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21.
Vassilios Karakostas Eleftheria Papadimitriou Maria Mesimeri Charikleia Gkarlaouni Parthena Paradisopoulou 《Acta Geophysica》2015,63(1):1-16
The 2014 Kefalonia earthquake sequence started on 26 January with the first main shock (MW6.1) and aftershock activity extending over 35 km, much longer than expected from the causative fault segment. The second main shock (MW6.0) occurred on 3 February on an adjacent fault segment, where the aftershock distribution was remarkably sparse, evidently encouraged by stress transfer of the first main shock. The aftershocks from the regional catalog were relocated using a 7-layer velocity model and station residuals, and their distribution evidenced two adjacent fault segments striking almost N-S and dipping to the east, in full agreement with the centroid moment tensor solutions, constituting segments of the Kefalonia Transform Fault (KTF). The KTF is bounded to the north by oblique parallel smaller fault segments, linking KTF with its northward continuation, the Lefkada Fault. 相似文献
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Eleftheria E. Papadimitriou 《Pure and Applied Geophysics》1993,140(2):301-316
The repeat times,T, of strong shallow mainshocks in fourteen seismogenic sources along the western coast of South and Central America have been determined and used in an attempt at long-term forecasting. The following relation was determined: $$\log T = 0.22M_{\min } + 0.21M_p + a$$ between the repeat time,T, and the magnitudes,M min, of the minimum mainshock considered andM p , of the preceding mainshock. No dependence of the magnitude,M f , of the following mainshock on the preceding intervent time,T, was found. These results support the idea that the time-predictable model is valid for this region. This is an interesting property for earthquake prediction since it provides the ability to predict the time of occurrence of the next strong earthquake. A strong negative dependence ofM f onM p was found, indicating that a large mainshock is followed by a smaller magnitude one, andvice versa. The probability for the occurrence of the expected strong mainshocks (M s ≥7.5) in each of the fourteen seismogenic sources during the next 10 years (1992–2002) is estimated, adopting a lognormal distribution for earthquake interevent times. High probabilities (P 10>0.80) have been calculated for the seismogenic sources of Oaxaca, Chiapas and Southern Peru. 相似文献
25.
Markos D. Tranos Eleftheria E. Papadimitriou Adamantios A. Kilias 《Journal of Structural Geology》2003,25(12):2109-2123
Active faulting and seismic properties are re-investigated in the eastern precinct of the city of Thessaloniki (Northern Greece), which was seriously affected by two large earthquakes during the 20th century and severe damage was done by the 1759 event. It is suggested that the earthquake fault associated with the occurrence of the latest destructive 1978 Thessaloniki earthquake continues westwards to the 20-km-long Thessaloniki–Gerakarou Fault Zone (TGFZ), which extends from the Gerakarou village to the city of Thessaloniki. This fault zone exhibits a constant dip to the N and is characterised by a complicated geometry comprised of inherited 100°-trending faults that form multi-level branching (tree-like fault geometry) along with NNE- to NE-trending faults. The TGFZ is compatible with the contemporary regional N–S extensional stress field that tends to modify the pre-existing NW–SE tectonic fabric prevailing in the mountainous region of Thessaloniki. Both the 1978 earthquake fault and TGFZ belong to a ca. 65-km-long E–W-trending rupture fault system that runs through the southern part of the Mygdonia graben from the Strymonikos gulf to Thessaloniki. This fault system, here called Thessaloniki–Rentina Fault System (TRFS), consists of two 17–20-km-long left-stepping 100°-trending main fault strands that form underlapping steps bridged by 8–10-km-long ENE–WSW faults. The occurrence of large (M6.0) historical earthquakes (in 620, 677 and 700 A.D.) demonstrates repeated activation, and therefore the possible reactivation of the westernmost segment, the TGFZ, could be a major threat to the city of Thessaloniki. Changes in the Coulomb failure function (ΔCFF) due to the occurrence of the 1978 earthquake calculated out in this paper indicate that the TGFZ has been brought closer to failure, a convincing argument for future seismic hazard along the TGFZ. 相似文献
26.
