Mass Movement Research Articles

The recent increasing frequency of strong cooling event in Southwest China in February

AbstractA strong cooling event refers to a sharp change in the average temperature over a short period. The rapid change of temperature has important effect on human health and is highly concerned recent years. Based on the observed temperature data set from stations in Southwest China (SWC) from 1979 to 2017, this paper analyses the characteristics of the strong cooling event (SCE). The result shows that SCE occurs with the highest frequency during the time from February to May. Among them, the frequency of SCE in February exhibits an abrupt change before and after 2005 with a significant increase. Further study reveals that the change of SCE frequency in February is associated with the large‐scale background circulation patterns. After 2005, there is a cyclonic circulation anomaly in Northeast Asia and an anticyclonic circulation anomaly in the Tibet Plateau (TP). This pattern provides a favourable condition for the southward movement of cold air mass, thereby increasing the frequency of SCE in SWC. Furthermore, it is revealed that there is a strong correlation between the variation of SCE frequency in February and sea surface temperatures (SST) in the Northwest Pacific in January before 2005. The cold SST anomaly could favour the occurrence of extreme TD events in SWC through vertical circulation. After 2005, the correlation between SCE and Northwest Pacific SST is not significant. The sea ice in the northern Barents Sea and Kara Sea becomes the dominant impact factor. The abnormally low sea ice concentration is conducive to strengthen the meridional circulation over East Asia, leading to an increasing frequency of SCE in SWC.

Political accountability and legislative behavior in Africa: evidence from the 2019 Kenyan Sugar Bill in the context of the political economy of sectoral policy

ABSTRACT Recent research on African legislatures, once considered rarely autonomous, has found that some broad-scale mass movements, including pro-poor campaigns, hold legislators accountable. This article meanwhile examines the conditions under which narrow local constituency issues, shaping partisan differences, can hold relevant representatives and parties accountable while prioritizing over executive pressures and clientelist personal gains. I argue that this sort of political accountability in legislatures can be observed concerning sectoral policy interests, which, in Africa, are often geographically concentrated along ethnicity and party support lines. Drawing on a combination of qualitative and quantitative approaches including interviews, news coverage reviews, and a statistical analysis of legislative debates on the 2019 Sugar Bill in Kenya, I show that the growing and collective efforts of sugar farmers to influence their local representatives and parties to support the legislation, tying them to the same electoral fate, prompt legislators to speak in favor of their local interests. This implies that sector-based policy concerns, when addressed by organized policy backers, are used as an effective mechanism for maintaining party unity and accountability in the legislature.

“Once it was Ireland, Now it is Kenya”: anti-colonialism and internationalism in the pages of the Connolly Association’s Irish Democrat in the 1950s–60s

ABSTRACT Irish Democrat was the paper of the Connolly Association, a diaspora organisation established to build support for Irish republicanism within the British labour movement. The Connolly Association and the Irish Democrat had strong links to the Communist Party of Great Britain, which advocated for a peaceful mass movement to challenge the British presence in Northern Ireland and to remove discrimination faced by Catholics in the Six Counties. Encouraged by the wave of decolonisation across the British Empire in the 1950s-60s, both the CA and the CPGB saw the struggle against Unionist rule in Northern Ireland as analogous to events in Asia, Africa and the Middle East. This paper explores the narration of anti-colonial and national liberation movements elsewhere in the British Empire in the pages of the Irish Democrat and the overdetermination of Irish national questions by post-war discourses of radical decolonisation. It also traces the formation across difference of specific solidarities between the Connolly Association and other migrant communities within the multicultural political geography of post-war Britain, including out of campaigns against racial discrimination, the “colour bar” and post-war immigration controls.

