Preprints
Filtering by Subject: Geophysics and Seismology
Review paper: The 10th March 1970 Mw 5.0 Calingiri surface rupturing earthquake, Australia
Published: 2019-08-17
Subjects: Earth Sciences, Geology, Geophysics and Seismology, Physical Sciences and Mathematics, Tectonics and Structure
The 10th March 1970 moment magnitude (Mw) 5.0 Calingiri earthquake surface rupture is 3.3 km long with a maximum vertical displacement of 0.4 m. The fault as defined by surface measurements is a shallow-dipping reverse fault (~ 20° east) with a probable shallow hypocentre (< 1 km). This is consistent with published hypocentral depths, though large uncertainties exist within the seismological [...]
Review paper: The 30th March 1986 Mw 5.7 Marryat Creek surface rupturing earthquake, Australia
Published: 2019-08-17
Subjects: Earth Sciences, Geology, Geophysics and Seismology, Physical Sciences and Mathematics, Tectonics and Structure
The 30th March 1986 Mw 5.7 Marryat Creek earthquake produced a highly arcuate 13 km long surface rupture with maximum vertical displacement of 0.9 m. Sinistral displacement on the NE-SW limb, dextral displacement on the NNE-SSW limb, and maximum vertical displacement in the central apex of rupture supports SW over NE movement of a hanging-wall block. Epicentre locations are poorly constrained and [...]
Review paper: The 14th October 1968 Mw 6.6 Meckering surface rupturing earthquake, Australia
Published: 2019-08-17
Subjects: Earth Sciences, Geology, Geophysics and Seismology, Physical Sciences and Mathematics, Tectonics and Structure
The 14th October 1968 MW 6.6 Meckering earthquake surface rupture is comprised of a main 37 km long concave Meckering scarp (with a 1.5 km wide dextral step-over along the Burges en-echelon rupture complex) and a minor 9 km long rupture on the Meckering scarp foot-wall (the Splinter scarp, also with a 1.5 km dextral step-over). We recommend a total surface rupture length of 44.4 km for [...]
Review paper: The 20th May 2016 Mw 6.1 Petermann surface rupturing earthquake, Australia
Published: 2019-08-17
Subjects: Earth Sciences, Geology, Geophysics and Seismology, Physical Sciences and Mathematics, Tectonics and Structure
The 20th May 2016 Mw 6.1 Petermann earthquake produced a 21 km long surface rupture with a maximum vertical offset of 0.9 m. Geological and geophysical data provide strong evidence that rupture occurred along a mylonite foliation plane with an orientation defined by deformation from the nearby Woodroffe Thrust, a major Neoproterozoic terrane suture. The most geologically and seismologically [...]
Review paper: The 23rd March 2012 Mw 5.2 Pukatja surface rupturing earthquake, Australia
Published: 2019-08-17
Subjects: Earth Sciences, Geology, Geophysics and Seismology, Physical Sciences and Mathematics, Tectonics and Structure
The 23rd March 2012 Mw 5.2 Pukatja earthquake produced an arcuate surface rupture 1.6 km long with a maximum vertical offset of 0.48 m. We reclassify its length to 1 km based on application of orientation and kinematic criteria used previously to measure other historic Australian surface ruptures. Epicentres are poorly constrained and inaccurate, located up to 17 km from the surface rupture with [...]
Real-Time High-Rate GNSS Displacements: Performance Demonstration During the 2019 Ridgecrest, CA Earthquakes
Published: 2019-08-17
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
Traditional real-time seismology has relied on inertial sensors to characterize ground motions and earthquake sources, particularly for hazards applications such as warning systems. In the past decade, a revolution in high-rate, real-time Global Navigation Satellite System (GNSS) displacement have provided a new source of data to augment traditional measurement devices. The Ridgecrest, California [...]
