Santorini is located in the central part of the Hellenic Volcanic Arc (South Aegean Sea) and is well known for the Late-Bronze-Age “Minoan” eruption that may have been responsible for the decline of ...the great Minoan civilization on the island of Crete. To use gravity to probe the internal structure of the volcano and to determine whether there are temporal variations in gravity due to near surface changes, we construct two gravity maps. Dionysos Satellite Observatory (DSO) of the National Technical University of Athens (NTUA) carried out terrestrial gravity measurements in December 2012 and in September 2014 at selected locations on Thera, Nea Kameni, Palea Kameni, Therasia, Aspronisi and Christiana islands. Absolute gravity values were calculated using raw gravity data at every station for all datasets. The results were compared with gravity measurements performed in July 1976 by DSO/NTUA and absolute gravity values derived from the Hellenic Military Geographical Service (HMGS) and other sources. Marine gravity data that were collected during the PROTEUS project in November and December 2015 fill between the land gravity datasets. An appropriate Digital Elevation Model (DEM) with topographic and bathymetric data was also produced. Finally, based on the two combined datasets (one for 2012–2014 and one for the 1970s), Free air and complete Bouguer gravity anomaly maps were produced following the appropriate data corrections and reductions. The pattern of complete Bouguer gravity anomaly maps was consistent with seismological results within the caldera. Finally from the comparison of the measurements made at the same place, we found that, within the caldera, the inner process of the volcano is ongoing both before, and after, the unrest period of 2011–2012.
Seima-Turbino bronzes spread in Eurasia at the transition to the Late Bronze Age. However, the absolute chronology of this horizon remains unclear. Radiocarbon chronology now determines their ...interval to have been ca. 22
–20
centuries BC, or the first third of the 2
millennium BC. The presence of this tradition from Europe to China makes it possible to associate them with historical chronology. The basis for this is the chronologies of the early Shang Dynasty in China, Central Europe and the Shaft Graves of Greece. The Santorini eruption presents an opportunity to compare these chronologies. As a result, the Seima-Turbino bronzes are dated to the first half of the 17
century BC, or within the 18
century BC to the first half of the 16
century BC. This suggests that as the radiocarbon method develops, its results will be close to historical chronology.
In this work, we document two distinct tsunami deposits on the coasts of Ios Island, Aegean Sea, Greece. The younger tsunami deposit, dated 1831–1368 cal. BCE, includes both marine sediments and ...pumices from the ~1600 BCE Minoan eruption of Santorini volcano. This is the first evidence of the Minoan tsunami in the Cycladic Islands North of Santorini. Tsunami waves inundated the Manganari coastal plain, southern coast of Ios, over a distance >200 m (>2 m a.s.l.). The second tsunami deposit reworks pumice from the 22 ka Cape Riva eruption mixed with marine sediment. We assume a Neolithic age for this major tsunami, with a wave runup >13 m a.s.l. on the southern and eastern coasts of Ios. The source of this tsunami - volcanic eruption, landslide, or earthquake - remains unknown. Additionally, we provide the first on-land evidence of Cape Riva deposits outside Santorini, thus questioning previous estimates on the magnitude of this eruption.
This paper critically examines the ways in which overtourism exacerbates as a result of the proliferation of new, non-institutionalized forms of tourism accommodation and their impacts on land uses, ...spatial planning and landscape management, using the case study of Santorini, Greece. The longstanding practice of policy favouring intensive exploitation of small-scale land ownership, for tourism and second residence development, has played a catalytic role in the dominant model of tourism development, escalating the fragmentation of Greek territory and Greek tourism space; largely on the margins of national regional plans and coupled with lack of proper controls or regulation of tourism land uses, it has proven especially detrimental to the Greek landscape. This paper describes, analyses and discusses such processes and their mechanisms, in the case of the island of Santorini, in light also of the recent proliferation of new forms of non-institutionalized tourism accommodation intensifying phenomena of overtourism and further impinging on spatial and landscape planning, use and management.
