scholarly journals Study on the relationship between multi-stage strike-slip mechanism and basin evolution in Fangzheng fault depression

2018 ◽  
Vol 22 (4) ◽  
pp. 335-339
Author(s):  
Jingfeng Wu ◽  
Qi'an Meng ◽  
Xiaofei Fu ◽  
Yuling Ma ◽  
Meifeng Sun ◽  
...  
Keyword(s):  
Seismic Data ◽  
Structural Characteristics ◽  
Stage Structure ◽  
Tectonic Stress ◽  
Strike Slip ◽  
The West ◽  
Lateral Strike Slip ◽  
Slip Mechanism ◽  
Pull Apart Basin ◽  
Multi Stage

Fangzheng fault depression is controlled by the northern of the Tan-Lu fault zone. It undergoes multi-stage strike-slip, extrusion modification, and erosion of the thermal uplift, forming a tectonic pattern of uplifts connected with sags. Through the regional dynamic analysis, the study of the activity law of the western Pacific plate has clarified the formation and transformation of the regional tectonic stress field. Under the background of the multi-stage of the strike-slip mechanism in the northern part of the Tan-lu fault, the Fangzheng fault depression has a characteristic of the “left-lateral strike-slip pull-apart basin, right-lateral strike-slip extrusion transformation.” According to the difference of the strike-slip, the Fangzheng fault depression has divided into two parts: the East fault depression and the West fault depression. The seismic data, seismic attribute analysis, and geological modeling techniques have applied to analyze the two fault depressions, the East fault depression has actively controlled by the strike-slip activity, and the structure is complex. The seismic data quality is poor; the structure of the West Fault Depression is the opposite and structural characteristics of asymmetrical difference strike-slip in the East and West fault depressions. Interpretation of seismic sections through a slippery background, the strike-slip attributes of the whole fault depression from south to north are segmented, and the strike-slip mechanism from east to west is different. Under the control of the multi-stage strike-slip mechanism, the Fangzheng fault depression is divided into six stages of strike-slip evolution, corresponding to the six different stages of the strike-slip control basin, the formation process of the asymmetric difference strike-slip fault basin is clarified, which provides a reference for the study of the strike-slip pull-apart basin with multi-stage structure.

Strong Ground-Motion Measurements during the 2003 Bam, Iran, Earthquake

2005 ◽  
Vol 21 (1_suppl) ◽  
pp. 165-179 ◽  
Author(s):  
Mehdi Zaré ◽  
Hossein Hamzehloo
Keyword(s):  
Ground Motion ◽  
Local Time ◽  
Strong Ground Motion ◽  
Strike Slip ◽  
Bam Earthquake ◽  
Lateral Strike Slip ◽  
Slip Mechanism ◽  
Motion Measurements ◽  
The City ◽  
Strong Ground

The Bam earthquake of 26 December 2003 ( Mw 6.5) occurred at 01:56:56 (GMT, 05:26:56 local time) near the city of Bam in the southeast of Iran. Two strong phases of energy are seen on the accelerograms. The first comprises a starting subevent with right-lateral strike-slip mechanism located south of Bam. The mechanism of the second subevent was a reverse mechanism.

The Midway sequence: a Timiskaming-type, pull-apart basin deposit in the western Wawa subprovince, Minnesota

2000 ◽  
Vol 37 (1) ◽  
pp. 1-15 ◽  
Author(s):  
Mark A Jirsa
Keyword(s):  
Structural Characteristics ◽  
Regional Scale ◽  
Volcanic Rocks ◽  
Strike Slip ◽  
Alluvial Fan ◽  
Pull Apart Basin ◽  
Tectonically Active ◽  
History Of ◽  
Fluvial Sedimentation ◽  
Magmatic History

The Midway sequence is an assemblage of subaerially deposited clastic and volcanic rocks that forms a narrow wedge within Neoarchean greenstone of the western Wawa subprovince of the Superior Province. Volcanic conglomerate in the Midway sequence contains clasts of stratigraphically older greenstone, together with clasts of a distinctive hornblende-phyric trachyandesite that is not represented among the older greenstone flows. The trachyandesite forms flows and pyroclastic units that are interbedded with lenticular deposits of volcanic conglomerate in a manner interpreted to indicate approximately coeval volcanism and alluvial fan - fluvial sedimentation within a linear, restricted, and tectonically active depocentre. The Midway sequence unconformably overlies greenstone on one side and is bounded by a regional-scale, strike-slip fault on the other. Structural analyses show that the Midway sequence was deposited after an early, precleavage folding event (D1) in greenstone, but before the regional metamorphic cleavage-forming D2 deformation. Lithologic and structural attributes are consistent with deposition in a strike-slip "pull-apart" basin. The stratigraphic and structural characteristics of the Midway sequence are generally similar to those of the Timiskaming Group and Timiskaming-type rocks in Canada, and more specifically to those of the Shebandowan Group in the Thunder Bay district. This similarity implies that the latest Archean tectonic and magmatic history of the western Wawa subprovince may have been nearly synchronous over great distances.

