bluuebunny/crossref_metadata_2025 huggingface dataset:
Ablative safety margin depicted by fusion imaging with post-treatment contrast-enhanced ultrasound and pre-treatment CECT/CEMRI after radiofrequency ablation for liver cancers
Authors: Bo Xiao-Wan , Xu Hui-Xiong , Guo Le-Hang , Sun Li-Ping , Li Xiao-Long , Zhao Chong-Ke , He Ya-Ping , Liu Bo-Ji , Li Dan-Dan , Zhang Kun , Wang Dan
Published: July 2017

Objective:

To evaluate the value of fusion imaging with post-treatment contrast-enhanced ultrasound (CEUS) and pre-treatment contrast-enhanced CT/MRI (CECT/CEMRI) in evaluating ablative safety margin after percutaneous ultrasound (US)-guided radiofrequency ablation (RFA) for liver cancers.

Methods:

34 consecutive patients with 47 liver lesions who had undergone RFA were included. Fusion imaging with post-treatment CEUS and pre-treatment CECT/CEMRI was carried out to evaluate local treatment response and ablative safety margin within 1–3 days after RFA. The minimal ablative safety margins of the ablation zones were recorded. The complete response (CR) rate was calculated with reference to CECT/CEMRI results 1 month after RFA. The local tumour progression (LTP) was also recorded.

Results:

Of the 47 ablation zones, 47 (100%) were clearly depicted with CEUS-CECT/CEMRI fusion imaging, 36 (76.6%) with US-CECT/CEMRI fusion imaging and 21 (44.7%) with conventional US (both p < 0.001). The minimal ablative safety margins were great than or equal to 5 mm in 28 ablation zones, between 0 and 5 mm in 15, and less than 0 mm in 4. For the four lesions without enough ablative safety margin, three were referred to follow-up because CEUS showed larger ablation zones than pre-treatment lesions and the remaining lesion was subject to additional RFA 5 days after the first RFA. The CR rate was 95.7% (45/47) with reference to CECT/CEMRI results 1 month after RFA. During 2 to 34 months follow-up, LTP was found in two (4.4%) of 45 lesions with CR. Insufficient ablative safety margin was more commonly found in those lesions with LTP than those without LTP (1/4 vs 1/43, p < 0.001).

Conclusion:

Fusion imaging with post-treatment CEUS and pre-treatment CECT/CEMRI can depict the ablative safety margin accurately after RFA. Inadequate ablative safety margin is associated with LTP. Depiction of ablative safety margin by fusion imaging after ablation might be considered as a routine procedure to assess the treatment response of RFA.

Advances in knowledge:

Fusion imaging with post-treatment CEUS and pre-treatment CECT/CEMRI is an effective method to evaluate the ablative safety margin early after RFA. Therefore, it should be recommended to be used as a routine procedure after RFA for liver cancers.
Diagnostic value of semi-quantitative and quantitative analysis of functional parameters in multiparametric MRI of the prostate
Authors: Hauth Elke , Halbritter Daniela , Jaeger Horst , Hohmuth Horst , Beer Meinrad
Published: July 2017

Objective:

To determine the diagnostic value of semi-quantitative and quantitative parameters of three functional techniques in multiparametric (mp)-MRI of the prostate.

Methods:

Mp-MRI was performed in 110 patients with suspicion of prostate cancer (PCA) before transrectal ultrasound (TRUS)-guided core biopsy.

Peak-enhancement, initial and post-initial enhancement, initial area under gadolinium curve, Ktrans (forward rate constant), Kep (efflux rate constant), Ve (extracellular volume), ADC (apparent diffusion coefficient) and MR spectroscopy ratio were obtained for malignant and benign lesions. For iAUGC, Ktrans, Kep and Ve we evaluated median, mean and the difference (Diff) between mean and median. For ADC we evaluated mean, median, Diff between mean and median, and min. In addition, we evaluated these parameters in dependence of Gleason score in PCA. Receiver operating characteristic analysis and area under curve (AUC) were determined.

Results:

ADC min and Kep Diff were the best predictors of malignancy in all lesions (AUC: 0.765). ADC min was the best predictor of malignancy for lesions in peripheral zone (PZ) (AUC: 0.7506) and Kep Diff was the best predictor of malignancy for lesions in transitional zone (AUC: 0.7514). Peak enhancement was the best parameter in differentiation of low-grade PCA with Gleason score 6 from high-grade PCA with Gleason score ≥ 7 (AUC: 0.7692).

Conclusion:

ADC min can differentiate PCA from benign prostate lesions in PZ. Kep Diff could possibly improve prostate cancer detection in. Peak enhancement might be able to differentiate low grade from high-grade PCA. Semi-quantitative and quantitative parameters may be useful for the functional techniques in mp-MRI.

Advances in knowledge:

ADC min can differentiate PCA from benign prostate lesions in PZ.

Peak enhancement might be able to differentiate low grade from high-grade PCA.
MRI assessment of sacroiliitis for the diagnosis of axial spondyloarthropathy: comparison of fat-saturated T2, STIR and contrast-enhanced sequences
Authors: Sung Siyoun , Kim Hyun Su , Kwon Jong Won
Published: July 2017

Objective:

To evaluate whether there are significant differences between contrast-enhanced fat-saturated T  1 weighted imaging and non-enhanced fat-suppression imaging for diagnosing sacroiliitis in patients with inflammatory back pain.

