UNIAXIAL COMPRESSIVE STRENGTH, DRY UNIT WEIGHT AND FRACTURE PATTERNS OF ULTRABASIC ROCKS IN OTHRYS MOUNTAIN (CENTRAL GREECE): CORRELATIONS AND EVALUATION

Στη παρούσα δημοσίευση μελετούνται τα υπερβασικά πετρώματα από την περιοχή της Όθρυος (Στερεά Ελλάδα). Η γεωλογική δομή και η τεκτονική της εξεταζόμενης περιοχής περιγράφοντα συνοπτικά. Οι αντοχές σε ανεμπόδιστη μονοαξονική θλίψη και τα φαινόμενα βάρη υπολογίζονται και οι γωνίες θραύσης μετρούνται. Τα αποτελέσματα αξιολογούνται στατιστικά και παρουσιάζονται εμπειρικές σχέσεις μεταξύ της αντοχής σε μονοαξονική θλίψη και του φαινόμενου βάρους. Εξαιτίας του χαμηλού συντελεστή συσχέτισης στους Σερπεντινιωμένους Περιδοτίτες, αποφασίσαμε οι Σερπεντινιωμένοι Περιδοτίτες και οι Σερπεντινίτες να εξεταστούν μαζί. Ο νέος συντελεστής συσχέτισης είναι πολύ μεγαλύτερος από τον προηγούμενο Επιπλέον, στην παρούσα δημοσίευση φαίνεται πως η πλειοψηφία των υπερβασικών πετρωμάτων θραύεται σε μια μόνο γωνία (φ°), η οποία κυμαίνεται κυρίως μεταξύ 75° και 90°, ενώ γίνεται και συσχετισμός των γωνιών θραύσης με την τεκτονική. Οι όποιες αποκλίσεις παρατηρήθηκαν αποδίδονται στην πετρογραφική ποικιλία, στη δομική πολυπλοκότητα, στον προτιμητέο προσανατολισμό του ολιβίνη και του ορθοπυρόξενου και στην εσωτερικά αποτυπωμένη τεκτονική παραμόρφωση.Ultrabasic rocks, taken from the Othrys mt. (Central Greece), are studied in this paper. The structural geology and tectonics of the study area are described. Uniaxial Compressive Strength (UCS) and dry unit weight (γ) values are calculated and fracture angles are measured. The results are statistically assessed and empirical relationships (exponential equations) between UCS and γ are presented for the ultrabasic roch, divided in Peridotites, Serpentinised Peridotites and Serpentinites. Due to the low correlation coefficient of the Serpentinised Peridotites, it was decided that the Serpentinised Peridotites and Serpentinites should be examined together. The correlation coefficient of the combined category is much better than the separate ones. Furthermore, this paper demonstrates that the majority of the ultrabasic rocks tested were breaking at one angle (φ°), which mainly fluctuated between 75° and 90°. The fracture angles correlate with previously recognised geological (mainly tectonic) structures. The observed deviations are due to pétrographie variety, structural complexity, preferred orientation of olivine and orthopyroxene and internal imprinted tectonic deformation

SHORT PERIOD CHANGE DETECTION OF SPERCHIOS LOWER DELTA AREA USING SPACE RADAR IMAGES

Being highly dynamic by nature, due to their changing hydrological regime and to the encroachment of urbanization, industrialization and changing patterns in agriculture, reliable and timely information of coastal areas is a prerequisite for their effective management. The aim of this paper is to assess the use of ERS-2 SAR satellite data to detect short period changes in the case of the R. Sperchios coastal area that is located at the eastern part of the Maliakos Gulf (near the middle of the east coast of the Greek mainland). A Landsat 7 (ΕΤΜ+) image served as a reference for the interpretation of the ERS images. In order to highlight and detect the changes occurred in the study area two methods were applied. The first method is based on the creation of a Temporal Differentiate Image, consisted of the three ERS-2 images (Figure 1). The second method concerns the implementation of Principal Component Transform (PCT) on the three multitemporal scenes. The final images derived from the two different methods were compared and evaluated. Both methods didn't show any significant change along the coastline. PCT method illustrates more clearly the seasonal changes of crops in the lower delta area. Eventually, radar technology gave the opportunity to discriminate shallow areas, which does not appear in satellite optical data. Concurrently, the effect of wind direction was investigated

Microsoft Word - RS4_138.doc

ABSTRACT Being highly dynamic by nature, due to their changing hydrological regime and to the encroachment of urbanization, industrialization and changing patterns in agriculture, reliable and timely information of coastal areas is a prerequisite for their effective management. The aim of this paper is to assess the use of ERS-2 SAR satellite data to detect short period changes in the case of the R. Sperchios coastal area that is located at the eastern part of the Maliakos Gulf (near the middle of the east coast of the Greek mainland). A Landsat 7 (ETM+) image served as a reference for the interpretation of the ERS images. In order to highlight and detect the changes occurred in the study area two methods were applied. The first method is based on the creation of a Temporal Differentiate Image, consisted of the three ERS-2 images The final images derived from the two different methods were compared and evaluated. Both methods didn't show any significant change along the coastline. PCT method illustrates more clearly the seasonal changes of crops in the lower delta area. Eventually, radar technology gave the opportunity to discriminate shallow areas, which does not appear in satellite optical data. Concurrently, the effect of wind direction was investigated