The connection between parotid gland and external auditory canal has long been described throughout the centuries. It can act as a gateway for infectious or neoplastic material to spread between ...those two structures.
To our surprise, this naturally occurring defect can serve as an option to conservatively treat a parotid abscess. We report a case of a parotid abscess with a concurrent presentation of an ipsilateral ear discharge. The purpose of our study is to highlight a unique process of resolution of parotid abscess through an opening in the ear canal.
In spite of the fact that the fissure of Santorini is known as the gateway and tunnel for a disease to spread, it has proven to serve as a pathway for disease elimination as well.
Active hydrothermal vents of volcanic origin provide a remarkable manifestation of life on Earth under extreme conditions, which may have consequences for our understanding of habitability on other ...terrestrial bodies as well.
Here, we performed for the first time Illumina sequencing of bacterial and archaeal communities on sub-seafloor samples collected from the Santorini-Kolumbo volcanic field. A total of 19 (3-m long) gravity corers were collected and processed for microbial community analysis.
From a total of 6,46,671 produced V4 sequences for all samples, a total of 10,496 different Operational Taxonomic Units (OTUs) were identified that were assigned to 40 bacterial and 9 archaeal phyla and 14 candidate divisions. On average, the most abundant phyla in all samples were Chloroflexi (Chloroflexota) (24.62%), followed by Proteobacteria (Pseudomonadota) (11.29%), Firmicutes (Bacillota) (10.73%), Crenarchaeota (Thermoproteota) (8.55%), and Acidobacteria (Acidobacteriota) (8.07%). At the genus level, a total of 286 known genera and candidate genera were mostly dominated by members of
, and
.
In most of the stations, the Chao1 values at the deeper layers were comparable to the surface sediment samples denoting the high diversity in the subsurface of these ecosystems. Heatmap analysis based on the 100 most abundant OTUs, grouped the sampling stations according to their geographical location, placing together the two hottest stations (up to 99°C). This result indicates that this specific area within the active Kolumbo crater create a distinct niche, where microorganisms with adaptation strategies to withstand heat stresses can thrive, such as the endospore-forming Firmicutes.
The iconic climate archive of Tenaghi Philippon (TP), NE Greece, allows the study of short-term palaeoclimatic and environmental change throughout the past 1.3 Ma. To provide high-quality age control ...for detailed palaeoclimate reconstructions based on the TP archive, (crypto)tephra studies of a peat core ‘TP-2005’ have been carried out for the 0–130 ka interval. The results show that the TP basin is ideally positioned to receive tephra fall from both the Italian and Aegean Arc volcanic provinces. Two visible tephra layers, the Santorini Cape Riva/Y-2 (c. 22 ka) and the Campanian Ignimbrite (CI)/Y-5 (c. 39.8 ka) tephras, and six primary cryptotephra layers, namely the early Holocene E1 tephra from the Aeolian Islands (c. 8.3 ka), the Campanian Y-3 (c. 29 ka) and X-6 tephras (c. 109.5 ka), as well as counterpart tephras TM-18-1d (c. 40.4 ka), TM-23-11 (c. 92.4 ka) and TM-33-1a (c. 116.7 ka) from the Lago Grande di Monticchio sequence (southern Italy), were identified along with repeatedly redeposited Y-2 and CI tephra material. Bayesian modelling of the ages of seven of the primary tephra layers, 60 radiocarbon measurements and 20 palynological control points have been applied to markedly improve the chronology of the TP archive. This revised chronology constrains the age of tephra TM-18-1d to 40.90–41.66 cal ka BP (95.4% range). Several tephra layers identified in the TP record form important isochrons for correlating this archive with other terrestrial (e.g., Lago Grande di Monticchio, Sulmona Basin and Lake Ohrid) and marine (e.g., Adriatic Sea core PRAD 1-2 and Aegean Sea core LC21) palaeoclimate records in the Mediterranean region.
•8 (crypto)tephras are identified in the MIS 1–5 peat record of Tenaghi Philippon.•Tephras have Italian and Aegean Arc provenances.•Most Italian tephras, including X-6, were found in their most distal sites.•The MIS 1–5 chronology of TP was improved by Bayesian modelling.