Methods:

92 patients, consisting of 46 males and 46 females (mean age: 34 years; range: 15–63 years), who met at least 4 out of 5 Assessment in SpondyloArthritis international Society criteria for inflammatory low back pain were enrolled in this study. All patients underwent MRI consisting of a coronal short tau inversion recovery (STIR) sequence, axial fat-saturated T  2 weighted imaging (T2FS), and coronal and axial contrast-enhanced fat-saturated T  1 weighted imaging (c & a T1CE). Two observers independently reviewed an image set of coronal STIR with axial T2FS, and an image set of c & a T1CE, at separate times. The degree of bone marrow edema and osteitis was evaluated from each image set. A decision for sacroiliitis positivity for each image set was made based on the findings. The presence of additional active inflammatory findings of spondyloarthropathy such as synovitis, enthesitis and capsulitis were also evaluated.

Results:

Interobserver and intersequence agreement for the degree of bone marrow edema and osteitis were good or excellent in all quadrants. Cohen’s kappa coefficients for sacroiliitis positivity between the two observers were 0.978 and 0.956, and Cohen’s kappa coefficients between the two image sets for each observer were 0.892 and 0.870, respectively. The intersequence agreement of additional active inflammatory findings was substantial, and the interobserver agreement was almost perfect or substantial.

Conclusion:

STIR with T2FS image is comparable to T1CE image for diagnosing spondyloarthropathy. T1CE images may have a role in evaluating additional active inflammatory findings of spondyloarthropathy such as synovitis, enthesitis and capsulitis.

Advances in knowledge:

Coronal STIR with axial T2FS may be sufficient for diagnosis spondyloarthropathy without use of contrast administration.
EFFECTS OF SLAB ROLLBACK ACCELERATION ON AEGEAN EXTENSION
Authors: Brun J.-P. , Faccenna C. , Gueydan F. , Sokoutis D. , Philippon M. , Kydonakis K. , Gorini C.
Published: July 2017

Aegean extension is a process driven by slab rollback that, since 45 Ma, shows a twostage evolution. From Middle Eocene to Middle Miocene it is accommodated by localized deformation leading to i) the exhumation of high-pressure metamorphic rocks from mantle to crustal depths, ii) the exhumation of high-temperature rocks in core complexes and iii) the deposition of Paleogene sedimentary basins. Since Middle Miocene, extension is distributed over the whole Aegean domain giving a widespread development of onshore and offshore Neogene sedimentary basins. We reconstructed this two-stage evolution in 3D at Aegean scale by using available ages of metamorphic and sedimentary processes, geometry and kinematics of ductile deformation, paleomagnetic data and available tomographic models. The restorationmodel shows that the rate of trench retreat was around 0.6 cm/y during the first 30 My and then accelerated up to 3.2 cm/y during the last 15 My. The sharp transition observed in the mode of extension, localized versus distributed, which occurred in Middle Miocene correlates with the acceleration of trench retreat and is more likely a consequence of the Hellenic slab tearing documented by mantle tomography. The development of large dextral NE-SW strike-slip faults during the second stage of Aegean extension, since Middle Miocene, is illustrated by the 450 Km-long fault, recently put in evidence, offshore from Myrthes to Ikaria and onshore from Izmir to Balikeshir, in western Anatolia. Therefore, the interaction between the Hellenic trench retreat and the westward displacement of Anatolia started in Middle Miocene,almost 10 Ma before the propagation of the North Anatolian Fault in the North Aegean. This raises a fundamental issue concerning the dynamic relationship between slab tearing and Anatolia displacement.
TECTONIC REGIME OF THE SUBURBAN (SOUTHERN) AREA OF CHANIA CITY IN CRETE ISLAND BY USING GEOPHYSICAL METHODS
Authors: Komelidou C. , Kirmizakis P. , Soupios P. , Savaidis A. , Tsourlos P.
Published: July 2017

The transient electromagnetic method (TEM) has gained increasing popularity over the last years especially in hydrogeophysical and geotectonic applications. TEM-Fast 48HPC was used for collecting the sounding data during summer 2015. The main purpose of this work was the definition of the geotectonic characteristics at the Southern area of the city of Chania by means of TEM-Fast sounding survey which was carried out in the summer of 2015. Detailed geological survey was applied prior the geophysical measurements and all the available borehole logs were collected. All data were integrated to provide a reliable geotectonic model of the area under investigation. Joint faults systems were detected which are in agreement with previous geophysical and tectonic studies in the area. This work shows clearly the applicability and efficiency of the TEM in studying complex geotectonic environment.
A MULTIDISCIPLINARY INVESTIGATION AT THE LASTROS-SFAKA GRABEN, CRETE
Authors: Mason J. , Schneiderwind S. , Pallikarakis A. , Wiatr T. , Mechernich S. , Papanikolaou I. , Reicherter K.
Published: July 2017

Results from a multidisciplinary investigation at the Lastros-Sfaka Graben located in eastern Crete are presented. 1.3 km of the Lastros fault was scanned with t-LiDAR and we identified areas with minor external influences (anthropogenic, depositional or erosional) to extract throw rates. Preliminary postglacial throw rates are 0.67 ± 0.15 mm/yr., which is significantly less than stated in the literature. Cemented colluvium is located on the Lastros fault, forming hanging-wall talus lobes and sheets of varying thickness attached to the fault plane. Stable isotope analysis on the cement ndicates that it has a meteoric origin and precipitated from water at temperatures between 5 and 8°C. Field mapping and GPR shows that cemented colluvium, is also present within the hanging-wall subsurface. Trenching (road cut) investigations on the Sfaka fault identified fill material most likely deposited soon after the last palaeoearthquakes that occurred on the fault; 14C dating is currently being carried out to date this fill material.
MAGNETIC SUSCEPTIBILITY CHANGES CORRELATED WITH PALEOENVIRONMENTAL AND LITHOLOGICAL CHANGES, WITHIN BOREHOLE CORES ON EITHER SIDES OF THE KALAMAKI-ISTHMIA FAULT IN CORINTH CANAL
Authors: Pallikarakis A. , Papanikolaou I. , Triantaphyllou M. , Grützner C. , Migiros G. , Reicherter K. , Mason J. , Schneiderwind S.
Published: July 2017