Lacustrine mass movements in active tectonic settings: Lake tsunami sources in New Zealand's South Island

Lake tsunamis generated from subaerial and subaqueous mass movements can pose a significant hazard to lakeshore communities. However, current knowledge of lake tsunamis is derived from a limited number of studies, primarily in low-seismicity settings such as Switzerland and Norway. Underrepresented are studies from active tectonic settings, characterised by high relief, high sediment yields, and frequent seismic shaking that is likely to produce episodic subaerial and subaqueous mass movements with the potential to produce lake tsunamis. This study seeks to address this gap in our understanding through an examination of four lakes in the active tectonic region of New Zealand's South Island (Lake Rotoiti, Lake Rotoroa, Lake Brunner, and Lake Mapourika). High-resolution multibeam bathymetry and high-resolution seismic reflection data were used to identify and characterize the landforms and sediment associations of large and potentially tsunamigenic mass movements. A qualitative evaluation of the tsunamigenic capacity of the identified mass movements was undertaken using established empirical relationships between mass movement volumes and run-up heights. The bathymetric and seismic surveys have revealed 16 previously undocumented mass movements capable of generating lake tsunami. Fluvial deltas and bedrock slopes proximal to active faults were the most prevalent mass movement source areas, with the largest mass movements identified being a 49 Mm3 delta collapse and a 110 Mm3 subaerial mass movement in Lake Rotoroa. The findings suggest the origin and characteristics of the potentially tsunamigenic mass movements identified were strongly influenced by the high rates of delta progradation, frequent seismic activity, and the preconditioning and displacement by active faults, typical of active tectonic settings. Our results provide new insights into the heterogeneity of lacustrine mass movements and the drivers of lake tsunami hazards in underrepresented high-seismicity regions. The findings illustrate the importance of developing regionally specific insights into lake tsunami susceptibility and may inform the direction of more detailed lake tsunami hazard assessment in New Zealand.

African Popular Protest and Political Change

Abstract: In the twenty-first century, African countries have hosted more mass movements than any other region in the world. In the last decade, one in every three nonviolent revolutionary campaigns has taken place in Africa. The region also has the highest short-term success rate for people power. But is this success predicated on the mobilizational force of "protest democracy" to hold elites accountable? Or are African social movements' remarkable successes an environmental artefact, the result of ordinary protests in contexts of extraordinary instability? The evidence suggests that African social movements are uniquely effective and that political and military elites are increasingly trying to harness their power. Ordinary people—marshalled in massive demonstrations and persistent civil society organizing—have played a necessary, often decisive role in agitating for democracy. However, eliciting successful breakthroughs requires the alignment of protester demands with the abandonment of the status quo by elite blocs. Recent cascades of irregular power transfers in African politics illustrate these distinctive dynamics, where diverse domestic political contexts share an important common ingredient: the combination of mass movements pushing for change and military power players who are willing to help them.

Progressive failure and quantitative stability analysis of rock slope with cross-type discrete fracture network using spring-based smoothed particle hydrodynamics method

The propagation and coalescence of discontinuous cross-type joints are often the primary drivers of rock slope failures. Due to the inherent randomness of these joints, identifying suitable methods to accurately characterize progressive failure and quantitatively assess the stability of slopes with cross-type joints is particularly challenging. To address this, a Discrete Fracture Network-Spring Based-Smoothed Particle Hydrodynamics (DFN-SB-SPH) method is proposed, which considers cross-type DFN generation, rock matrix heterogeneity, cracking, block contact, and deposition within a unified SPH framework. In this approach, damage and contact of blocks are achieved by introducing a fracture sign to enhance the kernel function and applying Newton's law to the damaged particles to realize the point to point contact. A uniaxial compression test on rock samples with double fissures is carried out to verify the accuracy of the proposed method. The influence of joint density, geometric parameters (i.e., trace length, dominate dip angle) of cross joints, and rock mass heterogeneity on the failure characteristics of RSCD are investigated. The results revealed that the DFN-SB-SPH model possesses robust capabilities for crack tracking, mass movement, and contact slipping along fracture surfaces. Moreover, DFN generation, heterogeneous characterization, shear and tensile fractures within a single SPH framework without mesh distortion are realized. Five typical failure modes calculated by DFN-SB-SPH are primarily determined by the combination of joint dip angles and trace lengths. Furthermore, the dip angle, trace length, joint density, and rock mass heterogeneity significantly alter the stability of RSCD with sensitivity coefficients for factor safety of 27.7 %, 44.6 %, 72.9 % and 35.0 %, respectively. Higher dominant dip angles (above 60°) lead to significantly longer run-out distances for RSCD compared to lower angles (below 30°) once instability occurs. The sudden rise in major principal stress at the slope's top and toe, along with the shift of tensile stress concentration towards the middle, predicts the stages of crack propagation and sliding in slope failure.