•Applying digital imaging to study Aegean stone slabs with cup-marks (stone kernoi).•Patterns on the cup-marks shape and arrangement are showcased.•Similar object from Cyprus and the levant have been ...identifies as ‘gameboards’.
Stone slabs with circularly arranged cup-marks (kernoi) in the Bronze Age Aegean have been interpreted as grave marks, offering tables, astronomical instruments, and recently as gameboards. This paper, in the context of the Bronze Age Akrotiri settlement, at Santorini (Thera), proposes the use of digital imaging methods for the recording of these objects. Reflectance Transformation Imaging and Structure from Motion Photogrammetry is used for the optimal recording of these objects and is proposed as a standardised method for the recording, analysis and interpretation of similar objects accross the Aegean and Eastern Mediterranean.
We document and show a state-of-the-art methodology that could allow geoheritage sites (geosites) to become accessible to scientific and non-scientific audiences through immersive and non-immersive ...virtual reality applications. This is achieved through a dedicated WebGIS platform, particularly handy in communicating geoscience during the COVID-19 era. For this application, we selected nine volcanic outcrops in Santorini, Greece. The latter are mainly associated with several geological processes (e.g., dyking, explosive, and effusive eruptions). In particular, they have been associated with the famous Late Bronze Age (LBA) eruption, which made them ideal for geoheritage popularization objectives since they combine scientific and educational purposes with geotourism applications. Initially, we transformed these stunning volcanological outcrops into geospatial models—the so called virtual outcrops (VOs) here defined as virtual geosites (VGs)—through UAV-based photogrammetry and 3D modeling. In the next step, we uploaded them on an online platform that is fully accessible for Earth science teaching and communication. The nine VGs are currently accessible on a PC, a smartphone, or a tablet. Each one includes a detailed description and plenty of annotations available for the viewers during 3D exploration. We hope this work will be regarded as a forward model application for Earth sciences’ popularization and make geoheritage open to the scientific community and the lay public.
In 2011–2012, Santorini was characterized by seismic‐geodetic‐geochemical unrest, which was unprecedented since the most‐recent eruption occurred in 1950 and led to fear an eruption was imminent. ...This unrest offered a chance for investigating the processes leading to volcanic reactivation and the compositional characteristics of involved magma. We have thus analyzed the He‐Ne‐Ar‐isotope composition of fluid inclusions in olivines and clinopyroxenes from cumulate mafic enclaves hosted in cogenetic dacitic lavas of the 1570–1573 and 1925–1928 eruptions of Nea Kameni. These unique data on Aegean volcanism were compared with those of gases collected in quiescent periods and during the unrest. The 3He/4He ratios (3.1–4.0 Ra) are significantly lower than the typical arc‐volcano values (R/Ra ∼ 7–8), suggesting the occurrence of magma contamination in Santorini plumbing system, which would further modify the 3He/4He ratio of parental magmas generated in the local metasomatized mantle. The 3He/4He values of enclaves (3.1–3.6 Ra) are comparable to those measured in gases during quiescent periods, confirming that enclaves reflect the He‐isotope signature of magma residing at shallow depths and feeding passive degassing. A significant increase in soil CO2 flux from Nea Kameni and anomalous compositional variations in the fumaroles were identified during the unrest, accordingly with previous studies. Simultaneously, 3He/4He ratios up to 4.0 Ra were also measured, demonstrating that the unrest was due to the intrusion into the shallow plumbing system of a more‐primitive 3He‐rich magma, which is even volatile richer and less contaminated than mafic magma erupted as enclaves. This new intrusion did not however trigger an eruption.
