Sterea Hellas Research Articles

NEOTECTONIC BASIN EVOLUTION IN CENTRAL-EASTERN MAINLAND GREECE: AN OVERVIEW

The neotectonic evolution of central-eastern mainland Greece (Sterea Hellas) is documented in the result of local extensional tectonics within a regional transtensional field, which is related to the westward propagation of the North Anatolian Fault. The observed tectonic structures within the neotectonic basins and their margins (range-bounding faults and fault zones, rotation of tectonic blocL·) suggest a close relation to the Parnassos Detachment Fault (PDF), which is a reused alpine thrust surface. Lokris basin (LB) occupied a central position in this neotectonic configuration, having received its first sediments in the Uppermost Miocene and subsequently been greatly affected by tectonic episodes, which continue until nowadays. LB is considered to have been separated from the present-day North Gulf of Evia not earlier than the Lower Pleistocene. Voiotihos Kifissos Basin, on the other hand, is tightly related to the activation of PDF, occupying the position of a frontal basin and having developed along the main detachment front.

Using Oxygen Isotopic Values in Order to Infer Palaeoclimatic Differences between Northern and Central-Southern Greece

Even though isotopic analyses have been extensively implemented on human skeletal remains for the purpose of dietary reconstruction, less attention has been given to the ingested water and thus to the investigation of palaeoclimatic conditions. In particular, oxygen isotopic fingerprinting has never been applied on human skeletal remains from Greece for the abovementioned purpose before. The basic aim of the present study is to compare climatic conditions from two ancient populations, deriving from two different ecological locations; Edessa (Greek Macedonia; 2nd-4th c. AD) and Thebes (Sterea Hellas, 13th-14th c. AD). Oxygen values in Edessa are at -7.69 ±1.13 ‰ and -9.18 ±1.88 ‰ for tooth enamel and bone apatite respectively. On the other hand, oxygen signals in Thebes are at -5.8 ±2.16 ‰ and -9.23 ±1.3 % for the enamel and bone apatite respectively. The utility of oxygen isotopic signatures for the purpose of palaeoclimatic investigation lies on the fact that the ratio of 18 to 16O of meteoric precipitation, expressed as δ18O per mill (‰), relative to the international standard (vSMOW) varies geographically by temperature, humidity, evaporation, distance to the sea, altitude and latitude. Therefore, results as expected, point out that Edessa do presents more negative enamel isotopic values in relation to Thebes, however the noted difference is not observed for the bone apatite samples. The lack of bone apatite differentiation between sites could be attributed to cultural diversity (particularly in Thebes), shift in dietary habits due to migration or social status, climatic fluctuations within each site or to possible diagenetic alteration of bone apatite samples.

Serological survey of antibodies against Toxoplasma gondii in organic sheep and goat farms in Greece

Toxoplasmosis is a parasitic infection with global distribution caused by the protozoon Toxoplasma gondii. The present study is divided into the preliminary and the basic research. In the preliminary research, 413 serum samples (184 sheep and 229 goats) from organic farms of Péloponnèse and Western Sterea Hellas were tested for IgG antibodies against Τ gondii, by using enzyme-linked immunosorbent assay (ELISA). Blood sampling took place during spring of 2005 and samples were taken from male animals and female that had aborted during the reproductive period of 2004-2005. Significant prevalence of antibodies was the reason that further research of toxoplasmosis in organic farms was conducted. For the basic research, small ruminants' blood samples from organic farms of Péloponnèse, Western Sterea Hellas and the county of Ioannina, were collected during summer of 2006. Blood samples were collected from flocks with cases of abortions during the reproductive period of 2005-2006. Animals were separated into 3 groups: males, females that had abortions during the reproductive period of 2005-2006 and females that did not have abortions during the same period. A total number of 182 sheep sera and 167 goat sera were tested by using the enzyme-linked immunosorbent assay (ELISA). The results showed that antibodies were detected in 38.46% of male sheep, 60.87% of female sheep that had abortions during the reproductive period 2005-2006 and in 54.21% of female sheep that did not have abortions during the same period. Significant difference was determined only between male and female animals (p<0.05). In addition, antibodies were detected in 12.12% of male goats, 14.29% of female goats that had abortions and in 22.35% of female goats that did not have abortions in the reproductive period 2005-2006. There was no significant difference between the results (p>0.05). Seroprevalence in goats was significandy lower than that of the sheep (p<0.05). In animals, aged less than 4 years old, seroprevalence was significantly lower (39.58% for sheep and 13.04% for goats) than that for animals aged more than 4 years old (61.97% for sheep and 24% for goats) (p<0.05). The results of the survey suggest that there is high prevalence of toxoplasmosis both in animals that had aborted and in animals that had not aborted and that there are different species and gender susceptibility. Results also indicate that toxoplasmosis is more common in older animals.

