Preprints
Filtering by Subject: Tectonics and Structure
Measuring Azimuth Deformation With L-Band ALOS-2 ScanSAR Interferometry
Published: 2020-04-06
Subjects: Aerospace Engineering, Civil and Environmental Engineering, Computational Engineering, Computer Engineering, Earth Sciences, Electrical and Computer Engineering, Engineering, Geology, Geomorphology, Geophysics and Seismology, Glaciology, Hydrology, Mining Engineering, Other Earth Sciences, Physical Sciences and Mathematics, Signal Processing, Tectonics and Structure, Volcanology
We analyze the methods for measuring azimuth deformation with the L-band Advanced Land Observing Satellite-2 (ALOS-2) scanning synthetic aperture radar (ScanSAR) interferometry. To implement the methods, we extract focused bursts from the ALOS-2 full-aperture product, which is the only product available for ScanSAR interferometry at present. The extracted bursts are properly processed to measure [...]
Estimating Azimuth Offset With Double-Difference Interferometric Phase: The Effect of Azimuth FM Rate Error in Focusing
Published: 2020-04-06
Subjects: Aerospace Engineering, Civil and Environmental Engineering, Earth Sciences, Electrical and Computer Engineering, Engineering, Environmental Sciences, Geology, Geomorphology, Geophysics and Seismology, Glaciology, Hydrology, Mining Engineering, Other Earth Sciences, Physical Sciences and Mathematics, Physics, Tectonics and Structure, Volcanology
Estimating azimuth offset with double-difference interferometric (DDI) phase, which is called multiple-aperture interferometric synthetic aperture radar (InSAR) or spectral diversity, is increasingly used in recent years to measure azimuth deformation or to accurately coregister a pair of InSAR images. We analyze the effect of frequency modulation (FM) rate error in focusing on the DDI phase with [...]
International disparities in open access practices of the Earth Sciences community
Published: 2020-03-31
Subjects: Biogeochemistry, Cosmochemistry, Earth Sciences, Geochemistry, Geology, Geomorphology, Geophysics and Seismology, Glaciology, Hydrology, Library and Information Science, Mineral Physics, Other Earth Sciences, Paleobiology, Paleontology, Physical Sciences and Mathematics, Sedimentology, Social and Behavioral Sciences, Soil Science, Speleology, Stratigraphy, Tectonics and Structure, Volcanology
Short communication on international disparities in open access practices of the Earth Sciences community
Structural controls on the location, geometry, and longevity of an intraplate volcanic system - The Tuatara Volcanic Field, Great South Basin, New Zealand
Published: 2020-03-18
Subjects: Earth Sciences, Geology, Geophysics and Seismology, Physical Sciences and Mathematics, Tectonics and Structure, Volcanology
Intraplate volcanism is widely distributed across continental interiors. Yet controls on the location, 3D geometry, and longevity of many individual intraplate volcanic systems are often poorly understood. Geophysical and geodetic data provide insights into active intraplate magma plumbing systems, particularly when coupled with petrological and chemical analyses of volcanic products, but these [...]
Sedimentation and viscosity controls on forearc highs
Published: 2020-03-18
Subjects: Earth Sciences, Geology, Physical Sciences and Mathematics, Tectonics and Structure
Crustal rheology and surface processes strongly influence strain distribution and shape of orogenic wedges at their front but how they influence the wedge rear is still unclear. Here, we analyze the coupled control of viscosity and sedimentation on forearc high growth during advanced stages of subduction accretion. We use 2D thermo-mechanical finite element models constrained with data of the [...]
Global dominance of tectonics over climate in shaping river longitudinal profiles
Published: 2020-03-18
Subjects: Earth Sciences, Geology, Geomorphology, Hydrology, Physical Sciences and Mathematics, Tectonics and Structure
River networks are striking features engraved into Earths surface, shaped by uplift and erosion under the joint influence of climate and tectonics. How a river descends along its course – its longitudinal profile – varies greatly from one basin to the next, reflecting the interplay between uplift and erosional processes. It has recently been argued that climatic aridity should be a first-order [...]
Dynamic recrystallisation can produce porosity in shear zones
Published: 2020-03-18
Subjects: Earth Sciences, Geology, Physical Sciences and Mathematics, Tectonics and Structure
Creep cavities are increasingly recognised as an important syn-kinematic feature of shear zones but much about this porosity needs investigation. Largely, observations of creep cavities are restricted to very fine grained mature ultramylonites and it is unclear when they developed during deformation. Specifically, a question that needs testing is; should grain-size reduction during deformation [...]
