Globally, oceanic crust has relatively uniform thickness and structure compared to continental crust, with typical ocean crust being ~5–8 km thick. However, a substantial proportion of oceanic crust is thickened outside the normal range in the form of oceanic plateaus and crust affected by hotspots. The Rio Grande Rise (RGR) is the most prominent bathymetric feature in the western South Atlantic Ocean

Archaeoseismological evidence of a strong earthquake, which probably occurred a year before the 252 CE Mt. Etna eruption, has been uncovered at Santa Venera al Pozzo site, located near to Acireale, along the lower eastern flank of the volcano. The site, known for its remarkable and peculiar hydrothermal fluids emissions exploited for thermal uses since the Greek and Roman age, has been investigated

Phase velocities at periods of 20–143 s are inverted from Rayleigh surface waves recorded at 201 stations of permanent and temporary seismic network deployed in the northern Ordos Block. We obtained the shear-wave velocities in the upper mantle from phase velocities. Our velocity models clearly reveal a striking low-velocity anomaly zone in the upper mantle beneath the northeastern margin of the Ordos

The stress field of the Earth's crust is spatially heterogeneous on various scales. The focal mechanism of an earthquake provides important information associated with the stress state at the seismogenic depths. These focal mechanisms are affected by the pore fluid pressure and/or friction coefficient. In this study, we focused on misfit angles, particularly the difference in the angle between the

The variations in faulting style at the Southwest Indian Ridge (SWIR) 46°–53.5°E segment, correspond to different patterns of crustal accretion under different magma supply in an ultraslow-spreading ridge. We use multi-beam and filtered bathymetry to identify the fault characteristics and measure the fraction of magmatic accretion M and axial valley depth D. Four styles of faulting, namely, mode-C

To gain better insight into the structure and complex deformation pattern of Madagascar island, we derived a 3-D heterogeneous and anisotropic velocity model of its crust and uppermost mantle based on ambient noise analyses. The data set comprises ~1 year of seismic ambient noise recorded by 63 broad-band seismic stations deployed in and around the island. Data from Ocean Bottom Seismometers were treated

The Jiaodong Peninsula, located in the eastern North China Craton (NCC), is a key region to study the genetic linkage between large-scale gold mineralization and craton destruction. We construct a fine crustal structural image across the Jiaodong Peninsula, using teleseismic P-wave receiver function data recorded by a dense linear array of 340 short-period seismic stations. The results reveal significant

The El Tigre fault provides a significant example of Pliocene-Quaternary tectonic activity at the West of Precordillera, receiving considerable attention in the last years. However, longitudinal thrusts of the nearest Sierra del Tigre and a minor piedmont deformation belt identified in its western piedmont are still poorly understood. The present work comprised a detailed map of the geomorphological

Understanding the structural evolution of complex convergent plate boundaries could contribute to linking the anticipated fluid production and transportation at depth to the measured amounts of fluid stored in hydrate methane. To better understand fluid behavior within a complex convergent boundary, we propose an evolution model for a set of doubly plunging, oppositely-verging structures referred to

Located along the coast of Norway, the Trøndelag Platform area corresponds to the proximal domain of the Mid Norwegian Vøring rifted margin. We investigated its architecture and structural evolution based on interpretation of a dense network of high-resolution seismic reflection profiles, supplemented by comparison with local onshore analogues. The entire area is floored by ductile crustal shearing

Thirty years ago, Rob Van der Voo proposed an elegant and simple system for evaluating the quality of paleomagnetic data. As a second-year Ph.D. student, the lead author remembers Rob waxing philosophical about the need to have an appropriate, but not overly rigid evaluation system. The end result was a 7-point system that assigned a (1) or (0) for any paleomagnetic result based on objective criteria

The origin of the Comoros archipelago in the Mozambique channel is the subject of a longstanding controversy. This volcanic chain has been successively interpreted as a hotspot track, as built on an intraplate fracture zone or a passive margin, or as the northern limit of a diffuse deformation zone in the Nubia-Somalia plate system, none of these interpretations being entirely satisfactory. It is also

Classical rock mechanics predicts that normal faults should form at 60–65°, rotating to 30–40° before locking, so widespread slip at around 20° is considered paradoxical. Furthermore, the dip distribution of normal fault earthquakes has a distinct, unexplained peak at ~45°. For both problems, some combination of low friction, high fluid pressures, stress rotation and efficiency of low-angle slip have