An M8.3 earthquake struck the southwestern part of the Hellenic Arc, near the Island of Crete, in AD 365, generating a tsunami
that affected almost the entire eastern Mediterranean region. Taking into account that the time history of seismicity in this
region is fairly complete for such earthquakes in the historical catalog, which can be dated as back as the 5th century B.C.,
there is no indication that this segment of plate boundary has been fully ruptured again. The seismic hazard associated with
this part of the Hellenic Arc necessitates the evaluation of the rupture characteristics of this great event. The constraint
of the faulting geometry was initially achieved by using information from seismicity, and the focal mechanisms of earthquakes
that occurred during the instrumental period. A rupture model for this great earthquake is constructed by assuming an elastic
medium and calculating the theoretical surface displacements for various fault models that are matched with the observed surface
deformation gleaned from historical reports. The resulted fault model concerns thrust faulting with a rupture length of 160
km and a seismic moment of 5.7 × 1028 dyn·cm, an average slip of 8.9 m and a corresponding moment magnitude equal to 8.4, in excellent agreement with the macroseismic
estimation. The absence of such events recurrence is an indication of the lack of complete seismic coupling that is common
in subduction zones, which is in accordance with the back arc spreading of the Aegean microplate and with previous results
showing low coupling for extensional strain of the upper plate. 相似文献
27.
Beata Orlecka-Sikora Eleftheria E. Papadimitriou Grzegorz Kwiatek 《Acta Geophysica》2009,57(2):413-434
We applied the Coulomb stress transfer technique to investigate interactions among seismic events induced by mining works
in the Rudna mine in the Legnica-Glogów Copper District in Poland. We considered events with energy greater than 105 J from the period 1993–1999.
We examined the influence of the cumulative static stress changes (ΔCFF) due to previous events on the generation of subsequent
ones. The results indicate that in many cases strong mining tremors produce changes in the state of stress of a sufficient
magnitude to influence subsequent events. The location of over 60% of events is consistent with stress-enhanced areas where
the values of ΔCFF were above 0.01 MPa. For most of the events located inside areas of a calculated negative ΔCFF, their modelled
rupture zone was partially located inside stress enhanced area, providing thus additional evidence for possible triggering
at the nucleation point. 相似文献
28.
Application of the stress evolutionary model along the Xiaojiang fault zone in Yunnan Province,Southeast China 总被引：1，自引：0，他引：1
Parthena M. Paradisopoulou Charikleia G. Garlaouni Xueshen Jin Eleftheria E. Papadimitriou Vasileios G. Karakostas Jialiang Yang 《Acta Geophysica》2007,55(4):577-593
The Xiaojiang fault zone constitutes part of the major Xianshuihe-Xiaojiang left lateral structure that bounds the rhombic-shaped
block of Yunnan-Sichuan to the east. Long strike slip fault zones that have repeatedly accommodated intense seismic activity,
constitute a basic feature of southeast China. Known historical earthquakes to have struck the study area are the 1713 Xundian
of M6.8, 1725 Wanshou mountain of M6.8, the 1733 Dongchuan of M7.8, and the strongest one, the 1833 Songming of M8.0. Although instrumental record did not report events of this magnitude class, the 18th century clustering as well as the
19th century large event prompted the investigation of stress transfer along this fault zone. Coulomb stress changes were
calculated assuming that earthquakes can be modeled as static dislocations in an elastic half-space, and taking into account
both the coseismic slip in strong (M ≥ 6.8) earthquakes and the slow tectonic stress buildup along the major fault segments. Geological and geodetic data are
used to infer the geometry of these faults and long term slip rates on them, as well as for the fault segments that slipped.
Evidence is presented that the strong historical events as well as the ones of smaller magnitude that occurred during the
instrumental era, are located in areas where the static stress was enhanced. By extending the calculations up to present,
possible sites for future strong events are identified. 相似文献