Preprints
Filtering by Subject: Geophysics and Seismology
Modeling megathrust earthquakes across scales: one-way coupling from geodynamics and seismic cycles to dynamic rupture
Published: 2019-02-15
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
Taking the full complexity of subduction zones into account is important for realistic modelling and hazard assessment of subduction zone seismicity and associated tsunamis. Studying seismicity requires numerical methods that span a large range of spatial and temporal scales. We present the first coupled framework that resolves subduction dynamics over millions of years and earthquake dynamics [...]
Structural architecture and composition of crystalline basement offshore west Norway
Published: 2019-02-13
Subjects: Earth Sciences, Geology, Geophysics and Seismology, Physical Sciences and Mathematics, Tectonics and Structure
Numerous studies have investigated the geodynamic history and lithological composition of the Proterozoic basement, Caledonian nappes, and Devonian extensional basins and shear zones onshore west Norway. However, the offshore continuation of these structures, into the northern North Sea, where they are suspected to have influenced the structural evolution of the North Sea rift, is largely [...]
Bayesian Dynamic Finite-Fault Inversion: 1. Method and Synthetic Test
Published: 2019-02-12
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
Dynamic earthquake source inversions aim to determine the spatial distribution of initial stress and friction parameters leading to dynamic rupture models that reproduce observed ground motion data. Such inversions are challenging, particularly due to their high computational burden, thus so far only few attempts have been made. Using a highly efficient rupture simulation code, we introduce a [...]
Surface Wave Imaging using Distributed Acoustic Sensing Deployed on Dark Fiber: Moving Beyond High Frequency Noise
Published: 2019-02-08
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
Several recent studies have demonstrated that Distributed Acoustic Sensing (DAS) can utilize existing subsurface telecom fiber (i.e. dark fiber) for high quality seismic measurements. Researchers to date have shown that this sensing combination, coupled to ambient noise interferometry techniques, can effectively image the shallow subsurface (< 30 m) using vehicle and infrastructure noise (f = [...]
Dynamic Rupture Propagation on Fault Planes with Explicit Representation of Short Branches
Published: 2019-02-06
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
Active fault zones are homes for a plethora of complex structural and geometric features that are expected to affect earthquake rupture nucleation, propagation, and arrest, as well as interseismic deformation. Simulation of these complexities have been largely done using continuum plasticity or scalar damage theories. In this paper, we use a highly efficient novel hybrid finite element-spectral [...]
The Future of Broadband Passive Seismic Acquisition
Published: 2019-02-06
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
It is an exciting time to be a seismologist. In November 2018, the InSight lander touched down on Mars and the first seismometer was deployed on another planet. This incredible feat means planetary seismologists are currently searching for marsquakes and will hopefully soon be providing images of its interior and helping us to understand how rocky planets form. However, we have been doing this [...]
Effect of fault roughness on aftershock distribution: Plastic off-fault material properties
Published: 2019-02-04
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
We perform spontaneous earthquake rupture simulations on rough strike- slip faults with off-fault plastic material properties. We examine the off-fault stress change and damage pattern resulting from dynamic fault slip in the near-fault region. We use the stress output from each simulation to calculate the Coulomb failure function (CFF). We calculate the CFF values at the extensional side of the [...]
Factor Analysis by R Programming to Assess Variability Among Environmental Determinants of the Mariana Trench
Published: 2019-01-28
Subjects: Computer Sciences, Earth Sciences, Education, Engineering, Environmental Monitoring, Environmental Sciences, Environmental Studies, Geographic Information Sciences, Geography, Geology, Geomorphology, Geophysics and Seismology, Graphics and Human Computer Interfaces, Life Sciences, Marine Biology, Oceanography, Oceanography and Atmospheric Sciences and Meteorology, Other Earth Sciences, Other Geography, Other Oceanography and Atmospheric Sciences and Meteorology, Physical and Environmental Geography, Physical Sciences and Mathematics, Programming Languages and Compilers, Remote Sensing, Science and Mathematics Education, Sedimentology, Social and Behavioral Sciences, Spatial Science, Tectonics and Structure, Water Resource Management
The aim of this work is to identify main impact factors affecting variations in the geomorphology of the Mariana Trench which is the deepest place of the Earth, located in the west Pacific Ocean: steepness angle and structure of the sediment compression. The Mariana Trench presents a complex ecosystem with highly interconnected factors: geology (sediment thickness and tectonics including four [...]
Are U-Th dates correlated with historical records of earthquakes? Constraints from co-seismic carbonate veins within the North Anatolian Fault Zone
Published: 2019-01-22
Subjects: Earth Sciences, Geochemistry, Geophysics and Seismology, Physical Sciences and Mathematics, Tectonics and Structure
U-Th dating of carbonate veins in connection with active tectonics has recently been used as an attractive tool for constraining the absolute timing of late Quaternary crustal deformations. In this study, for the first time we correlate U-Th ages of travertine deposits in co-seismic fissures along the North Anatolian Fault Zone (NAFZ) with records of Paleoseismological studies supported by [...]
Ionospheric Correction of InSAR Time Series Analysis of C-band Sentinel-1 TOPS Data
Published: 2019-01-18
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
The Copernicus Sentinel-1A/B satellites operating at C-band in TOPS mode bring unprecedented opportunities for measuring large-scale tectonic motions using interferometric synthetic aperture radar. However, while the ionospheric effects are only about one sixteenth of those at L-band, the measurement accuracy might still be degraded by long-wavelength signals due to the ionosphere. We implement [...]
Earthquakes within Earthquakes: Patterns in Rupture Complexity
Published: 2019-01-17
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
Earthquake source time functions carry information about the complexity of seismic rupture. We explore databases of source time functions of earthquakes and find that source time functions are composed of distinct peaks that we call subevents. We observe that earthquake complexity, as represented by the number of subevents, grows with earthquake magnitude. We find that subevent magnitudes are [...]
Seismic and aseismic fault growth lead to different fault orientations
Published: 2019-01-10
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
Orientations of natural fault systems are subject to large variations. They often contradict classical Andersonian faulting theory as they are misoriented relative to the prevailing regional stress field. This is ascribed to local effects of structural or stress heterogeneities and reorientations of structures or stresses on the long-term. To better understand the relation between fault [...]
Development of an inversion method to extract information on fault geometry from teleseismic data
Published: 2019-01-04
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
Teleseismic waveforms contain information on fault slip evolution during an earthquake, as well as on the fault geometry. A linear finite-fault inversion method is a tool for solving the slip-rate function distribution under an assumption of fault geometry as a single or multiple-fault-plane model. An inappropriate assumption of fault geometry would tend to distort the solution due to Greens [...]
Impulsive source of the 2017, Mw =7.3, Ezgeleh, Iran, earthquake
Published: 2019-01-03
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
On November 12th 2017, a MW =7.3 earthquake struck near the Iranian town of Ezgeleh, close to the Iran-Iraq border. This event was located within the Zagros fold and thrust belt which delimits the continental collision between the Arabian and Eurasian Plates. Despite a high seismic risk, the seismogenic behaviour of the complex network of active faults is not well documented in this area due to [...]
A New Method for Simultaneously Determining The Magnitude And Orientation of SHmax And Rock Strength Using Wellbore Failures in Deviated Wells
Published: 2019-01-03
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
Forward constraining of the magnitude of SHmax on a stress polygon using wellbore failures observed from deviated wells requires the orientation of SHmax known a priori. This orientation can be separately determined from, e.g., wellbore failures in vertical/near-vertical wells. Unfortunately, in the case where image logs are available only in highly deviated wells, SHmax orientation cannot be [...]