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The Earth's crust is exposed by tectonic processes and is not static over time. Modelling of the Earth's surface velocities is of utmost importance for research in geodesy, geophysics, structural geology, and other geosciences. It may support positioning, navigation, seismic risk, and volcano notification services, for example. Space geodetic techniques can be used to provide high-quality velocities in a network of geodetic sites. Velocity field modelling should, however, expand the velocities from a discrete set of points to any location in-between. This paper presents four new methods for the Earth's surface velocity interpolation. Contrary to the widely used approach dividing the velocity field to the horizontal and vertical components, a full 3D interpolation approach is proposed based on the Delaunay triangulation and the n-simplex interpolation. The use of a combination of all three components is advantageous for geophysical interpretation. The proposed interpolation approach is entirely local but enables global modelling, which does not suffer from map projection distortions and singularities at the poles. Various global and regional position/velocity datasets are used to evaluate the performance of the proposed velocity interpolation methods. The latter provide practically the same results when applied to regional velocity field modelling. However, the so-called continuous piecewise quasi-radial 3D velocity field interpolation method is recommended for its favourable properties. It introduces an ellipsoidal Earth model, appropriately considers vertical/up and horizontal velocity components, tends to radial symmetry, and provides continuity for the interpolated velocity components as well as for the estimated uncertainties. [ABSTRACT FROM AUTHOR]

Plate tectonics theory, established in the 1960s, has been successful in explaining many geological phenomena, processes and events that occurred in the Phanerozoic. However, the theory has often struggled to provide a coherent framework in interpreting geological records in continental interior and Precambrian period. In dealing with the relationship between plate tectonics and continental geology, continental interior tectonics was often separated from continental margin tectonics in the inheritance and development of their structure and composition. This separation led to the illusion that the plate tectonics theory is not applicable to Precambrian geology, particularly in explaining the fundamental geological characteristics of Archean cratons. Although this illusion does not mean that the Archean continental crust did not originate from a regime of plate tectonics, it led to the development of alternative tectonic models, often involving vertical movements under a regime of stagnant lid tectonics, including not only endogenous processes such as gravitational sagduction, mantle plumes and heat pipes but also exogenous processes such as bolide impacts. These vertical processes were not unique to the Archean but persisted into the Phanerozoic. They result from mantle poloidal convection at different depths, not specific to any particular period. Upgrading the plate tectonics theory from the traditional kinematic model in the 20th century to a holistic kinematic-dynamic model in the 21st century and systematically examining the vertical transport of matter and energy at plate margins, it is evident that plate tectonics can explain the common geological characteristics of Archean cratons, such as lithological associations, structural patterns and metamorphic evolution. By deciphering the structure and composition of convergent plate margins as well as their dynamics, the formation and evolution of continental crust since the Archean can be divided into ancient plate tectonics in the Precambrian and modern plate tectonics in the Phanerozoic. In addition, there are the following three characteristic features in the Archean: (1) convective mantle temperatures were 200–300°C higher than in the Phanerozoic, (2) newly formed basaltic oceanic crust was as thick as 30–40 km, and (3) the asthenosphere had a composition similar to the primitive mantle rather than the depleted mantle at present. On this basis, the upgraded plate tectonics theory can successfully explain the major geological phenomena of Archean cratons. This approach provides a new perspective on and deep insights into the evolution of early Earth and the origin of continental crust. In detail, Archean tonalite-trondhjemite-granodiorite (TTG) rocks would result from partial melting of the over-thick basaltic oceanic crust at convergent plate margins. The structural patterns of gneissic domes and greenstone keels would result from the buoyancy-driven emplacement of TTG magmas and its interaction with the basaltic crust at convergent margins, and komatiites in greenstone belts would be the product of mantle plume activity in the regime of ancient plate tectonics. The widespread distribution of high-grade metamorphic rocks in a planar fashion, rather than in zones, is ascrible to separation of the gneissic domes from the greenstone belts. The shortage of calc-alkaline andesites in bimodal volcanic associations suggests the shortage of sediment accretionary wedges derived from weathering of granitic continental crust above oceanic subduction zones. The absence of Penrose-type ophiolites suggests that during the subduction initiation of microplates, only the upper volcanic rocks of the thick oceanic crust were offscrapped to form basalt accretionary wedges. The absence of blueschist and eclogite as well as classic paired metamorphic belts suggests that convergent plate margins were over-thickened through either warm subduction or hard collision of the thick oceanic crust at moderate geothermal gradients. Therefore, only by correctly recognizing and understanding the nature of Archean cartons can plate tectonics reasonably explain their fundamental geological characteristics. [ABSTRACT FROM AUTHOR]

The Java ‐ Lesser Sunda margin, which features multi‐scale subducting oceanic basement relief, is classified as neutral (Lombok and Sumbawa) to erosional (Central Java to Bali) in comparison to its accretionary counterpart offshore Sumatra. However, a comprehensive analysis of how plate boundary and upper plate structure across the neutral to erosional transition are modulated by the subduction of oceanic basement relief is lacking to date. To shed light on the tectonic parameters that push the margin into the neutral or erosional domain, we combine multi‐channel reflection seismic images derived through a grid‐based P‐wave velocity inversion, and multibeam bathymetric maps. The data document how different scales of subducting topography modify seafloor morphology, upper plate structure, and décollement position. Large‐scale subducting features cause a landward shift of the deformation front, shortening of the accretionary wedge, and seafloor steepening at the relief's trailing edge. Small‐scale subducting ridges primarily impact the frontal prism resulting in over‐steepening at the trench and localized slope failure. Ahead of subducting relief, deformation of the accretionary wedge encompasses enhanced compression and a reduction in seafloor slope but appears independent of the size of the relief. Ridge and seamount subduction induce frontal erosion and basal erosion offshore Lombok and Bali, respectively. Our P‐wave velocity models indicate that the rigidity of the upper plate's base along the eastern Sunda margin is significantly lower than the worldwide trend. We conclude that this favors the genesis of tsunami earthquakes that have occurred on the Java margin. Plain Language Summary: The convergence of the tectonic plates drives a wide variety of geological processes along the plate margins, including the formation of the forearc accretionary wedge, volcanic activities, and megathrust earthquakes. Over the past 40 years, marine research shows that different sizes of oceanic reliefs (seamounts and ridges) are widely distributed over the seafloor, approaching the trench, and eventually subducted underneath the overriding plate. An accurate observation of the subducted reliefs and their tectonic impact on the overriding plate depends on different observation approaches, data processing methods, and the evolutionary history of the forearc. In the Java margin, the oceanic seafloor features massive seamounts with different scales and shapes, and the bathymetry of the overriding plate is highly disturbed. This provides us with the best opportunity of studying the rugged seafloor's seismogenic and geological impacts. By using state‐of‐the‐art seismic imaging techniques, we image the subsurface structures, obtain the forearc velocity, identify the seamounts, and discuss the seamounts' effect on structural deformation and megathrust earthquake occurrence. Distinctively, the marine forearc gets shortened and thickened significantly by seamount subduction. Structural images sharply illustrate different deformation patterns and stress regimes at the seamount's different flanks and reveal the possible process of subduction erosion. Key Points: Upper plate deformation scales with variable subducting relief, as observed along the Java Trench in seismic sections and bathymetrySubduction of seafloor topography induces progression from an accretion‐dominated domain toward a phase of subduction erosionThe overall low rigidity of the upper plate's base may contribute to the Java margin earthquake's tsunami‐genesis [ABSTRACT FROM AUTHOR]