Τhe most important active fault that intersects the eastern tip of Corinth Canal,the Kalamaki-Isthmia fault, is studied in detail, involving data analysis from nine boreholes, magnetic susceptibility measurements within boreholes and paleoenvironmental interpretations. Samples taken from boreholes were analysed and paleoenvironmental changes in the sequence are described. We correlate magnetic susceptibility (MS) measurements with paleoenvironmental and lithological alternations within the boreholes. We have ascribed low MS values to marine highstand deposits and high MS values to lowstand terrestrial deposits. Glacioeustatic sea level changes and tectonic movements have led to a very complicated lithosedimentary pattern that involves subaerial exposure, fluvialterrestrial, lagoonal, shallow marine environments and possibly even some lake sediments. Our results indicate that the Kalamaki fault is active and has a low slip rate of 0.05±0.02 mm/yr.
DEFORMATION PATTERN IN THE WESTERN NORTH AEGEAN TROUGH: PRELIMINARY RESULTS
Authors: Sakellariou D. , Rousakis G. , Vougioukalakis G. , Ioakim Ch. , Panagiotopoulos I. , Morfis I. , Zimianitis E. , Athanasoulis K. , Tsampouraki-Kraounaki K. , Mpardis D.
Published: July 2017

Preliminary interpretation of swath bathymetry data and seismic profiles acquired during four cruises of "YPOTHER/Aegean Explorations" project aboard R/V Aegaeo provides insights into the fault network, fault kinematics and deformation pattern of the western part of the North Aegean Trough (NAT). The N40°E trending western part of the dextral North Anatolian Fault (NAF) runs along the southern margin of the NAT. Numerous high-angle fault splays initiate from and at low angle to NAF. They run firstly in NE-SW direction and then gradually turn to SE-NW forming an imbricate fault pattern, a nicely developed horsetail structure at the western termination of the NAF. The horsetail pattern deforms the NAT's sedimentary infill forming elongate, curved, uplifting or subsiding tectonic blocks arranged along the fault splays. Instead of the expected transtension, the Western NAT's infill displays dextral shearing and transpression associated with a major stress axis in NW-SE direction. The possible explanation for the transpressional deformation of the Western NAT infill may be related with the change of the trend of NAF from N40°E in the western trough to N70°E east of Lemnos Island.
DETERMINATION OF ASEISMIC DEFORMATION ON NORTH ANATOLIAN FAULT IN ISMETPASA AND DESTEK REGIONS USING GPS DATA, TURKEY
Authors: Yavasoglu H. , Alkan M.N. , Aladogan K. , Ozulu I.M , Ilci V. , Sahin M. , Tombus F.E. , Tiryakioglu I. , Kıvrak S.O.
Published: July 2017

The North Anatolian Fault Zone (NAFZ) is one of the most destructive fault in the eastern Mediterranean region. After Izmit and Düzce earthquakes, the projects on monitoring the fault motion increase using instrumental tools like GPS, InSAR, LIDAR, creepmeter, etc. The eastern and central part of the NAFZ from Karlıova to Vezirköprü has almost strike slip mechanism. The western part of the central NAFZ from Vezirköprü to Bolu has transpressive character. The aseismic fault deformation (creep) is also important phenomena for these two sections. The InSAR and LIDAR studies showed that the Ismetpasa and Destek regions have creep motions. For this purpose, the new project has been started to proof this phenomena with GPS data and to determine quantitatively the rate of convergence and its variation along segment of the NAF between Bolu and Çorum. The main aim of this study is determination of creep rate with geodetic measurements and combination of the data obtained from seismology, geodesy and geophysics to understand fault mechanism. Therefore, in this paper we discuss tectonic phenomena on the central part of the NAFZ and present the first results of the project.
“INDUSTRIAL” ROCKS AND MINERALS IN STRABO’S ANCIENT WORLD (1ST CENTURY A.D.)
Authors: Iordanidis A.
Published: July 2017

Industrial rocks and minerals of the modern world comprise of natural products applied in e.g. energy, cement, plastics, fillers, food, computer hardware etc. Indeed, the applications of these minerals are enormous and versatile. On the other hand, industrialization had not occurred during the 1st century A.D., when Strabo, the famous geographer of the Roman era lived. Thus, the term “industrial” used in this study has a rather philological meaning and refers to the useful rocks and minerals in the ancient times. Metallic ores (copper, iron, zinc etc.), precious metals (gold, silver) and earth minerals (e.g. Kimolo’s earth, Chalkidiki’s earth, Sinopi’s earth etc.) are not included in this study. Humans of the antiquity needed building rocks, medical and pharmaceautical minerals, fertilizers for their crops, sealing agents and millstones, just to mention a few of them. The identification and classification of these valuable “industrial” rocks and minerals, mentioned in Strabo’s Geographica, is the scope of this work. The spatial distribution of these mineral resources in the ancient world of that time, is also studied. The main industrial rocks and minerals are (in descending order of the number of citations): salt, marble, asphalt, quarry rocks, sulphur, millstones, pyroclastics, clays, soda (sodium carbonate), naphtha (petroleum), asbestos and sand.
EXPLOITATION OF PALAEONTOLOGICAL AND HYDROGEOLOGICAL FEATURES FOR GEOTOURISM IN MESOPOTAMIA - OINOI, KASTORIA, NORTHERN GREECE
Authors: Kazakis N. , Syrides G. , Voudouris K.
Published: July 2017

