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1.
Haubold Herbert Scholger Robert Kondopoulou Despina Mauritsch Hermann J. 《Geologie en Mijnbouw》1997,76(1-2):45-55
Various Oligocene formations from NE Greece (ignimbrites from the Medousa area, rhyolites from Zagradenia, granodiorites from Elatia) show discordant paleomagnetic signatures, in each case indicating small cw (clockwise) rotation and also inclination flattening. Marls from Pithion were partly remagnetized in a present-day field. Samples that contain ancient magnetization components also indicate small cw rotation and inclination flattening. However, the magnetization of andesites from Peplos reflects a considerably larger rotation, likely owing to local tectonics. In the context of previous work in the area, these results are used to propose a subdivision of NE Greece into four structural zones of distinctive rotational behaviour (from east to west): sites in zone 1, east of the Kavala-Xanthi-Komotini fault (KXK), show various cw and ccw (counterclockwise) rotation angles owing to complex kinematics resulting from the interaction of the KXK and the north-Anatolian fault zone. However, zone 2, between the KXK and the Strymon valley, is structurally homogeneous ( 10° cw rotation). The paleomagnetic signature of the Vertiskos massif (zone 3) implies a larger (> 30°) cw rotation, whereas sites in the Vardar basin (zone 4) contain a paleomagnetic signature similar to that of zone 2. This suggests a motion of the Vertiscos massif, a meta-ophiolitic nappe, relative to underlying strata. Indeed, zones 2 and 4 may be parts of the same structural unit which underlies this nappe. 相似文献
2.
Perceptions of hazard and risk on Santorini 总被引：1，自引：0，他引：1
Dale Dominey-Howes Despina Minos-Minopoulos 《Journal of Volcanology and Geothermal Research》2004,137(4):4
Santorini, Greece is a major explosive volcano. The Santorini volcanic complex is composed of two active volcanoes—Nea Kameni and Mt. Columbo. Holocene eruptions have generated a variety of processes and deposits and eruption mechanisms pose significant hazards of various types. It has been recognized that, for major European volcanoes, few studies have focused on the social aspects of volcanic activity and little work has been conducted on public perceptions of hazard, risk and vulnerability. Such assessments are an important element of establishing public education programmes and developing volcano disaster management plans. We investigate perceptions of volcanic hazards on Santorini. We find that most residents know that Nea Kameni is active, but only 60% know that Mt. Columbo is active. Forty percent of residents fear that negative impacts on tourism will have the greatest effect on their community. In the event of an eruption, 43% of residents would try to evacuate the island by plane/ferry. Residents aged >50 have retained a memory of the effects of the last eruption at the island, whereas younger residents have no such knowledge. We find that dignitaries and municipal officers (those responsible for planning and managing disaster response) are informed about the history, hazards and effects of the volcanoes. However, there is no “emergency plan” for the island and there is confusion between various departments (Civil Defense, Fire, Police, etc.) about the emergency decision-making process. The resident population of Santorini is at high risk from the hazards associated with a future eruption. 相似文献
3.
Morgane Surdez Julien Beck Dimitris Sakellariou Hendrik Vogel Patrizia Birchler Emery Despina Koutsoumba Flavio S. Anselmetti 《Swiss Journal of Geoscience》2018,111(3):573-588
Franchthi Cave, bordering Kiladha Bay, in Greece, is a key archaeological site, due to its long occupation time, from?~?40,000 to?~?5000 year BP. To date, no clear evidence of Neolithic human dwellings in the cave was found, supporting the assumption that Neolithic people may have built a village where there is now Kiladha Bay. During the Neolithic period/Early Holocene, wide areas of the bay were indeed emerged above sea level. Bathymetric and seismic data identified a terrace incised by a valley in?~?1 to 2 m sediment depth. Eight sediment cores, up to 6.3-m-long, were retrieved and analysed using petrophysical, sedimentological, geochemical, and chronostratigraphic methods. The longest core extends into the exposure surface, consisting of a layer of carbonate rubble in a finer matrix, representing weathering processes. Dated organic remains place this unit at?~?8500 cal year BP. It is overlain by stiff silty mud representing an estuarine environment. This mud is capped by reduced sediments with roots marking an exposure surface. A shell-layer, dated to?~?6300 cal year BP, overlies this terrestrial sequence, reflecting the marine transgression. This layer occurs at 10.8 mbsl, 7.7 m deeper than the global sea level at that time, suggesting tectonic subsidence in the area. It is overlain by finer-grained marine carbonate-rich sediments. The top of the core shows traces of eutrophication, pebbles and marine shells, all likely a result of modern anthropogenic processes. These results are interpreted in the context of human occupation: the exposed surface contains pottery sherds, one dating to the Early to Middle Neolithic period, indicating that Neolithic people were present in this dynamic landscape interacting with a migrating coastline. Even if the artefacts are isolated, future investigations of the submerged landscape off Franchthi Cave might lead to the discovery of a Neolithic village, which eventually became buried under marine sediments. 相似文献
4.
