowstand wedge in the Adriatic Sea : Controls on architecture variability and sediment partitioning

The authors dedicate this study to their colleague Giovanni Bortoluzzi, who passed away in 2015. A special tanks is due to Marco Ligi and Nevio Zitellini for geophysical data acquisition and processing; Marco Pastore and Filippo D'Oriano for their support during the cruise LSD2014 and processing of geophysical data. Elisabetta Campiani provided additional support for processing the multibeam bathymetry. A particular thank goes to Cpt. Emanuele Gentile and the crew of the R/V Urania during cruise LSD 2014. We thank Ronald Steel and an anonymous Reviewer for their constructive comments. This project was funded by ExxonMobil Upstream Research Company and by the Flagship Project RITMARE–The Italian Research for the Sea. We acknowledge the European Union Project PROMESS-1 (contract EVR1-2001-41) for borehole PRAD 1-2. This is ISMAR-CNR contribution number 1959.Peer reviewedPostprin

A fleet of multiparameter observatories for geophysical and environmental monitoring at seafloor

Seafloor long-term, multiparameter, single-frame observatories have been developed within the framework of European Commission and Italian projects since 1995. A fleet of five seafloor observatories, built-up starting from 1995 within the framework of an effective synergy among research institutes and industries, have carried out a series of long-term sea experiments. The observatories are able to operate from shallow waters to deep sea, down to 4,000 m w.d., and to simultaneously monitor a broad spectrum of geophysical and environmental processes, including seismicity, geomagnetic field variations, water temperature, pressure, salinity, chemistry, currents, and gas occurrence. Moreover, they can transmit data in (near)-real-time that can be integrated with those of the on-land networks. The architecture of the seafloor observatories follows the criteria of modularity, interoperability and standardisation in terms of materials, components and communication protocols. This paper describes the technical features of the observatories, their experiments and data

Strategi Pelayanan Administrasi KBIH Al-Munawwaroh Deket Lamongan

Penelitian ini bertujuan untuk mengetahui: pertama, apa saja strategi yang diterapkan pada KBIH al-Munawwaroh Deket Lamongan. Kedua, pelaksanaan strategi pelayanan administrasi KBIH Al-Munawwaroh Deket Lamongan .Pada penelitian ini menggunakan pendekatan kualitatif dari jenis deskriptif. Data yang diperoleh peneliti yaitu data primer. Data tersebut diperoleh dari hasil wawancara, dokumentasi, dan observasi. Pada keabsahan data peneliti menggunakan metode triangulasi untuk menguji validitas data. Pada tahap analisis data peneliti melakukan deskripsi secara detail, coding, kategorisasi dan analisis atau penafsiran. Hasil dari penelitian yang diperoleh adalah Strategi pelayanan administrasi pada KBIH Al-Munawwaroh. Strategi tersebut antara lain: pertama, keunggulan biaya menyeluruh untuk meringankan beban jamaah haji. kedua, diferensiasi yaitu memberikan pelayanann yang terbaik untuk memberikan manfaat pada jamaah haji. Pelaksanaan strategi pelayanan administrasi pada KBIH Al-Munawwaroh sesuai dengan teori implementasi strategi yaitu: pertama, meluruskan inisiatif yang adanya relevansi dengan strategi pelayanan untuk mempermudah pelaksanaannya. Kedua, Melibatkan staff dan karyawan, pelaksanaan strategi pelayanan administrasi KBIH Al-Munawwaroh melibatkan pengurus di dalamnya. Pengurus merupakan penanggung jawab dari pelaksana strategi koordinator tiap wilayah tersebut

Preservation of Transgressive System Tract Geomorphic Elements during the Holocene Sea Level Rise in the South-Eastern Sicilian Tyrrhenian Margin

Understanding of complex sedimentary records formed by transgressive systems is critical because they provide information on sea level changes which control the evolution of the coastal environment. This paper discusses the preservation of the Transgressive System Tracts (TST) in the south-eastern Sicilian Tyrrhenian margin during the last Holocene eustatic cycle. The available dataset consists of high-resolution bathymetry (multibeam), whose description and interpretation through a Digital Elevation Model (DEM) has been integrated with six seismic profiles (CHIRP). Within the whole study area, four bathymetric contours (−120 m, −100 m, −80 m and −70 m) were identified and assumed as the markers of the main locations of the paleo-coastlines, corresponding with the steps of the main changes in the sea level. The transgressive deposits are preferentially preserved in the 70–100 m bathymetric range, bounded at the top by the maximum flooding surface and consisting of the relict geomorphic elements that represent past landscapes (coastal barrier lagoons, transgressive sheet areas, cuspate beaches, transgressive dune-field systems). Furthermore, with the support of 3D bathymetric maps, a reconstruction of the geomorphological evolution of the past coastal systems during the last transgressive stage is also provided

Preservation of Transgressive System Tract Geomorphic Elements during the Holocene Sea Level Rise in the South-Eastern Sicilian Tyrrhenian Margin

Understanding of complex sedimentary records formed by transgressive systems is critical because they provide information on sea level changes which control the evolution of the coastal environment. This paper discusses the preservation of the Transgressive System Tracts (TST) in the south-eastern Sicilian Tyrrhenian margin during the last Holocene eustatic cycle. The available dataset consists of high-resolution bathymetry (multibeam), whose description and interpretation through a Digital Elevation Model (DEM) has been integrated with six seismic profiles (CHIRP). Within the whole study area, four bathymetric contours (−120 m, −100 m, −80 m and −70 m) were identified and assumed as the markers of the main locations of the paleo-coastlines, corresponding with the steps of the main changes in the sea level. The transgressive deposits are preferentially preserved in the 70–100 m bathymetric range, bounded at the top by the maximum flooding surface and consisting of the relict geomorphic elements that represent past landscapes (coastal barrier lagoons, transgressive sheet areas, cuspate beaches, transgressive dune-field systems). Furthermore, with the support of 3D bathymetric maps, a reconstruction of the geomorphological evolution of the past coastal systems during the last transgressive stage is also provided