Deceleration of kicked objects due to the Galactic potential

Context. Various stellar objects experience a velocity kick at some point in their evolution. These include neutron stars and black holes at their birth, or binary systems when one of the two components goes supernova. For most of these objects, the magnitude of the kick and its impact on the object dynamics remains a topic of debate. Aims. We investigate how kicks alter the velocity distribution of objects born in the Milky Way disc, both immediately after the kick and at later times, and whether these kicks are encoded in the observed population of Galactic neutron stars. Methods. We simulated the Galactic trajectories of point masses on circular orbits in the disc after being perturbed by an isotropic kick, with a Maxwellian distribution where σ = 265 km s−1. Then, we simulated the motion of these point masses for 200 Myr. These trajectories were then evaluated, either for the Milky Way population as a whole or for those passing within two kiloparsecs of the Sun, to get the time evolution of the velocities. Results. During the first 20 Myr, the bulk velocity of kicked objects becomes temporarily aligned with the cylindrical radius, implying an anisotropy in the velocity orientations. Beyond this age, the velocity distribution shifts towards lower values and settles to a median of ∼200 km s−1. Around the Sun, the distribution also loses its upper tail, primarily due to unbound objects escaping the Galaxy. We compared this to the velocities of Galactic pulsars and find that pulsars show a similar evolution with characteristic age. Conclusions. The shift in the velocity distribution is due to bound objects spending most of their orbits at larger radii after the kick. They are, therefore, decelerated by the Galactic potential. We find the same deceleration for nearby objects and the total population, and conclude that it is also observed in Galactic pulsars. Because of this effect, the (scalar) speeds of old neutron stars provide little information about their kicks at birth.

Cemani chicken: characteristics of fresh semen, testes morphometric, and the relationship between the two traits

Abstract The monitoring of the reproductive performance of roosters can be conducted by examining the characteristics of fresh semen, the morphometric approach of the testes, and the correlation between these two traits. To analyze the semen traits, a total of ten rooster heads were utilized, while the morphometric analysis of the testes was performed on five rooster heads. Descriptive methods were employed to assess the shape and characteristics of the fresh semen. The average length, width, weight, and circumference of the testes were evaluated using a T-test with a confidence level of 95%. Furthermore, Pearson’s correlation was employed to investigate the association between the traits of the semen and the morphology of the testes. The effects confirmed that the testes of Cemani chickens had been no extraordinary from chickens in general, placed inside the frame hollow space close to the spine, connected to the dorsal belly hollow space, or simply in the back of the lungs and the front of the kidneys and testes, elongated and oval. Typically, the left testes were relatively longer, wider, and heavier than the right testes. The semen exhibited a creamy white color, with a thick consistency and an acidity level of seven. Furthermore, it displayed a satisfactory mass movement with an average value of 2.80 ± 0.92. The motility and viability of the spermatozoa were within the normal range (70.50 ± 5.50 and 80.90 ± 4.58, respectively) at a concentration of 1402 ± 382 x 106/ml. The characteristics of the semen and the size of the testes (both left and right) demonstrated a correlation with motility. This observation concluded was that Cemani chickens exhibit remarkably accurate semen characteristics and testicular morphometrics.

Changing Social Movements in Lisbon? Housing Financialisation and Post-pandemic Activism

During the last decade, following years of austerity and rapid growth driven by tourism, real estate, and external investment, Lisbon has become a paradigmatic case of the financialisation/crisis nexus in the housing field. The simultaneous emergence and growth of social movements for the right to housing has been widely documented, with some accounts focusing on anti-financialisation struggles. In this article, we present the repertoires and claims of four activist groups and platforms born between 2022 and 2023 and discuss how Portuguese social movements are contending with the increasing centrality of financialisation in housing. In sum, we present three broad patterns of rescaling – intersectionality, internationalisation, and relations with political parties – in relation to the general endeavour to build a mass movement.

Migration crisis fueled by the challenges and uncertainties facing the new Afghanistan

After the US withdrew from Afghanistan by ending its 20-year occupation, the country was completely under the administration of the Taliban. However, at the end of this process, some uncertainties emerged such as what the political administration, social life and economic situation would be in Afghanistan, as well as how security and justice would be established. The Interim Government, formed by the Taliban, had to meet the expectations in the international arena while overcoming these uncertainties. However, it has also been understood that the integration of Afghanistan under the Taliban administration with the contemporary world will not be rapid. In addition, irregular migration to the West due to the long-lasting war in Afghanistan, and the effect of these increasing mass movements over time, the new uncertainties that emerged in Afghanistan, on irregular migration were also analyzed. Thus, it has been tried to determine whether irregular migration originating from Afghanistan can be prevented.