The aim of this study is to reveal the geological, paleontological and hydrogeological features of the surrounding area of Oinoi in municipality of Kastoria, Northern Greece. These features can attract visitors and develop geotourism in the area. Fossil mollusk shells (Pectinidae family, Pecten and Flabellipecten) were recognized in three fossiliferous sites. Additionally, the palaeontological features are supplemented by impressive alternations of sedimentary strata, cavities, springs, small natural waterfalls and lakes as well as a small dam. Three routes (the longest is 12.3 Km) were defined for the promotion of these features. The routes are suitable for walking, jogging, mountain biking, climbing, for students, elder people and adults. This is a preliminary approach, since further research in the wider area is needed, in order to include more existing natural features, as well as to create a comprehensive management plan and define the criteria for the proposal of the site as a Geopark.
PRESERVING THE NON-PRESERVABLE GEOHERITAGE OF THE ALIAKMON RIVER: A CASE STUDY IN GEOEDUCATION LEADING TO CUTTING-EDGE SCIENCE
Authors: Rassios A. , Grieco G. , Batsi A. , Myhill R. , Ghikas D.
Published: July 2017

The initial documentation of an ophiolite as oceanic lithosphere and the significance of an ophiolite’s basal sole in its emplacement were based on the research of E. Moores (1969) and J. Zimmerman (1968) at the Vourinos Ophiolite, Greece: their work became a lynch-pin in the establishment of plate tectonic theory. Key localities of their research were located along the Aliakmon River Valley between Ilariona Monastery and the village of Panayia. This same area has since been flooded (2012) with the construction of a new hydroelectric reservoir. There was no option for “saving” these sites of the birth of plate tectonic theory: what could be done to preserve their geoheritage? Between 2005 and 2008, the Institute of Geology and Mineral Exploration, with funding provided from the Public Power Corporation, sponsored geo-education to provide a “last chance” of geologic documentation of the Aliakmon Valley. In a three year period, over 60 international student and professorial-level researchers participated in the project. 37 Senior Theses were produced and 6 masters’ dissertations. The greatest achievement of the program was the revitalization of the Aliakmon data base within current, cutting-edge scientific models.
GLOBAL GEOPARKS NETWORK AND THE NEW UNESCO GLOBAL GEOPARKS PROGRAMME
Authors: Zouros N.
Published: July 2017

The Geopark concept was introduced at late 90’s aiming to protect and promote Earth heritage sites through the sustainable local development of territories containing abiotic nature of significant value. The Global Geoparks Network (GGN) established in 2004 operates as an international platform of cooperation among Geoparks around the world The GGN includes 120 Geoparks in 33 countries working to protect Geological heritage and promote local sustainable development. The 38th UNESCO General Conference (November 2015) ratified the statutes of the new International Geoscience and Geoparks Programme and the UNESCO Global Geoparks Operational Guidelines, introducing the brand UNESCO Global Geopark as a label of excellence for areas that meet the criteria set by the above mentioned guidelines. In doing so, it has legally endorsed the new UNESCO label of “UNESCO Global Geopark" and the endorsement of all the existing 120 Global Geoparks to become UNESCO Global Geoparks with immediate effect.The UNESCO Global Geopark branding could strongly contribute to raising EarthHeritage sites visibility in the world and in high-quality public outreach onsustainable development linked to issues on geodiversity, the environment,geohazards, climate change and the sustainable use of natural resources.
SEDIMENTOLOGICAL AND PALAEOENVIRONMENTAL CHARACTER OF LAKE KORONIA SEDIMENTS
Authors: Doani S. , Albanakis K. , Koukousioura O. , Koliadimou K.K.
Published: July 2017

The aim of the present study is to investigate the sedimentological characteristics of Lake Koronia down to a depth of 3.5m below lake bottom. Sampling operations took advandage of a season that the lake bottom was exposed to subaerial conditions. The sedimentological analysis proved that sediments consist of mud to sandy mud, with 2 phases of very fine sand fractions. The proportion of dry organic matter contained into sediment, appears to be generally small while the rates of moisture and volatiles are relatively high. Furthermore, this study examines the distribution of ostracod populations in the sediments of the lake in relation to depth, grain size and other environmental conditions of this water body. Four ostracod species were identified: Candona neglecta, Darwinula stevensoni, Heterocypris spp. and Limnocythere inopinata. The study of freshwater ostracods provides information for the palaeoecological/palaeoenvironmental conditions during the sedimentation.
PRELIMINARY STUDIES ON SEDIMENT CORE FROM THE TYRO BASIN
Authors: Geraga M. , Anagnostou Ch. , Iliopoulos I. , Kontali M.
Published: July 2017

The present paper summarizes the preliminary results of the mineralogical and micropaleontological analysis conducted on sediment samples from core TYR05 retrieved from the anoxic and hypersaline Tyro basin in the eastern Mediterranean Sea. The core comprises a complex lithostratigraphic sequence attributed to the strong geodynamic regime of the area. The planktonic foraminifera associations present fluctuations which coincide with changes in the lithology of the core. The mineralogical composition of the sediments shows influence from the evaporites developed on the bottom of the basin. The mineral constituents in association to the microfauna assemblages suggest that the sediments include sapropelic layers. Further analyses are needed in order to determine safely the sapropelic deposits.
APPLICATION OF OSL METHOD IN DATING PAST EARTHQUAKES
Authors: Tsodoulos I. , Stamoulis K.C. , Papachristodoulou C. , Pavlides PS. , Ioannides K.G.
Published: July 2017