scholarly journals New data on the latest stress state of the earth’s crust on Sakhalin Island (based on structural and geomorphological indicators of tectonic stress)

2020 ◽  
Vol 4 (4) ◽  
pp. 372-383
Author(s):  
L.A. Sim ◽  
◽  
P.A. Kamenev ◽  
L.M. Bogomolov ◽  
◽  
...  
Keyword(s):  
Stress State ◽  
Crustal Deformation ◽  
Field Measurements ◽  
Field Work ◽  
Tectonic Stress ◽  
Strike Slip ◽  
The West ◽  
North Eastern ◽  
Central Sakhalin Fault ◽  
Entire Island

To verify the ideas about neotectonic and modern stresses of Sakhalin, we analyze structural and geomorphological signs of the stress state of this region, discovered during field work in 2019–2020. Along with updated field measurements using the structural-geomorphological method, data on crustal deformation based on GPS/GLONASS measurements are presented. Data from geophysical studies (seismological and borehole methods) are given. The identification of three types of areas with different geodynamic regime: transtension, transpression and strike – slip (simple shift) is confirmed. Variations of the current stress field at the boundaries of regions with different geodynamic regime for the formation of new faults are noted. Northern Sakhalin has specific directions of compression axes of neotectonic stresses, expressed in North-Eastern orientations, in contrast to the prevailing sublatitudinal orientations on the entire island. Studies have shown that in the south of Sakhalin, the border between the Amur and Okhotsk microplates runs along the West Sakhalin fault rather than the Central Sakhalin fault.

Automated Microseismic Processing and Integrated Interpretation of Induced Seismicity during a Multistage Hydraulic-Fracturing Stimulation, Alberta, Canada

2020 ◽  
Vol 110 (5) ◽  
pp. 2018-2030 ◽  
Author(s):  
Germán Rodríguez-Pradilla ◽  
David W. Eaton
Keyword(s):  
Hydraulic Fracturing ◽  
Seismic Data ◽  
Middle Devonian ◽  
Induced Seismicity ◽  
Strike Slip ◽  
3D Seismic ◽  
Lateral Strike Slip ◽  
Multistage Hydraulic Fracturing ◽  
Integrated Interpretation ◽  
3D Seismic Data

ABSTRACT The development of organic-rich, low-permeability formations for hydrocarbon production requires the use of unconventional techniques such as multiwell pad drilling of horizontal wells and massive multistage hydraulic-fracturing stimulations. However, proliferation of these unconventional development methods has been linked to localized cases of fault reactivation during or shortly after hydraulic fracturing. In the Duvernay formation, located in Alberta, Canada, induced seismicity from hydraulic fracturing has occurred on nearly vertical strike-slip faults that are difficult to detect with conventional seismic exploration methods. In such cases, faults may only be discernible from seismic events with precise and accurate locations, which generally requires dense seismic monitoring arrays deployed near the stimulated wells. In this study, we introduce a new, semiautomated workflow for processing passive seismic data from a dense array and then integrate it with a 3D seismic dataset to characterize seismicity clusters related to hydraulic fracturing and pre-existing faults. The reactivated faults inferred from the distribution of the microseismic events directly overlie a system of incised, middle Devonian channels below the Duvernay formation observed in time slices extracted from the 3D seismic data. The channel system exhibits a set of lateral offsets, interpreted as ancient strike-slip fault displacements, the detection of which is further enhanced by use of a similarity attribute calculated from the 3D seismic data. Taken together, integrated interpretation of induced seismicity and 3D seismic data support a model of a regional left-lateral strike-slip fault system that was active during the middle Devonian and reactivated in a reverse sense (right-lateral strike slip) during hydraulic-fracturing operations.

scholarly journals Determinants of successful guideline implementation: a national cross-sectional survey