Species of honeydew producing insects useful to apicu1ture in Greece

Μέχρι σήμeρα έχουν αναφeρθeί στην Eλλάδα 38 eίδη μeλιτογόνων eντόμων. Τα τeλeυταία χρόνια, άλλα δέκα eίδη eντόμων των οποίων τις μeλιτώδeις eκκρίσeις βόσκουν και eκμeταλλeύονται οι μέλισσeς βρέθηκαν στη χώρα μας. Τα eίδη αυτά, που ανήκουν στα Hemiptera-Homoptera eίναι τα: οι αφίδeς Acyrthosiphon caraganae (Cholodkovsky) σe ποντίκια (Coluteci arborescens L.), Corylobiuiii avellanae (Schrank) σe φουντουκιά (Corylus avellana L.), Hyalopterus amygdali (Blanchard) σe αμυγδαλιά (Prunus diilcis (Miller) D. A. Webb), Cinara juniperi (De Geer) σe κέδρο (Juniperus spp.), Cinara tujufiliiui (del Guercio) σe τούγια (Thuja spp.), Phillaphis fagi (L.) σe οξυά (Fagus silvatica L.), Pterocallis maculata (Von Heyden) σe κλήθρα (Alnus glutinosa Garth.) και Tuberculoides eggleri Bornes (Quercus spp.). Από αυτές οι τρeις πρώτeς ανήκουν στην οικογένeια Aphididae, δύο στην οικογένeια Lachnidae και οι τρeις τeλeυταίeς στην οικογένeια Drepanosiphidae. Τα κοκκοeιδή Aclerda berlesei Buffa της οικογένeιας Aclerdidae σe καλάμι (Arundo donax L.), και Physokermes piceae Schrank της οικογένeιας Coccidae σe έλατο (Abies cephalonica Loud.). Από τα δέκα αυτά μeλιτογόνα έντομα δύο, τα C. tujujilina και Ph. piceae, αναφέρονται για πρώτη φορά στην πανίδα της χώρας, η δe αφίδα Cinara juniperi και το κοκκοeιδές Aclerda berlesei παρουσιάζουν το μeγαλύτeρο μeλισσοκομικό eνδιαφέρον.

Landscape and agriculture under the reformed Common Agricultural Policy in Greece: Constructing a typology of interventions

Geografisk Tidsskrift-Danish Journal of Geography 111(2):131–147, 2011 A critical review of the European Union (EU) environmental and rural policies suggests that in the case of environmental policy an almost complete segregation between nature and areas where human activity is acceptable seems to be the main rationale. However, when agricultural and rural development policy measures are examined the focus seems to be on the integration of environmental conservation efforts in all activities across space. At the same time the scope of this policy is gradually widening from a strictly sectorial (agricultural) to a policy for the management of rural space. The above and the gradual integration of spatial elements in policy making could explain the increasing emphasis on rural landscape issues. The paper focuses on three cases of public intervention in three areas of Greece: A) The Amfissa olive grove (Sterea Hellas), where support from the first pillar of the Common Agricultural Policy (CAP) and a local agri-environmental measure, complement the existing landscape protection regulations of archaeological and land planning legislation; B) the Anthili plain (Sterea Hellas) where a production support lead to an intensification process with negative impacts on the landscape, and finally C) Santorini (Cyclades), where the incentive based policies implemented, due to the absence of a robust land use regulatory framework, seem to have been ineffective.