Based on comparison of morphotectonic analysis results with the SL index analysis, airborne geophysical measurements and field geological and structural data, possible Miocene to Holocene development of the landscape relief of Novohradské Mts. (southern Moldanubian Zone; Bohemian Massif) with a significant contribution of active faulting is interpreted. We suppose a polyphase reactivation of pre-existing faults under (a) the Miocene-Pliocene stress-field (regional ∼ NNW–SSE extension) as (oblique) normal faults trending ∼ SW–NE to ∼NW–SE were responsible for the subsidence of the Třeboň Basin and Kaplice Furrow and (b) the Pliocene to Holocene stress-field (Shmax = 146°) when horizontal in the ∼NNW–SSE direction with possible activity of the prevailing ∼ NNE-SSW trending faults as a sinistral strike-slips or weak reverse oblique-slip movement. The second set of subvertical ∼ WNW–ESE faults was predominantly reactivated in a dextral strike-slip regime or as gentle reverse oblique-slip faults. These Miocene to Holocene events reflect the coupling between the East-Alpine–Carpathian segment and its northern foreland, mainly due to northward motion of the African and the Arabian lithospheric plates. The core of the Novohradské hory Mts. experienced a significant uplift compared to the neighboring areas of the Kaplice Furrow and the Třeboň Basin. The most significant uplift has been found near Rychnov nad Malší, and on the tectonic border between the Kaplice Furrow and the Bukovský hřbet Ridge. This uplift took place during the late Pliocene and Pleistocene, after the sedimentation of lacustrine sediments in the Kaplice Furrow. Although the combination of GIS, morphotectonic and geophysical analyses with validation by field structural data does not provide the final proof of young tectonic activity, we conclude that there is strong indication of Neogene-Quaternary reactivation of several faults in the Novohradské Hory Mts. Based on similar morphological features, it can be supposed that many areas in the Alpine Foreland and Bohemian Massif underwent similar tectonic evolution during the Miocene to Holocene era. [ABSTRACT FROM AUTHOR]

A comprehensive study of geophysical, geological, tectonic, lithofacies, petrophysical and a number of other factors of oil and gas content and their changes in space over time make it possible to develop the foundations of the main criteria for predicting the distribution of oil and gas territories and the development of hydrocarbon deposits. In order to assess the prospects for prospecting for oil and gas accumulations and reduce the risks of ineffectiveness of exploration and further development and drilling operations in the lower section of the Productive Strata (PS) of the western side of the South Caspian Basin (SKV), based on the available material and taking into account the large number of published works, We considered the tectonic criteria and conditions for the preservation of the formed accumulations of hydrocarbons in the South Absheron archipelago, in the example of the Gum-Deniz and Bahar areas. By specifying the development of uplifts, tectonic faults and the lithofacies composition of more ancient sediments, paleostructural analysis can provide significant assistance in identifying promising areas for prospecting and exploration, and ultimately thereby significantly reduce the risks of inefficiency in drilling operations. [ABSTRACT FROM AUTHOR]

Tectonic tremor and low‐frequency earthquakes (LFEs) are two different representations of the high‐frequency (>1 Hz) components of broadband slow earthquakes, which have been discovered in various tectonic regions. Although LFEs are considered building blocks of tremor, it is difficult to find constituent LFEs for some long‐duration tremor sequences. Here we introduce a new scheme to synthesize an impulsive response from a tremor source, or empirical LFE (eLFE), from complex tremor sequences. The eLFE is constructed by maximizing the absolute amplitude (L∞ norm) of the normalized and stacked waveforms of many tremor sequences at many stations. This problem includes a highly multimodal objective function, which is maximized via a combined optimization method that incorporates a genetic algorithm and iterative improvements. We first apply this method to several validation tests using synthetic tremor waveforms and real LFEs, and then tremor activities where few nearby LFEs have been detected. One example is the Okayama tremor, which has been known to be extraordinarily sensitive to tidal stress. The eLFE is helpful in determining the accurate hypocentral location and recovering the long‐term comprehensive tremor activity via a matched‐filter analysis. The well‐constrained depth of the Okayama tremor sources is less than 30 km, which suggests that the subducting Philippine Sea Plate is very shallow at this distant location from the trench axis. This eLFE scheme highlights the fact that tremor sequences may be composed of random fluctuations that are not necessarily impulsive and emphasizes the importance of characterizing such randomness to better understand slow earthquake behavior. Plain Language Summary: Slow earthquakes are underground shear slip events that are similar to ordinary earthquakes but radiate weak seismic waves. The locations of these slow earthquakes are often close to the estimated source regions of past and future giant earthquakes, and may therefore be important in advancing our understanding of the genesis of hazardous earthquakes. Two types of slow earthquakes are tectonic tremors and low‐frequency earthquakes (LFEs), which have been discovered in various regions around the world over the past two decades. LFEs are often, but not always, identified within long‐duration tectonic tremor signals. It is generally easy to constrain the source location and elementary mechanism of LFEs since they are impulsive events. Therefore, it is desirable to find or extract LFEs from a given tectonic tremor sequence since they are rather easy to detect. Here we developed a new method to empirically synthesize LFEs for tremor sequences based on a statistical measure, and successfully applied it to some tremor activities. The method worked effectively, especially for the Okayama tremor, and significantly improved both the accuracy of the source location and the completeness of the regional tremor/LFE catalog. Key Points: We can synthesize the waveforms of an impulsive low‐frequency earthquake by stacking non‐impulsive continuous tremor recordsThe empirical low‐frequency earthquake is synthesized by maximizing the L∞ norm, which is solved via a multimodal optimization approachThe Okayama tremor is constrained to less than 30 km depth, suggesting a complex geometry of the subducting Philippine Sea Plate [ABSTRACT FROM AUTHOR]