Empirical Green’s Function Retrieval using Cross-correlation of Ambient Noise Correlations (C2)
Published: 2019-08-12
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
Empirical Greens function (EGF) retrieval commonly relies on cross-correlating the long-term ambient seismic wavefield that is simultaneously recorded at multiple stations. Recent studies have demonstrated observationally that cross-correlating the coda of ambient noise cross-correlation functions (C3) enables reconstruction of the EGFs, regardless of the operating time of the stations. In this [...]
Small baseline InSAR time series analysis: Unwrapping error correction and noise reduction
Published: 2019-08-07
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
We present a review of small baseline interferometric synthetic aperture radar (InSAR) time series analysis with a new processing workflow and software implemented in Python, named MintPy (https://github.com/insarlab/MintPy). The time series analysis is formulated as a weighted least squares inversion. The inversion is unbiased for a fully connected network of interferograms without multiple [...]
Introduction of covariance components in slip inversion of geodetic data following a non-uniform spatial distribution and application to slip deficit rate estimation in the Nankai Trough subduction zone
Published: 2019-08-02
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
When spatial distribution of observation stations has bias in geodetic slip inversion, modeling errors in the inversion scheme may result in significant unnatural short-wave components in estimated slip distribution, which overfit to data. Combined use of both land and seafloor geodetic data in slip inversion often leads to such situations. To avoid overfitting, I proposed a method to [...]
Fracture and Weakening of Jammed Subduction Shear Zones, Leading to the Generation of Slow Slip Events
Published: 2019-07-31
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
Geodetic data have revealed that parts of subduction interfaces creep steadily or transiently. Transient slow slip events (SSEs) are typically interpreted as aseismic frictional sliding. However, SSEs may also occur via mixed visco‐brittle deformation, as observed in shear zones containing mixtures (mélange) of strong fractured clasts embedded in a weak visco‐brittle matrix. We test the [...]
Basal melting over Subglacial Lake Ellsworth and it catchment: insights from englacial layering
Published: 2019-07-25
Subjects: Earth Sciences, Geophysics and Seismology, Glaciology, Hydrology, Physical Sciences and Mathematics
Deep-water ‘stable’ subglacial lakes likely contain microbial life adapted in isolation to extreme environmental conditions. How water is supplied into a subglacial lake, and how water outflows, is important for understanding these conditions. Isochronal radio-echo layers have been used to infer where melting occurs above Lake Vostok and Lake Concordia in East Antarctica but have not been used [...]
Geostatistical characterisation of internal structure of mass-transport deposits from seismic reflection images and borehole logs
Published: 2019-07-24
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
Seismic reflection images of mass-transport deposits often show apparently chaotic, disorded or low-reflectivity internal seismic facies. The lack of laterally coherent reflections can prevent horizon-based interpretation of internal structure. This study instead inverts for geostatistical parameters which characterise the internal heterogeneity of mass-transport deposits from depth-domain [...]
Investigating the role of faults in fluid migration and gas hydrate formation along the southern Hikurangi Margin, New Zealand
Published: 2019-07-22
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
The Hikurangi Margin off the east coast of the North Island (Te Ika-a-Māui) is a tectonically active subduction zone and the location of New Zealand’s largest gas hydrate province. Faults are internally complex volumetric zones that may play a significant role in the migration of fluids beneath the seafloor. The combined processes of deformation and fluid migration result in the formation of [...]
Are we in the right path in using early warning systems?
Published: 2019-07-22
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
This article focusses on the recent tsunami in Indonesia, and the factors led to a large number of fatalities. We also discussed the failure of early warning systems, steps, methods and technologies, in general, to improve the early warning systems in the future to mitigate the loss of lives and property during these impending disasters. This article is timely as Indonesia has seen one of the [...]
Urban Seismic Site Characterization by Fiber-Optic Seismology
Published: 2019-07-16
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
Accurate ground-motion prediction requires detailed site effect assessment, but in urban areas where such assessments are most important, geotechnical surveys are difficult to perform, limiting their availability. Distributed acoustic sensing (DAS) offers an appealing alternative by repurposing existing fiber-optic cables, normally employed for telecommunication, as an array of seismic sensors. [...]