Geogrid-type geotextile made from Typha domingensis fibers with high tensile strength for erosion control

The present invention relates to a geotextile of the geogrid type manufactured with fibers from the Typha domingensis plant, known as cumbungi, recognized for its remarkable tensile strength. This geotextile is developed to mitigate erosive processes and is produced from natural fibers arranged in a mat configuration. This product fit in with the technical fields of civil engineering and textile materials. The central innovation of this geotextile lies in the provision of a natural alternative featuring biodegradable fibers and high tensile strength. Its applications in environmental engineering include erosion prevention, slope stabilization, and reinforcement of road structures, with the fundamental goal of preserving the soil against degradation and erosion. This high-strength geotextile is composed of Typha domingensis fibers skillfully interwoven and connected to form a grid structure, with each unit covering approximately 0.25 m2s. Furthermore, a double layer of waterproofing material is incorporated to provide greater cohesion, environmental durability, and tensile strength. In practical applications, this geotextile demonstrates a remarkable ability to withstand mass movements even before local vegetation develops. This makes it a technological alternative that synergistically combines technological and ecological processes, incorporating the principles of soil bioengineering while offering a sustainable alternative to synthetic geotextiles. The use of this geotextile in the field is preferably combined with living components such as seeds, plant stakes, wood, or rocks for slope or embankment stabilization, with a primary focus on effective erosion control and the promotion of environmental sustainability.

Evolution of motions in a resistive medium of a body with a movable mass

Evolution of motions in a resistive medium of a body with a movable mass

Multi-temporal morphological analysis coupled to seismic survey of a mass movement from southern Italy: a combined tool to unravel the history of complex slow-moving landslides

Multi-temporal morphological analysis coupled to seismic survey of a mass movement from southern Italy: a combined tool to unravel the history of complex slow-moving landslides

Genetic Selection Approach for Semen Characteristics in Thai Native Grandparent Roosters (Pradu Hang Dum) Using Random Regression Test-Day Models and Selection Indices.

The aim of this study was to analyze suitable genetic models and selection indices to estimate the genetic parameters and breeding values of native Thai roosters. A total of 3475 records of seven semen traits (mass movement, semen pH, semen color, volume, sperm viability, sperm abnormalities, and sperm concentration) from 242 Thai native grandparent roosters were analyzed. Multiple-trait random regression test-day models with five covariance functions were used to analyze the variance components, genetic parameters, and breeding values. The selection index (SI) was calculated to determine the optimal genetic value for different selection percentages. The results showed that a multiple-trait random regression test-day model with a second-order Legendre polynomial function was the most appropriate genetic model for this population. The estimated heritability values were low to moderate, ranging from 0.110 to 0.112 (mass movement), 0.040 to 0.051 (semen pH), 0.092 to 0.097 (semen color), 0.220 to 0.225 (semen volume), 0.067 to 0.083 (sperm viability), 0.086 to 0.099 (sperm abnormalities), and 0.134 to 0.138 (sperm concentration). The repeatability values exceeded the heritability values and were within the range of 0.133 to 0.688. The genetic correlations among semen traits ranged from -0.332 to 0.677, and phenotypic correlations ranged from -0.260 to 0.460. When considering heritability and genetic correlation values, semen volume, sperm concentration, and mass movement were the top three priority semen traits calculated as selection indices. Finally, the top 10% of the selection index was recommended for creating the next generation. Our findings provide useful information on genetic parameters and an appropriate selection index of semen traits for selecting the genetics of individual Thai native grandparent roosters. The heritability estimates for semen traits reported here suggest an adequate response to selection through a genetic evaluation approach. Our results indicate that it is possible to select grandparent roosters with better reproductive performance.