Fault slip rates are critical to quantify continental deformation. Those along the Karakax fault (northwestern Altyn Tagh Fault: ATF) have been debated, even though it is one of Tibet's most outstanding active faults. At Taersa, using LiDAR measurements of terrace and fan riser offsets (∼6 to ∼500 m) and 10Be/26Al dating of alluvial surfaces (<210 ka), we obtain a late Quaternary slip rate of ∼2.5 ± 0.5 mm/yr. This doubles the ∼2.6 ± 0.5 mm/yr rate time span found to the east and west. We interpret the ∼150 km‐long, free‐faced rupture along the fault to be that of the M ∼ 7.6 event felt in Hotan in 1882. Characteristic slip (∼6 m) during four large earthquakes since ∼10 ka implies a ∼2500 ± 500 years return time. A ∼3 mm/yr rate is consistent with the ∼80 km offset of the Karakax river since uplift of the West Kunlun range and sediment deposition in the Tarim foreland accelerated, ∼24 Ma ago. The faster slip rate (∼10.5 mm/yr) on the central ATF matches the sum of those along the reactivated West Tibetan terrane boundaries (Karakax and Longmu‐Gozha Co faults) at the Uzatagh triple junction (∼36°N, 83°E). The abrupt termination and altitude drop of the Karakorum range where the Longmu Co and Karakorum faults meet (Angmong junction), also reflect triple junction kinematics. Such localized changes account for the rise of the Karakorum and West Kunlun ranges and support lithospheric block tectonics rather than diffusely distributed deformation. Plain Language Summary: How the Tibetan plateau rose to ∼4500 m and deforms today remain outstanding questions. Tibet's northern edge follows the ∼2000 km‐long ATF, whose westernmost branch is the Karakax fault. Despite the spectacular escarpments and offsets observed along that fault, its slip rate, critical to quantify continental deformation, has remained controversial. Here, we corroborate that, for the last ∼210,000 years, that rate has been ∼2.5 ± 0.5 mm/yr, based on high‐resolution topography and dating of left‐laterally offset fluvial surfaces. The ∼80 km offset of the Karakax river implies that this rate may have remained constant since the rise of the Kunlun range above the Tarim basin started ∼24 Ma ago. The sharp fault trace reflects the exceptional preservation, since ∼10,000 years ago, of four M ∼ 7.6 earthquake ruptures (the last in 1882), each with ∼6 m of slip (∼2500 years return time). Fault slip rates, GPS vectors and mountain altitudes across western Tibet reflect block motions and triple junction kinematics rather than continuum deformation. Specifically, localized velocity changes appear to account for the rise of the West Kunlun and Karakorum ranges. Our results bridge the gaps between present and long‐term geological history, and broad‐scale geodesy and local field evidence. Key Points: The ∼400 km‐long, left‐lateral Karakax fault (western Altyn Tagh fault) slip rate has been ∼2.5 ± 0.5 mm/yr for ∼210 kaFour M ∼ 7.6 earthquakes (150 km rupture length; 2.5 ka return time) have offset Holocene terraces (6, 12, 18, and 24 m characteristic slip)Block tectonics and triple junction kinematics account for 24 Ma deformation of west Tibet and rise of ≥8000 m‐high Karakorum range [ABSTRACT FROM AUTHOR]

Tectonic and surface processes (e.g., erosion) act in concert to denude and flatten elevated topography during and following collisional uplift. In orogens that collapsed rapidly (<10 Myr), the effectiveness and relative contribution of erosion remains poorly understood. Here, we use 1‐D and 2‐D finite‐difference models to test plausible magnitudes of erosion during denudation of the Scandian orogenic wedge, in northern Scotland, which previous work suggests may have been very rapid. Thermochronologic, stratigraphic, and thermobarometric data constrain initial post‐collision uplift rates as well as the cumulative post‐collisional exhumation magnitude. Using these constraints, we consider an idealized orogen subjected to fluvial incision, hillslope diffusion, and subsequent isostatic compensation for a duration of 10 Myr. Using a range of geomorphic parameters, we evaluate whether erosion alone is sufficient to achieve the observed cumulative exhumation. Additionally, we apply a thermal model during the same period to determine the viability of the previous erosion estimates in the presence of a transient geothermal gradient. For most cases with initial uplift rates of 0.5–2.5 mm yr−1, total erosion is insufficient to account for the observed Scandian denudation history, regardless of whether a fixed or transient geothermal gradient is assumed. Average elevations near the crest of the modeled orogen after 10 Myr are >1.4 km, which is inconsistent with the post‐Scandian landscape relief interpreted from the reconstructed depositional surface of the Emsian (407–403 Ma) Old Red Sandstone, Collectively these findings imply a combination of rapid erosion and tectonic denudation likely accomplished the rapid collapse of the Scandian wedge. Plain Language Summary: The destruction of mountain ranges is accomplished by numerous physical processes, which include erosion of the landscape and subsurface deformation of the Earth's crust. In mountains where this destruction occurred very rapidly, such as in northern Scotland, there is poor understanding of the relative effectiveness of each process in wearing mountains down. In this paper, we use computer models to calculate how much erosion might have occurred in the geologically short time frame after the mountains in Scotland stopped growing. These models track the effects of river erosion, hillslope movement, and crustal buoyancy on elevation change after mountain‐building has essentially ceased. We compare the model results to pressure‐temperature‐time data recorded in rocks exposed at the surface today that give us information about how fast the rocks were brought up to the Earth's surface from depth. Our inference based on these models is that erosion alone cannot remove material quickly enough to explain available geologic data, implying the importance of crustal thinning by deformation in the Scottish Highlands. Key Points: Published thermochronologic data for metamorphic rocks of the Scottish Highlands indicate rapid denudation following orogenesisThe models in this work suggest that denudation was not accomplished by surface processes alone, but required additional tectonic processesThis may indicate a role for channelized crustal flow similar to that proposed for the Himalaya and the East Greenland Caledonides [ABSTRACT FROM AUTHOR]

