scholarly journals Evolution of normal fault displacement and length as continental lithosphere stretches

2021 ◽  
Author(s):  
Sophie Pan ◽  
Rebecca E. Bell ◽  
Christopher A‐L. Jackson ◽  
John Naliboff
Keyword(s):  
Normal Fault ◽  
Continental Lithosphere ◽  
Fault Displacement

scholarly journals Evolution of normal fault displacement and length as the continental lithosphere stretches

2020 ◽  
Author(s):  
Sophie Pan ◽  
Rebecca Bell ◽  
Christopher Jackson ◽  
John Naliboff
Keyword(s):  
Normal Fault ◽  
Continental Lithosphere ◽  
Fault Displacement

scholarly journals The impact of earthquakes on fluids in the crust

1994 ◽  
Vol 37 (6) ◽  
Author(s):  
G. C. P. King ◽  
R. M. Wood
Keyword(s):  
Water Discharge ◽  
Normal Fault ◽  
Reverse Fault ◽  
Crustal Rocks ◽  
Decay Times ◽  
Crystalline Crust ◽  
Chemical Behaviour ◽  
Deformation Models ◽  
Fault Displacement ◽  
The Impact

The character of the hydrological changes that follow major earthquakes has been investigated and found to be critically dependent on the style of fault displacement. In areas where fracture-flow in the crystalline crust communicates uninterrupted with the surface the most significant response is found to accompany major normal fault earthquakes. Increases in spring and river discharges peak a few days after the earthquake and typically excess flow is sustained for a period of 4 12 months. Rainfall equivalent discharges, have been found to ceed 100 mm close to the fault and remain above 10 mm at distances greater than 50 km. The total volume of water released in two M 7 normal fault earthquakes in the Western U.S.A. was 0.3-0.5 km3. In contrast, hydroIogical changes accompanying reverse fault earthquakes are either undetected or else involve falls in well-levels and spring-flows. The magnitude and distribution of the water-discharge for these events is compared with deformation models calibrated from seismic and geodetic information, and found to correlate with the crustal volume strain down to a depth of at least 5 km. Such relatively rapid drainage is only possible if the fluid was formerly contained in high aspect ratio fissures interconnected throughout much of the seismogenic upper crust. The rise and decay times of the discharge are shown to be critically dependent on crack widths, for which the «characteristic» or dominant cracks cannot be wider than 0.03 mm. These results suggest that fluid-filled cracks are ubiquitous throughout the brittle continental crust, and that these cracks open and close through the earthquake cycle. Seismohydraulic fluid flows have major implications for our understanding of the mechanical and chemical behaviour of crustal rocks, of the tectonic controls of fluid flow associated with petroleum migration, hydrothermal mineralisation and a significant hazard for underground waste disposal.

scholarly journals Paleoseismological analysis of the Rurrand fault near Jülich, Roer Valley graben, Germany: Coseismic or aseismic faulting history?

2001 ◽  
Vol 80 (3-4) ◽  
pp. 155-169 ◽  
Author(s):  
K. Vanneste ◽  
K. Verbeeck
Keyword(s):  
Normal Fault ◽  
Historical Earthquakes ◽  
Early Pleistocene ◽  
Moderate Activity ◽  
Rhine River ◽  
Fault Creep ◽  
Vertical Movements ◽  
Roer Valley Graben ◽  
Fault Displacement ◽  
German Part

AbstractA first trench has been excavated for paleoseismological analysis in the German part of the Roer Valley graben, which has experienced several historical earthquakes with a maximum intensity up to VIII on the MSK-scale.The trench has exposed the Rurrand fault as a complex fault zone with at least five separate, SW-dipping, normal fault strands displacing an early Pleistocene terrace of the Rhine river by more than 7 m. The major part of the observed deformation was produced during or after deposition of an overlying unit of stratified loess of middle Weichselian to probably Saalian age. The faulting history is shown to be episodic, with different fault strands active at different times. Growth faulting that would be indicative of continuous, aseismic fault motion has not been observed. Our stratigraphic control is not sufficient to constrain the timing and to provide evidence of the coseismic nature for each observed fault displacement. However, two units of structureless, gravelly loess are interpreted as the result of extensive solifluction triggered by two large surface-rupturing events. This is suggested by the position of these units, which is controlled by the main faults, and by their remarkably young age (< 400 cal. BC), indicated by radiocarbon and OSL datings and by the presence of historic brick fragments. At least two faults show moderate activity that is even younger. Our interpretation is not in agreement with earlier hypotheses that ongoing vertical movements of circa 1 mm/a in the German part of the Lower Rhine graben are the result of aseismic fault creep, but is in line with the results of similar investigations on the southwestern border fault of the Roer Valley Graben in Belgium, which demonstrates the need for further paleoseismological research in this region. The Rurrand fault is presently experiencing aseismic slip on its superficial portion, induced by extensive groundwater lowering for mining purposes. This ongoing deformation seems to be expressed in the trench as diffuse bundles of anastomosing cracks extending up to, and in some cases even into the plough zone, rather than as sharp fault planes which are typical of older, tectonic fault movements.