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Ying-hui Jin ◽  
Li-Ming Tan ◽  
Khalid S. Khan ◽  
Tong Deng ◽  
Chao Huang ◽  
...  
Keyword(s):  
Guideline Development ◽  
Guideline Implementation ◽  
Medical Specialty ◽  
Cross Sectional Survey ◽  
The West ◽  
Cross Sectional ◽  
Adherence To Guidelines ◽  
Multi Stage ◽  
Geographical Regions ◽  
Tertiary Hospitals

Abstract Background CPGs are not uniformly successful in improving care and several instances of implementation failure have been reported. Performing a comprehensive assessment of the barriers and enablers is key to developing an informed implementation strategy. Our objective was to investigate determinants of guideline implementation and explore associations of self-reported adherence to guidelines with characteristics of participants in China. Methods This is a cross-sectional survey, using multi-stage stratified typical sampling based on China's economic regional divisions (the East, the Middle, the West and the Northeast). 2–5 provinces were selected from each region. 2–3 cities were selected in each province, and secondary and tertiary hospitals from each city were included. We developed a questionnaire underpinned by recommended methods for the design and conduct of self-administered surveys and based on conceptual framework of guideline use, in-depth related literature analysis, guideline development manuals, related behavior change theory. Finally, multivariate analyses were performed using logistic regression to produce adjusted odds ratios (OR) and 95% confidence intervals (95% CI). Results The questionnaire consisted of four sections: knowledge of methodology for developing guidelines; barriers to accessing guideline; barriers to guideline implementation; and methods for improving guideline implementation. There were 1732 participants (87.3% response rate) from 51 hospitals. Of these, 77.2% reported to have used guidelines frequently or very frequently. The key barriers to guideline use were lack of education or training (46.2%), and overly simplistic wording or overly broad scope of recommendations (43.8%). Level of adherence to guidelines was associated with geographical regions (the northeast P < 0.001; the west P = 0.02; the middle P < 0.001 compared with the east), hospital grades (P = 0.028), length of practitioners’ practice (P = 0.006), education background (Ph.D., P = 0.027; Master, P = 0.002), evidence-based medicine skills acquired in work unit (P = 0.012), and medical specialty of practitioner (General Practice, P = 0.006; Surgery, P = 0.043). Conclusion Despite general acknowledgement of the importance of guidelines, the use of guidelines was not as frequent as might have been expected. To optimize the likelihood of adherence to guidelines, guideline implementation should follow an actively developed dissemination plan incorporating features associated with adherence in our study.

scholarly journals Analysis of the Impact of Fault Mechanism Radiation Patterns on Macroseismic Fields in the Epicentral Area of 1998 and 2004 Krn Mountains Earthquakes (NW Slovenia)

2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
Andrej Gosar
Keyword(s):  
Site Effects ◽  
Strike Slip ◽  
Radiation Patterns ◽  
Seismogenic Fault ◽  
Active Growth ◽  
Epicentral Area ◽  
Slip Mechanism ◽  
Radiation Amplitude ◽  
The Difference ◽  
The Impact

Two moderate magnitude (Mw = 5.6 and 5.2) earthquakes in Krn Mountains occurred in 1998 and 2004 which had maximum intensity VII-VIII and VI-VII EMS-98, respectively. Comparison of both macroseismic fields showed unexpected differences in the epicentral area which cannot be explained by site effects. Considerably, different distribution of the highest intensities can be noticed with respect to the strike of the seismogenic fault and in some localities even higher intensities have been estimated for the smaller earthquake. Although hypocentres of both earthquakes were only 2 km apart and were located on the same seismogenic Ravne fault, their focal mechanisms showed a slight difference: almost pure dextral strike-slip for the first event and a strike-slip with small reverse component on a steep fault plane for the second one. Seismotectonically the difference is explained as an active growth of the Ravne fault at its NW end. The radiation patterns of both events were studied to explain their possible impact on the observed variations in macroseismic fields and damage distribution. Radiation amplitude lobes were computed for three orthogonal directions: radial P, SV, and SH. The highest intensities of both earthquakes were systematically observed in directions of four (1998) or two (2004) large amplitude lobes in SH component (which corresponds mainly to Love waves), which have significantly different orientation for both events. On the other hand, radial P direction, which is almost purely symmetrical for the strike-slip mechanism of 1998 event, showed for the 2004 event that its small reverse component of movement has resulted in a very pronounced amplitude lobe in SW direction where two settlements are located which expressed higher intensities in the case of the 2004 event with respect to the 1998 one. Although both macroseismic fields are very complex due to influences of multiple earthquakes, retrofitting activity after 1998, site effects, and sparse distribution of settlements, unusual differences in observed intensities can be explained with different radiation patterns.

