Preprints
Filtering by Subject: Tectonics and Structure
Shallow slow slip events along the Nankai Trough detected by the GNSS-A
Published: 2019-05-16
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics, Tectonics and Structure
Various slow earthquakes (SEQs), including tremors, very-low-frequency events, and slow slip events (SSEs), occur along megathrust zones. In a shallow plate boundary region, although many SEQs have been observed along pan-Pacific subduction zones, SSEs with a duration on the order of a year or with a large slip have not yet been detected due to difficulty in offshore observation. We try to [...]
Extension at the coast of the Makran subduction zone (Iran)
Published: 2019-05-14
Subjects: Earth Sciences, Physical Sciences and Mathematics, Tectonics and Structure
In the Makran subduction zone, earthquake focal mechanisms and geodetic data indicate that the deforming prism currently experiences N-S compression. However, paleostress inversions performed on normal faults observed along the coast reveal local stress components consistent with N-S extension. Previously proposed mechanisms such as gravitational collapse are not in line with N-S compression and [...]
Pre-existing intra-basement shear zones influence growth and geometry of non-colinear normal faults, western Utsira High–Heimdal Terrace, North Sea
Published: 2019-05-06
Subjects: Earth Sciences, Geology, Physical Sciences and Mathematics, Tectonics and Structure
Pre-existing intra-basement shear zones can induce mechanical and rheological heterogeneities that may influence rifting and the overall geometry of rift-related normal faults. However, the extent to which physical and kinematic interaction between pre-existing shear zones and younger rift faults control the growth of normal faults is less-well understood. Using 3D reflection seismic data from [...]
Dating and morpho-stratigraphy of uplifted marine terraces in the Makran subduction zone (Iran)
Published: 2019-05-03
Subjects: Earth Sciences, Geomorphology, Physical Sciences and Mathematics, Tectonics and Structure
The western part of the Makran subduction zone (Iran) is currently experiencing active surface uplift, as attested by the presence of emerged marine terraces along the coast. To better understand the uplift recorded by these terraces, we investigated seven localities along the Iranian Makran and we performed radiocarbon, 230Th/U and optically stimulated luminescence (OSL) dating of the layers of [...]
Characterising strong force networks produced during granular shear using percolation methods: Revealing the bridge between local grain scale processes and macroscopic sliding
Published: 2019-04-08
Subjects: Earth Sciences, Geology, Geophysics and Seismology, Other Earth Sciences, Physical Sciences and Mathematics, Physics, Tectonics and Structure
Faults, landslides and subglacial till often contain accumulations of granular debris. Their macroscopic motion is at least to some extent determined by the processes operating in this sheared granular material. A valid question in these environments is how the local behaviour at the individual granular contacts actually sums up to influence macroscopic sliding. Laboratory experiments and [...]
Comment on “Long-term strain oscillations related to the hydrogeological interaction between aquifers in intra-mountain basins: A case study from Apennines chain (Italy)” by Devoti, Riguzzi, Cinti and Ventura
Published: 2019-03-28
Subjects: Earth Sciences, Geology, Geomorphology, Physical Sciences and Mathematics, Tectonics and Structure
The paper by Devoti et al. (2018) analyses the GPS time series from seventeen stations located inside and in the neighboring of the L’Aquila intermountain basin. The authors suggest that the observed movements are due to regional hydrological processes likely associated with multi-annual climatic variations. The analysis performed by Devoti et al. (2018) contains an issue in the GPS-InSar [...]
The competition for salt and kinematic interactions between minibasins during density-driven subsidence: observations from numerical models
Published: 2019-03-20
Subjects: Earth Sciences, Physical Sciences and Mathematics, Tectonics and Structure
Stratal geometries of salt-floored minibasins provide a record of the interplay between minibasin subsidence and sedimentation. Minibasin subsidence and resulting stratal geometries are frequently interpreted by considering the minibasins in isolation and implicitly assuming that internal geometries are the result of purely vertical halokinetic processes. However, minibasins rarely form in [...]
Temporally constant Quaternary uplift rates and their relationship with extensional upper-plate faults in south Crete (Greece), constrained with 36Cl exposure dating.
