Thrust Component Research Articles

Preliminary Observations of the 5 April 2024 Mw 4.8 New Jersey Earthquake

Abstract On 5 April 2024, 10:23 a.m. local time, a moment magnitude 4.8 earthquake struck Tewksbury Township, New Jersey, about 65 km west of New York City. Millions of people from Virginia to Maine and beyond felt the ground shaking, resulting in the largest number (>180,000) of U.S. Geological Survey (USGS) “Did You Feel It?” reports of any earthquake. A team deployed by the Geotechnical Extreme Events Reconnaissance Association and the National Institute of Standards and Technology documented structural and nonstructural damage, including substantial damage to a historic masonry building in Lebanon, New Jersey. The USGS National Earthquake Information Center reported a focal depth of about 5 km, consistent with a lack of signal in Interferometric Synthetic Aperture Radar data. The focal mechanism solution is strike slip with a substantial thrust component. Neither mechanism’s nodal plane is parallel to the primary northeast trend of geologic discontinuities and mapped faults in the region, including the Ramapo fault. However, many of the relocated aftershocks, for which locations were augmented by temporary seismic deployments, form a cluster that parallels the general northeast trend of the faults. The aftershocks lie near the Tewksbury fault, north of the Ramapo fault.

Spatial variation of the source mechanisms in the Egyptian continental margin

The spatial variability of the focal mechanism solutions in the NW Egypt Cyrenaica and Levant-north Egypt domains of the Egyptian Continental margin is investigated based on the polarity of the P-wave first motions of eleven earthquakes with local magnitudes ML ranging from 4.2 to 6.2. The identified focal mechanism solutions in the Levant-north Egypt domain are evaluated in two sub-provinces with different geological settings. The first sub-province shows strike-slip faulting mechanisms with right-lateral motion along the NE-trending Rosetta-Qattara fault zone, while the NW-trending Temsah fault zone produces left-lateral strike-slip motion. The inland extension of the Rosetta-Qattara fault zone towards the Western Desert reflects the same sense of motion. Strike-slip faulting with thrust components dominates the focal mechanisms in the second sub-province but with a different stress orientation. A single thrust faulting mechanism event which occurred on the periphery of the continental shelf shows the same common orientation of the stress field at the Hellenic Arc. This type of mechanism in this locality can be explained by the mean of compressional stress transfer towards the coast generated by the accelerated southwest retreat of the Hellenic Trench. The complex regional stress along the Cyprian and Hellenic arcs, the current local structure features, and the dominant orientation of the pre-existing fault are the factors that contribute to the changeable stress pattern field in the Levant-north Egypt domain. A single event in the second domain, the NW Egypt Cyrenaica, is a strike-slip with a right-lateral sense of motion on a WNW-oriented plane, consistent with motion along the WNW tectonic fault which separates the continental shelf from the oceanic crust.

Aero-propulsion analysis of distributed ducted-fan propulsion based on lifting-line driven body-force model

As the environmental problems become increasingly serious, distributed electrical propulsion systems with higher aerodynamic efficiency and lower pollution emission have received extensive attention in recent years. The distributed electrical propulsion usually employs the new aero-propulsion integrated configuration. A simulation strategy for internal and external flow coupling based on the combination of lifting line theory and body force method is proposed. The lifting line theory and body force method as source term are embedded into the Navier-Stokes formulation. The lift and drag characteristics of the aero-propulsion coupling configuration are simulated. The results indicate that the coupling configuration has the most obvious lift augmentation at 12° angle of attack, which can provide an 11.11% increase in lift for the airfoil. At 0° angle of attack, the pressure difference on the lip parts provides the thrust component, which results in a lower drag coefficient. Additionally, the failure impact of a ducted fan at the middle or edge on aerodynamics is investigated. For the two failure conditions, the lift of the coupling configuration is decreased significantly by 27.85% and 26.14% respectively, and the lip thrust is decreased by 70.74% and 56.48% respectively.