The seismicity and seismotectonics of Madagascar have been studied using an island-wide distribution of broadband seismic stations. The 28-station MAdagascar-COmoros-MOzambique (MACOMO) array was deployed for a 23-month period between 2011 and 2013. MACOMO data were supplemented by seven temporary stations from the Seismological Signatures in the Lithosphere/Asthenosphere system of Southern Madagascar

As occurred during the tourist season, the 2017 Mw 6.5 Jiuzhaigou (China) earthquake led to destructive damages. The seismogenic fault of this event was merely speculated to be the northern extension of the Huya fault, while no apparent surface ruptures were discovered in the field investigation. Previous studies and released moment tensor solutions indicated the Jiuzhaigou earthquake was dominated

The Canadian High Arctic preserves a long and complex tectonic history, including craton formation, multiple periods of orogenesis, extension and basin formation, and the development of a passive continental margin. We investigate the possible preservation of deformational structures throughout the High Arctic subcontinental lithosphere using measurements of seismic anisotropy from shear wave splitting

Southern Tibet is characterized by seven main N-S trending rifts bounded by normal faults which accommodate E-W extension. Quantifying the throw and extension rates along these rifts is essential to understand their activity, onset timing, regional seismic hazard and kinematic role in the tectonic evolution of the Tibetan Plateau. The Yadong-Gulu rift (YGR), near Lhasa, is the longest and most prominent

The Song Hong Basin situated at the distal part of the Ailaoshan-Red River Shear Zone (ASRRSZ) holds important information on the role of extrusion tectonics in the marginal basin development in the South China Sea. Based on an extensive dataset of 2 and 3-D seismic and stratigraphic information from 27 exploration wells, the Paleogene structural evolution of the northern Song Hong Basin and adjacent

To better understand the upper crustal shortening and orogenic uplift in the northeastern margin of the Tibetan Plateau, we have utilized magnetotelluric (MT) data at 116 sites along two lines around the SE Gonghe Basin to determine a three-dimensional (3D) resistivity model by a 3D MT inversion package ModEM. Our resistivity model reveals a significant feature of step discontinuities between high

The forearc of the North-Central Peruvian Andes (FNCPA, 6–10°S) provides an exceptional opportunity to study the long-term processes that affect a convergent plate boundary. First, it shows long-term subsidence, depocenter superimposition and individualization. Second, although being mostly extensional and characterized as a typical erosive margin, the FNCPA shows complex uplifted regions. Older deformation

The kinematic evolution of the West Iberian margin during the opening of the southern North Atlantic has been of interest for several decades and provides a well-constrained environment to study and develop new concepts related to the formation of non-volcanic (magma poor) passive margins. Building upon previous rigid and deformable plate tectonic modelling studies, the aim of this work is to create

Fault permeability is an important parameter for understanding the occurrence of natural hazards and evaluation of natural gas and oil reservoirs. In this study, effects of shear velocity on the permeability perpendicular to the shear zone formed after large shear displacements are revealed for silica sand. To this end, ring-shear experiments were performed for four shearing velocities under conditions

The Qilian Shan is located along the northeastern margin of the Tibetan Plateau, which is a key area for studying the growth and expansion of the Tibetan Plateau. There have been several geodynamic models developed to explain the deformation pattern of the Tibetan Plateau extending to the northeast, but they remain controversial. The magnetotelluric (MT) method can study subsurface electrical conductivity

The thermal regime of the lithosphere could be a clue for the processes of geodynamics. Based on the Yuquan-Yulin seismic reflection transect along the Sichuan Basin (Yangtze Craton)–Qinling Orogenic Belt (QOB)–Weihe Basin–Ordos Basin (North China Craton), we modified crustal and mantle lithospheric structures to fit the observed data such as elevation, gravity, geoid height, and heat flow. Then we

This paper presents a new study on 3-D structure, temperature and water content estimation of the mantle transition zone (MTZ) by P-wave receiver functions common conversion point (CCP) method on broadband array with 267 temporary stations and 203 permanent stations in southeastern China. The results show different structural characteristics of the MTZ to the north and south of the 29°N line. In the

We study the source properties of the 2005 Kashmir earthquake and its aftershocks to unravel the seismotectonics of the NW Himalayan syntaxis. The mainshock and larger aftershocks have been simultaneously relocated using phase data. We use back-projection of high-frequency energy from multiple teleseismic arrays to model the spatio-temporal evolution of the mainshock rupture. Our analysis reveal a