The erosion of sandy beaches creates a significant impact on the local society, the economy and the environment. The present study is an attempt to adapt the innovative DESSIN (Demonstrate Ecosystem ...Services Enabling Innovation in the Water Sector) framework that specializes in freshwater applications, to urban coastal systems. The framework is applied in the case of Kamari beach, Santorini (Greece), to assess the sustainability of all possible anti-erosion measures. To identify the most vulnerable parts of the coastline, the study used two sensitivity indices: the Coastal Vulnerability Index (CVI), and the Socioeconomic Index (SocCVI). A supply-demand model was applied for the integration of all three aspects that characterize the system: social, economic, and environmental. To project the impact of erosion in the future, the system's state was analyzed in three steps a) the present, b) after the installation of the coastal protection measures and c) a scenario where no protection actions were taken (RCP4.5 scenario). In the current situation the most susceptible part of the coastline due to anthropogenic and environmental pressures is the central one, which does not immediately affect the socio-economic activities of the urban area. In contrast, future changes brought about by climate change will endanger the system's equilibrium and anti-erosion actions are necessary. With the application of the adapted DESSIN framework, the combined installation of submerged breakwaters with sediment replacement is the most sustainable action, promoting socio-economic growth and the protection of essential ecosystem services.
Display omitted
•Beyond freshwater bodies, DESSIN framework could be applied to coastal studies.•DESSIN's flexible structure makes it possible to adapt it to coastal systems.•The Demand-Supply model is a useful tool to summarize all aspects of these systems.•Currently Kamari's socio-economic activities are not affected by the erosion.•The main pressure on the beach is due the morphology and seas hydrodynamics.
During a volcanic unrest period with magma-chamber rupture, fluid-driven fractures (dykes) are injected either from deep reservoirs or shallow magma chambers. Subsequently, the dykes follow ...propagation paths towards the surface, some eventually reaching the surface to erupt while others become arrested. Here we study dyke paths resulting in eruption or arrest in an excellent 5-km wide exposure of the northern caldera wall of the Santorini volcano in Greece. Mapping of >90 dyke segments shows that they were emplaced in a host rock consisting of layers (of breccia, tuff, scoria, and lava) with a wide variety of mechanical properties. At the contacts, some dykes are arrested or deflected and hence change their propagation paths. Here we combine the field data with numerical models to explore dyke paths resulting in (1) arrest and (2) eruption. We investigate the effect of different host-rock mechanical properties, magmatic overpressures, and tectonic loading on dyke paths. We find that layers with unfavorable local stresses for dyke propagation, namely stress barriers, result from layer stiffness (Young's modulus) contrast and thickness variations and are a common cause of dyke arrest. The study also shows how the details of the dyke path, and eventually dyke-fed eruptions, depend on the mechanical layering and local stresses in volcanoes. The results are of great importance for understanding dyke-propagation paths, and the likelihood of eruption, during unrest periods, particularly in stratovolcanoes fed by shallow chambers, such as Santorini.
•Mapping of dyke segments emplaced in the northern caldera wall of Santorini.•The dyke geometries are used in a suite of numerical models.•Sensitivity tests were performed to analyse the stress field during emplacement.•Layer stiffness and thickness contrasts promote dyke arrest on Santorini.•Stress barrier and elastic mismatch influence dyke paths in heterogeneous volcanoes.
Santorini Island (Greece) is an active volcano which has alternated between dormant and active periods over the last 650,000 years with the latest volcanic unrest occurring in 2011–2012. Here we ...report a geochemical survey of fumarolic gases collected at Nea Kameni islet located in the center of the caldera over the period 2015–2022 in order to study the activity of the volcano and changes in hydrothermal conditions. This period is marked by the absence of significant geochemical anomalies compared to the unrest of 2011–2012, implying that no new magma upwelling has occurred. This is evident from the low CO 2 /CH 4 ratio and H 2 concentration of fumaroles. An increase of the atmospheric contribution in gases after the 2011–2012 unrest suggests a decrease of the deep gas flow and the chemical and C-He-isotope compositions are compatible with a model of Rayleigh fractionation in which CO 2 dissolves in water at decreasing temperatures over time. These results are consistent with temperature estimates obtained using the H 2 /N 2 geothermometer, seismic and geodetic evidences. This implies a slowing of the degassing of the hydrothermal/volcanic system and a cooling of the magma injected at shallow depth in 2011–2012. All these conclusions support a quiescent state of the Santorini volcano over the period 2015–2022.