Strong earthquakes and tsunami potential in the Hellenic Subduction Zone

The tsunamigenic potential of an earthquake depends on its size, source depth and focal mechanism. The Hellenic Subduction Zone (HSZ) has been selected in the paper to study this important issue. The HSZ was ruptured by 11 strong (Mw6.0) earthquakes in the time period 2009–2023. One earthquake ruptured onshore but only three out of ten offshore earthquakes produced tsunamis: 1 July 2009 (Mw6.4), 25 October 2018 (Mw6.8), 5 May 2020 (Mw6.6). For each one of the two more recent earthquakes of 5 May 2020 (tsunamigenic, thrust faulting) and 12 October 2021 (non-tsunamigenic, strike-slip faulting) we developed heterogeneous fault models from the inversion of teleseismic P-waveforms, and homogeneous fault models from published moment-tensor solutions. For each fault model tsunami generation and propagation was numerically simulated based on an advanced phase-resolving wave model with the use of higher-order Boussinesq-type equations. The modelled tsunami mareograms are consistent with tide records of the small tsunami (height ∼30 cm) produced by the 2020 earthquake. For the 2021 earthquake the modelled mareograms showed tsunami-like disturbance with amplitude not exceeding the noise level. The tsunamigenic earthquakes of 2009, 2018 and 2020 shared magnitude Mw≥ 6.4, shallow depth (h<20 km), moderate-to-high dip-angle and thrust faulting or oblique slip with significant thrust component. In the remaining seven non-tsunamigenic earthquakes, including the 2021 one, at least one of these features is missing. The results obtained help to better understand the seismic mechanisms of tsunami generation in the HSZ. Further investigation is needed for the central HSZ segment to the south of Crete Island, which historically has not been ruptured by large (Mw>7.0) tsunamigenic earthquakes. In contrast, the western and eastern HSZ segments ruptured by the large 365 AD and 1303 AD tsunamigenic earthquakes.

Energy Contribution Study of Blade Cavitation Control by Obstacles in a Waterjet Pump Based on mPOD and EEMD

Abstract It has been confirmed that the passive obstacles would substantially depress the leading-edge cavitation in a waterjet pump. Combined with the experiments and numerical simulations, this work revisits blade cavitation evolutions to demonstrate the stabilizing effects of obstacles on cavitation unsteadiness. The multiscale proper orthogonal decomposition (mPOD) and ensemble empirical mode decomposition (EEMD) are adopted to study the energy contributions regarding the cavitation-induced loading and thrust. The mPOD modes illuminate that the leading-edge loading oscillations of the obstacle blade are consequently eliminated where the cavitation is completely depressed and the obstacle cavitation wakes greatly contribute to loading excitation. The thrust statistics demonstrate that the thrust extremes and standard deviation in some revolutions can be well reduced as the large-scale leading-edge cavity depression. The adaptive spectra obtained by EEMD further illuminate that both the tonal and broadband components of blade thrust would be reasonably degraded to some degree. The pump with only one obstacle implementation, as an improvement strategy, is comparatively studied and indicates that single obstacle configuration presents positive effects on the leading-edge cavity depression owing to the pressure-raising effects and can reduce the un-necessary energy loss compared with two obstacles.

Investigating paleoseismicity using high-resolution airborne LiDAR data - A case study of the Huangxianggou fault in the northeastern Tibetan plateau

Fault-offset landforms have long been recognized as holding important information about paleoseismic slip. Constructing an along-strike fault slip distribution could help reveal a fault's long-term rupture patterns and facilitate a more precise assessment of its future behavior. In this study, we documented the paleoseismic history of the Huangxianggou Fault, an oblique sinistral-thrust segment of the West Qingling Fault in the northeastern region of the Tibetan Plateau, using LiDAR-derived high-resolution DEM (0.1 m/pixel) and measurement of offset landforms. A total of 46 well-preserved and well-shaped landforms were chosen for horizontal and vertical displacement measurements, and the dense measurement data allow us to generate the cumulative offset probability distribution curves of horizontal and vertical displacements. Statistical analysis revealed at least seven surface-rupturing events, each with similar coseismic horizontal displacements of ∼7.0 m and vertical displacements of ∼0.7 m, in agreement with previous paleoseismic trench results. Using empirical relationships between moment magnitude and horizontal displacement, a plausible moment magnitude range of Mw7.3–7.7 was determined for these paleoearthquakes. Furthermore, by evaluating rupture parameters and fault slip rate, we determined a recurrence interval of 2.7–3.4 kyr for significant surface-rupturing events on this fault. The elapsed time since the last earthquake closely approaches this interval, suggesting a potential seismic risk for the Huangxianggou Fault. Our results emphasizes the importance of high-resolution topographic data in paleoseismic investigations, enabling the identification of numerous offset landforms and precise displacement measurements across faults. Paleoearthquake counts derived from horizontal and vertical displacement analyses were found to be consistent, highlighting the significance of vertical displacements in quantifying paleoearthquakes for strike-slip faults with a thrust component.