Gravity data as a tool for detecting faults: In-depth enhancement of subtle Almada’s basement faults, Brazil

Geophysics ◽  
2007 ◽  
Vol 72 (3) ◽  
pp. B59-B68 ◽  
Author(s):  
Valeria C. Barbosa ◽  
Paulo T. Menezes ◽  
João B. Silva
Keyword(s):  
Gravity Data ◽  
Synthetic Data ◽  
Normal Fault ◽  
Northeastern Brazil ◽  
Normal Faults ◽  
Gravity Inversion ◽  
Inversion Method ◽  
Basement Faults ◽  
Depth Enhancement ◽  
Fault Displacement

We demonstrate the potential of gravity data to detect and to locate in-depth subtle normal faults in the basement relief of a sedimentary basin. This demonstration is accomplished by inverting the gravity data with the constraint that the estimated basement relief presents local abrupt faults and is smooth elsewhere. We inverted the gravity data from the onshore Almada Basin in northeastern Brazil, and we mapped several normal faults whose locations and plane geometries were already known from seismic imaging. The inversion method delineated well both the discontinuities with small or large slips and a sequence of step faults. Using synthetic data, we performed a systematic search of normal fault slips versus fault displacement depths to map the fault-detectable region in this space. This mapping helps to assess the ability of gravity inversion to detect normal faults. Mapping shows that normal faults with small [Formula: see text], medium (about [Formula: see text]), and large (about [Formula: see text]) vertical slips can be detected if the maximum midpoint depths of the fault planes are smaller than 1.8, 3.8, and [Formula: see text], respectively.

Displacement-length scaling relationships for a fault array reveal that faults grow via alternating phases of lengthening and localisation

2020 ◽  
Author(s):  
Sophie Pan ◽  
Rebecca Bell ◽  
Christopher Jackson
Keyword(s):  
Growth Models ◽  
Early Stage ◽  
Normal Fault ◽  
Scaling Exponent ◽  
Borehole Data ◽  
Natural Systems ◽  
Scaling Relationships ◽  
Fault Systems ◽  
Stress Shadow ◽  
Fault Displacement

&lt;p&gt;Rifting of the continental lithosphere is accommodated by the development of large, linked, normal fault arrays. However, the timescales over which fault arrays develop - from the interaction of small, isolated faults towards localisation of through-going fault systems, has not been well constrained from observations in natural systems. Our limited knowledge of timescales over which fault arrays develop has also resulted in the development of different and debated fault growth models. While scaling relationships between fault displacement and length have been extensively used to understand fault evolution, the scaling exponent value is still not resolved due to significant scatter in global displacement-length profiles.&lt;/p&gt;&lt;p&gt;Here we use 3D seismic reflection and borehole data from the Exmouth Plateau, NW Shelf of Australia to investigate the timescales of faults growth within an array. The excellent quality seismic data allows for the entire Jurassic to Early Cretaceous fault array to be analysed over a large areal extent (~1200 km&lt;sup&gt;2&lt;/sup&gt;), and the fault activity can be dated using biostratigraphy from wells. Our study is novel in that we reconstruct and quantify the length and throw on faults back through time to investigate how fault populations evolve. We find that the early stage of rifting was characterised by distributed faulting, where fault trace lengths were established early within the first 7.2 Myrs of rifting (out of a total rifting duration of 85.5 Myrs). By 28.5 Myrs of rifting (33% of the total rifting duration), strain localises on major west dipping faults as a fully linked system. Localisation continues on major faults until the cessation of rifting where strain is accommodated with maximum throw in the centre of faults decreasing towards its tips. Our results suggest that fault displacement and length may scale linearly, but grow in alternations of fault lengthening and fault displacement phases. The growth of active fault systems and death of inactive faults located in stress shadow zones is responsible for the scatter of data points frequently observed in global displacement-length profiles.&lt;/p&gt;

Deformed streams reveal growth and linkage of a normal fault array in the Canyonlands graben, Utah

Geology ◽  
2005 ◽  
Vol 33 (8) ◽  
pp. 645-648 ◽  
Author(s):  
Deirdre Commins ◽  
Sanjeev Gupta ◽  
Joseph Cartwright
Keyword(s):  
Normal Fault ◽  
Initial Component ◽  
Length Ratio ◽  
Normal Faults ◽  
Fault Interaction ◽  
Single Fault ◽  
Coupling Fault ◽  
Fault Displacement ◽  
Interaction Phase

Abstract We use the deformation of streams by the growth of active normal faults within the Canyonlands graben of southeastern Utah to constrain the displacement evolution of a fault array during segment interaction and linkage. Coupling fault displacement data with geomorphic analysis of present-day streams and paleostreams permits sequential reconstruction of a three-segment fault array from initial component segments to its final displacement geometry. Our results show that although segment interaction causes enhanced displacement addition at overlap zones, postlinkage displacement accumulation is significant and permits array equilibration to a displacement-length ratio characteristic of a single fault. Evidence of stream disequilibrium indicates that this postlinkage displacement addition was rapid compared to that during the fault interaction phase.