The rhyodacitic magma discharged during the 30–80 km
3
DRE (dense rock equivalent) Late Bronze Age (LBA; also called ‘Minoan’) eruption of Santorini caldera is known from previous studies to have had ...a complex history of polybaric ascent and storage prior to eruption. We refine the timescales of these processes by modelling Mg–Fe diffusion profiles in orthopyroxene and clinopyroxene crystals. The data are integrated with previously published information on the LBA eruption (phase equilibria studies, melt inclusion volatile barometry, Mg-in-plagioclase diffusion chronometry), as well as new plagioclase crystal size distributions and the established pre-LBA history of the volcano, to reconstruct the events that led up to the assembly and discharge of the LBA magma chamber. Orthopyroxene, clinopyroxene and plagioclase crystals in the rhyodacite have compositionally distinct rims, overgrowing relict, probably source-derived, more magnesian (or calcic) cores, and record one or more crystallization (plag ≫ opx > cpx) events during the few centuries to years prior to eruption. The crystallization event(s) can be explained by the rapid transfer of rhyodacitic melt from a dioritic/gabbroic region of the subcaldera pluton (mostly in the 8–12 km depth range), followed by injection, cooling and mixing in a large melt lens at 4–6 km depth (the pre-eruptive magma chamber). Since crystals from all eruptive phases yield similar timescales, the melt transfer event(s), the last of which took place less than 2 years before the eruption, must have involved most of the magma that subsequently erupted. The data are consistent with a model in which prolonged generation, storage and segregation of silicic melts were followed by gravitational instability in the subcaldera pluton, causing the rapid interconnection and amalgamation of melt-rich domains. The melts then drained to the top of the pluton, at fluxes of up to 0.1–1 km
3
year
− 1
, where steep vertical gradients of density and rheology probably caused them to inject laterally, forming a short-lived holding chamber prior to eruption. This interpretation is consistent with growing evidence that some large silicic magma chambers are transient features on geological timescales. A similar process preceded at least one earlier caldera-forming eruption on Santorini, suggesting that it may be a general feature of this rift-hosted magmatic system.
The Kolumbo submarine volcano in the southern Aegean (Greece) is associated with repeated seismic unrest since at least two decades and the causes of this unrest are poorly understood. We present a ...ten‐month long microseismicity data set for the period 2006–2007. The majority of earthquakes cluster in a cone‐shaped portion of the crust below Kolumbo. The tip of this cone coincides with a low Vp‐anomaly at 2–4 km depth, which is interpreted as a crustal melt reservoir. Our data set includes several earthquake swarms, of which we analyze the four with the highest events numbers in detail. Together the swarms form a zone of fracturing elongated in the SW‐NE direction, parallel to major regional faults. All four swarms show a general upward migration of hypocenters and the cracking front propagates unusually fast, compared to swarms in other volcanic areas. We conclude that the swarm seismicity is most likely triggered by a combination of pore‐pressure perturbations and the re‐distribution of elastic stresses. Fluid pressure perturbations are induced likely by obstructions in the melt conduits in a rheologically strong layer between 6 and 9 km depth. We conclude that the zone of fractures below Kolumbo is exploited by melts ascending from the mantle and filling the crustal melt reservoir. Together with the recurring seismic unrest, our study suggests that a future eruption is probable and monitoring of the Kolumbo volcanic system is highly advisable.
Key Points
Seismicity is clustered in a cone‐shaped volume beneath Kolumbo; the cone's tip coincides with a melt reservoir at 2–4 km depth
Seismicity swarms occupy nearby, yet different portions of the crust, ruling out an origin on a single fault
Swarms were likely triggered by a combination of fluid pressure perturbations and redistribution of elastic stresses
The late Bronze Age eruption of the Thera volcano was among the largest eruptions of the Holocene era. This catastrophic event might perish all organisms from the ancient Santorini and could ...seriously impact the sand fly fauna of the Aegean islands. To investigate these effects, the survival possibility of the sand fly fauna in the Santorini islands and the biogeographic investigation of the sand fly fauna of eleven Aegean islands were conducted. It was found that only the south and east slopes of the massifs of Thira could provide refuge for sand fly populations. The expression-based heat map of the Jaccard coefficient matrix data showed that the Santorini islands and their neighbouring Anafi, Folegandros had clearly different z-score patterns compared to the other islands. It could be a late sign of the devastating effect of the Minoan eruption and/or the consequence of the distance of these islands from the mainland. Neither the glacial seashore patterns nor the geographic-climatic conditions can explain the present sand fly fauna of the Aegean Archipelago. If the sand fly populations of ancient Santorini survived the Minoan cataclysm, it could indicate that the environmental tolerance and the resilience of the sand fly populations can be high, and local geological and geomorphological conditions can play a greater role in the survival of sand fly species than previously assumed.
PDF