An Investigation on the Effect of Watertightness Criteria on the Structural Assessment of Prestressed Concrete Substructures of Floating Wind Turbines

The effect of watertightness criteria on structural assessment was investigated in this study through the design of a semi-submersible floater for a 10 MW wind turbine. A structural assessment was carried out for the ultimate, fatigue, and serviceability limit states, where six cases of combinations of the loading conditions and structural requirements were assumed for the assessment of watertightness. The different assessment conditions for watertightness resulted in different designs of prestressing tension, which also caused differences in the design margins for the ultimate limit states as well as the SN diagram used for the assessment of the fatigue limit states. The maximum stress acting on the member of the floating wind turbine differed by about 7.6 to 16.2% for the 50-year and 1-year environmental conditions. The small difference between the stresses for the two return periods can be attributed to the large component of the wind turbine thrust in the variable loads. When the partial load factor of 1.0 was used, the structural requirement in the prestressing design caused larger differences compared to the return period of the loading conditions in the watertightness assessment. The use of the partial load factor of 0.5 for the prestressing design also caused a large difference in the results of the structural assessment, indicating the necessity of further investigation of the determination of the partial load factor for floating offshore wind turbines.

Improvement of the efficiency for rim-driven thrusters through acceleration of gap flow

Efficiency optimization of the rim-driven thruster (RDT) has emerged as a prominent research topic in recent years. In this work, the Reynolds-averaged Navier-Stokes (RANS) solver is employed for simulating open water performance of RDTs, aiming at improving the efficiency of RDTs. Specifically, a series of RDTs are obtained by modifying the Ka4-70 propeller with a 19A duct, and their thrust and torque components, as well as efficiency and gap flow, are thoroughly examined. The investigation commences by exploring the impact of different rim sizes on RDT efficiency. A comparison is conducted between the open water performance of RDTs and the ducted propeller. Subsequently, a case with relatively high efficiency is identified, serving as a basis for the development of a series of modified RDTs equipped with acceleration devices. These devices facilitate accelerated axial flow in the gap, thereby enhancing the thrust generated by the duct, while simultaneously reducing the torque exerted on the rim through accelerated circumferential gap flow. Comparative analysis reveals that the improved RDTs can achieve an open water efficiency increase of up to 10.9% when the advance coefficient is set to 0.6, resulting in an efficiency value of 0.519. The findings presented in this paper introduce a novel direction for optimizing the efficiency of RDTs, contributing to the advancement of this field of study.

Результати проектування надзвукового сопла з подвійним розширенням для рідинного ракетного двигуна першого ступеня методами обчислювального аналізу

The subject of this study is dual-bell supersonic nozzles of liquid rocket engines. The goal is to design a dual-bell supersonic nozzle that will provide maximum thrust for a liquid rocket engine in the first stage of a launch vehicle by solving an optimization problem using numerical simulation methods. The goal of the study is to choose the exit pressures of each part of the dual-bell nozzle based on the known flight trajectory of the launch vehicle, set and solve the problem of optimizing the dual-bell nozzle contour, and assess the impact of the use of a dual-bell nozzle on the efficiency of a liquid-propellant rocket engine. The methods used are: numerical methods for solving the hyperbolic system of unsteady equations of gas dynamics and multidimensional minimization problems. The following results were obtained. The formulation and solution of the optimization problem of the contour of a dual-bell supersonic nozzle, considering the design limitations in the form of a fixed length of the nozzle, is carried out. By analyzing the flight path of the first stage of the launch vehicle, a first approximation of the nozzle contour was obtained. For further calculations, both sections were approximated by parabolas, the coefficients of which, together with the lengths of the sections, formed a vector of optimized parameters. An expression for the axial component of thrust with the opposite sign was used as the objective function to solve the minimization problem. Because of solving the optimization problem, a dual-bell nozzle contour was designed to provide maximum thrust. An assessment of the effectiveness of his work was also conducted. The calculated value of the average along the trajectory of the specific impulse when using a dual-bell nozzle was higher by 1.6% than when using a standard nozzle. Conclusions. The scientific novelty of the obtained results is as follows: the design of the dual-bell nozzle contour was performed by solving the problem of multidimensional optimization, taking into account the design constraints, and using computational analysis methods

