The seismic activity of the middle strand of the North Anatolian Fault (MNAF), Northwestern Turkey, is debated because of its quiescence during the instrumental period, in contrast to a significant ...historical activity documented by several chronicles over the last two millennia. Here, we focus on Lake Iznik, bordered by the MNAF, to get a new insight into its long‐term seismicity and its tectonic setting. The study of lacustrine sediment cores reveals 14 earthquake‐induced turbidites since their ages correspond to seismic events during the past two millennia. Bathymetry and high‐resolution seismic reflection data allow to describe two hitherto unknown subaquatic active fault structures (the South Boyalica and Iznik faults) that belong to the MNAF system. Sediment cores sampled on both sides of the Iznik Fault document an event deposit and a sedimentary unit vertically offset of ~40 cm interpreted as the last rupture during the 1065 CE destructive earthquake. Older events are supposed on this fault more than thousand years ago. Further studies will help to estimate the horizontal co‐seismic offset of this oblique‐slip fault and the calendar of older ruptures. The current seismic gap of thousand years on this segment greatly increases the seismic hazard in this region and must be considered in the seismic risk assessment of the NAF system.
Plain Language Summary
During large earthquakes, sediments are generally transported from lake slopes to the lake basin. The resulting event deposits can provide information on the recurrence of past regional earthquakes, which is crucial for seismic hazard assessment. In this study, we discovered two underwater fault structures in Lake Iznik, using geophysical methods. Studying the sedimentation on both sides of the southernmost fault, we observed an increased sedimentation rate on the hanging wall of the fault immediately after an event deposit, dated to 1077 ± 77 cal. CE. We interpreted these indicators as resulting from a co‐seismic displacement along the fault plane, linked to the 1065 CE historical earthquake, which had significantly impacted the city of Iznik. We also show that most of the other event deposits in the sediment cores are confidently associated to 14 historical earthquakes since 2,000 years.
Key Points
Previously unknown faults that belong to the North Anatolian Fault system have been discovered in Lake Iznik through geophysical surveys (from multibeam bathymetry and high‐frequency seismic reflection data)
Assessment of the recent activity of the Iznik Fault, based on multiproxy analysis of sediment cores from each side of the fault
Evidence for the timing of the last rupture corresponding to the 1065 CE historical earthquake, which had significantly impacted the city of Iznik
Pancreatic fluid collections (PFCs) are one of the local complications of acute pancreatitis and include walled-off pancreatic necrosis (WOPN), which are complex entities with challenging management. ...The infection of pancreatic necrosis leads to a poorer prognosis, with a growth of the mortality rate up to 30%. The primary strategy for managing PFCs is a minimally invasive step-up approach, with endosonography-guided transmural drainage and debridement as the preferred and less invasive method. Percutaneous drainage (PCD) can be the technique of choice when endoscopic drainage is not feasible, for example for early PFCs without a mature wall or for the anatomic location and extension to the paracolic gutter of the collection. As PCD alone may be ineffective, especially when a great amount of necrosis is present, a percutaneous endoscopic necrosectomy (PEN) has been proposed, showing interesting results. The technique consists of the placement of an esophageal fully or partially covered self-expandable metal stent (SEMS) percutaneously into the collection and a direct debridement can be performed using a flexible endoscope through the SEMS. In this review, we will discuss about the role of metal stent and PEN for the management of complex walled-off pancreatic necrosis.
To investigate the history of the Aare Glacier and its overdeepened valley, a high-resolution multibeam bathymetric dataset and a 2D multi-channel reflection seismic dataset were acquired on ...perialpine Lake Thun (Switzerland). The overdeepened basin was formed by a combination of tectonically predefined weak zones and glacial erosion during several glacial cycles. In the deepest region of the basin, top of bedrock lies at ∼200 m below sea level, implying more than 750 m of overdeepening with respect to the current fluvial base level (i.e. lake level). Seismic stratigraphic analysis reveals the evolution of the basin and indicates a subaquatic moraine complex marked by high-amplitude reflections below the outermost edge of a morphologically distinct platform in the southeastern part of the lake. This stack of seven subaquatic terminal moraine crests was created by a fluctuating, “quasi-stagnant” grounded Aare Glacier during its overall recessional phase. Single packages of overridden moraine crests are seismically distuinguishable, which show a transition downstream into prograding clinoforms with foresets at the ice-distal slope. The succession of subaquatic glacial sequences (foresets and adjacent bottomsets) represent one fifth of the entire sedimentary thickness.
Exact time constraints concerning the deglacial history of the Aare Glacier are very sparse. However, existing 10Be exposure ages from the accumulation area of the Aare Glacier and radiocarbon ages from a Late-Glacial lake close to the outlet of Lake Thun indicate that the formation of the subaquatic moraine complex and the associated sedimentary infill must have occurred in less than 1000 years, implying high sedimentation rates and rapid disintegration of the glacier.