Numerical investigation of the effect of landslide relative density on the impulse wave amplitude

Landslide-induced waves, generated by mass movements such as ice and rock avalanches impacting water bodies, represent significant hazards. These phenomena have garnered considerable attention from the scientific and engineering communities. Previous studies have explored the influence of landslide density on the characteristics of impulse waves, but the specific conditions of deep water, where the landslide thickness is less than several times the water depth, remain less extensively examined. This gap in knowledge hinders the accurate assessment of the risks associated with landslide-induced waves. In this study, we systematically examine the parameters of landslide density ρs, velocity vs, thickness hs, and water depth hw to elucidate the effects of ρs. Additionally, we analyze wave amplitudes along the propagation path using the smoothed particle hydrodynamics (SPH) method, which incorporates a density diffusion term. Our findings reveal that the landslide density significantly influences the maximum wave amplitude in water conditions where the relative landslide thickness S=hs/hw≥0.5, whereas it has a negligible impact in water conditions where the relative landslide thickness S=hs/hw<0.5. We observe three distinct patterns in wave amplitude evolution along the propagation path: linear decrease, exponential decrease, and an initial increase followed by an exponential decrease. Finally, we propose a model for predicting the amplitudes of landslide-induced waves at varying distances from the starting point of a landslide into a water body. This study is beneficial for the prediction and prevention of landslide-induced wave disasters.

Designing Intelligent Rock Support Systems to Detect Gravity-Driven Wedges

AbstractIntelligent rock bolts can be used in mining operations to acquire information on the bolt's status and movements of the rock mass. The future value of this technology resides in optimizing the support layout and increasing safety. The primary goal of this research is to investigate the sensor spatial distribution necessary for efficiently identifying roof wedges in mines. Roof wedges occur when three joints intersect over the roof, forming a triangular shape. They present a hazard by falling and causing damage. Sensor density refers to the number of sensors on a single rock bolt and the number of intelligent rock bolts in the mine or one section. Too many sensors drive costs up, and too few sensors compromise measurement quality. This research visualizes and investigates the results of the simulated models of intelligent rock bolts depending on the number of installed sensors and intelligent bolts to get a better understanding of the problem and describe the technique used, including numerical simulations and the considered parameters. Furthermore, it offers insight into the findings' possible implications, providing knowledge about the viability of using intelligent rock bolts.

An integrated DEM code for tracing the entire regolith mass movement on asteroids

ABSTRACT This paper presents a general strategy for tracking the scale-span movement process of asteroid regolith materials. It achieves the tracking of the mass movement on the asteroid at a realistic scale, under conditions of high-resolution asteroid surface topography (submeter level) and actual regolith particle sizes. To overcome the memory exponential expansion caused by the enlarged computational domain, we improved the conventional cell-linked list method so that it can be applied to arbitrarily large computational domains around asteroids. An efficient contact detection algorithm for particles and polyhedral shape models of asteroids is presented, which avoids traversing all surface triangles and thus allows us to model high-resolution surface topography. A parallel algorithm based on Compute Unified Device Architecture for the gravitational field of the asteroid is presented. Leveraging heterogeneous computing features, further architectural optimization overlaps computations of the long-range and short-range interactions, resulting in an approaching doubling of computational efficiency compared to the code lacking architectural optimizations. Using the above strategy, a specific high-fidelity discrete element method code that integrates key mechanical models, including the irregular gravitational field, the interparticle and particle-surface interactions, and the coupled dynamics between the particles and the asteroid, is developed to track the asteroid regolith mass movement. As tests, we simulated the landslide of a sand pile on the asteroid’s surface during spin-up. The simulation results demonstrate that the code can track the mass movement of the regolith particles on the surface of the asteroid from local landslides to mass leakage with good accuracy.

Assessment of stabilizing feedback control of walking: A tutorial

Walking without falling requires stabilization of the trajectory of the body center of mass relative to the base of support. Model studies suggest that this requires active, feedback control, i.e., the nervous system must process sensory information on the state of the body to generate descending motor commands to the muscles to stabilize walking, especially in the mediolateral direction. Stabilization of bipedal gait is challenging and can be impaired in older and diseased individuals. In this tutorial, we illustrate how gait analysis can be used to assess the stabilizing feedback control of gait. We present methods ranging from those that require limited input data (e.g. position data of markers placed on the feet and pelvis only) to those that require full-body kinematics and electromyography. Analyses range from simple kinematics analyses to inverse dynamics. These methods assess stabilizing feedback control of human walking at three levels: 1) the level of center of mass movement and horizontal ground reaction forces, 2) the level of center of mass movement and foot placement and 3) the level of center of mass movement and the joint moments or muscle activity. We show how these can be calculated and provide a GitHub repository (https://github.com/VU-HMS/Tutorial-stabilizing-walking) which contains open access Matlab and Python code to calculate these. Finally, we discuss what information on feedback control can be learned from each of these.