Diffractive Sail-Based Displaced Orbits for High-Latitude Environment Monitoring

This paper analyzes the possibility of maintaining a circular displaced non-Keplerian orbit around the Sun by means of a Sun-facing diffractive sail. With the goal of monitoring the Earth’s high-latitude regions, the spacecraft is required to track its displaced orbit at an angular velocity equal to the mean motion of the planet. In doing so, the spacecraft keeps a constant average phase shift with respect to Earth’s angular position along its orbit, allowing the objectives of the scientific mission to be achieved. The diffractive sail, recently proposed by Swartzlander and chosen in this paper as the spacecraft’s primary propulsion system, is a special photonic solar sail in which the membrane film is covered by an advanced diffractive metamaterial. In particular, a Sun-facing diffractive sail with a grating at normal incidence generates radial and transverse thrust components of equal magnitude; that is, the thrust vector is tilted 45 degrees from the Sun-spacecraft line. This peculiarity enables the diffractive sail to maintain a family of circular displaced non-Keplerian orbits, each of which is characterized by unique values of radius and a lightness number for an assigned value of spacecraft displacement relative to the Ecliptic. A comparison with the ideal reflecting sail shows that the diffractive sail performs better because for the same overall spacecraft mass, the latter needs about 30% less surface area exposed to the Sun. Finally, this paper discusses the classical stability problem, assuming an error in orbit insertion of the diffractive sail-based spacecraft. In this context, extensive numerical simulations show that such displaced orbits are marginally stable.

Shallow Fault Slip of the 2020 M 5.1 Sparta, North Carolina, Earthquake

Abstract The 2020 M 5.1 Sparta, North Carolina, earthquake is the largest in the eastern United States since the 2011 M 5.8 Mineral, Virginia, earthquake and produced a ∼2.5-km-long surface rupture, unusual for an event of this magnitude. A geological field study conducted soon after the event indicates oblique slip along a east-southeast-trending fault with a consistently observed thrust component. My analysis of regional seismic waveforms, Interferometric Synthetic Aperture Radar, and Global Positioning System survey data yields a compact shallow rupture extending from Earth’s surface down-dip to the southwest over a ∼3 km fault length. The inferred kinematic rupture is primarily toward the up-dip and eastward along-strike directions and has predominantly thrust motion in the west, transitioning to roughly equal thrust and left-lateral strike-slip motion in the east. No normal faulting component, as proposed in an earlier geophysical study, is necessary to explain the data. The prevalence of only dip-slip motions observed at Earth’s surface may demand slip partitioning between dip slip and lateral motions at depth.

Autonomous Flight in Hover and Near-Hover for Thrust-Controlled Unmanned Airships

The ability of airships to fly in hover is a major plus of this category of flying vehicles. However, especially for the case of autonomous flight, this feature can be exploited only recurring to a carefully designed layout of the thrusters on board. Furthermore, the thrusters need to be suitably governed by a dedicated control algorithm. This paper explores a scheme for the control in hover of a thrust-controlled airship without thrust vector control, also assessing its effectiveness in near-hover positioning problems. The control scheme proposed herein extends the capability of a stability augmentation and guidance controller for forward flight, previously introduced by the authors for a conceptually similar airship. A control action based on a system of thrust forces required for hover, and additional thrust components for stabilizing and steering the airship in slow (near-hover) navigation, is thoroughly described. The ensuing control suite is applied and tested in the present paper on the high-fidelity virtual model of a five-thruster airship, showing reasonable stability levels and navigation accuracy of the controlled system.

The Source Characteristics of the 2022 Ms 6.1 Lushan Earthquake: An Event That Occurred on the Conjugated Fault of the 2013 Ms 7.0 Lushan Earthquake

Abstract The 2022 Ms 6.1 Lushan earthquake occurred in the southern segment of the Longmenshan fold-and-thrust belt, Sichuan Province, China, ∼7 km north-northwest of the 2013 Ms 7.0 Lushan earthquake. To understand its source characteristics and interplay with the 2013 Lushan event, we evaluate the 2022 Lushan earthquake in terms of focal mechanism, aftershock relocation, and rupture process. Results show that it is a purely thrust earthquake with a source depth of 14 km and a focal mechanism nodal plane of 29°/51°/80°. The automatic phase picker-based aftershock locus clarifies that the 2022 Lushan earthquake occurred on a blind northeast-trending conjugate fault of the 2013 Lushan earthquake. The finite-fault model constrained by teleseismic waveforms suggests that the high slip is concentrated in an asperity near the epicenter with a peak slip of 42 cm, which is characterized by thrust components. Based on the promotion of postseismic deformation following the 2013 Lushan earthquake and the similarity of the seismotectonic system, we argue that the 2022 Lushan earthquake may be an aftershock of the 2013 Lushan earthquake that occurred on a blind thrust fault.