These new data improve our comprehension of the landforms associated with the ice-contact zone in water, the facies architecture of the sub- to proglacial units, the related depositional processes, and thus the retreat mechanisms of the Aare Glacier.
•The overdeepening of the perialpine Aare Valley reaches down to −220 m a.s.l.•A subaquatic moraine complex marks a short dramatic halt during LGM deglaciation.•The complex was built in <1000 years with sedimentation rates >8 cm/yr.
Coastal monitoring is fundamental to studying dune and beach behaviour related to natural and anthropogenic factors as well as coastal management programs. Various tools have been used in recent ...years for such investigations, including LIDAR, satellite images, terrestrial laser scanning, and photogrammetry, allowing for both qualitative and quantitative analyses. These tools are applied based on the spatial and temporal scales of the coastal zone being studied. In this study, seasonal coastal changes are monitored using high-accuracy and high-quality photogrammetry frames acquired using unmanned aerial vehicle (UAV). The UAV surveys were performed over two sessions during summer 2014 (September) and winter 2015 (March). Additional data were also acquired during the strongest winter storms of the 2014–2015 season. The results of these two UAVs surveys are compared to identify the changes that occurred on beaches and dunes due to: i) anthropogenic changes such as tourist facilities and winter storm defence construction; and ii) the winter storms of 2014–2015 from dune erosion, investigating the magnitude of impact across all coastal zones under study. Moreover, this study demonstrates the efficacy and applicability of photogrammetry from UAVs for coastal work, analyses whether it is a useful technique for scientific studies and authorities to use due to its greater cost/benefit, and also whether it contributes to the application of local Integrated Coastal Zone Management.
•UAV survey to apply on the Integrated Coastal Zone Management.•High-resolution data to apply on the coastal environments.•Monitoring of the coastal environmental behaviour on a winter season.•Identification of the anthropogenic and natural pressures above the coastal system.
Objectives
Repeated endoscopic ultrasound (EUS)‐guided tissue acquisition represents the standard practice for solid pancreatic lesions after previous nondiagnostic or inconclusive results. Since ...data are lacking, we aimed to evaluate the diagnostic performance of repeated EUS fine‐needle biopsy (rEUS‐FNB) in this setting. The primary outcome was diagnostic accuracy; sample adequacy, sensitivity, specificity, and safety were secondary outcomes.
Methods
Consecutive patients undergoing rEUS‐FNB for solid pancreatic lesions at 23 Italian centers from 2019 to 2021 were retrieved. Pathology on the surgical specimen, malignant histology together with ≥6‐month follow‐up, and benign pathology together with ≥12‐month follow‐up were adopted as gold standards.
Results
Among 462 patients, 56.5% were male, with a median age of 68 (59–75) years, malignancy prevalence 77.0%. Tumor size was 26 (20–35) mm. Second‐generation FNB needles were used in 89.6% cases. Diagnostic accuracy, sensitivity, and specificity of rEUS‐FNB were 89.2%, 91.4%, and 81.7%, respectively (19 false‐negative and 12 false‐positive results). On multivariate analysis, rEUS‐FNB performed at high‐volume centers (odds ratio OR 2.12; 95% confidence interval CI 1.10–3.17; P = 0.03) and tumor size (OR 1.03; 95% CI 1.00–1.06; P = 0.05) were independently related to diagnostic accuracy. Sample adequacy was 94.2%. Use of second‐generation FNB needles (OR 5.42; 95% CI 2.30–12.77; P < 0.001) and tumor size >23 mm (OR 3.04; 95% CI 1.31–7.06; P = 0.009) were independently related to sample adequacy.
Conclusion
Repeated EUS‐FNB allowed optimal diagnostic performance after nondiagnostic or inconclusive results. Patients' referral to high‐volume centers improved diagnostic accuracy. The use of second‐generation FNB needles significantly improved sample adequacy over standard EUS‐FNB needles.
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•We describe a Roman gypsum quarry in the Northern Apennines.•Archeological excavations have revealed multiple occupations.•This quarry was surveyed with laser scanner and UVA ...photogrammetry.•Gypsum blocks were measured and extracted volumes were estimated.•Landscape evolution of the quarrying site is reconstructed.
