scholarly journals STATISTICKÉ ZHODNOCENÍ SEISMICKÉ AKTIVITY ZÓNY MUR-MÜRZ-LEITHA

2016 ◽  
Vol 22 (1-2) ◽  
Author(s):  
Vít Růžička

Mur-Mürz-Leitha fault system represents the most important seismically active zone in the Eastern Alps. Its part of the geological units of the Eastern Alps. Pushing the influence of alpine units to the north during the Cretaceous there was a lateral extrusion, resulting in the formation of shear fractures (eg .: system MML). Based on data provided from the project ACORN, IPE and ZAMG. frequency-magnitude graph and temporal distribution chart since 1980 were compiled. Frequency-magnitude distribution show that borded of completeness of the data since 1980, have a value of magnitude 2 and higher. Therefore, the temporal distribution chart was created just since 1980, and magnitude of 2 and more. Above all the chart takes a set of occurrences of 2000, which number 37 events with a magnitude of 2 and 2 events with magnitude over 4. These occurrences come under the area 4. Then was made another temporal distribution chart since 1980, but this one is only for area 4. In area 4 Ebreichsdorf town is situated that is near the seismic swarm from the years of 2000 and 2013. The seismic swarm from 2013 is the similar like seismic swarm in 2000 just in a slightly smaller. These seismic occurrences of Ebreichsdorf are important, because they were macroseismic felt in the southern regions of the Czech Republic, including Brno.

Fractals ◽  
1993 ◽  
Vol 01 (03) ◽  
pp. 539-546 ◽  
Author(s):  
B. BODRI

Fractal approach has been applied to investigate regional seismicity at the Izu peninsula—Tokai area, Central Japan. The frequency-magnitude distribution of earthquakes, distribution of epicenters, origin times of earthquakes, the fracture fault system in the region have been considered, and the fractal dimensions corresponding to them were calculated. A good correspondence in the fractal dimension values was found. The frequency-magnitude distribution in the area shows a fractal dimension of 1.28, whilst D=1.15±0.18 is representative of the geometry of the distribution of earthquake epicenters. The fractal dimension of faults for the Izu peninsula is found to be 1.16±0.04, and in the whole Izu-Tokai region, values 1.1<D<1.3 are characteristic. The temporal distribution of earthquakes yields a fractal dimension of 0.51±0.03, which indicates a relatively weak clustering of events in time. Independent autocorrelation analysis also shows that the earthquakes in the area of study occur to a large extent statistically independent. The general conclusion is that crustal deformation in the Izu-Tokai region occurs on a scale-invariant matrix faults. The behavior of the system is controlled by a single parameter, the fractal of dimension.


2021 ◽  
Author(s):  
Vincent F. Verwater ◽  
Eline Le Breton ◽  
Mark R. Handy ◽  
Vincenzo Picotti ◽  
Azam Jozi Najafabadi ◽  
...  

Abstract. Neogene indentation of the Adriatic plate into Europe led to major modifications of the Alpine orogenic structures and style of deformation in the Eastern Alps. Especially, the offset of the Periadriatic Fault by the Northern Giudicarie Fault marks the initiation of strike-slip faulting and lateral extrusion of the Eastern Alps. Questions remain on the exact role of this fault zone in changes of the Alpine orogen at depth. This necessitates quantitative analysis of the shortening, kinematics and depth of decoupling underneath the Northern Giudicarie Fault and associated fold-and thrust belt in the Southern Alps. Tectonic balancing of a network of seven cross sections through the Giudicarie Belt parallel to the local shortening direction reveals that it comprises two kinematic domains with different amounts and partly overlapping ages of shortening. These two domains are delimitated by the NW-SE oriented strike-slip Trento-Cles – Schio-Vicenza fault system, cross-cutting the Southern Alpine orogenic front in the south and merging with the Northern Giudicarie Fault in the north. The SW kinematic domain (Val Trompia sector) accommodated at least ~18 km of Late Oligocene to Early Miocene shortening. Since the Middle Miocene, the SW kinematic domain experienced a minimum of ~12–22 km shortening, whereas the NE kinematic domain underwent at least ~25–35 km shortening. Together, these domains contributed to an estimated ~53–75 km of sinistral strike-slip motion along the Northern Giudicarie Fault, implying that (most of) the offset of the Periadriatic Fault is due to Late Oligocene to Neogene indentation of the Adriatic plate into the Eastern Alps. Moreover, the faults linking the Giudicarie Belt with the Northern Giudicarie Fault reach ~15–20 km depth, indicating a thick-skinned tectonic style of deformation. These fault detachments may also connect at depth with a lower crustal Adriatic wedge that protruded north of the Periadriatic Fault and was responsible for N-S shortening and eastward escape of deeply exhumed units in the Tauern Window. Finally, the east-west lateral variation of shortening indicates internal deformation and lateral variation in strength of the Adriatic indenter, related to Permian – Mesozoic tectonic structures and paleogeographic domains.