The aim of this study was to establish a chronological frame of paleoseismic events  of Gyrtoni Fault, (Thessaly, Central Greece), with the use of OSL dating method. The Gyrtoni Fault, defines the north-eastern boundary of the Middle-Late Quaternary Tyrnavos Basin, and was previously investigated with geological methods. Twenty five fluvial-colluvial sediment and pottery samples were collected from two paleoseismological trenches, excavated along the Gyrtoni Fault, from both the upthrown and the downthrown fault blocks. Optically Stimulated Luminescence (OSL) dating was applied to coarse grain quartz using the single-aliquot regenerative-dose (SAR) protocol. Investigations of luminescence characteristics using various tests confirmed the suitability of the material for OSL dating using the SAR protocol. Radioactivity measurements were performed in order to estimate the annual dose rateof the surrounding soils to which the quartz grains were submitted during the burial period of the collected samples. The estimated OSL ages agreed well with the available stratigraphical data, and archaeological evidence. The occurrence of three surface faulting events in a time span between 1.42 ± 0.06 ka and 5.59 ± 0.13 ka was revealed while an earlier faulting event (fourth) was also recognized to be older than 5.59 ± 0.13 ka.
BEACHROCKS CEMENT CHARACTERISTICS AND CONDITIONS OF FORMATION. CASE STUDY PLATANIAS BEACH, CHANIA, GREECE
Authors: Petropoulos A. , Baziotis I. , Anagnostou Ch. , Evelpidou N.
Published: July 2017

Beachrocks represents a coastal deposition in the intertidal area, and studying their properties may lead to create a model which identifies the conditions of their formation (paleo-environment). This paper focuses most intently on the cement material which is able to recover the paleo-environment conditions during diagenesis of such coastal sediment. We used optical microscopy, secondary electron microscopy and Raman Spectroscopy to characterize the cement texture, mineralogy and chemistry in the beachrocks. The existence of pure calcite primarily controlled by the meteorite water, while Mg-calcite appears between the lowermeteoric and the upper marine phreatic zone. Finally, the presence of aragonite associated with the marine phreatic to lower marine vadose environment.
FIELD OBSERVATIONS OF THE 2015 (NOVEMBER 17, MW 6.4) LEFKAS (IONIAN SEA, WESTERN GREECE) EARTHQUAKE IMPACT ON NATURAL ENVIRONMENT AND BUILDING STOCK OF LEFKAS ISLAND
Authors: Lekkas E. , Mavroulis S. , Alexoudi V.
Published: July 2017

On Tuesday, November 17, 2015 at 07:10:07 (UTC) a strong earthquake struck Lefkas Island (Ionian Sea, Western Greece) with magnitude Mw 6.4, depth of about 7 km and epicenter located 20 km southwest of Lefkas town. The seismic activity in the region was essentially expected after the 2003 Lefkas earthquake and the 2014 Cephalonia earthquakes. Between these earthquake affected areas, the tectonic stresses were not released after the 1948 Lefkas earthquakes. Instead, they were intensifying and accumulating until the generation of the 2015 event. It was felt in Lefkas and the surrounding region and caused the death of 2 people, the injury of 8 others, earthquake environmental effects (EEE) and damage to buildings and infrastructure. Secondary EEE were observed in western Lefkas and included ground cracks, slope movements and liquefaction. Primary effects were not detected in the field. Buildings damage were mainly observed in villages of Dragano-Athani graben in southwestern Lefkas. Among structures constructed with no seismic provisions, the stone masonry buildings and monumental structures suffered most damage, while the traditional buildings with dual structural system performed relatively well. Reinforced-concrete buildings were affected not so much by the earthquake itself but by the generation of secondary effects.
NUMERICAL MODELLING OF SLOPE STABILITY IN OPEN PIT LIGNITE MINES: A COMPARATIVE STUDY
Authors: Deliveris A.V. , Zevgolis I.E. , Koukouzas N.C.
Published: July 2017

Slope stability of an open pit lignite mine was studied using numerical methods (FEM and FDM), by means of three different software packages whose performance was compared and similarities - differences were identified. Plane strain analyses were performed using the shear strength reduction technique under drained conditions and Mohr-Coulomb constitutive models. Based on the results, all three programs demonstrated qualitatively a good agreement in the determination of safety factors and the kinetics of the collapse mechanisms. Small differences were observed in terms of shear strains localizations. Important differences were evident in the development of plastic (shear) and tensile failure indicators. Nevertheless, the problem under examination may be addressed satisfactorily by all three programs.
LIQUID LIMIT VALUES OBTAINED BY DIFFERENT TESTING METHODS
Authors: Kollaros G.
Published: July 2017

Specifications in European countries include a variety of methods for determining the liquid limit based on Casagrande type devices and on the fall cone penetrometer. The results of a comparative study of the liquid limits determined using these two fall-cone methods are presented for lime stabilized soil. Soil material sampled in the area of Evros Regional Unit has been stabilized with lime in order to enhance its engineering characteristics. The soil and the soil-lime mixtures subjected in Atterberg limit testing. The liquid limit values were correlated through a linear regression analysis with the rest of the consistency limits of both the natural soil and its mixtures with various lime contents. The correlation coefficients in all cases were high, with those referring to results obtained by the Casagrande method to be dominant. The comparison of liquid limit values determined by either method showed that there is a systematically good correlation between them, with the decrease rate in function of the lime content in the mixture to be more intense in the case of the drop-cone procedure. There is a need for a universal specification for the determination of the consistency limits.
OVEREXPLOITATION OF GROUNDWATER RESOURCES IN THE COASTAL AQUIFER SYSTEM OF ARGOLIS
Authors: Mitropapas A. , Koumantakis I. , Vasileiou E. , Perdikaki M. , Kallioras A.
Published: July 2017