The Alpine Fault zone in New Zealand marks a major transpressional plate boundary that is late in its typical earthquake cycle. Understanding the subsurface structures is crucial to understand the tectonic processes taking place. A unique seismic survey including 2D lines, a 3D array, and borehole recordings, has been performed in the Whataroa Valley and provides new insights into the Alpine Fault zone down to ∼2 km depth at the location of the Deep Fault Drilling Project (DFDP)‐2 drill site. Seismic images are obtained by focusing prestack depth migration approaches. Despite the challenging conditions for seismic imaging within a sediment filled glacial valley and steeply dipping valley flanks, several structures related to the valley itself as well as the tectonic fault system are imaged. A set of several reflectors dipping 40°–56° to the southeast are identified in a ∼600 m wide zone that is interpreted to be the minimum extent of the damage zone. Different approaches image one distinct reflector dipping at ∼40°, which is interpreted to be the main Alpine Fault reflector located only ∼100 m beneath the maximum drilled depth of the DFDP‐2B borehole. At shallower depths (z < 0.5 km), additional reflectors are identified as fault segments with generally steeper dips up to 56°. Additionally, a glacially over‐deepened trough with nearly horizontally layered sediments and a major fault (z < 0.5 km) are identified 0.5–1 km south of the DFDP‐2B borehole. Thus, a complex structural environment is seismically imaged and shows the complexity of the Alpine Fault at Whataroa. Plain Language Summary: The Alpine Fault in New Zealand is a major plate boundary, where a large earthquake will likely occur in the near future. Thus, it is important to understanding the detailed processes of how and where such an earthquake occurs. Many scientists are involved in this work, particularly in the attempt of drilling through the fault zone with a ∼900 m deep borehole. We analyzed new seismic data from this area using sensors in the borehole and at the surface to record small ground movements caused by a vibrating surface source causing waves that travel through the ground. From these data, we obtained a detailed image of the structures in the subsurface, for the first time in 3D, by applying advanced analysis methods. Hence, we can better understand the shape of the glacial valley and of the fault zone, that is, the local structures of the continental plate boundary. We interpret at least 600 m wide zone of disturbed rocks and identify a potential major fractured plane down to about 1 km depth. Our studies may help to understand structures that host earthquakes in this area. Key Points: We use focusing prestack depth migration with detailed seismic data to analyze the complex subsurface environment of the Alpine Fault zoneSeismic images show Alpine Fault zone related reflectors at a depth of ∼0.2–1 km dipping ∼40°–56° around the DFDP‐2B boreholeComplex structures within the glacial Whataroa Valley are imaged showing steep valley flanks, faults, and internal sedimentary horizons [ABSTRACT FROM AUTHOR]

Subduction interface thermal structure changes drastically within the first few million years of underthrusting (i.e., subduction infancy). Metamorphic soles beneath ophiolites record snapshots of dynamic conditions and mechanical coupling during subduction infancy. Beneath the Samail Ophiolite (Oman), the sole comprises structurally higher high‐temperature (HT) and lower low‐temperature (LT) units. This inverted metamorphic gradient has been attributed to evolving metamorphic Pressure‐Temperature (P‐T) conditions during infancy; however, peak P‐T and timing of LT sole subduction are poorly constrained. Oman Drilling Project core BT‐1B sampled the base of the ophiolite in a location lacking the HT sole. Metasedimentary and meta‐mafic samples collected from 104 m of core reveal that the LT sole subducted to similar peak P as HT rocks preserved elsewhere in Oman, but experienced ∼300°C lower peak T. Prograde fabrics record Si‐in‐phengite and amphibole chemistries consistent with peak P‐T of ∼7–10 kbar and ∼450–550°C in the epidote‐amphibolite facies. Retrograde fabrics record a transition from near‐pervasive ductile to localized brittle strain under greenschist facies conditions. Titanite U‐Pb ages (n = 2) constrain timing of peak LT sole subduction to ∼91 Ma (post‐dating initial HT sole subduction by ∼12–13 Myr) and dynamic retrogression through ∼90 Ma. Combined with existing geo/thermo‐chronology, our results support a model of protracted subduction and accretion while the infant subduction zone experienced multi‐phase, slow‐fast‐slow cooling. Temporal overlap of HT sole cooling (rehydration?) and ophiolite formation suggests that cooling may lead to interface weakening, facilitating upper‐plate extension and spreading. The LT sole formed in a rapidly‐refrigerating forearc after ophiolite formation and may reflect the transition to self‐sustaining subduction. Plain Language Summary: Subduction zones continuously renew and recycle the surface of the Earth, influence global water and geochemical cycling, and generate a driving force for Plate Tectonics that is unique to our Earth. However, the mechanisms and tectonic conditions that allow subduction to initiate in the first place are poorly understood. Studies of metamorphic rocks from ancient subduction zones can provide insight into how pressure, temperature, metamorphic rock types, and water content change within tectonic plate boundaries. Using rocks from Oman that formed in an infant subduction zone, this study applies metamorphic petrology (quantitative measurements of mineral chemistry) and geochronology (timing of mineral growth) to constrain the changes in temperature through time spanning the first ∼10–15 million years of the subduction zone's lifetime. We synthesize new and pre‐existing data that together suggest the infant subduction zone experienced a multi‐phase cooling history, characterized by slow‐fast‐slow cooling. The first slow‐fast transition may represent a point in time where the infant subduction zone "turned on," that is, the transition from slow, forced convergence of two tectonic plates, to a faster‐moving, self‐sustaining, and plate‐boundary scale subduction zone. Key Points: The low‐temperature metamorphic sole beneath the Samail Ophiolite records subduction and return flow before juxtaposition with the ophioliteHigh sampling density of the 104 m‐thick core reveals it comprises three subunits that record continuous and stepwise changes in peak P‐TLow‐T sole rocks reached similar peak P as the high‐T sole but colder peak T (7–10 kbar, 500°C) and witnessed rapid interface refrigeration [ABSTRACT FROM AUTHOR]