Optimal interplanetary trajectories for Sun-facing ideal diffractive sails

A diffractive sail is a solar sail whose exposed surface is covered by an advanced diffractive metamaterial film with engineered optical properties. This study examines the optimal performance of a diffractive solar sail with a Sun-facing attitude in a typical orbit-to-orbit heliocentric transfer. A Sun-facing attitude, which can be passively maintained through the suitable design of the sail shape, is obtained when the sail nominal plane is perpendicular to the Sun–spacecraft line. Unlike an ideal reflective sail, a Sun-facing diffractive sail generates a large transverse thrust component that can be effectively exploited to change the orbital angular momentum. Using a recent thrust model, this study determines the optimal control law of a Sun-facing ideal diffractive sail and simulates the minimum transfer times for a set of interplanetary mission scenarios. It also quantifies the performance difference between Sun-facing diffractive sail and reflective sail. A case study presents the results of a potential mission to the asteroid 16 Psyche.

Non-coaxial deformation of foreland basement involved in a fold-and-thrust belt: a strain partitioning approach to the Eastern Variscan orogen

The general SW–NE course of the Variscan orogen in Europe is abruptly bent to the N–S course at its eastern margin, where an oblique convergence occurred. The main suture in this part of the Variscan orogenic belt is called the Moldanubian Thrust, characterized by a dominant dextral strike-slip kinematics and a minor thrust component. The deep level of erosion and the good exposure of this structure allowed us to study the mechanisms of oblique convergence and the incorporation of the foreland basement into the orogenic belt. The combination of small-scale structures with the anisotropy of magnetic susceptibility studies allowed the recognition of two deformations in the studied rocks: dextral simple shearing and drag folding. Due to oblique convergence, the deformations induced by this mechanism were non-coaxial; therefore, their contributions can be easily distinguished. Finally, an overturned, almost recumbent large-scale synformal fold structure in the footwall and an antiformal structure in the hanging wall of the Moldanubian Thrust were formed. These two folds can be interpreted as structures formed by dragging along the Moldanubian Thrust. The previously described sinistral simple shearing in the upper limb of the synform resulted from the original dextral strike-slip shearing, which was overturned during progressive deformation.

Horizontal Fixed Attitude Flight of Quad Rotor Helicopter with Tilting Rotor

A quad rotor helicopter (QRH), a type of unmanned aerial vehicle (UAV), uses a tilted attitude to generate a horizontal thrust component in the flying direction. In the case of autonomous control, the attitude control system is used to tilt the airframe against disturbances such as crosswinds. Consequently, the flying attitude of a QRH is always inclined. In this study, a tilting mechanism for rotors (TMR) was mounted on a QRH to maintain a horizontal attitude. The TMRs were tilted to generate thrust against disturbances without inclining the airframe. The system was constructed using a QRH and TMRs tilted around only one axis and allocated every 90°. Because the airframe is always horizontal, this system can be used for the precise measurement of landforms and buildings. This paper reports the dynamic modeling of QRH equipped with TMRs and discusses the horizontal constant attitude flight using the proposed system.

Onto Quantifying Unsteady Propulsion Characteristics Using Momentum and Energy Control Volume Assessments

AbstractThis effort presents a novel approach to interrogate efficiency for unsteady, undulating propulsion using variable momentum and energy conservation (VMEC) assessments. These integral approaches utilize large amounts of data from computational fluid dynamics (CFD) to address present difficulties associated with separating thrust from drag associated with propelling bodies as well as potentially resolve issues associated with defining a nonzero efficiency for a body in self-propulsion. Such a fundamental issue is addressed through strategic control volume assessments of the momentum and energy conservation equations. In this work, the Method of Manufactured Solutions (MMS) is used to verify the integral-based evaluation approach and better quantify output. The MMS results indicate the method is valid and that one can separate work associated with lift and drag from the energy budget. This separation procedure provides a means to separate propulsive and drag forces. The effort then studies previously validated CFD simulations of heaving and pitching foils to provide insight associated with separating axial forces into their thrust and drag components for highly complex systems. The effort then presents a new efficiency metric that can obtain nonzero efficiencies in self-propulsion. Overall, the results indicate that energy-based assessments provide insight that is a step forward toward isolating loss from propulsive mechanisms and developing proper metrics of efficiency.