Intense abstraction of groundwater resources in the coastal aquifer system of Argolis is investigated since the late 1950’s. The increasing water demands due to the agricultural development of the area (mainly citrus trees) during the last years, in combination with the touristic growth, has led to the overexploitation of groundwater resources of the coastal aquifer system of Argolis. This paper presents the piezometric conditions in the plain of Argos during the period between 1986 and 2014, analysing the fluctuations of groundwater levels and highlighting the problem of seawater intrusion in the study area. In October 2014, measurements were made in app. 160 wells and drills which are located within the boundaries of the granular aquifer of the study area. Selected piezometric maps are presented, which demonstrate the problem of overexploitation of groundwater in the plain of Argos.
CONTRIBUTION TO HYDRAULIC CHARACTERISTICS OF PLIO-PLEISTOCENE DEPOSITS OF THRIASSION PLAIN OF ATTICA
Authors: Hermides D. , Mimides T. , Stamatis G.
Published: July 2017

The geological structure of Thriassion Plain is generally complex and has been affected at different times by many tectonic activities. The last ones are the neotectonic, which caused horsts and grabens structures. Geologic and tectonic structures have influenced the hydrogeological conditions and the groundwater flow. Hydraulic characteristics of Plio-Pleistocene deposits differ throughout their extent. In this study, pumping tests in Plio-Pleistocene deposits are represented and the hydraulic characteristics transmissivity T, storativity S and hydraulic conductivity K are assigned. Pumping tests, in 8 totally wells, were conducted in the dry period. Methods as Cooper-Jacob’s, Theis’s, Papadopoulos Cooper’s and Neuman’s and last the Recovery method, are used to assign the hydraulic characteristics. These tests highlighted the Recovery method as the most reliable. Transmissivity T: 18-279.1 m2/d, storativity S: 2.5*10-3 3*10-2and hydraulic conductivity K: 0.4-25.1 m/d. Specific capacity is also determined ranging between 16-360 m3/d/m. This study contributes, essentially, in the approach of hydrogeological conditions of Thriassion Plain.
MODELING THE TRANS-ATLANTIC TRANSPORTATION OF SAHARAN DUST
Authors: Tsikerdekis A. , Zanis P. , Steiner L.A. , Amiridis V. , Marinou E. , Katragkou E. , Karacostas Th. , Solmon F.
Published: July 2017

In the present study we are simulating the trans-Atlantic transport of dust from Sahara to the South-Central America, using the regional climate model RegCM4 and its online dust scheme, for the year 2007. The simulated horizontal and vertical distributions of the mineral dust optical properties were evaluated against the LIVAS CALIPSO satellite dust product. The Trans-Atlantic dust transport is simulated adequately with RegCM4, but there are some spatial discrepancies. Dust optical thickness is overestimated in the eastern Sahara throughout the year by 0.1-0.2, while near the gulf of Guinea is underestimated during winter and spring. Although RegCM4 dust plume is located southern on winter and spring, it doesn't spatially match the dust optical thickness of LIVAS. In summer and autumn the vertical distribution of dust between 3-4km during the Trans-Atlantic transport is simulated by the model adequately up to 30ºW 40ºW longitude. However, during winter-spring RegCM4 misplaces dust loading into higher altitude. Finally, we discuss some possible reasons and mechanisms that might be responsible for the differences between the model and the observations.
THE HELLENIC NATIONAL TSUNAMI WARNING CENTER: RESEARCH, OPERATIONAL AND TRAINING ACTIVITIES
Authors: Papadopoulos G.A. , Tselentis G.A. , Charalampakis M. , All the scientific staff of the Institute of Geodynamics1 All the scientific staff of the Institut
Published: July 2017

The Hellenic National Tsunami Warning Center (HL-NTWC), which is a unit of the Institute of Geodynamics of the National Observatory of Athens (NOA-IG), was officially established in Greece by law in September 2010. It operates a 24/7 tsunami monitoring service for Greece and the eastern Mediterranean Sea, providing warning messages to the General Secretariat for Civil Protection in Greece. Since August 2012, HL-NTWC acts as Candidate Tsunami Service Provider (CTSP) in the framework of the North-Eastern Atlantic, the Mediterranean and connected seas Tsunami Warning System (NEAMTWS) of the IOC/UNESCO providing tsunami messages to a large number of subscribers. The HL-NTWC function is based on the national seismograph and tide gauge networks of NOA-IG and incorporates several data bases, algorithms and computational tools. Collaboration with top class research institutions in the framework of important EC funded tsunami research projects strengthens the scientific background of the center. Tests, exercises and training of the duty officers involved in the 24/7 operation of the HL-NTWC are carried on constantly, in order to maintain a high level of readiness and response in case of emergency. In its operational life since August 2012 the HL-NTWC has timely issued tsunami warning messages for 14 potentially tsunamigenic earthquake events.
SCISOLA: REAL-TIME MOMENT TENSOR MONITORING FOR SEISCOMP3
Authors: Triantafyllis N. , Sokos E. , Ilias A.
Published: July 2017