The interconnection between anthropogenic and natural surface loads and seismicity continues to be poorly understood. The metropolitan Salt Lake City in Utah hosts various industrial, hydrological, and tectonic processes, including the Bingham Canyon mine and its associated tailings facility, precipitation and water storage at the surface and in aquifers, as well as the seismically active Wasatch Fault Zone. The March 18, 2020 M5.7 Magna earthquake occurred east of a mine tailings impoundment that receives ∼60 million tons/yr of ore waste products since the early 1900s. Here we investigate the spatiotemporal elastic stress changes due to anthropogenic mass transfer and natural hydrological loading and unloading. Two local earthquake clusters host persistent microseismicity and the 2020 M5.7 Magna earthquake sequence. The amplitude and sign of the computed Coulomb stress changes at seismogenic depths strongly vary with the receiver fault geometry, the frictional coefficient, and the location, and can reach tens of kPa and ∼1 kPa/yr due to the tailings loads, a substantial fraction of background tectonic loading. The long‐term and seasonal stress changes from regional hydrological processes are only up to a few kPa. A lack of statistically significant seasonality in seismicity across Utah suggests a weak control by cyclic hydrological loads. Explicit knowledge of the fault architecture is essential to allow for seismic hazard assessment considering external stress loading. Plain Language Summary: The anthropogenic surface modifications in naturally hazardous environments have received relatively little attention due to their small dimensions and shallow locations. We note a compelling spatial correlation between a mine tailings impoundment and the March 18, 2020 M5.7 Magna earthquake, its aftershocks, and persistent earthquake clusters in the Salt Lake City region. This highly populated region hosts various industrial, hydrological, and tectonic processes. Here we characterize the spatiotemporal stress changes since the early 1900s due to the industrial and hydrological sources. The modeled elastic stress changes in the three dimensional subsurface vary in sign and magnitude, depending on the location, geometry, and frictional properties of active faults. Comprehensive characterization of fault architecture and seismic monitoring near sites of industrial production is warranted in critical geological and tectonic settings to ensure socioeconomic health and sustainable development. Key Points: The M5.7 Magna earthquake and its aftershocks, as well as persistent historical seismicity occurred in two clustersThe elastic stresses near the hypocenter produced by nearby industrial loads exceed those from hydrological sources by two orders of magnitudeThe magnitude and sign of loading stresses resolved on receiver faults are sensitive to fault geometry, frictional coefficient, and location [ABSTRACT FROM AUTHOR]

The article discusses a study which examined the causes of the formation of normal faults at the Leh basin in the Northwest Himalaya. Topics covered results which showed that gravity tectonics is the cause of normal faults in the basin, the difference between the normal faults mapped within the intermontane basins with those that are tectonically driven, and the distribution of lithology, location of major Himalayan faults and the major fluvial streams.

Crustal deformation and seismic activity in the Levant is mainly related to the interplate Dead Sea Fault (DSF) and the intraplate Carmel–Gilboa Fault System (CGFS). In this study, we analyze the interseismic deformation along these fault systems using 23 years of Global Positioning System (GPS) measurements obtained from 209 campaign and 60 continuous stations. This GPS data set is the longest record and the densest data set for the DSF, the CGFS, and the Levant region. We use this data set to investigate the spatial variations of slip and creep rates along the southern and central sections of the DSF and the CGFS. Our inversion model results indicate that part of the tectonic motion is transferred from the DSF to the CGFS. We find that the left‐lateral strike‐slip motion along the DSF decreases in a rate of 0.9 ± 0.4 mm/year, from 4.8 ± 0.3 mm/year south to the intersection with the CGFS to 3.9 ± 0.4 mm/year north to this intersection. Along the CGFS, the left‐lateral strike‐slip motion ranges between ∼0.3 and 0.5 mm/year and the extension rate between ∼0.6 and 0.7 mm/year, indicating a total slip rate vector of 0.8 ± 0.4 mm/year in the DSF direction, in agreement with the reduction of slip rate along the DSF near the intersection with the CGFS. Shallow creep is found along the southern and central sections of the Dead Sea basin and the northern Jordan Valley section of the DSF, with creep rates of 3.4 ± 0.4 and 2.3 ± 0.4 mm/year, respectively. These creeping sections were identified as areas with thick Halite layers at the shallow subsurface. We suggest that shallow creep behavior along the DSF is govern by the presence and mechanical properties of the Halite, which probably allows plastic deformation and the transition to velocity strengthening at the shallow subsurface and promotes creep. Plain Language Summary: The variations in slip and creep rates along major faults and the distribution of strain rates are key factors in seismic hazard assessment. In this study, we address these factors for the Dead Sea Fault (DSF) and the Carmel–Gilboa Fault System (CGFS) using the longest record and the densest Global Positioning System (GPS) measurements for the Levant region. The DSF is the boundary between Arabia and Sinai tectonic plates, and the CGFS is a major intraplate fault system within the Sinai plate. We used 23 years of GPS measurements obtained from 269 stations. We find that the left‐lateral strike‐slip motion along the southern DSF is ∼5 mm/year and decreases to ∼4 mm/year north to the intersection with the CGFS. Along the CGFS, a total slip rate of ∼0.8 mm/year in the DSF direction is found. Shallow creep is found along the southern and central sections of the Dead Sea basin and the northern Jordan Valley section of the DSF. These creeping sections were identified as areas with thick salt layers at the shallow subsurface. We therefore suggest that the shallow creep along the DSF is due to the salt behavior, which can deform plastically and creep. Key Points: The interseismic deformation along the Dead Sea Fault (DSF) and the Carmel–Gilboa Fault System (CGFS) is analyzed using 23 years of dense Global Positioning System (GPS) measurementsA decrease in the slip rate along the DSF due to slip partitioning with the CGFS is found near the intersection of these faultsShallow creep is found along the southern and central sections of the Dead Sea basin and the northern Jordan Valley section of the DSF [ABSTRACT FROM AUTHOR]

Four large hydropower stations have recently been built downstream the Jinsha River in Southwestern China with a strong regional tectonic activity background. There is widely felt seismicity since the impoundment of the Xiluodu and Xiangjiaba reservoirs, increasing the public concern in this region. We begin with a criticality analysis of the faults near these reservoirs to quantify their susceptibility to triggered seismicity. Then we focus on the Xiluodu reservoir to investigate the correlation between the impoundment and seismicity nearby. We analyze the spatio‐temporal distribution of seismicity near the Xiluodu reservoir, and identify the plausible rapid and delayed seismic response due to the impoundment. According to the impoundment record, we explicitly model the hydro‐mechanical changes due to diffusion and reservoir water load, that is, pore pressure, elastic stress, and the resulting Coulomb stress. Our results show that the pore pressure changes can reach a level that may trigger fault reactivation and consequently, seismicity nearby. The water load can also induce the positive Coulomb stress changes on faults, depending on the fault orientation, which is especially important for understanding the earthquakes that occurred shortly after the impoundment and at more than 10 km distance from the reservoir. The combination of these two effects can induce positive Coulomb stress change over a larger area, which overlaps the majority of the events after the impoundment, including two M5+ events. While the causal relationship between the impoundment and seismicity warrants further analysis, we hope to inform the regional seismic impact of impoundment with this timely study. Plain Language Summary: There has been increasing concern over the construction of four hydropower stations situated along the Jinsha River, Southwestern China, due to the increased seismicity following the impoundment of Xiluodu and Xiangjiaba reservoirs. This calls for an in‐depth analysis of the temporal and spatial correlation between the increased seismicity and reservoir impoundment. In this study, we first quantify the relative criticality of the faults. The results suggest that the faults near the Wudongde and Baihetan hydropower stations are more likely to be reactivated and produce earthquakes. Then, we take the Xiluodu Reservoir as a timely example to analyze two possible mechanisms for increased seismicity, corresponding to the effect of the increased weight of reservoir water and the process of reservoir water pressure seepaging into the crust, respectively. We calculate the water pressure and stress changes due to the Xiluodu impoundment with numerical simulations. The results show that these two mechanisms can explain the occurrence of most earthquakes near the reservoir and nearby faults after the impoundment, including two M5+ events. Our study is important to understand the impact of reservoir impoundment on regional seismicity and its evolution, and to offer a scientific perspective for the long‐term operational decisions for these hydropower stations. Key Points: The plausible link between the Xiluodu reservoir impoundment and the increased seismicity is evidenced by spatio‐temporal correlationsThe pore pressure diffusion and reservoir water load can contribute to fault reactivation and earthquake triggering in the Xiluodu areaThe fault criticality analysis reveals that the NNW‐ and NS‐striking faults downstream the Jinsha River are more prone to reactivation [ABSTRACT FROM AUTHOR]