2021 ◽  
Author(s):  
Arthur Borzi ◽  
Werner E. Piller ◽  
Mathias Harzhauser ◽  
Wolfgang Siedl ◽  
Philipp Strauss

&lt;p&gt;&lt;strong&gt;ABSTRACT&lt;/strong&gt;&lt;/p&gt;&lt;p&gt;The Vienna Basin is a rhombohedral SSW-NNE oriented Neogene extensional basin that formed along sinistral fault systems during Miocene lateral extrusion of the Eastern Alps. The basin fill consists of shallow marine and terrestrial sediments of early to late Miocene age reaching a thickness of 5500 m in the central part of the basin. The early Pannonian was a crucial time in the development of the Vienna Basin, as It coincided with the formation of Lake Pannon. The lake formed at 11.6 Ma when a significant regressive event isolated Lake Pannon from the Paratethys Sea, creating lacustrine depositional environments. At that time the delta of the Paleo-Danube started shedding its sediments into the central Vienna Basin. Based on an existing age model delta deposition commenced around 11.5 Ma and continued until 11.1 Ma. These subsurface deltaic deposits of the Hollabrunn-Mistelbach Formation represent the coeval fluvial deposits of the Paleo-Danube in the eastern plains of the North Alpine Foreland Basin. Therefore, the Palaeo-Danube represents an extraordinary case in where coeval fluvial and deltaic deposits of a Miocene river are continuously captured.&lt;/p&gt;&lt;p&gt;This study provides an interpretation of depositional architecture and depositional environments of this delta in the Austrian part of the central Vienna Basin based on the integration of 3D seismic surveys and well data. The mapped delta has an area of about 580 km&lt;sup&gt;2&lt;/sup&gt;, and solely based on the geometry we classify the delta as a mostly river &amp;#8211; dominated delta with significant influence of wave &amp;#8211; reworking processes. For seven time slices paleogeographic maps are created, showing the interplay between the lacustrine environments of Lake Pannon, delta evolution and fluvial systems incising in the abandoned deltaplain. Onlaps between single deltalobes indicate a northward-movement of the main distributary channel. Approximate water-depth estimates are carried out with in-seismic measurements of the true vertical depth between the topset deposits of the delta and the base of the bottomset deposits. These data suggest a decrease of lake water depth from about 170 m during the initial phase of delta formation at 11.5 Ma to about 100 m during its terminal phase at 11.1 Ma. A major lake level rise of Lake Pannon around 11.1 Ma caused a flooding of the margins of the Vienna Basin, resulting in a back stepping of riverine deposits and termination of delta deposition in the study area.&lt;/p&gt;&lt;p&gt;&amp;#160;&lt;/p&gt;


2014 ◽  
Vol 08 (04) ◽  
pp. 1450010 ◽  
Author(s):  
Santi Pailoplee

In this study, the geospatial frequency–magnitude distribution (FMD) b-value images of the prospect sources of upcoming earthquakes were investigated along the Indonesian Sunda Margin (ISM) that strikes parallel to and near the Indonesian Island chain. After enhancing the completeness and stability of the earthquake catalogue, the seismicity data were separated according to their seismotectonic setting into shallow crustal and Intraslab earthquakes. In order to verify the spatial relationship between the b-values and the occurrence of subsequent major earthquakes, the complete shallow crustal seismicity dataset (1980–2005) was truncated into the 1980–2000 sub-dataset. Utilizing the suitable assumption of fixed-number of earthquakes, retrospective tests of both the complete and truncated datasets supported that areas of comparatively low b-values could reasonably be expected to predict likely hypocenters of future earthquakes. As a result, the present-day distributions of b-values derived from the complete (1980–2005) shallow crustal and Intraslab seismicity datasets revealed eight and six earthquake-prone areas, respectively, along the ISM. Since most of these high risk areas proposed here are quite close to the major cities of Indonesia, attention should be paid and mitigation plans should be developed for both seismic and tsunami hazards.


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