Strike-slip earthquakes on quasi-vertical transcurrent faults: Inferences for general scaling relations

1992 ◽  
Vol 19 (5) ◽  
pp. 481-484 ◽  
Author(s):  
Barbara Romanowicz
Keyword(s):  
Strike Slip ◽  
Scaling Relations ◽  
Transcurrent Faults

scholarly journals ‘Conjugate’ coseismic surface faulting related with the 29 December 2020, Mw 6.4, Petrinja earthquake (Sisak-Moslavina, Croatia)

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Emanuele Tondi ◽  
Anna Maria Blumetti ◽  
Mišo Čičak ◽  
Pio Di Manna ◽  
Paolo Galli ◽  
...  
Keyword(s):  
Relevant Information ◽  
Strike Slip ◽  
Secondary Effects ◽  
Epicentral Area ◽  
Field Surveys ◽  
Fundamental Information ◽  
Tension Cracks ◽  
Transcurrent Faults ◽  
Conjugate Fault ◽  
Geometry And Kinematics

AbstractWe provide here a first-hand description of the coseismic surface effects caused by the Mw 6.4 Petrinja earthquake that hit central Croatia on 29 December 2020. This was one of the strongest seismic events that occurred in Croatia in the last two centuries. Field surveys in the epicentral area allowed us to observe and map primary coseismic effects, including geometry and kinematics of surface faulting, as well as secondary effects, such as liquefaction, sinkholes and landslides. The resulting dataset consists of homogeneous georeferenced records identifying 222 observation points, each of which contains a minimum of 5 to a maximum of 14 numeric and string fields of relevant information. The earthquake caused surface faulting defining a typical ‘conjugate’ fault pattern characterized by Y and X shears, tension cracks (T fractures), and compression structures (P shears) within a ca. 10 km wide (across strike), NW–SE striking right-lateral strike-slip shear zone (i.e., the Petrinja Fault Zone, PFZ). We believe that the results of the field survey provide fundamental information to improve the interpretation of seismological, GPS and InSAR data of this earthquake. Moreover, the data related to the surface faulting may impact future studies focused on earthquake processes in active strike-slip settings, integrating the estimates of slip amount and distribution in assessing the hazard associated with capable transcurrent faults.

Granitoid complexes and the Archean tectonic record in the southern part of northwestern Ontario

1979 ◽  
Vol 16 (10) ◽  
pp. 1965-1977 ◽  
Author(s):  
W. M. Schwerdtner ◽  
D. Stone ◽  
K. Osadetz ◽  
J. Morgan ◽  
G. M. Stott
Keyword(s):  
Large Scale ◽  
Vertical Motion ◽  
Strike Slip ◽  
Horizontal Motion ◽  
Tectonic Deformation ◽  
Northwestern Ontario ◽  
Greenstone Belts ◽  
Second Period ◽  
Transcurrent Faults ◽  
Regional Compression

Two principal, possibly overlapping, periods of tectonic deformation can be distinguished in the Archean of northwestern Ontario, a period of dominantly vertical-motion tectonics and a period of dominantly horizontal-motion tectonics. Gigantic diapirs of foliated to gneissic tonalite–granodiorite developed during the first period and appear to be responsible for the gross structure of, and the major folds within, the metavolcanic–metasedimentary masses ("greenstone belts"). These diapirs are most likely due to mechanical remobilization of early tabular batholiths which originally intruded the oldest supracrustal rocks presently exposed. Later massive to foliated, dioritic to granitic plutons that vary from concordant, crescentic plutons to partly discordant plutons of various shapes and sizes were emplaced into the diapirs.The second period of tectonic deformation is characterized by large-scale dextral shearing and the development of major transcurrent faults under northwesterly regional compression. The strike-slip motions of this period outlasted the late plutonism, and led to the development of mylonitic zones which cut all Archean granitoid plutons.

Coseismic surface "conjugate" faulting of the 29 December 2020., MW 6.4, Petrinja earthquake (Sisak-Moslavina, Croatia)

2021 ◽  
Author(s):  
Emanuele Tondi ◽  
Anna Maria Blumetti
Keyword(s):  
Fault Zone ◽  
Relevant Information ◽  
Strike Slip ◽  
Secondary Effects ◽  
Epicentral Area ◽  
Field Surveys ◽  
Fundamental Information ◽  
Tension Cracks ◽  
Transcurrent Faults ◽  
Geometry And Kinematics

<p>We provide here a first-hand description of the coseismic surface effects caused by the Mw 6.4 Petrinja earthquake that hit central Croatia on 29 December 2020. This was one of the strongest seismic events that occurred in Croatia in the last two centuries. Field surveys in the epicentral area allowed us to observe and map primary coseismic effects, including geometry and kinematics of surface faulting, as well as secondary effects, such as liquefaction, sinkholes and landslides. The resulting dataset consists of homogeneous georeferenced records identifying 222 observation points, each of which contains a minimum of 5 to a maximum of 14 numeric and string fields of relevant information. The earthquake caused surface faulting defining a typical ‘conjugate’ fault pattern characterized by Y and X shears, tension cracks (T fractures), and compression structures (P shears) within a ca. 10 km wide, right-lateral strike-slip fault zone (i.e. the Petrinja Fault Zone, PFZ). We believe that the results of the field survey provide fundamental information to improve the interpretation of seismological, GPS and InSAR data of this earthquake. Moreover, the data related to the surface faulting may impact future studies focused on earthquake processes in active strike-slip settings, integrating the estimates of slip amount and distribution in assessing the hazard associated with capable transcurrent faults.</p>