Monitoring vertical land motions (VLMs) at the level of 0.1 mm/yr remains one of the most challenging scientific applications of global navigation satellite systems (GNSS). Such small rates of change can result from climatic and tectonic phenomena, and their detection is important to many solid Earth‐related studies, including the prediction of coastal sea‐level change and the understanding of intraplate deformation. Reaching a level of precision allowing to detect such small signals requires a thorough understanding of the stochastic variability in GNSS VLM time series. This paper investigates how the aperiodic part of non‐tidal atmospheric and oceanic loading (NTAOL) deformations influences the stochastic properties of VLM time series. Using the time series of over 10,000 stations, we describe the impact of correcting for NTAOL deformation on 5 complementary metrics, namely: the repeatability of position residuals, the power‐spectrum of position residuals, the estimated time‐correlation properties, the corresponding velocity uncertainties, and the spatial correlation of the residuals. We show that NTAOL deformations cause a latitude‐dependent bias in white noise plus power‐law model parameter estimates. This bias is significantly mitigated when correcting for NTAOL deformation, which reduces velocity uncertainties at high latitudes by 70%. Therefore, removing NTAOL deformation before the statistical analysis of VLM time series might help to detect subtle VLM signals in these areas. Our spatial correlation analysis also reveals a seasonality in the spatial correlation of the residuals, which is reduced after removing NTAOL deformation, confirming that NTAOL is a clear source of common‐mode errors in GNSS VLM time series. Plain Language Summary: Monitoring vertical land motions (VLMs) at the level of 0.1 mm/yr remains one of the most challenging scientific applications of global navigation satellite systems (GNSS). Such small rates of change can result from climatic and tectonic phenomena, and their detection is important to the prediction of coastal sea‐level change and the understanding of deformation processes acting within tectonic plates. In this paper, we investigate to what extent accounting for the deformation of the Earth's crust due to changes in the distribution of the atmospheric and the oceanic pressure helps to detect small vertical ground deformation. By analyzing the data from over 10,000 globally distributed GNSS stations, we show that accounting for such atmospheric and oceanic deformation can reduce by 70% the uncertainty on the vertical velocity of GNSS stations at high latitudes, which could, for instance, improve sea‐level change monitoring in these areas. Key Points: Non‐tidal atmospheric and oceanic loading (NTAOL) deformations cause a latitudinal bias in parameter estimates of the white + power‐law noise model usually describing global navigation satellite systems (GNSS) time seriesRemoving NTAOL deformations corrects the latitudinal bias and dramatically reduces station velocity uncertainties at high latitudesNTAOL deformations also introduce a seasonal spatial correlation in GNSS vertical land motion time series [ABSTRACT FROM AUTHOR]

Tectonic research of the Tibetan Plateau has long focused on its deformation style and mechanisms. The 2008 Mw7.9 Wenchuan earthquake ruptured the Longmen Shan fault located at the eastern rim of the plateau and excited a viscoelastic response of the lithosphere. We infer a three‐dimensional (3D) rheological structure of eastern Tibet from modeling nine years of postseismic displacements observed by GPS. Our solution provides tight constraints on the lower‐crustal and upper‐mantle steady‐state viscosities of the Songpan‐Ganzi Terrane as (5.0 ± 0.7) × 1018 and (1.3 ± 0.3) × 1019 Pa s, respectively, consistent with a "jelly sandwich" model of Tibet, but not with some crustal channel flow models featuring much lower viscosities. The inferred lower‐crustal and upper‐mantle transient viscosities are (5.0 ± 1.3) × 1017 and (5.0 ± 1.5) × 1018 Pa s, respectively, suggesting nonlinear deformation mechanisms. The adjacent West Qinling and Sichuan blocks feature an order‐of‐magnitude higher rheological strength, which is consistent with the changes in the crustal material properties and interseismic deformation style across the East Kunlun‐Tazang and Longmen Shan faults. Our results enable us to propose a conceptual 3D tectonic deformation model, in which the eastward extrusion of Tibet is absorbed in the Songpan‐Ganzi crust mainly by E‐W shortening and N‐S extension, accommodated through faulting of conjugate strike‐slip faults in the upper crust and distributed shear in the lower crust. Plain Language Summary: One of the fundamental questions in Earth science is the deformation mechanism of the continents, which controls the topography of the land we live on, the distribution of the resources extracted to support our living, and the origins of natural hazards such as landslides and earthquakes. The Tibetan Plateau, arguably, is the best natural laboratory to study the deformation mechanism of the continents. In this study, we address two critically important and much debated problems in Tibetan Plateau dynamics; that is, the rheologic structure of the Tibetan lithosphere and how it deforms under tectonic loading. We use nine years of mostly unpublished three‐dimensional (3D) deformation data collected in the aftermath of the 2008 Mw7.9 Wenchuan earthquake to infer the rheological structure of the eastern Tibet lithosphere. Our results are consistent with a "jelly sandwich" model, with a relatively weak lower crust underlain by a stronger upper mantle. However, they do not support the very low viscosities envisioned by some of the channel flow models of lower crustal deformation in eastern Tibet. We also propose a conceptual 3D tectonic deformation model, in which the eastward extrusion of Tibet is absorbed in the Songpan‐Ganzi crust by E‐W shortening and N‐S extension, accommodated through conjugate faults in the upper crust and distributed shear in the lower crust. Key Points: A comprehensive GPS data set is provided to cover nine years of three‐dimensional (3D) postseismic displacements after the 2008 Wenchuan earthquakeGPS constrained eastern Tibet Lithospheric rheological structure agrees with a "jelly sandwich" model, not models of much lower viscositiesA conceptual 3D tectonic deformation model in eastern Tibet is proposed to characterize its dynamic deformation style and mechanisms [ABSTRACT FROM AUTHOR]