Acta Geotechnica - There is extensive data to show that heating and cooling produces irrecoverable deformations in clays under fully drained conditions. The effects are most pronounced for normally... 相似文献
5.
Anitha Senthamizhan Brabu Balusamy Doriana Debellis Jose Alejandro Heredia-Guerrero Giorgio Mancini Riccardo Carzino Luca Ceseracciu Athanassia Athanassiou Despina Fragouli 《洁净——土壤、空气、水》2023,51(1):2200284
Conversion of waste biomass into valuable functional materials accomplishes the concept of circular economy in the development of sustainable waste management, and also recovery of such resources possibly reduces the requirement of feedstocks. In this scenario, the development of methodologies toward the direct conversion of the raw biomass into solid adsorbent materials without the use of any templates is highly desirable, but exceptionally challenging due to the complexity of the process. Here the direct synthesis of 3D porous carbon traps by a simple, cost-effective, and template-free process starting from a kitchen-based recipe and fermented food waste is described. Precisely, a robust carbon trap is formed with a spongy structure and highly interconnected hierarchical pores after the pyrolysis of a rice-based foam in the air. The developed materials float on water and interact efficiently with cationic dyes at static conditions. Importantly, such performance of the 3D carbon traps is not affected in the presence of anionic dyes, indicating the excellent selectivity towards the adsorption of cationic dyes. The adsorbent can be easily recovered and reused for up to 3 cycles without releasing any byproducts, thus, without causing hazardous risk of any secondary pollution to the environment. 相似文献
6.
N. Theodoulidis G. Cultrera C. Cornou P.-Y. Bard T. Boxberger G. DiGiulio A. Imtiaz D. Kementzetzidou K. Makra The Argostoli NERA Team 《Bulletin of Earthquake Engineering》2018,16(2):529-560
In this study data and results of a high-resolution experiment in Cephalonia (Greece) regarding empirical basin effects are presented. A total of 59 velocimeters and 17 accelerometers were deployed in the basin of Argostoli Cephalonia (Greece), for a period of 7 months (September 2011–April 2012). Due to high seismicity of the western Greece and surrounding area this array recorded thousands of local, regional and global events. Data used in this work come from a selection of 162 regional and local earthquakes, 3 km ≤ R ≤ 600 km, with magnitude range, 1.0 ≤ M ≤ 5.2. Based on high signal-to-noise ratio recordings and two selected reference stations, variation of several intensity measures (PGA, PGV, Arias Intensity, Cumulative Absolute Velocity), significant duration, HVSR and SSR of ground motion recordings on soil sites within the basin is carefully examined for a range of frequencies of engineering interest. Comparison of results with a detailed 2D geologic model shows a good consistency both in amplification and frequency domain. Influence of “reference” site on ground motion variation of soil sites is also discussed in light of our results. Finally, it is suggested that 2D or/and 3D theoretical modeling should be performed given the availability of geological and geophysical parameters to define a realistic model of the basin. Results of this study can undoubtedly serve in model validation and improvement of ground motion simulation tools. 相似文献
7.
Maria Mesimeri Christos Kourouklas Eleftheria Papadimitriou Vassilios Karakostas Despoina Kementzetzidou 《Acta Geophysica》2018,66(4):479-495
A thorough spatiotemporal analysis of the intense seismic activity that took place near the Aegean coast of NW Turkey during January–March 2017 was conducted, aiming to identify its causative relation to the regional seismotectonic properties. In this respect, absolute and relative locations are paired and a catalog consisting of 2485 events was compiled. Relative locations are determined with high accuracy using the double-difference technique and differential times both from phase pick data and from cross-correlation measurements. The spatial distribution of the relocated events revealed a south-dipping causative fault along with secondary and smaller antithetic segments. Spatially, the seismicity started at the westernmost part and migrated with time to the easternmost part of the activated area. Temporally, two distinctive periods are observed, namely an early period lasting 1 month and a second period which includes the largest events in the sequence. The investigation of the interevent time distribution revealed a triggering mechanism, whereas the ETAS parameters show a strong external force (μ?>?1), which might be attributed to the existence of the Tuzla geothermal field. 相似文献
8.