Automatic Moment Tensor (MT) calculation is exceptionally valuable in many realtime seismological applications, such as shake map generation or tsunami warning. Scisola, a new software for automatic MT retrieval, has been recently developed. This software binds the extensively used ISOLA MT inversion code with the widely known real-time seismological processing tool, SeisComP3. Automatic MT calculation is achieved by passing the event location information, the waveforms and the station meta-data produced by SeisComP3 to ISOLA. Scisola has been written in Python, many powerful libraries were used and significantly reduced the MT computation time by calculating the Green's functions and the centroid position/time grid search in parallel mode. This tool provides a graphical user interface for easy solution overview of the extended graphical output and a quick revision of the corresponding solution; a database for storing the results and an extensive configuration customized to the user's preferences. Apart from the real-time MT approach, scisola is capable of running in offline mode mostly for testing or playback purposes. Lately, a scisola plug-in was completed for real-time MT monitoring by automatically updating a Web page with the latest MT calculations. The code's performance was compared to manual MT solutions and proved to be satisfying.
SEISMOGENIC SOURCES IN THE AEGEAN AREA AND THEIR PREDICTIVE PROPERTIES
Authors: Papazachos B.C. , Karakaisis G.F. , Scordilis E.M. , Papaioannou Ch.
Published: July 2017

On the basis of all available information eight circular seismogenic sources, where shallow (h 100km) earthquakes occur, are defined in the broader Aegean area. The location of each source is further improved by optimization of the quasi-periodic properties of the strong (M≥6.0) instrumentally recorded mainshocks, identified in a complete catalogue of earthquakes (1911-2014) after declustering. Moreover, in the same seismogenic sources, all M≥6.3 mainshocks that comprise another complete catalogue (1850-2014) have also occurred. Interevent times of mainshocks generated in each source have predictive properties expressed by the TIMAPR (Time and Magnitude Predictable Regional) model whereas preshocks of recent mainshocks have also such properties expressed by the D-AS (Decelerating-Accelerating Seismicity) model. Retrospective prediction of the last mainshock in each source by the joint application of the two models resulted in reasonable uncertainties. Then, as a forward test, data up to the end of 2014 were used to predict the next expected mainshock in each of the eight sources and to identify the fault where its epicentre will probably be located.
ON THE NATURE AND DYNAMICS OF THE SEISMOGENETIC SYSTEM OF SOUTH CALIFORNIA, USA: AN ANALYSIS BASED ON NON-EXTENSIVE STATISTICAL PHYSICS
Authors: Efstathiou A. , Tzanis A. , Vallianatos F.
Published: July 2017

We examine the nature of the seismogenetic system in South California, USA, by searching for evidence of non-extensivity in the earthquake record. We attempt to determine whether earthquakes are generated by a self-excited Poisson process, in which case they obey Boltzmann-Gibbs thermodynamics, or by a Critical process, in which long-range interactions in non-equilibrium statesare expected (correlation) and the thermodynamics deviate from the Boltzmann-Gibbs formalism. Emphasis is given to background earthquakes since it is generally agreed that aftershock sequences comprise correlated sets. Accordingly, the analysis is based on the accurate earthquake catalogue compiled of the South California Earthquake Data Center, in which aftershocks are either included or have been removed with a stochastic declustering procedure. We examine multivariate cumulative frequency distributions of earthquake magnitudes, interevent time and interevent distance, in the context of Non-Extensive Statistical Physics, which is a generalization of extensive Boltzmann-Gibbs thermodynamics to non-equilibrating (non-extensive) systems. The results indicate a persistent subextensive seismogenetic system exhibiting long-range, moderate to high correlation. Criticality appears to be a plausible causative mechanism although conclusions cannot be drawn until alternative complexity mechanisms can be ruled out.
SIGNIFICANT EARTHQUAKES NEAR THE CITY OF THESSALONIKI (NORTHERN GREECE) AND PROBABILITY DISTRIBUTION ON FAULTS
Authors: Paradisopoulou P.M. , Papadimitriou E.E. , Mirek J.
Published: July 2017

Stress triggering must be incorporated into quantitative earthquake probability estimate, given that faults are interacted though their stress field. Using time dependent probability estimates this work aims at the evaluation of the occurrence probability of anticipated earthquakes near the city of Thessaloniki, an urban center of 1 million people located in northern Greece, conditional to the time elapsed since the last stronger event on each fault segment of the study area. A method that calculates the macroseismic epicenter and magnitude according to macroseismic intensities is used to improve the existing earthquake catalog (from AD 1600 - 2013 with M≥6.0) in order to compute new interevent and elapsed time values which form the basis for time-dependent probability estimates. To investigate the effects of stress transfer to seismic hazard, the probabilistic calculations presented here employ detailed models of coseismic stress associated with the 20 June 1978 M=6.5 Thessaloniki which is the latest destructive earthquake in the area in the instrumental era. The combined 2015-2045 regional Poisson probability of M≥6.0 earthquakes is ~35% the regional time-dependent probability varies from 0% to 15% and incorporation of stress transfer from 0% to 20% for each fault segment.
SEISMIC DAMAGE SCENARIOS IN KALAMATA (S. GREECE)
Authors: Kazantzidou-Firtinidou D. , Kassaras I. , Ganas A. , Tsimi C. , Sakellariou N. , Mourloukos S. , Stoumpos P. , Michalaki K. , Giannaraki G.
Published: July 2017