The ongoing India‐Asia collision has led to the formation of the northern Himalayan gneiss domes belt in southern Tibet. The domes are the result of the ongoing convergence and were formed by geological processes that may include crustal thickening, metamorphism, partial melting, and exhumation of middle crustal rocks to the surface. A combination of compressional, extensional, and diapiric processes has been invoked to explain the formation and evolution of these domes. Differentiating among these competing hypotheses requires well‐defined geophysical images of the internal structure of the domes. The Mabja dome is the largest dome within the northern Himalayan gneiss domes belt. A 70‐km long deep seismic reflection profile across Mabja dome was acquired in 2016. The seismic data could provide new information about the structural elements beneath the domes to the depth of 25 Km. We address the structure of the Mabja dome by conducting an integrated analysis of shallow crustal velocity structure and a normal‐incidence seismic reflection image of deeper crust. Our work suggests that the Mabja dome is underlain by shear zones at depths of 10–15 km and two high‐velocity bodies at depths of 3 km possibly representing the eclogitic‐facies rocks or mafic intrusions. We propose that the dome formation may have been controlled by collision‐induced north‐south shortening expressed by thrust stacking of middle crustal rocks, which led to the doming of the upper‐crustal rocks. The proposed mechanism inferred for Mabja dome can be applied to interpret the widespread domes throughout the southern Tibet and other related structures in orogenic mountain belts. Key Points: Two high‐velocity bodies, with an average velocity as high as 6.6 and 7.2 km/s, are constrained at a depth of 3 km from the surfaceA series of sub‐horizontal reflections are observed at depths of 11–20 km which are interpreted to represent a thrust systemThe thrust stacking in the middle crust is the main mechanism that controls the formation of the Mabja dome formation [ABSTRACT FROM AUTHOR]

Studying transient postseismic deformation is one of the key approaches to probe fault kinematics and rheological behavior of rocks surrounding tectonic faults. Previous studies have shown that transient postseismic deformation is dominantly induced by afterslip and postseismic viscoelastic relaxation. However, effects of these two mechanisms are generally overlapped in space and time, making the analysis of the observations challenging. Here, we investigate the overlapping effects of afterslip and viscoelastic relaxation following the 2015 Gorkha earthquake based on the first 4‐years' Global Positioning System observations and finite element models. Separated mechanisms either fail to explain the observations or lead to unreasonable model parameters. A combined model that incorporates stress‐driven afterslip and viscoelastic relaxation can overcome the limitations of separated mechanisms. Our results indicate that only short‐term (<1 year) postseismic deformation in near‐to middle‐fields is caused mainly by afterslip, whereas that in far‐field or long‐term are dominated by the viscoelastic relaxation effect. The stress‐driven afterslip is mainly confined to a narrow zone adjacent to the coseismic rupture asperities, in contrast to the widespread deep afterslip as suggested by previous studies. The total seismic moment released by the afterslip is ∼5% of that released by the Mw 7.8 main shock. The optimal viscosity of the lower crust beneath the south Tibet is estimated to be 2.5 × 1018 Pa∙s, which is at least one order lower than that beneath Indian plate, suggesting a significant lateral variation across the Himalayan fault. Validations by using independent InSAR observations further confirm the reliability of the combined model. Key points: A combined mechanism of afterslip and viscoelastic relaxation is proposed for 4‐years' deformation after the 2015 Gorkha earthquakeThe combined model is well constrained by Global Positioning System data and validated by independent InSAR observationsRelative contributions of afterslip and viscoelastic relaxation show significant spatiotemporal variation [ABSTRACT FROM AUTHOR]

In the Gulf of Mexico and adjacent landmasses, faults are very complex, and their distribution is closely related to plate tectonics, ocean–land boundary, and former structure. The plane position of the faults can be identified by the maximum characteristic of the vertical derivative of the normalized vertical derivative of the total horizontal derivative (NVDR‐THDR) of the Bouguer gravity anomaly. The apparent depth of the faults is inverted by the Bouguer gravity anomaly curvature property. Based on tectonic evolutionary processes and the plane distribution and apparent depth characteristics of the faults, a complete fault system for the Gulf of Mexico and adjacent areas has been established, including 102 faults. The apparent depths of 33 first‐class faults are 16–20 km and for 69 second‐class faults are 12–16 km. The F1‐2 and F1‐3 subduction fault zones are two caused by the subduction of the Cocos Plate into the old Yucatan and Chorti landmasses; F1‐11 and F1‐12 fault zones extend westward to the coast of Guatemala and do not extend into the continent; F1‐17 and F1‐20 faults, which control the boundary of the oceanic crust, do not extend southward into the continent. The fault system, which radiates in a "fan‐shaped" structure as a whole, unfolds to the northeast. Faults of different nature and sizes are distributed in the Cocos Plate subduction zone, Continental, Gulf of Mexico, Yucatan old landmass and Caribbean Plate in NW, NNW, NS, NE and NEE directions. In the Gulf of Mexico region, the fault system is a comprehensive reflection of former tectonic movements, such as plate movement, drift of old landmasses and expansion of oceanic crusts. The first‐class faults control the plate and ocean–continental boundaries. The second‐class faults are subordinate to the first‐class faults or related to the distribution of different sedimentary layers. [ABSTRACT FROM AUTHOR]

Probably by dint of seductive appearances and overflowing passion for cartography, by dint of instant accessibility to all kind of maps and any graphic representations commonly called 'maps' and finally by dint of confusions between what is an IMAGE and what is a DATA, everyone forgets that, at the dawn of a cartographic project, 'THE MAP STILL DOESN'T EXIST'. For it to exist, a scope of collective work and essential skills are necessary. First of all, the aim of a mapping project must be identified. Its specifications, statement of requirements, its schedule of conditions must be sealed by a contract between an orderer and a cartographer.The objective of this presentation is to recall how a keyboard is neither a magic thought nor a magic wand. Clicking on it will never finalize our work without us, cartographers, but engages us to follow series of timeless execution process over the entire duration of the cartographic production, in anticipating each action.Our work consists in making every effort, by all the necessary technical and human means, to gather the knowledge of a subject (or several) to 'Map-draw' with the ultimate goal of returning this acquired knowledge to the readers. Their eye has to find at first glance the information sought. Indeed, the more beautiful and easier to grasp the map is, the more it will be consulted with pleasure.Through a range of cartographic memories, the following characteristic examples of out-of-standard cartographic productions will detail the pertinence of this meticulous cartographical articulation. [ABSTRACT FROM AUTHOR]