Geochemistry and quality of the groundwater from the karstic and coastal aquifer of Geropotamos River Basin at north-central Crete, Greece 总被引：2，自引：2，他引：0
Francesco Sdao Serena Parisi Despina Kalisperi Stefania Pascale Pantelis Soupios Nikos Lydakis-Simantiris Maria Kouli 《Environmental Earth Sciences》2012,67(4):1145-1153
In Geropotamos River Basin, located on the north-central part of Crete, Greece, two main factors were believed to be affecting the geochemistry of the groundwater with high salt contents: seawater intrusion and/or Miocene evaporates. To identify the origin of the high salinity in groundwater, a hydrogeochemical and isotopic study was performed. Water samples from 22 wells and 2 springs were analyzed for physico-chemical parameters, major ions analysis, as well as stable isotopes (??18O, ??D). From the present survey, in which detailed hydrogeochemical investigation was conducted, the uncertainty of the contamination sources was decreased in the northern part of Geropotamos Basin. The results complement the scenario in which seawater and the widespread human activities are the principal sources of groundwater contamination. Moreover, the results of the stable isotopes analyses (??18O and ??D) support the same hypothesis and make seawater intrusion the most probable cause for the highest salinity waters. It is indicated that saline intrusion is likely to occur along fractures in a fault zone through otherwise low-permeability phyllite?Cquartzite bedrock, which demonstrates the critical role of fracture pathways in salination problems of coastal aquifers. 相似文献
9.
Andre Salvaro Furtado Despina Kopanaki Luis Otavio Alvares Vania Bogorny 《Transactions in GIS》2016,20(2):280-298
Most existing approaches aiming at measuring trajectory similarity are focused on two‐dimensional sequences of points, called raw trajectories. However, recent proposals have used background geographic information and social media data to enrich these trajectories with a semantic dimension, giving rise to the concept of semantic trajectories. Only a few works have proposed similarity measures for semantic trajectories or multidimensional sequences, having limitations such as predefined weight of the dimensions, sensitivity to noise, tolerance for gaps with different sizes, and the prevalence of the worst dimension similarity. In this article we propose MSM, a novel similarity measure for multidimensional sequences that overcomes the aforementioned limitations by considering and weighting the similarity in all dimensions. MSM is evaluated through an extensive experimental study that, based on a seed trajectory, creates sets of semantic trajectories with controlled transformations to introduce different kinds and levels of dissimilarity. For each set, we compute the similarity between the seed and the transformed trajectories, using different measures. The results showed that MSM was more robust and efficient than related approaches in the domain of semantic trajectories. 相似文献
10.
Coastal aquifer assessment based on geological and geophysical survey,northwestern Crete,Greece 总被引：6，自引：3，他引：3
Pantelis M. Soupios Despina Kalisperi Asimina Kanta Maria Kouli Pavel Barsukov Filippos Vallianatos 《Environmental Earth Sciences》2010,61(1):63-77
Groundwater preservation comprises a major problem in water policy. The comprehension of the groundwater/hydraulic systems
can provide the means to approach this problem. Generally, drilling is expensive and time-consuming. On the other hand, new
techniques have been applied during the last few decades that provide useful information on the depth and quality of aquifers.
Among them, transient electromagnetic method (TEM) is an appealing method that provides fast results with minimum field crew
and solves several hydrogeological problems. Many portable systems for single-site measurements are commercially available.
The TEM-Fast 48HPC was used for acquiring 106 soundings in the northwestern Crete in Greece for defining the hydrogeological
characteristics of the study area, since there were no available data from boreholes. Detailed geological, hydrolithological
and tectonic survey was applied prior to the geophysical measurements. All the data were integrated to produce a secure and
reliable hydrogeological model for the study area prior to any future hydrowell. Specifically, geometrical and hydraulic data
of the study area groundwater were acquired. Two unconnected aquifers were detected and their possible contamination due to
saltwater intrusion was analyzed and eliminated. Moreover, a location for borehole construction and groundwater pumping based
on the potential of the aquifer system was proposed. Finally, the contribution of TEM (and electrical resistivity tomography)
geophysical methods in studying complex coastal aquifers is shown by this work. 相似文献