​Slip modes and interaction in a simplified strike-slip fault system with increasing geometrical complexity

2021 ◽  
Author(s):  
Michael Rudolf ◽  
Joscha Podlesny ◽  
Esther Heckenbach ◽  
Matthias Rosenau ◽  
Anne Glerum ◽  
...  
Keyword(s):  
Strike Slip ◽  
Fault System ◽  
Scaling Relations ◽  
Stick Slip ◽  
Multiple Faults ◽  
Fault Surface ◽  
Magnitude Scaling ◽  
Geometrical Complexity ◽  
Wide Range ◽  
Fault Heterogeneity

<p>The release of elastic energy along an active fault is accommodated by a wide range of slip modes. It ranges from long-term slow slip events (SSEs) and creep to short-term tremors and earthquakes. They vary not only in their characteristic duration but also in their magnitude, spatial exten<span><span>t</span></span> and slip velocities. The exact relationship is unclear, as in some regions many slip modes occur simultaneously (e.g. Tohoku-Oki) and in others certain slip modes are completely absent (e.g. Cascadia).</p><p>One of the driving factors in the generation of this large variety of slip modes is the interplay of fault heterogeneity and geometrical complexity of the fault system. We test various settings in terms of fault heterogeneity and geometrical complexity with a scaled physical model. The experimental results are then validated and benchmarked through multi-scale numerical simulations. We describe <span><span>the</span></span> system using <span><span>a</span></span> rate-and-state frictional framework and introduce on-fault heterogeneity with variable frictional properties. All properties are the same for analogue and numerical simulation as far as they can be determined or realized experimentally (a-b, v<sub>load</sub>, S<sub>hmax</sub>, S<sub>hmin</sub>, etc...). As analogue material we use segmented, decimetre sized neoprene foam blocks in multiple configurations (e.g. biaxial shear at forces <1 kN) to simulate the elastic upper crust. The contact surfaces are spray-painted with acrylic paint to generate velocity weakening characteristics in between the blocks which is similar to the frictional behaviour of natural faults. We add heterogeneity to the fault surface by varying the fault area that is velocity weakening using grease. Geometrical complexity is implemented using conjugated or parallel sets of additional faults with the same characteristics.</p><p>We are able to reliably generate frequent stick-slip events of variable size and recurrence intervals. The slip characteristics, such as slip distribution, are in good agreement with analytical solutions of fault slip in elastic media. In a geometrically simple strike-slip model the recurrence behaviour and magnitude follows straightforward scaling relations in accordance with existing studies. If geometrical complexity is added to the model we observe clustering and variable recurrence that differ from the simpler geometry. Additionally, we are going to give an outlook on the interaction behaviour of multiple faults in dependence of their geometric configuration and the generation of power-law type magnitude scaling relations.</p>

scholarly journals Neotectonic structure of the Lakonikos gulf

2001 ◽  
Vol 34 (1) ◽  
pp. 297 ◽  
Author(s):  
D. PAPANIKOLAOU ◽  
C. METAXAS ◽  
G. CHRONIS
Keyword(s):  
Seismic Reflection ◽  
Single Channel ◽  
Strike Slip ◽  
High Angle ◽  
Upper Pleistocene ◽  
Sea Bottom ◽  
Holocene Sediments ◽  
Transcurrent Faults ◽  
Slip Motion

Detailed single-channel seismic reflection survey has been carried out in the Lakonikos Gulf, Southern Péloponnèse, aiming to a better understanding of the neotectonic structure of the Lakonikos Basin. Our survey showed that, contrary to the model of a simple N-S asymmetric graben previously considered, a tectonic horst occurs within the tectonic graben of Lakonikos. A subsidence of more than 1000m is produced by the N-S marginal faults, whereas, the N-S faults creating the central horst structure within the Lakonikos graben are high-angle reverse faults, which have uplifted the sea bottom together with the Pleistocene and Holocene sediments by about 100m. Several E-W vertical transcurrent faults, with strike-slip motion deform the N-S structures. The central tectonic horst structure is very recent as the observed deformation of the Upper Pleistocene and Holocene sediments indicated and a transtensional geodynamic regime is suggested.

scholarly journals Ocorrência de Rocha Alcalina no Município de Piraí, RJ, e sua Relação com o Lineamento de Além Paraíba (Nota Preliminar)