How the Space-Time as A Field of Mass Reconciles Quantum and Classical Mechanics

The invariance of the speed of light in RFs in relative motion between them is a clear indication of the nature of space-time. Lorenz's transformation equations were obtained by analysing the propagation of a single ray of light in a single direction and therefore are valid only for that single case. A set of general transformation equations can be obtained by analysing the propagation of an omnidirectional flash of light emitted by a source in motion with respect to a stationary observer. According to these equations, motion generates a spatial component normal to the velocity v and to the coordinates (x, y, z) of the source’s RF, displacing it into an “imaginary” fourth dimension for a value v/c, thus reducing its "density" by a ratio. The density of a RF plays a major role in the perception of physical reality. In fact, two observers in motion between them, watching the same phenomenon, would measure different spaces and times, same velocities, but different acceleration and therefore different forces acting on the same object. The transformation equations show that motion modifies only the RF, i.e the space-time, of objects, but as we cannot separate them from their space, they too are modified by a component transverse to the motion, and their “density” is also reduced. If the object is an electric charge, the transverse component of its field is identified with the magnetic field, which induces attractive or repulsive (or nil) forces only on other charges in motion, depending on the angle between their velocities. The same happens for the motion of a mass, with the fundamental difference that a rotating mass, in addition to a gravito-magnetic field, produces a transverse field which lines of flux are parallel to the axis of rotation, and therefore it propagates indefinitely, without attenuation, inside a cylinder with the same diameter of the mass. This field has a critical importance if we assume that the space-time is a field of the mass, coinciding with its gravitational field. The space-time of the Earth-bound observer would be made by the sum of the gravitational fields of the surrounding atomic masses, plus that of the transverse fields generated by the motion of those same masses; the main part of it would be produced by a sort of “ether” formed by “quanta” of space-time generated by the rotation around themselves of the atomic components of the whole universe. This would imply that the space-time at the atomic level is extremely "denser" than that at macroscopic level, therefore the Earth-bound observer would measure forces interacting amongst the atomic masses extremely higher than those calculated with Newton’s law. He will then be forced to postulate the existence of a mysterious agent, the electric charge, capable of developing those forces. With this assumption, instead, the atomic world would be populated only by masses subject, at their level, to gravitational and gravito-magnetic forces. It will become similar to the macroscopic world.

3D investigation of gully headcut processes: A slicing segmentation based on filed scouring experiments and laser scanning

Gully headcut erosion is a major gully development process contributing to soil-related economic and environmental problems. However, the current understanding of gully headcut is severely lacking due to the difficulty of effectively monitoring relevant processes. In this study, three small-scale experimental plots were established on a field slope of the hilly-gully region of the Chinese Loess Plateau. Fifteen scouring experiments were conducted on each of the plots, while terrestrial laser scanning was used to acquire morphological data of gully headcuts. Using the volume calculations algorithm based on multiscale model-to-model cloud comparison (3D-M3C2), the spatiotemporal distribution of gully headcut erosion was derived, while the erosion mass, deposition mass and sediment yield were also quantified. An improved slicing algorithm and a point cloud segmentation algorithm were proposed to extract the sub-processes of gully headcut erosion. Results showed: (i) Gully headcut erosion was dominated by erosion in cave areas (contributed 67.09% of the sediment yield) and supported by erosion in collapse areas (contributed 33.35% of the sediment yield). This indicated that runoff shear was the main driver of gully headcut erosion and mass movement played a secondary role. (ii) From a vertical perspective, gully headcut erosion was a cyclic process in which erosion of cave areas and collapse areas reinforced each other. From a horizontal perspective, runoff tended to erode the area with weak concavity. (iii) The channel areas contributed the least (even negatively) to sediment yield of gully headcut erosion (−0.44%), while it contained the most complex processes, involving erosion and deposition caused by plunging pool formation and filling, as well as deposition resulting from mass movement and subsequent re-erosion processes. The study provided a valuable reference for the monitoring and process understanding of gully headcut erosion.