Engineering Design, Kinematic and Dynamic Analysis of High Lugs Rigid Driving Wheel, a Traction Device for Conventional Agricultural Wheeled Tractors

Traction failure on loose terrain is common in conventional agricultural wheeled tractors due to poor traction ability and lower power transfer efficiency of drive wheels, which leads to excessive energy consumption and soil compaction in agriculture. To overcome the problem, this paper presents a new design of a rigid lugged wheel for use in field tillage operations. This wheel was designed according to field operational requirements and also provided with rubber pads for smooth on-road drives. Kinematic and dynamic analysis of new wheel designs were carried out to study how they move, how they interact with the soil, and how they generate drive force in loose terrain soil. The relationship of wheel lug motion trajectories, displacement, and velocity of the wheel relative to field conditions, different travel reduction rates, and lug penetration/wheel sinkage were analyzed. Wheel-terrain interaction and shear stress-shear displacement relationships when the wheel is driven in soft, deformable terrain were studied using classic soil mechanics principles. It is found that the component of thrust in the direction of driving, i.e., driving force, is ranged between 81.52% and 86.17%, while the vertical component is reported to be less than 30% and further decreases to 9%, which is the compaction avoiding factor. The relationships, thus developed, of wheel parameters, soil stress and thrust characteristics, and wheel drive force were derived and revealed that the traction performance, power transfer efficiency, and trafficability of tractors in loose terrain can be improved by using the newly proposed wheel. A finite element method was used to analyze the designed wheel model for structural stability and optimization. The theoretical analysis results of the new drive wheel are convincing, so further tests and field operation research are recommended for sustainable adoption.

Refined MagSail thrust model for preliminary mission design and trajectory optimization

A magnetic sail is an advanced propellantless propulsion system concept for deep space missions, proposed by Dana Andrews and Robert Zubrin about 30 years ago. The thrust is generated by the electromagnetic interaction between the solar wind charged particles and an artificial magnetic field obtained through a large current-carrying coil made of superconducting material. This paper discusses an up-to-date single-loop magnetic sail thrust model based on the numerical and experimental results obtained in the last decade. In particular, a particle model is initially used to evaluate the performance of a reference configuration in terms of thrust components in a body reference frame. Then, some scaling relationships are used to estimate the magnetic sail performance as a function of the design parameters. The proposed thrust model is used to analyze the minimum-time transfer problem between two circular and coplanar heliocentric orbits. Minimum flight times necessary to complete ephemeris-free Earth-Venus and Earth-Mars transfers are calculated as a function of the magnetic sail characteristic size in a parametric way.

Fault slip of the 2022 Mw6.7 Menyuan, China earthquake observed by InSAR, and its tectonic implications

In this article the ascending and descending Sentinel-1A satellite data are used to investigate the coseismic slip model of the 2022 Mw6.7 Menyuan earthquake in Qinghai, China. The optimal slip model indicates that this event ruptured two fault segments. The main rupture concentrated on the western Lenglongling fault (LLLF) with a purely left-lateral striking-slip motion. A small part of the eastern Tuolaishan fault (TLSF) section was also ruptured, and the motion on it is mainly oblique slip at depth, with an obvious thrust component. Combined with the rupture characteristics of historical events, GPS velocity map, and slip rate studies, we suggest that the TLSF–LLLF junction is a demarcation point where the deformation partitioning pattern has changed. Along the whole LLLF segment, the oblique convergence has completely partitioned into slip on the purely strike-slipping LLLF and thrusting faults in the north. The TLSF segment accommodates a fraction of compressional shortening, which compensates for the discrepancy in the left-lateral slip rate between the LLLF and TLSF. Such transformation in the strain partitioning pattern is likely to be determined by the geometric relationship between the fault strike and the direction of regional block movement.