Many volcanoes are buried within Te Riu-a-Māui/Zealandia sedimentary basins. Based on a large collection of seismic reflection and drillhole data, this paper outlines the morphology, location and age of over 400 volcanoes buried and preserved in offshore New Zealand basins. We discuss the relationships of these volcanoes to the timing and locations of the main tectonic events that shaped Zealandia in the last 105 Myr. Late Cretaceous volcanism mainly formed large (>20 km3) composite cones and volcanic complexes that erupted along rift faults related to the break-up of Zealandia from south-eastern Gondwana. Cenozoic intraplate volcanic activity was widespread, typically forming clusters of scattered small-volume (<1 km3) craters and cones. In contrast, large Cenozoic volcanic complexes, composite cones and shield volcanoes erupted along linear arcs associated with subduction along the Pacific-Australian plate boundary. In detail, the presence of pre-existing structures and types of host rocks also influence the passage of magma in the shallow (<5 km) crust and the location of eruptive centres, regardless the tectonic setting of eruption. Insights from this work demonstrate the value of characterising volcanoes buried in sedimentary basins for improved understanding of the interplay between volcanism and plate tectonics in Zealandia and further afield. [ABSTRACT FROM AUTHOR]

The article reports on science research based on geology which informs about the seismological evidence for the earliest global subduction network with earliest evidence for subduction, which have been localized, does not signify when plate tectonics global phenomenon. Topics include investigated Paleoproterozoic time, for which seismic evidence is available from multiple continents; and high-density seismic array in North China to image the crustal structure that exhibits a dipping Moho.

To better understand the Wudalianchi intraplate volcanism and mantle dynamics in NE China, we collect abundant teleseismic waveform data during 2008 to 2018 recorded at 259 seismic stations around the Wudalianchi volcano. These stations include 148 WAVESArray portable stations, 66 NECESSArray portable stations and 45 Chinese provincial stations. Our newly deployed WAVESArray makes the station intervals of ~20–30 km around the Wudalianchi volcano. Using the minimum transverse‐energy grid‐search method, we make effective SKS splitting measurements at 192 stations. Our results show that the fast direction in the study region is mainly NW‐SE, but there are obvious contrasts within and between different tectonic units. To the east of the North‐South Gravity Lineament, around the Wudalianchi volcano, our SKS splitting measurements show a southeastward opening U‐shaped pattern in the fast direction and splitting time. Such a pattern of seismic anisotropy could be caused by horizontal and vertical flows in the big mantle wedge due to the deep subduction, long stagnancy, and deep dehydration of the Pacific slab in the mantle transition zone. The horizontal flow in the big mantle wedge could be obstructed by the thicker lithosphere under the Great Xing'an range and disturbed by hot and wet upwelling flow under the Wudalianchi volcano. Around the Nuominhe and Halaha volcanic groups, variations in the splitting parameters may also be associated with lithospheric deformation and delamination, though they are located at the edge of our study region. These results shed new light on the intraplate volcanism and mantle dynamics in NE China. Key Points: Our measurements show a southeastward opening U‐shaped pattern in fast direction and splitting time around the Wudalianchi volcanoSuch a pattern of seismic anisotropy could be caused by the horizontal and vertical flows in the big mantle wedgeHorizontal flow is obstructed by thicker lithosphere under Great Xing'anrang and disturbed by hot upwelling under Wudalianchi volcano [ABSTRACT FROM AUTHOR]

I outline and discuss my career in the context of the history of structural geology and tectonics, the progressive developments that led to plate tectonics, the people who have encouraged and influenced me, the events that changed my life, my fifty six doctoral students who have taught me so much, and my principal interests in tectonics. I discuss, in particular, nine topics of special current interest: the evolution of Tibet, the geomorphology of the British Isles, transtension, the Precambrian, the complexities of plate boundary evolution, Appalachian–Caledonian evolution, ophiolites, the structure and strength of the lithosphere, and the subducting slab. [ABSTRACT FROM AUTHOR]

A number of large landslides, which have strongly affected fluvial processes in the upstream catchment of the Minjiang River along the eastern margin of the Tibetan Plateau, Sichuan, were investigated with regard to both geological structure and topographic development. Topographic analysis suggested that there is a major knickpoint that formed not as a result of landslides but via tectonic activity and that the knickpoint propagated upstream, forming an inner gorge and undercutting and destabilizing nearby slopes. The effects of the knickpoint propagation and inner gorge formation on slope stability are dependent on the geometrical relationships between the river and geological structures. When the geological trend is normal or highly oblique to the river axis, landslides generally do not occur, but gigantic rockslides have occurred on one side of the Minjiang valley, which can be attributed to a wedge structure consisting of bedding planes and joints with intersections dipping valleyward and tight folds with hinges plunging valleyward. When the beds are planar, moderately dipping, and strike nearly parallel to the river, buckling deformation commonly occurs on cataclinal slopes, often transforming into catastrophic failure. Landslide dams form another type of knickpoint on the river channel that gradually disappear from the downstream to upstream as a result of river erosion. Our findings strongly suggest that the study of slope development by river incision must consider geological structures and that an understanding of geological structures and river incision history can provide a conceptual model for the prediction and mitigation of geohazards in tectonically active drainage basins. [ABSTRACT FROM AUTHOR]

Tectonic tremor in Taiwan is known for its short duration and weak amplitude. Recent observations from the mountain area (Central Range) allows us to document such type of tectonic tremor recorded at a close distance and to investigate a single station technique for a minute‐long tremor. To effectively distinguish tremor from earthquakes and noise, we applied the Fisher's class separability criterion to automatically select the optimal feature subset from a set of commonly adopted feature candidates. During the study period of 1 January to 16 September 2016 when a local seismic array was deployed, we successfully differentiated tremor from local earthquakes and noise with high accuracy of 86.6% to 98.9% from three stations using a k‐nearest neighbors classifier. Other than the maximum amplitude, number of peaks, and energy of the 2‐ to 8‐Hz passband, the spikiness of discrete Fourier transforms median in time is also found to be important to separate tremor from noise. Key Points: Recent observation from a mountain array allows us to document the tremor events recorded at the closest distanceWe evaluate the possibility of detecting minutes‐long tremor using a single stationWe obtain a collection of efficient seismic features for successful classification [ABSTRACT FROM AUTHOR]