On the formation of oceanic detachment faults and their influence on intra-oceanic subduction initiation: 3D thermomechanical modeling
Published: 2020-03-04
Subjects: Earth Sciences, Physical Sciences and Mathematics, Tectonics and Structure
Extensional detachment faults, which have been widely documented in slow-spreading and ultraslow-spreading ridges on Earth, can effectively localize deformation due to their weakness. After the onset of oceanic closure, these weak oceanic detachments may directly control the nucleation of a subduction zone parallel to the former mid-ocean ridge, as is suggested for the Neotethys in Middle [...]
Slip on wavy frictional faults: is the 3rd dimension a sticking point?
Published: 2020-03-03
Subjects: Earth Sciences, Physical Sciences and Mathematics, Tectonics and Structure
The formulation for the 3D triangular displacement discontinuity boundary element method with frictional constraints is described in detail. Its accuracy in comparison to analytical solutions is then quantified. We show how this can be used to approximate stress intensity factors at the crack tips. Using this method, we go on to quantify how slip is reduced on fault surfaces with topography, [...]
Analytical prediction of seismicity rate due to tides and other oscillating stresses
Published: 2020-03-03
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics, Planetary Geophysics and Seismology, Planetary Sciences, Tectonics and Structure
Oscillatory stresses are ubiquitous on earth and other solid-surface bodies. Tides and seasonal signals perpetually stress faults in the crust. Relating seismicity to these stresses offers fundamental insight into earthquake triggering. We present a simple model that describes seismicity rate due to perpetual oscillatory stresses. The model applies to large amplitude, non-harmonic, and [...]
Pre-inversion normal fault geometry controls inversion style and magnitude, Farsund Basin, offshore southern Norway
Published: 2020-02-28
Subjects: Earth Sciences, Geology, Physical Sciences and Mathematics, Tectonics and Structure
Inversion may localise along pre-existing structures within the lithosphere, far from the plate boundaries along which the causal stress is greatest. Inversion style and magnitude is expressed in different ways, depending on the geometric and mechanical properties of the pre-existing structure. A three-dimensional approach is thus required to understand how inversion may be partitioned and [...]
Mapping surface displacement using a pair of interferograms: comparative study
Published: 2020-02-26
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics, Tectonics and Structure, Volcanology
Interferometric analysis of Synthetic Aperture Radar satellite images (InSAR) measures only one component of ground deformation, in the satellite line-of-sight direction. In order to fully resolve the three dimensional (3D) ground displacement field, InSAR images acquired with different imaging geometries are required. Despite the increase in the number of SAR missions, an area is most frequently [...]
Structural inheritance and border fault reactivation during active early-stage rifting along the Thyolo fault, Malawi
Published: 2020-02-26
Subjects: Earth Sciences, Geology, Geomorphology, Physical Sciences and Mathematics, Tectonics and Structure
We present new insights on the geometry, initiation and growth of the Thyolo fault, an 85 km long active border fault in the southern Malawi Rift, from high-resolution topography, field and microstructural observations. The Thyolo fault is located towards the edge of the Proterozoic Unango Terrane, and is the border fault of the Lower Shire Graben, which has experienced four phases of extension [...]
Geodetic Evidence for a Buoyant Mantle Plume Beneath the Eifel Volcanic Area, NW Europe
Published: 2020-02-24
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics, Tectonics and Structure, Volcanology
The volcanism of the Eifel volcanic field (EVF), in west-central Germany, is often considered an example of hotspot volcanism given its geochemical signature and the putative mantle plume imaged underneath. EVF’s setting in a stable continental area provides a rare natural laboratory to image surface deformation and test the hypothesis of there being a thermally buoyant plume. Here we use Global [...]
P wave anisotropy caused by partial eclogitization of descending crust demonstrated by modelling effective petrophysical properties
Published: 2020-02-21
Subjects: Earth Sciences, Physical Sciences and Mathematics, Tectonics and Structure
Seismological studies of large-scale processes at convergent plate boundaries typically probe lower crustal structures with wavelengths of several kilometers, whereas field-based studies typically sample the resulting structures at a much smaller scale. To bridge this gap between scales, we derive effective petrophysical properties on the 20-m, 100-m, and kilometer scales based on numerical [...]