The earthquake intervent time distribution along the Hellenic subduction Zone.

Η ελληνική ζώνη υποβύθισης είναι η πιο σεισμική περιοχή της Ευρώπης. Η κατανομή Weibullέχει χρησιμοποιηθεί σαν μοντέλο για την περιγραφή των χρονικών διαστημάτων μεταξύ διαδοχικών σεισμών σε συγκεκριμένες ρηξιγενείς ζώνες (Rikitake, 1976; Rikitake, 1991), καθώς και για την περιγραφή της σεισμικότητας μίας ευρύτερης περιοχής (Hasumietal., 2009). Taδεδομένα που αναλύουμε σε αυτή την εργασία αφορούν την ελληνική ζώνη υποβύθισης και καλύπτουν την περίοδο 1976-2009. Χρησιμοποιούμε τις σεισμικές πηγές επιφανειακών σεισμών όπως αυτές ορίζονται από τους PapaioannouandPapazachos(2000), καθώς και τονκατάλογο σεισμών των Makropoulosetal. (2012) για την Ελλάδα και τις παρακείμενες περιοχές. Η εφαρμογή της κατανομής Weibullστα χρονικά διαστήματα μεταξύ διαδοχικών σεισμών αναλύεται και περιγράφεται σε αυτή την εργασία.The Hellenic Subduction Zone (HSZ) is the most seismically active region in Europe (Becker and Meier, 2010). The evolution of such an active region is characterized by complex phenomenology and is expressed through seismicity. Seismicity temporal patterns remain as one of the most important topics in earth sciences. The Weibull distribution has been used as a recurrence time model for large earthquakes (Rikitake, 1976; Rikitake, 1991). Moreover,Hasumi et al. (2009) used the Weibulllog Weibull distribution for the study of the interoccurrence times of earthquakes in Japan.The dataset formed in this study concerns the seismic belt of the HSZ during the period 1976-2009. We use the external seismic sources of shallow earthquakes in the Aegean and the surrounding area (Papaioannou and Papazachos, 2000) along with the updated and extended earthquake catalogue for Greece and adjacent areas (Makropoulos et al., 2012).The application of the Weibull distribution to the interevent times of the formed dataset is analyzed and discussed

Dynamic Multifractality in Earthquake Time Series: Insights from the Corinth Rift, Greece

Earthquake time series are widely used to characterize the main features of seismicity and to provide useful insights into the dynamics of the seismogenic system. Properties such as intermittency and non-stationary clustering are common in earthquake time series such that multifractal concepts seem essential to describe the temporal clustering variability. Here we use a multifractal approach to study the time dynamics of the recent earthquake activity in the Corinth rift. The results indicate the degree of heterogeneous clustering and correlations acting at all time scales that suggest non-Poissonian behavior. Additionally, the multifractal analysis in different time periods showed that the degree of multifractality exhibits strong variations with time, which are associated with the dynamic evolution of the earthquake activity in the rift and the transition between periods of high and low seismicity

Evidence of non-extensivity in the seismicity observed during the 2011–2012 unrest at the Santorini volcanic complex, Greece

During the period of October 2011–January 2012, an increase of earthquake activity has been observed in the volcanic complex of Santorini Island, Greece. Herein, the magnitude distribution of earthquakes as well as the temporal distribution of seismicity are studied. The statistics of both parameters exhibit complexity that is evident in the frequency-magnitude distribution and the inter-event time distribution, respectively. Because of this, we have used the analysis framework of non-extensive statistical physics (NESP), which seems suitable for studying complex systems. The observed inter-event time distribution for the swarm-like earthquake events, as well as the energy and the inter-event earthquake energy distributions for the observed seismicity can be successfully described with NESP, indicating the inherent complexity of the Santorini volcanic seismicity along with the applicability of the NESP concept to volcanic earthquake activity, where complex correlations exist

HYDROTHERMAL METHANE FLUXES FROM THE SOIL AT SOUSAKI (GREECE)

Methane soil flux measurements have been made in 38 sites at the geothermal system of Sousaki (Greece) with the closed chamber method. Fluxes range from –47.6 to 29,150 mg m-2 d-1 and the diffuse CH4 output of the system has been estimated in 19 t/a. Contemporaneous CO2 flux measurements showed a fair positive correlation between CO2 and CH4 fluxes but the flux ratio evidenced methanotrophic activity within the soil. Laboratory CH4 consumption experiments confirmed the presence of methanotrophic microorganisms in soil samples collected at Sousaki. These results further confirm recent studies on other geothermal systems that revealed the existence of thermophilic and acidophilic bacteria exerting methanotrophic activity also in hot and acid soils thereby reducing methane emissions to the atmosphere

Earnings management and audit quality:stakeholders’ perceptions

This paper examines the perceptions of Libyan Commercial Banks’ (LCBs) stakeholders regarding the role of the external auditor in relation to earnings management (EM). A total of 28 semi-structured interviews were carried out with a range of LCB stakeholders comprising preparers of financial statements, users, regulators and academics. A questionnaire survey of stakeholders which yielded 102 Responses (response rate 53%) was also carried out. A variety of views were held which varied to some extent according to stakeholder group. A widely held perception amongst interviewees was that the auditor has the ability to detect EM practices but may not be able to prevent it. However questionnaire respondents were, in aggregate, more confident of the auditor’s ability to deter EM due to the influence of the audit report. The paper provides insights into stakeholders’ perceptions of the quality of bank audits. The findings are of particular relevance to regulators, and specifically, the Central Bank of Libya. Perceptions of audit quality raise questions about its guidance and regulations especially in connection with audit firm rotation. Perceptions of audit quality, and therefore, of the credibility of financial statements should be of interest to all stakeholders. The importance of the banking sector for society has been amply demonstrated in recent years. A well-functioning audit function is a key component of its regulation. To the best of our knowledge, this paper is the first to examine issues related to banks’ audit quality and audit firm rotation in Libya

Automated office blood pressure measurements in primary care are misleading in more than one third of treated hypertensives: The VALENTINE-Greece Home Blood Pressure Monitoring study

Abstract Background This study assessed the diagnostic reliability of automated office blood pressure (OBP) measurements in treated hypertensive patients in primary care by evaluating the prevalence of white coat hypertension (WCH) and masked uncontrolled hypertension (MUCH) phenomena. Methods Primary care physicians, nationwide in Greece, assessed consecutive hypertensive patients on stable treatment using OBP (1 visit, triplicate measurements) and home blood pressure (HBP) measurements (7 days, duplicate morning and evening measurements). All measurements were performed using validated automated devices with bluetooth capacity (Omron M7 Intelli-IT). Uncontrolled OBP was defined as ≥140/90 mmHg, and uncontrolled HBP was defined as ≥135/85 mmHg. Results A total of 790 patients recruited by 135 doctors were analyzed (age: 64.5 ± 14.4 years, diabetics: 21.4%, smokers: 20.6%, and average number of antihypertensive drugs: 1.6 ± 0.8). OBP (137.5 ± 9.4/84.3 ± 7.7 mmHg, systolic/diastolic) was higher than HBP (130.6 ± 11.2/79.9 ± 8 mmHg; difference 6.9 ± 11.6/4.4 ± 7.6 mmHg, p Conclusions In primary care, automated OBP measurements are misleading in approximately 40% of treated hypertensive patients. HBP monitoring is mandatory to avoid overtreatment of subjects with WCH phenomenon and prevent undertreatment and subsequent excess cardiovascular disease in MUCH