Published: 2019-03-20
Subjects: Earth Sciences, Physical Sciences and Mathematics, Tectonics and Structure
Preserved sets of marine terraces and palaeoshorelines above subduction zones provide an opportunity to explore the long-term deformation that occurs as a result of upper-plate extension. We investigate uplifted palaeoshorelines along the South Central Crete Fault and over its western tip, located above the Hellenic Subduction Zone, in order to derive uplift rates and examine the role that known [...]
Segmentation of rifts through structural inheritance: Creation of the Davis Strait
Published: 2019-03-19
Subjects: Earth Sciences, Physical Sciences and Mathematics, Tectonics and Structure
Mesozoic-Cenozoic rifting between Greenland and North America created the Labrador Sea and Baffin Bay, while leaving preserved continental lithosphere in the Davis Strait which lies between them. Inherited crustal structures from a Palaeoproterozoic collision have been hypothesized to account for the tectonic features of this rift system. However, the role of mantle lithosphere heterogeneities in [...]
Early exhumation of the Frontal Cordillera (Southern Central Andes) and implications for Andean mountain-building at ~33.5°S
Published: 2019-03-13
Subjects: Earth Sciences, Geology, Physical Sciences and Mathematics, Tectonics and Structure
The Andes are the modern active example of a Cordilleran-type orogen, with mountain-building and crustal thickening within the upper plate of a subduction zone. Despite numerous studies of this emblematic mountain range, several primary traits of this orogeny remain unresolved or poorly documented. The onset of uplift and deformation of the Frontal Cordillera basement culmination of the Southern [...]
The effect of stress changes on time-dependent earthquake probabilities for the central Wasatch Fault Zone, Utah, USA.
Published: 2019-03-12
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics, Tectonics and Structure
Static and quasi-static Coulomb stress changes produced by large earthquakes can modify the probability of occurrence of subsequent events on neighboring faults. This approach is based on physical (Coulomb stress changes) and statistical (probability calculations) models, which are influenced by the quality and quantity of data available in the study region. Here, we focus on the Wasatch Fault [...]
A secondary zone of uplift due to megathrust earthquakes
Published: 2019-03-11
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics, Tectonics and Structure
The 1960 M9.5 Valdivia and 1964 M9.2 Alaska earthquakes caused a decimeters-high secondary zone of uplift a few hundred kilometers landward of the trench. We analyze GPS data from the 2010 M8.8 Maule and 2011 M9.0 Tohoku-Oki earthquakes to confirm the existence of a secondary zone of uplift due to great earthquakes at the megathrust interface. This uplift varies in magnitude and location, but [...]
Unfolding Veined Fold Limbs to Deduce a Basins Prefolding Stress State
Published: 2019-03-06
Subjects: Earth Sciences, Education, Outdoor Education, Physical Sciences and Mathematics, Tectonics and Structure
Tectonic structures that developed prior to folding, such as pre- and early-kinematic veins, hold valuable information on the stress state of the paleobasin in which these early structures formed. To derive the parental orientation of these prefolding brittle structures, folds need to “unfold.” A fold restoration methodology is presented in which fold limbs, and the structures they contain, are [...]
Structural and geodynamic modelling of the influence of granite bodies during lithospheric extension: application to the Carboniferous basins of northern England
Published: 2019-02-22
Subjects: Earth Sciences, Geology, Physical Sciences and Mathematics, Tectonics and Structure
Intra-basinal highs within classic ‘block and basin’ style tectonic frameworks, in areas such as northern England, are underpinned by large granite bodies. This is widely believed to relate to the relative ‘rigidity’ and ‘buoyancy’ of granite in relation to accommodating basement. It has been suggested that during periods of tectonic extension, normal faulting around the peripheral regions of [...]
The influence of base-salt relief, rift topography and regional events on salt tectonics offshore Morocco
Published: 2019-02-19
Subjects: Earth Sciences, Geology, Physical Sciences and Mathematics, Tectonics and Structure
This study integrates borehole-calibrated 2D and 3D seismic interpretation with numerical models to provide a regional analysis of the complex salt tectonics offshore central Morocco. We investigate the mechanisms controlling along-margin structural variations, the effects of thick-skinned shortening and the sequential evolution of allochthonous sheets. Additionally, we analyse how base-salt [...]