Tectonic stress field and seismic faulting in the area of Greece

Papazachos, B. C.; Delibasis, N.

doi:10.1016/0040-1951(69)90069-9

Cited by 88 publications

(49 citation statements)

References 5 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Focal mechanisms illustrate the connection between earthquakes and specific known faults, the general and local stress field, as well as their relation with other possible faults not already known, whose existence we can often only hypothesize. The contribution of fault plane solutions in the progress of seismotectonic understanding in the broader Aegean/southern Balkan area is very important, as they historically allowed the determination of the reverse faulting zones of the convex part of the Hellenic Arc and Albanian coast (Papazachos and Delibasis, 1969), of the extension field in continental Greece and surrounding southern Balkan area (McKenzie, 1970(McKenzie, , 1972 and its continuation to the north of the North Aegean (Papazachos et al, 1979;Taymaz et al, 1991). Dextral strike-slip faults in the Cephalonia area and the North Aegean Trough (Galanopoulos, 1967;McKenzie, 1972) are some other examples of the important contribution of fault plane solutions.…”

Section: Fault Plane Solution Informationmentioning

confidence: 99%

“…Anderson and Jackson, 1987), (2) the continuation of this reverse faulting zone along the southern Aegean Hellenic Arc (e.g. Papazachos and Delibasis, 1969), (3) the extension faulting zone across the Hellenides mountain range (e.g. Papazachos et al, 1984), (4) the extension faulting zone in the back-arc region with general N-S direction, located in the inner part of the arc, that geographically covers the area from S. Bulgaria and FYROM, northern and central Greece and follows the curvature of the volcanic arc in the South Aegean to southwestern Turkey (e.g.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

A detailed seismic zonation model for shallow earthquakes in the broader Aegean area

Vamvakaris

Papazachos

Papaioannou

et al. 2016

Nat. Hazards Earth Syst. Sci.

View full text Add to dashboard Cite

Abstract. In the present work we propose a new seismic zonation model of area type sources for the broader Aegean area, which can be readily used for seismic hazard assessment. The definition of this model is based not only on seismicity information but incorporates all available seismotectonic and neotectonic information for the study area, in an attempt to define zones which show not only a rather homogeneous seismicity release but also exhibit similar active faulting characteristics. For this reason, all available seismological information such as fault plane solutions and the corresponding kinematic axes have been incorporated in the analysis, as well as information about active tectonics, such as seismic and active faults. Moreover, various morphotectonic features (e.g. relief, coastline) were also considered. Finally, a revised seismic catalogue is employed and earthquake epicentres since historical times (550 BC-2008) are employed, in order to define areas of common seismotectonic characteristics, that could constitute a discrete seismic zone. A new revised model of 113 earthquake seismic zones of shallow earthquakes for the broader Aegean area is finally proposed. Using the proposed zonation model, a detailed study is performed for the catalogue completeness for the recent instrumental period.Using the defined completeness information, seismicity parameters (such as G-R values) for the 113 new seismic zones have been calculated, and their spatial distribution was also examined. The spatial variation of the obtained b values shows an excellent correlation with the geotectonic setting in the area, in good agreement with previous studies. Moreover, a quantitative estimation of seismicity is performed in terms of the mean return period, T m , of large (M ≥ 6.0) earthquakes, as well as the most frequent maximum magnitude, M t , for a typical time period (T = 50 yr), revealing significant spatial variations of seismicity levels within the study area. The new proposed seismic zonation model and its parameters can be readily employed for seismic hazard assessment for the broader Aegean area.

show abstract

Section: Fault Plane Solution Informationmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

A detailed seismic zonation model for shallow earthquakes in the broader Aegean area

Vamvakaris

Papazachos

Papaioannou

et al. 2016

Nat. Hazards Earth Syst. Sci.

View full text Add to dashboard Cite

show abstract

“…Seismicity observations contributed to the understanding of Aegean seismotectonics via earthquake locations which delineate active faults (Comninakis and Papazachos, 1980;Papazachos et al, 1984Papazachos et al, , 2009Papazachos, 1990), via focal mechanisms of earthquakes which allow an (ambiguous) determination of fault planes and slip direction (e.g. Papazachos et al, 1991;Taymaz et al, 1991;Benetatos et al, 2004;Bohnhoff et al, 2005;Kiratzi et al, 2007), via observation of aftershocks which permit inferences on the size of the fault plane and the amount of slip (Drakatos and Latoussakis, 2001) and finally via stress field determinations from catalogues of focal mechanisms (Papazachos and Delibasis, 1969;Bohnhoff et al, 2005;Rontogianni et al, 2011).…”

Section: W Friederich Et Al: Focal Mechanisms and Stress Field In Tmentioning

confidence: 99%

Focal mechanisms in the southern Aegean from temporary seismic networks – implications for the regional stress field and ongoing deformation processes