Understanding how long-term subduction dynamics relates to the short-term seismicity and crustal tec tonics is a challenging but crucial topic in seismotectonics. We attempt to address this issue by linking long-term geodynamic evolution with short-term seismogenic deformation in the Northern Apennines. This retreating subduction orogen displays tectonic and seismogenic behaviors on various spatiotemporal

The Qilian Shan, north eastern Tibetan Plateau, is an area of active deformation caused by convergence in the India-Eurasia collision zone. Geomorphic indices capture the landscape response to competition between tectonics and climate, reflecting the spatial distribution of erosion. We use geomorphic indices (hypsometric integral (HI), normalised channel steepness (ksn), elevation-relief ratio (ZR)

Characterizing the inelastic strain field around co-seismic faults is a key to understanding earthquake rupture processes. We aim to detect zones of inelastic deformation around surface ruptures, using Anisotropy of Magnetic Susceptibility (AMS) analyses. To characterize the paleo-seismic setting we measured 29 normal faults, which cut the late Pleistocene lacustrine Lisan Formation and were associated

Botswana experienced a Mw 6.5 earthquake on 3rd April 2017, the second largest earthquake event in Botswana's recorded history. This earthquake occurred within the Limpopo-Shashe Belt, ~350 km southeast of the seismically active Okavango Rift Zone. The region has no historical record of large magnitude earthquakes or active faults. The occurrence of this earthquake was unexpected and underscores our

The north-south convergence between the Indian and Eurasian continents since Cenozoic has produced the Tibetan plateau, and east-west extension structures have also developed since late Cenozoic. Whether these extensional structures are limited to the crust or extend to the deep lithosphere remains controversial. The uppermost mantle serves as a link between the crust and deep lithosphere, the velocity

The collision between the Qiangtang and Lhasa blocks is a critical factor in understanding the geodynamics of the central Tibetan Plateau. However, the process of the Qiangtang-Lhasa collision remains contentious. A direct way to study the history of the Qiangtang-Lhasa collision would be to determine the evolution of the paleolatitude positions of the Qiangtang and Lhasa blocks during the Jurassic-Cretaceous

Vertical edges along subducted slabs have been recognized in the majority of subduction zones. Surprisingly, slab edges evolved into Subduction-Transform-Edge-Propagator (STEP) faults in only a few regions; the conditions under which STEPs form are special. It is relevant to constrain the conditions that facilitate STEP fault initiation because they leave a clear geological footprint in the overriding

Two end-member scenarios have been proposed for the tectonic situation along the eastern margins of Gondwanaland before Zealandia was formed ca. 100 million years ago (Ma), namely: (1) A subduction zone located far from the eastern margin of Zealandia, wherein Zealandia may have separated from Gondwanaland by plume push of an active hotspot plume.; (2) A subduction zone located along the eastern margin

The Kaikōura Peninsula lies at the transition from subduction to continental collision at the southern end of the Hikurangi subduction system. This study uses a 2012 lidar survey over the Kaikōura Peninsula to re-map a flight of four uplifted Late Pleistocene marine terraces at high resolution. The lidar shows that the terraces are being progressively tilted landwards in a manner consistent with listric

We used high-resolution (500 × 250 m) two-dimensional lithospheric-scale thermo-mechanical numerical modeling to unravel the unexpected topographic and thermal evolutions recorded during the necking phase of several rift systems worldwide. Through a systematic analysis we studied how the lithosphere rheology impacts the topographic and thermal evolutions across the entire width of magma-poor and sediment-starved

We use two-dimensional numerical simulations to investigate the interaction of folding (buckling) and thrusting (localized shearing) during the structural evolution of fold-and-thrust belts (FTB). We model layer-parallel shortening of mechanically strong layers resting above a weaker layer, referred to as detachment. We consider a viscoplastic rheology with linear viscosity and frictional-plastic Drucker-Prager

The crustal structure between different subregions of the North China craton (NCC) plays an important role in improving our understanding on the craton evolution. Here we present a flexural Moho map and isostatic residual gravity field of the NCC derived from the GO_CONS_GCF_2_TIM_R3 model. We first investigate the influence of additional sources on the forward flexure calculation, especially the distinct

The Kuqa depression is associated with complex salt structures. Variation in fold geometries and subsalt fault activities were investigated using parallel cross-sections to reveal detailed along-strike variations within the Keshen 5 segment and their controlling factors. Along-strike variations were identified in both suprasalt and subsalt units. Linkages, such as the location of a transfer zone, were