1977 ◽  
Vol 1 ◽  
pp. 114-121
Author(s):  
André Luiz Ferrari ◽  
Ivan Sérgio Siqueira Dupuy ◽  
Thomas Lafayette Brenner
Keyword(s):  
Rio De Janeiro ◽  
Sao Paulo ◽  
Strike Slip ◽  
The State ◽  
Alkaline Magmatism ◽  
São Paulo ◽  
Transcurrent Fault ◽  
Transcurrent Faults

The Serra dos Tomazes, located in the Pirai District, RJ, consists of an intrusive alkaline body, composed mainly of micronepheline-syenites. This alkaline body intrudes metatexites of the "Paraiba do Sul" folded belt. Mylonitic Zones we re recognized south of the intrusive alkaline body, and they may be associated with the Alem Paraiba Lineament. This lineament corresponds to an ENE striking transcurrent fault. This fault belongs to a system of transcurrent faults that is called the "São Paulo Transcurrence Zone". The strike-slip faults that form the bulk of the "Sao Paulo Transcurrence Zone" are generally right-lateral. The Serra dos Tomazes alkaline body is probably associeted, in time and in origin, with other alkaline intrusions in the State of Rio de Janeiro. This alkaline magmatism seems to be associated, at least geographically, with the "Sao Paulo Transcurrence Zone".

Failure Analysis Of Buried Gas Pipelines Crossing Seismic Faults

2020 ◽  
Vol 3 (2) ◽  
pp. 781-790
Author(s):  
M. Rizwan Akram ◽  
Ali Yesilyurt ◽  
A.Can. Zulfikar ◽  
F. Göktepe
Keyword(s):  
Ground Deformation ◽  
Warning System ◽  
Strike Slip ◽  
Gas Pipelines ◽  
Steel Pipes ◽  
Seismic Fault ◽  
Fault Parameters ◽  
Dip Angle ◽  
Permanent Ground Deformation ◽  
Recent Earthquakes

Research on buried gas pipelines (BGPs) has taken an important consideration due to their failures in recent earthquakes. In permanent ground deformation (PGD) hazards, seismic faults are considered as one of the major causes of BGPs failure due to accumulation of impermissible tensile strains. In current research, four steel pipes such as X-42, X-52, X-60, and X-70 grades crossing through strike-slip, normal and reverse seismic faults have been investigated. Firstly, failure of BGPs due to change in soil-pipe parameters have been analyzed. Later, effects of seismic fault parameters such as change in dip angle and angle between pipe and fault plane are evaluated. Additionally, effects due to changing pipe class levels are also examined. The results of current study reveal that BGPs can resist until earthquake moment magnitude of 7.0 but fails above this limit under the assumed geotechnical properties of current study. In addition, strike-slip fault can trigger early damage in BGPs than normal and reverse faults. In the last stage, an early warning system is proposed based on the current procedure. 

Zircon geochronology and paleomagnetism of an Archean harzburgite intrusion, eastern Bighorn Mountains, Wyoming

2020 ◽  
Vol 57 (1) ◽  
pp. 21-40
Author(s):  
Alexandra Wallenberg ◽  
Michelle Dafov ◽  
David Malone ◽  
John Craddock
Keyword(s):  
Hanging Wall ◽  
Vertical Axis ◽  
Shear Zones ◽  
Strike Slip ◽  
Zircon Geochronology ◽  
Weighted Mean ◽  
Mafic Complex ◽  
Laramide Orogeny ◽  
Axis Rotation ◽  
Bighorn Mountains

A harzburgite intrusion, which is part of the trailside mafic complex) intrudes ~2900-2950 Ma gneisses in the hanging wall of the Laramide Bighorn uplift west of Buffalo, Wyoming. The harzburgite is composed of pristine orthopyroxene (bronzite), clinopyroxene, serpentine after olivine and accessory magnetite-serpentinite seams, and strike-slip striated shear zones. The harzburgite is crosscut by a hydrothermally altered wehrlite dike (N20°E, 90°, 1 meter wide) with no zircons recovered. Zircons from the harzburgite reveal two ages: 1) a younger set that has a concordia upper intercept age of 2908±6 Ma and a weighted mean age of 2909.5±6.1 Ma; and 2) an older set that has a concordia upper intercept age of 2934.1±8.9 Ma and a weighted mean age 2940.5±5.8 Ma. Anisotropy of magnetic susceptibility (AMS) was used as a proxy for magmatic intrusion and the harzburgite preserves a sub-horizontal Kmax fabric (n=18) suggesting lateral intrusion. Alternating Field (AF) demagnetization for the harzburgite yielded a paleopole of 177.7 longitude, -14.4 latitude. The AF paleopole for the wehrlite dike has a vertical (90°) inclination suggesting intrusion at high latitude. The wehrlite dike preserves a Kmax fabric (n=19) that plots along the great circle of the dike and is difficult to interpret. The harzburgite has a two-component magnetization preserved that indicates a younger Cretaceous chemical overprint that may indicate a 90° clockwise vertical axis rotation of the Clear Creek thrust hanging wall, a range-bounding east-directed thrust fault that accommodated uplift of Bighorn Mountains during the Eocene Laramide Orogeny.

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