Allium brussalisii(Alliaceae), a new species from Greece

Allium brussalisii, from Mount Parnitha near Athens (Sterea Hellas, Greece), is described as a species new to science and compared with related species of Allium section Codonoprasum and Allium section Brevispatha. It is a diploid species (2n = 2x = 16) that flowers in early autumn. On the basis of its unilateral and more or less entire spathe and the simple filaments, it resembles species of Allium section Brevispatha; however, its sectional taxonomy remains unclear as, on the basis of several other morphological, cytological, and ecological characteristics, it also resembles species of Allium section Codonoprasum. The new species is presently known only from the type locality and is of particular interest for the phylogeny of the genus. © 2008 The Linnean Society of London, Botanical Journal of the Linnean Society, 2008, 158, 140–146.

EARTHQUAKE PREDICTION IN THE AREA OF N. EVIA ON THE BASIS OF GROUNDWATER RADON CONCENTRATION CHANGES

Significant changes in the groundwater radon concentration, were observed on the 29/7/2003, at Kammena Vourla. The radon concentration changes can be attributed to the temporary enrichment of the groundwater by radon from the surrounding rocks due to the action of stress release or stress accumulation prior an earthquake. EPPO was immediately informed for the existence of these changes. On the 3/8/2003, a significant number of earthquakes in Northern Evia were recorded in an interval of a few hours. The epicentres of the earthquakes were located in the conceivable line between the epicentre of the strong earthquake of Skyros island (July 2001) and the site of the station of radon measurement at Kammena Vourla, on the extension of the Northern Aegean fault. In the 23/1/2003, in the same station, 3 significant changes of radon concentration were measured EPPO was immediately informed for impending seismic activity in Northern Evia. On the 29th of January three earthquakes were recorded. Their epicentres were located in N. Evia, close to the radon measurement, station. On the 2/2/2003, a new significant radon change occurred at Kammena Vourla followed by an earthquake (7/2/2003). In the 12/2/2003 in a letter that we addressed to the EPPO administration, the beginning of a new radon change was reported which also led to an earthquake with the same epicentre. The changes that are recorded in the system of radon measurement of Kammena Vourla are precursors of earthquakes, related to the extension of the N. Aegean fault towards the Sterea Hellas and have their epicentre in N. Evia. It seems that the method can be an important tool for local, short term earthquake prediction.

Egio earthquake (15 June 1995): An episode in the neotectonic evolution of Corinthiakos Gulf

Egio earthquake (15 June 1995) produced a series of destructive geological surficial effects in northern Peloponnessos and southern Sterea Hellas. After a brief review on the current opinions on the tectonic regime of the area has been made, we give a description of these effects, focusing mainly on the fractures along the Egio fault. Then, we present a model to interpret the earthquake activity of 15 June 1995; finally a discussion concerning the extensional tectonic regime of the area is made based on seismic data, the geometry of onshore and the recently described offshore faults.

Influence of atmospheric circulation types on space‐time distribution of intense rainfall

The influence of the prevailing weather situation on the temporal evolution and geographical distribution of intense rainfall is studied, as a potential tool to improve rainfall prediction. A classification scheme of the atmospheric circulation over the east Mediterranean territory is used for the analysis. The study area is the Sterea Hellas region (central Greece) with an area of about 25,000 km2. Daily data from 71 rain gages and hourly data from three rain recorders over a 20 year period are used. From these data sets, the intense rainfall events were extracted and analyzed. Several empirical and statistical methods (also including the available tools of a Geographical Information System) are used for the analysis and comparison of rainfall distribution both in time and in space. The analysis shows that the contribution of the concept of weather types to the quantitative point rainfall prediction in short timescale is small, and only the estimation of the probability of occurrence of an intense event is feasible. On the contrary, the relation between the spatial distribution of rainfall and the atmospheric circulation patterns is significant and may be used for improving the forecasting of the geographical distribution of rainfall.