The study of bedrock fault scarps is a useful approach to identify paleo-earthquakes and acquire the faulting history in bedrock areas where traditional trench techniques are not applicable. Here, we report a study on the Luoyunshan piedmont fault (LYSPF), southwestern Shanxi Rift, China. Although several studies have analyzed the LYSPF, its faulting behavior is still under debate. For example, the

This study uses work optimization to predict the spatial and temporal development of faults. We focus on the growth of small fractures that develop into thrust faults at the toe of accretionary prisms because observations from physical laboratory accretion experiments provide rich data with which to validate the models, and the processes of accretionary thrust fault initiation remain unclear. In order

In this work we used analogue models in order to better understand how two orthogonal fold-and-thrust belts may interact in the foreland and influence the geometry and kinematics of the resulting structures. Our experimental device has two vertical mobile backstops oriented perpendicular with respect to each other, independent and moving coevally with variable or equal velocities. There are strong

In this study, we analyze 100 crustal Precordilleran earthquakes recorded in 2008 and 2009 by 52 broadband seismic stations from the SIEMBRA and ESP, two temporary experiments deployed in the Pampean flat slab region, between the Andean Cordillera and the Sierras Pampeanas in the Argentine Andean backarc region. In order to determine more accurate hypocenters, focal mechanisms and regional stress orientations

The Itapirapuã Shear Zone is a major NE-trending dextral transcurrent zone from the southern Ribeira Belt (Brazil), which was active during the Neoproterozoic Brasiliano-Pan African Orogeny, related with West Gondwana assembly. Macroscopic sigmoid-shaped blocks in its northernmost splay termination present a NE-trending subvertical tectonic foliation and subvertical stretching lineation suggesting

The enigmatic 85°E Ridge crosses the Bay of Bengal from north to south. Its strong gravity anomaly low is associated with Cretaceous hotspot volcanism. South of 5°N, the gravity low bends into a SW-NE orientation and continues as far SW as the Afanasy Nikitin Seamounts. This change has been interpreted to represent a bent hotspot track. We report new constraints on the crustal structure and genesis

The Chaînons Béarnais is a salt-detached fold belt in the northern Pyrenees that formerly occupied the axis of the Cretaceous Pyrenean rift. Geological map revision and cross-section construction from surface geology and industrial well and seismic reflection data emphasize the role of salt diapirism in the folding of the belt during the Cretaceous extension and the subsequent Pyrenean orogeny. Pre-rift

The Tajik Basin, located at the west of the Pamir, is characterized by a series of thin-skinned folds and thrusts within its interior. Constraining the onset of deformation of these structures is important both for illustrating basin inversion process and for understanding growth history of the adjacent Pamir. To date, the timing of thrusting and folding within the Tajik Basin has not been well studied

In order to clarify the weakening mechanism of quartz rocks at subseismic slip rates of 0.1–10 cm/s, we conducted two series of rotary-shear friction experiments at a normal stress of 1.5 MPa and equivalent slip rates (Veq) of 0.1–10 cm/s; one on intact agate controlling background temperature (TBG) and atmosphere, and the other on intact agate and silica-gel gouge monitoring temperature (T) adjacent

We model the contribution of the stresses generated by the topography and density heterogeneities in the stress field of NE Brazil and the interplay between these and regional stresses. Our model consists of a horizontally layered elastic slab (the lithosphere) that floats above an inviscid fluid (the asthenosphere), where the surface load is generated by the topography and bathymetry, and the internal

It is difficult to identify and assess the recently active faults, representing a risk factor for key human activities, in the areas of stable crust with slow tectonic deformation and reduced seismicity. We face the problem in the eastern Bohemian Massif (Central European Variscides) at a contact with the Eastern Alpine – Western Carpathian orogenic belt through building its integrated geodynamic model

Heterogeneous initial stresses are extremely important in understanding the physics of earthquake rupture processes. We propose a method to estimate heterogeneous initial stresses by comparing the slip from dynamic rupture simulations and the input joint inversion result and apply it to the 2017 Mw 6.5 Jiuzhaigou earthquake, which occurred in the intersection area of the Minjiang, Tazang and Huya faults

The Atlas Mountains of Tunisia belong to the seismically active zone of the Africa (Nubia) - Eurasia plate boundary in the central-western Mediterranean. We study the eastern section of the Maghrebian thrust belt using a subset (6 days) from each of 5 years (2014 to 2018) of permanent (survey-mode) GPS data and active tectonics. WNW to NNW-trending velocities express crustal motion and geodetic strain