Friederich

Brüstle

Küperkoch³

et al. 2014

Solid Earth

View full text Add to dashboard Cite

Abstract. The lateral variation of the stress field in the southern Aegean plate and the subducting Hellenic slab is determined from recordings of seismicity obtained with the CYCNET and EGELADOS networks in the years from 2002 to 2007. First motions from 7000 well-located microearthquakes were analysed to produce 540 wellconstrained focal mechanisms. They were complemented by another 140 derived by waveform matching of records from larger events. Most of these earthquakes fall into 16 distinct spatial clusters distributed over the southern Aegean region. For each cluster, a stress inversion could be carried out yielding consistent estimates of the stress field and its spatial variation. At crustal levels, the stress field is generally dominated by a steeply dipping compressional principal stress direction except in places where coupling of the subducting slab and overlying plate come into play. Tensional principal stresses are generally subhorizontal. Just behind the forearc, the crust is under arc-parallel tension whereas in the volcanic areas around Kos, Columbo and Astypalea tensional and intermediate stresses are nearly degenerate. Further west and north, in the Santorini-Amorgos graben and in the area of the islands of Mykonos, Andros and Tinos, tensional stresses are significant and point around the NW-SE direction. Very similar stress fields are observed in western Turkey with the tensional axis rotated to NNE-SSW. Intermediate-depth earthquakes below 100 km in the Nisyros region indicate that the Hellenic slab experiences slab-parallel tension at these depths. The direction of tension is close to east-west and thus deviates from the local NW-oriented slab dip presumably owing to the segmentation of the slab. Beneath the Cretan sea, at shallower levels, the slab is under NW-SE compression. Tensional principal stresses in the crust exhibit very good alignment with extensional strain rate principal axes derived from GPS velocities except in volcanic areas, where both appear to be unrelated, and in the forearc where compressional principal stresses are very well aligned with compressional principal strain rates. This finding indicates that, except for volcanic areas, microseismic activity in the southern Aegean is not controlled by small-scale local stresses but rather reflects the regional stress field. The lateral and depth variations of the stress field reflect the various agents that influence tectonics in the Aegean: subduction of the Hellenic slab, incipient collision with continental African lithosphere, roll back of the slab in the southeast, segmentation of the slab, arc volcanism and extension of the Aegean crust.

show abstract

“…This thrust-faulting zone, which follows the Hellenic trench, is in the southwestern part of this margin (Papazachos and Delibasis, 1969). The faults of this zone, which exhibit the NWeSE direction and dip towards NE, i.e., toward the concave side of the arc (Aegean), are responsible for the generation of strong, mostly shallow earthquakes.…”

Section: The European Radio Networkmentioning

confidence: 96%

The LF radio anomaly observed before the M w = 6.5 earthquake in Crete on October 12, 2013

Maggipinto

Biagi

Colella

et al. 2015

Physics and Chemistry of the Earth, Parts A/B/C

View full text Add to dashboard Cite

a b s t r a c tOn October 12, 2013, an earthquake with M w ¼ 6.5 occurred in the southern Hellenic Arc, approximately 20 km off the west coast of Crete. The main shock, the focal depth of which is on the order of 40 km, was followed by aftershocks felt in the nearby cities and villages, although the aftershock sequence was poor. The epicentre was located at approximately 60 km from a radio receiver in Crete (CRE), which belongs to the European VLF/LF Radio Network. Several days before the earthquake, a clear disturbance occurred in one of the ten radio signals that the CRE receiver sampled. The disturbance, which can be considered an anomaly, appeared in the 216 kHz radio signal radiated by the Radio Monte Carlo (MCO) transmitter. The radio path MCO-CRE crossed directly over the epicentre area of the aforementioned earthquake. In this work, we present a detailed analysis of the MCO signal anomaly using spectral tools. We also investigate the behaviour of other radio signals sampled by the CRE receiver and consider other possible causes of disturbances on the MCO radio signal. We conclude that the disturbance in the MCO radio signal is a convincingly possible precursor of the earthquake in Crete. Emission of electromagnetic waves with a frequency band that includes 216 kHz from the focal zone of the earthquake can provide a satisfactory explanation of the radio anomaly.

show abstract

Tectonic stress field and seismic faulting in the area of Greece

Cited by 88 publications

References 5 publications

A detailed seismic zonation model for shallow earthquakes in the broader Aegean area

A detailed seismic zonation model for shallow earthquakes in the broader Aegean area

Focal mechanisms in the southern Aegean from temporary seismic networks – implications for the regional stress field and ongoing deformation processes

The LF radio anomaly observed before the M w = 6.5 earthquake in Crete on October 12, 2013

Contact Info

Product

Resources

About