Barriers on seismogenic faults in central Greece

Structural mapping, morphotectonic analysis and existing seismological data are synthesized to characterize barriers—regions of high strength along the fault which can impede or arrest rupture propagation—on the most active and prominent traced fault zones in central Greece. Inhomogeneous and non-conservative barriers are the two different structures that have been identified on the Eliki fault (in northern Peloponnesos), and the Kaparelli and Atalanti fault zones (in Sterea Hellas), respectively. The Eliki fault consists of two colinear segments of different rupture characteristics that intersect at an inhomogeneous barrier. The eastern fault segment has had, in Late Quaternary, repeatedly activated earthquake sequences, whereas the western segment remained unaffected by these events. The Kaparelli and the Atalanti fault zones are the WNW and ENE fault segments of a single primary fault zone with a surface trace bent. The fault zone bends represent asperities—strong stable barriers—that effectively blunt the fault displacements and permit independent deformation of the fault segments. Earthquakes on these fault zones occur when the asperities fail. Repeated deformation and evolution of faulting change these asperities into non-conservative barrier structure. That is, surface rupturing is accommodated by a new, third direction of faulting developed in the zone of intersection between the two adjacent oblique segments of the primary fault zone. This third direction of faulting involves a major cumulative dip slip within the barrier region and it is responsible for repeated earthquakes during the Quaternary time. In response to this faulting process, a primary bent fault zone activated by repeated earthquake events tends to be curvilinear in trace and preserves a perched basin on its footwall block. The proposed rupture model of fault zone bends by a third direction of faulting during large earthquake events and is suitable for widespread application in Greece, regarding: (1) the interpretation of the distribution of fault strikes between dominant WNW and ENE inherited strikes; and (2) the initiation of earthquakes from the fault zone bends.

Geometry and kinematics of active faults and their seismotectonic significance in the western Corinth-Patras rift (Greece)

The western part of the Corinth-Patras rift is formed in an area which is being uplifted. Rifted domains have subsided relative to the adjacent areas in NW Peloponnesus and Sterea Hellas, but subsidence rates rarely exceed uplift rates. Extension is mainly accomplished by WNW-trending active faults with lengths up to 25 km. Most of these faults show an along-strike segmentation and often terminate against transfer faults. Displacement analysis, along 170 mesoscopic faults and 36 mappable faults, has been carried out to assess slip rates and to estimate the magnitudes and recurrence time intervals of earthquakes occurring along them. Earthquake magnitude ranges between 5 and 6.7. Only eight faults appear to be capable of producing earthquake magnitudes larger than 6. Recurrence times of these large earthquakes vary between 80 and 1690 years. Upper crustal deformation in the western Corinth graben can be described by six large asymmetric grabens which are inferred to bottom out to a N-dipping curved ramp. The asymmetric shape of most WNW-trending rifts in the Hellenic peninsula, including the Corinth-Patras rift promotes the simple shear model of extension against the pure shear model in the upper crustal layer.

The regional distribution of selenium in Greek cereals

The selenium content of hard and soft wheat, barley, oats, rye and corn grown in ∼100 different locations of Greece has been determined fluorimetrically. The mean values ± SD for these cereal types were 0.29 ± 0.19, 0.21 ± 0.12, 0.16 ± 0.10, 0.14 ± 0.10, 0.19 ± 0.10 and 0.12 ± 0.08 ppm Se (dry weight basis), respectively. Based on data for selenium in corn from 96 different locations, a geobotanic map of Greece for the selenium in soil available for uptake by plants was prepared. Macedonia, West Epirus, south-east Thessaly, north-east Sterea Hellas and the Aegean Islands produce corn deficient or low in selenium, but only sporadic selenium-deficiency diseases in animals have been observed in many of these areas, probably because the farm animals are given mixed food or they are free to graze. No areas with toxic levels of selenium in soil were found.

A gravity network in central Greece for secular gravity studies

The Sterea Hellas (central Greece) gravity network was remeasured in 1982, with the addition of 40 new stations. There were no statistically significant gravity differences for most of the gravity stations first established in 1968, but four stations—Arta, Preveza, Levadia, and Kymi—exhibited gravity changes of −121, −74, −39, and −67 μgal, respectively.