Geotechnical Challenges for Design of a Crude Oil Pipeline Across an Active Normal Fault in an Urban Area

2008 ◽  
Author(s):  
Jeffrey R. Keaton ◽  
Douglas G. Honegger
Keyword(s):  
Crude Oil ◽  
Fault Location ◽  
Salt Lake ◽  
Axial Strain ◽  
Normal Fault ◽  
Interesting Case ◽  
Burial Depth ◽  
Oil Pipeline ◽  
Fault Displacement ◽  
The City

The proposed construction of a crude oil pipeline through a residential area north of Salt Lake City, Utah, with an alignment that crossed the Wasatch fault provides an interesting case history of the numerous uncertainties and competing constraints associated with designing a pipeline fault crossing in an urban environment. Several issues raised during project design needed to be resolved with representatives of the city in which the project was located; the city had obtained technical input from the state geological survey and a local pipeline engineering specialist. The definition of the fault location and design fault displacement required reconciling suggested fault displacement estimates that ranged from 2.4 m to 4.2 m. The desire on the part of the pipeline owner and the city to have the oil pipeline buried relatively deeply (at least 1.5 m of cover) needed to be resolved with the fact that improved pipeline performance for imposed fault displacements typically is achieved with shallower soil cover. Special trench construction measures to increase the pipeline fault displacement capacity, such as reduced burial combined with protective concrete slabs above the pipeline or use of geofoam material as trench backfill, needed to be balanced with potential consequences on normal pipeline operational and maintenance activities, as well as street maintenance by the city. Increases in pipe wall thickness, that would permit an increase in the burial depth of the pipeline, needed to be balanced with concerns regarding potential problems that could be created with the measurement quality of internal inspection devices. The requirement that the pipeline be located beneath city streets, including a 90° corner 125 m from the fault crossing, limited the ability of the pipeline to distribute axial strain developed as a result of the fault displacement and led to optimization of the pipeline bend geometry with respect to available space and impact on existing utility lines. Resolving these issues was facilitated by examining the pipeline response to a variety of postulated design alternatives using finite element analyses. The final design recommendations that satisfied the owner and city provided a reasonable assurance that the pipeline would maintain pressure integrity for a fault displacement of 3.75 m.

A new release of the SURE database of earthquake surface ruptures suited to Fault Displacement Hazard Analysis

2021 ◽  
Author(s):  
Stéphane Baize ◽  
Anna Maria Blumetti ◽  
Paolo Boncio ◽  
Francesca Romana Cinti ◽  
Riccardo Civico ◽  
...  
Keyword(s):  
Land Use Planning ◽  
Hazard Analysis ◽  
Active Faults ◽  
Normal Fault ◽  
Surface Expression ◽  
Reverse Fault ◽  
Empirical Relationships ◽  
Global Database ◽  
Ranking Scheme ◽  
Fault Displacement

&lt;p&gt;Fault displacement hazard assessment is based on empirical relationships derived from data of historical surface rupturing earthquakes. This approach is used for land use planning, sizing of lifelines or major sensitive infrastructures located in the proximity of active faults. These relationships provide the probability of occurrence of surface rupture and predict the amount of displacement, both for the main ruptures (principal) and for distributed ones appearing beyond.&lt;/p&gt;&lt;p&gt;Following the first version of the global database SURE 1.0 (Baize et al., 2019), we are continuing the effort to compile observations from well-documented historical and recent surface faulting events in order to feed and improve empirical relationships. The new SURE2.0 global database consolidates the previous version SURE 1.0 data, rejecting some poorly constrained cases, reviewing some cases already in, and adding well-documented new ones (e.g. Ridgecrest sequence, USA, 2019). In total, the SURE 2.0 database has 46 earthquakes, including 15 normal fault cases, 16 reverse fault cases and 15 strike-slip cases from 1872 to 2019. The magnitude range is from M4.9 to 7.9, with ruptures from 5 to 300 km long.&lt;/p&gt;&lt;p&gt;SURE 2.0 provides the geometric location and attribute information of rupture segments in a GIS environment and a spreadsheet reports the amplitude and characteristics of deformation, including data sources and its eventual geometric refinement during analysis. In this new version, we completed an essential task to derive attenuation relationships, by classifying each rupture segment and each slip measurement point, using a ranking scheme based on the pattern and amplitude of the observed rupture traces, and considering the structural context and the long-term geomorphology. This distinguishes the principal rupture (class 1), which is the main surface expression of the source of the earthquake. Typically, in the siting study, this class is assigned to the identified active fault. Class 2 features (distributed ruptures) are characterized by shorter lengths and smaller displacements that appear randomly close and around the main rupture. We introduced the distributed main fracture category (class 1.5), which corresponds to the relatively long minor fractures recognized on cumulative structures secondary to the main fault. Class 3 represents triggered slip evidences on remote active faults, clearly not connected with the earthquake causative fault (sympathetic ruptures).&lt;/p&gt;&lt;p&gt;As was done with reverse fault cases (Nurminen et al., 2020), this new SURE 2.0 version will be used to derive probabilities associated with the rupture distribution &amp;#160;during any type of earthquake.&lt;/p&gt;

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