Roman-period extractive sites in gypsum outcrops are very rare, and most have become very degraded by later weathering or quarrying activities. This paper describes, using laser scanning, photogrammetry and survey using a UAV-based survey, the uniquely well-preserved Roman-period gypsum quarry of Ca’ Castellina (Northern Apennines, Italy). This site was excavated only in the last few years and the excavations have brought to light some gypsum blocks and the ancient quarry benches showing excavation marks, the remains of a rectangular building and a great number of artefacts that range between the Protohistoric Period and the modern times. The size of the extracted blocks, the extraction methodologies and the age of a charcoal fragment (361 – 178B CE) found immediately at the contact between the gypsum quarry floor and the infilling sediments date the quarry back to the Roman age. Archaeological evidences demonstrate the building to have been used for a short period of time during the XVI-XVII century. Immediately after its abandonment most of the quarry floor has been covered with a thick detrital layer, protecting it from dissolution (fossilizing this floor and leaving it as if it was abandoned very recently), whereas the naked or poorly covered floor of this quarry has been subjected to dissolution phenomena of the exposed gypsum rocks, with a lowering of the surface, the smoothening of the corners and the formation of a set of deeply carved karren features.
A 3D survey using both a laser scanning instrument and a drone-mounted photo camera have allowed to get precise measures on the size of the blocks that were extracted in this quarry, the traces of pick axe marks, and on the dissolution morphologies that have developed on the bare gypsum rock. These typical gypsum landforms show how fast these solution forms can develop where concentrated runoff flows on bare gypsum. To prevent this exceptional archaeological extractive site of being further dissolved, it will be important to plan some measures to be put in place in order to protect this delicate historical landmark.
The Gargano Promontory, located on the eastern margin of the Apulia Platform, represents a distinctive Tethyan area where the transition from carbonate platform to adjacent basin is exposed on land. ...The Albian stratigraphic record, represented by shallow-water, slope and deep-water deposits, provides a good opportunity to investigate the regional response to oceanic anoxic events (OAEs) in different depositional settings by using an integrated, high-resolution micropalaeontological (planktonic foraminifers and calcareous nannofossils) approach. Results show that organic matter preservation is confined to the more distal areas (Marne a Fucoidi Formation), and consists of black shale intervals from the middle and late Albian (
Ticinella primula/Prediscosphaera columnata Zones; upper
Ticinella praeticinensis Subzone/
R. achlyostaurion Zone, respectively). Integrated biostratigraphic data correlate the intervals of black shale deposition to the Urbino and Amadeus levels, previously identified and named in the Umbria-Marche Basin. These black shales record the effects of OAEs 1b and 1c. The biotic changes in the pelagic Albian succession of the Apulian Platform Margin provide evidence for episodes of eutrophication that correlate to the deposition of these black shales. Genetic models for the two episodes of organic matter preservation are proposed, taking into account both global and local controlling factors.
Le promontoire de Gargano, situé sur la marge orientale de la plate-forme apulienne, représente une région privilégiée, où la transition entre plate-forme carbonatée et ses bassins adjacents est exposée sur terre. L’enregistrement stratigraphique de l’Albien, représenté au sein de dépôts peu profonds ou de talus ou de bassin profond, offre une très bonne occasion pour étudier la réponse régionale aux événements d’anoxie océanique dans des contextes de dépôt différents, en utilisant une approche micropaléontologique (foraminifères planctoniques et nannofossiles calcaires) intégrée et de haute résolution. Les résultats montrent que la préservation de la matière organique est confinée aux endroits les plus distaux (Formation des Marnes à Fucoidi) et constitués d’intervalles d’argillites noires enregistrées dans la partie de l’Albien moyen et supérieur (Zones à
Ticinella primula–Prediscosphaera columnata ; partie supérieure des sous-zones
Ticinella praeticinensis–R. achlyostaurion, respectivement). Les données biostratigraphiques intégrées corrèlent les intervalles de dépôt d’argillites noires aux niveaux Amadeus et Urbino, déterminés auparavant et nommés dans le bassin d’Ombrie-Marches. Ces argillites noires enregistrent les effets des événements anoxiques 1b et 1c. Les changements biotiques dans la série pélagique albienne de la marge de la plate-forme apulienne fournissent des preuves pour des épisodes d’eutrophisation qui se corrèlent avec le dépôt des argillites noires. Des modèles génétiques sont avancés pour les deux épisodes de préservation de matière organique en tenant aussi bien compte des facteurs globaux que locaux.
Coastal dunes play an important role in protecting the coastline. Unfortunately, in the last decades dunes have been removed or damaged by human activities. In the Emilia- Romagna region significant ...residual dune systems are found only along Ravenna and Ferrara coasts. In this context, the RIGED-RA project "Restoration and management of coastal dunes along the Ravenna coast" (2013-2016) has been launched with the aims to identify dynamics, erosion and vulnerability of Northern Adriatic coast and associated residual dunes, and to define intervention strategies for dune protection and restoration. The methodology is based on a multidisciplinary approach that integrates the expertise of several researchers and investigates all aspects (biotic and abiotic), which drive the dune-beach system. All datasets were integrated to identify test sites for applying dune restoration. The intervention finished in April 2016; evolution and restoration efficiency will be assessed.
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