Rampart seismic zone of central Alaska

1983 ◽  
Vol 73 (3) ◽  
pp. 813-829
Author(s):  
P. Yi-Fa Huang ◽  
N. N. Biswas
Keyword(s):  
Main Shock ◽  
Fault Plane ◽  
B Value ◽  
Aftershock Sequence ◽  
Strike Slip ◽  
Lithospheric Plate ◽  
Normal Faults ◽  
Seismic Zone ◽  
The West ◽  
Fault Plane Solutions

abstract This paper describes the characteristics of the Rampart seismic zone by means of the aftershock sequence of the Rampart earthquake (ML = 6.8) which occurred in central Alaska on 29 October 1968. The magnitudes of the aftershocks ranged from about 1.6 to 4.4 which yielded a b value of 0.96 ± 0.09. The locations of the aftershocks outline a NNE-SSW trending aftershock zone about 50 km long which coincides with the offset of the Kaltag fault from the Victoria Creek fault. The rupture zone dips steeply (≈80°) to the west and extends from the surface to a depth of about 10 km. Fault plane solutions for a group of selected aftershocks, which occurred over a period of 22 days after the main shock, show simultaneous occurrences of strike-slip and normal faults. A comparison of the trends in seismicity between the neighboring areas shows that the Rampart seismic zone lies outside the area of underthrusting of the lithospheric plate in southcentral and central Alaska. The seismic zone outlined by the aftershock sequence appears to represent the formation of an intraplate fracture caused by regional northwest compression.

Late Pleistocene extension and strike-slip in the Dead Sea Basin

2004 ◽  
Vol 141 (5) ◽  
pp. 565-572 ◽  
Author(s):  
YUVAL BARTOV ◽  
AMIR SAGY
Keyword(s):  
Internal Structure ◽  
Slip Rate ◽  
Dead Sea ◽  
Strike Slip ◽  
Normal Faults ◽  
Small Scale ◽  
Dead Sea Basin ◽  
Pull Apart Basin ◽  
Western Border ◽  
The Dead

A newly discovered active small-scale pull-apart (Mor structure), located in the western part of the Dead Sea Basin, shows recent basin-parallel extension and strike-slip faulting, and offers a rare view of pull-apart internal structure. The Mor structure is bounded by N–S-trending strike-slip faults, and cross-cut by low-angle, E–W-trending normal faults. The geometry of this pull-apart suggests that displacement between the two stepped N–S strike-slip faults of the Mor structure is transferred by the extension associated with the normal faults. The continuing deformation in this structure is evident by the observation of at least three deformation episodes between 50 ka and present. The calculated sinistral slip-rate is 3.5 mm/yr over the last 30 000 years. This slip rate indicates that the Mor structure overlies the currently most active strike-slip fault within the western border of the Dead Sea pull-apart. The Mor structure is an example of a small pull-apart basin developed within a larger pull-apart. This type of hierarchy in pull-apart structures is an indication for their ongoing evolution.

scholarly journals Mass and Heat Transfer at Different Heat Exchange Surfaces and Their Suitability for Use in Thermal Desalination Plants

2016 ◽  
Vol 10 (1) ◽  
pp. 74-86 ◽  
Author(s):  
T. Schwarzer ◽  
H.J. Bart
Keyword(s):  
Heat Transfer ◽  
Salt Water ◽  
Structural Characteristics ◽  
Small Scale ◽  
User Friendliness ◽  
Multi Stage ◽  
Water Side ◽  
Thermal Desalination ◽  
Actual Use ◽  
Desalination Plants

A new concept for small scale multi-stage distillation (MSD) desalination plants is presented allowing an installation in remote rural areal due to low maintenance, operating and investment costs. It is based on extensive studies on heat and mass transfer using 6 different condensation / heat transfer surfaces or material combinations. Basically all 6 condensation surfaces except glass are of a sheet metal or an expanded metal (to the evaporation side) in combination to an acid- and heat-resistant foil (on the salt water side). The basic experiments were performed in a "lab scale" unit to determine their thermodynamic and structural characteristics and user-friendliness. After validation in a prototype novel oxidic condensation surfaces (AF) and material combinations are in actual use in the new MSD systems, following the requirements, including a good wetting and condensation behavior and a good heat transfer.

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