Key Points:
We studied the He‐Ne‐Ar isotopes in mafic enclaves and in gases from Santorini
The 3He/4He ratios of gases and enclaves is in the range 3.0–4.0 Ra
The 2011–2012 unrest at Santorini was due to the intrusion of a new mafic magma
Geologic maps are foundational products for natural hazard assessments but developing them for submarine areas is challenging due to a lack of physical access to the study area. In response, ...submarine geomorphologic maps are used to provide geologic context and spatial information on landforms and related geo-hazards for risk management. These maps are generated from remotely sensed data, e.g. digital elevation models (DEMs), which introduce unique hurdles to submarine mapping. To address this issue, we produced a workflow for applying planetary geologic mapping methods to submarine data. Using this, we created an onshore-offshore geomorphologic map of the Christiana-Santorini-Kolumbo Volcanic Group, Greece. This product can be used to enhance hazard assessments on Santorini, which is a tourist hot-spot at high risk for volcanically- and seismically-induced hazards. We present this workflow as a tool for generating uniform geomorphologic map products that will aid natural hazard assessments of submarine environments.
Historical review of the procedures and maneuvers described in the literature for the control of Santorini's venous plexus.
Review of original articles on the design of procedures and maneuvers for ...the control of the Santorini's venous plexus.
The control of Santorini's plexus is crucial to reduce blood loss and dissect the prostatic apex. The procedure was first performed by Chute in 1954 and has undergone subsequent modifications by several authors (Reiner and Walsh, Hayashi, Myers, etc.) who have published different maneuvers for its control.
There is no ideal procedure or maneuver for the control of the Santorini's plexus.
Revisión histórica de los procedimientos y maniobras descritos en la literatura para el control del plexo venoso de Santorini.
Revisión fundamentalmente de los artículos originales sobre el diseño de procedimientos y maniobras para el control del plexo venoso de Santorini.
El control del plexo venoso de Santorini es fundamental para reducir las pérdidas hemáticas y disecar el ápex prostático. El primer control lo realizó Chute en 1954. Posteriormente varios autores (Reiner y Walsh, Hayashi, Myers, etc.) publicaron distintas maniobras para su control.
No existe el procedimiento o la maniobra ideal para el control del plexo de Santorini.
The volcanic center of Santorini Island is the most active volcano of the southern Aegean volcanic arc. Α dense seismic array consisting of fourteen portable broadband seismological stations has been ...deployed in order to monitor and study the seismo-volcanic activity at the broader area of the Santorini volcanic center between March 2003 and September 2003. Additional recordings from a neighbouring larger scale temporary network (CYCNET) were also used for the relocation of more than 240 earthquakes recorded by both arrays. A double-difference relocation technique was used, in order to obtain optimal focal parameters for the best-constrained earthquakes.
The results indicate that the seismic activity of the Santorini volcanic center is strongly associated with the tectonic regime of the broader Southern Aegean Sea area as well as with the volcanic processes. The main cluster of the epicenters is located at the Coloumbo Reef, a submarine volcano of the volcanic system of Santorini Islands. A smaller cluster of events is located near the Anydros Islet, aligned in a NE–SW direction, running almost along the main tectonic feature of the area under study, the Santorini–Amorgos Fault Zone. In contrast, the main Santorini Island caldera is characterized by the almost complete absence of seismicity. This contrast is in very good agreement with recent volcanological and marine studies, with the Coloumbo volcanic center showing an intense high-temperature hydrothermal activity, in comparison to the corresponding low-level activity of the Santorini caldera.
The high-resolution hypocentral relocations present a clear view of the volcanic submarine structure at the Coloumbo Reef, showing that the main seismic activity is located within a very narrow vertical column, mainly at depths between 6 and 9 km. The focal mechanisms of the best-located events show that the cluster at the Coloumbo Reef is associated with the “Kameni–Coloumbo Fracture Zone”, which corresponds to the western termination of the major ENE–WSW Santorini–Amorgos Fault Zone. Stress–tensor inversion of the available fault plane solutions from Coloumbo Reef, as well as existing neotectonic fault information from NE Santorini (Coloumbo peninsula), suggests that the NE Santorini–Coloumbo faults belong to a single rupture system, with a ~
30° rotation of the local stress field with respect to the NNW–SSE regional extension field of the southern Aegean Sea. The observed change of the fault plane solutions shows that local conditions at the Coloumbo submarine volcano area control the observed faulting pattern.
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