Damage scenarios are necessary tools for stakeholders, in order to prepare protection strategies and a total emergency post-earthquake plan. To this aim, four seismic hazard models were developed for the city of Kalamata, according to stochastic simulation of the ground motion, using site amplification functions derived from ambient noise HVSR measurements. The structural vulnerability of the city was assessed following an empirical macroseismic model, developed for the European urban environment (EMS-98). The impact of the vulnerability due to the seismic hazard potential is also investigated by means of synthetic response spectral ratios at 108 sites of the city. The expected damage grade per building block, is calculated by combining vulnerability with the respective seismic intensities, derived for the four seismic sources. The importance of the followed methodology for implementing microzonation studies is emphasized, since the expected influence of the ground motion amplification due to local soil conditions has been approximated in detail. Moreover, new fragility curves for the main structural types in Kalamata are proposed for each seismic scenario.
MONITORING SEISMIC DISPLACEMENTS USING GNSS DATA WITH PPP METHOD
Authors: Pikridas C. , Bitharis S. , Fotiou A. , Rossikopoulos D. , Katsougiannopoulos S. , Spanakaki K. , Karolos I.
Published: July 2017

The Precise Point Positioning (PPP) analysis method adapted for monitoring coordinate displacements from GNSS permanent stations data. One week period data were analyzed covering the Samothrace strong earthquake event of 6.8M. The sample data were processed with Bernese v5.2 PPP engine and with the online web platform of JPL which uses the GIPSY/OASIS v6.3 software package. Also, for validation purposes the output results were compared with those derived by network analysis by means of the GAMIT processing software of MIT. Our experiments proved the ability to measure dynamic seismic related coordinate variations at sub-centimeter level using the PPP algorithm. But this is efficient when strong earthquakes occurs and for stations close to epicenter.
MODELS AND TECHNIQUES IN GEODETIC MONITORING OF TECTONIC DEFORMATIONS IN GREECE
Authors: Rossikopoulos D. , Fotiou A. , Pikridas C. , Bitharis S.
Published: July 2017

The assessment and interpretation of the geodetic results regarding the detection of possible spatial displacements and the deformation parameters have to be combined with a realistic geophysical model for the area. Usually, this study is carried out by fitting the geodetic data to a polynomial function, which is considered sufficient to describe adequately the deformation pattern. In terms of the computational steps needed, this polynomial fitting can be accomplished simultaneously by the analysis of the geodetic observations in a dynamic adjustment or non simultaneously in a sequential approach. The main goal of this article is to give a short description of the related methods and to present rigorous processing strategies for the analysis of GNSS observations from continuously permanent stations in order to create a modern and improved geodetic velocity field for Greece. Emphasis is given on the reference frame definition problem.
ASSESSING GROUND SUBSIDENCE PHENOMENA WITH PERSISTENT SCATTERER INTERFEROMETRY DATA IN WESTERN THESSALY, GREECE
Authors: Ilia I. , Loupasakis C. , Tsangaratos P.
Published: July 2017

The main objective of the present study was to investigate ground subsidence in the wider area of Farsala, western Thessaly basin, by means of remote sensing techniques and to identify potential geo environmental mechanisms that contribute to the development of the observed surface fractures affecting the site. In this context, a set of Synthetic Aperture Radar (SAR) images, acquired in 1995-2003 by the European Space Agency (ESA) satellites ERS1 and ERS2 and processed with the Persistent Scatterer Interferometry (PSI) technique by the German Space Agency (DLR) during the Terrafirma project, were evaluated in order to investigate spatial and temporal patterns of deformation. Groundwater table levels of three water boreholes within the research area were processed providing the mean piezometric level drawdown and the mean annual drawdown rate. In addition, a quantitative comparison between the deformation subsidence rate and the thickness of the compressible sediments was also performed. The outcomes of the present study indicated a clear relationship in the subsidence deformation rate and the groundwater fluctuation and also a correlation between the depth of the bedrock and the deformation subsidence rate. Overall, the multitemporal SAR interferometry (DInSAR) data are proved as a valuable and suitable technique for increasing knowledge about the extent and the rate of the deformations in the current study area, proved to be affected with an increasing intensity.
SENTINEL-1 DATA TO MAP FLOODED AREAS: THE ROLE OF INSAR COHERENCE AND POLARIMETRIC INFORMATION
Authors: Papastergios A. , Chini M. , Parcharidis I.
Published: July 2017

SAR earth observation data can provide high quality flood maps and information to better assess the flood risk accordingly planning as well as to support civil protection authorities during emergency phase. The scope of this paper is to create flood extent maps from a series of SAR scenes of the Evros basin which represents a transboundary floodplain. The study uses time series SAR images of Sentnel-1 ESA’s Copernicus satellite system covering the period October 2014 to May 2015. The methodology tries to identify the flood that occurs in three main land cover classes, such as urban areas, bare or poorly vegetated soil and vegetated areas, taking advantage of co- and cross-polarized SAR backscattering channels, and the InSAR coherence to better characterize the landscape. Dual-pol SAR data provides the opportunity to have a better understanding and interpretation of flood detection due to way different land cover react to different polarizations. Thus, with the implementation of InSAR coherence estimation we may achieve a better record and knowledge of the flooded areas, over time, in the specific region.
TECHNIQUES OF ROCKFALL INVENTORY IN EARTHQUAKE PRONE ROCK SLOPES
Authors: Zygouri V. , Koukouvelas I.
Published: July 2017

A relevant hazard in mountainous regions is the steep rock slopes concentrating rock falls. Although rock falls are characterized by smaller rock volumes compared to other landslide types, can also provoke severe damage to buildings, infrastructures and human life due to their sudden and highly fast movement. The key to understand the processes that result in rock fall onset is an integrated study of the major causing parameters that affect slope stability. A rock slope may be subjected to many forms of triggering factors including tectonic, geomorphic, seismic, climatic or even human induced damages. This contribution provides an overview of the previous and current research related to rock falls and uses case studies of North Peloponnese in order to prove the usefulness of these methods in the Greek territory. Collecting data and production of thematic maps by means of field and remote sensing investigations can yield far more updated results incorporated in hazard assessment techniques and protection measures.