Preprints
Search for earthquake (513 results)
On the statistical significance of foreshock sequences in Southern California
Published: 2019-11-05
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
Earthquake foreshocks may provide information that is critical to short-term earthquake forecasting. However, foreshocks are far from ubiquitously observed, which makes the interpretation of ongoing seismic sequences problematic. Based on a statistical analysis, Trugman & Ross (2019) suggested that as much as 72% of all mainshocks in Southern California is preceded by foreshock sequences. In [...]
The variation and visualisation of elastic anisotropy in rock-forming minerals
Published: 2019-11-01
Subjects: Earth Sciences, Geochemistry, Geology, Geophysics and Seismology, Mineral Physics, Physical Sciences and Mathematics, Tectonics and Structure
All minerals behave elastically, a rheological property that controls their ability to support stress, strain and pressure, the nature of acoustic wave propagation and influences subsequent plastic (i.e. permanent, non-reversible) deformation. All minerals are intrinsically anisotropic in their elastic properties – that is, they have directional variations that are related to the configuration [...]
The Earthquake Arrest Zone
Published: 2019-11-01
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
Earthquake ruptures are generally considered to be cracks that propagate as fracture or frictional slip on preexisting faults. Crack models have been used to describe the spatial distribution of fault offset and the associated static stress changes along a fault, and have implications for friction evolution and the underlying physics of rupture processes. However, field measurements that could [...]
Did deglaciation of the Greenland ice sheet cause a large earthquake and tsunami around 10,600 years ago?
Published: 2019-10-31
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
Due to their large mass, ice sheets induce significant stresses in the Earth’s crust. Stress release during deglaciation can trigger large-magnitude earthquakes, as indicated by surface faults in northern Europe. Although glacially-induced stresses have been analyzed in northern Europe, they have not yet been analyzed for Greenland. We know that the Greenland Ice Sheet experienced a large melting [...]
Surface faulting earthquake clustering controlled by fault and shear-zone interactions
Published: 2019-10-25
Subjects: Earth Sciences, Physical Sciences and Mathematics, Tectonics and Structure
Surface faulting earthquakes are known to cluster in time, from historical and palaeoseismic studies, but the mechanism(s) responsible for clustering, such as fault interaction, strain-storage, and evolving dynamic topography, are poorly quantified, and hence not well understood. We present a quantified replication of observed earthquake clustering in central Italy. Six active normal faults are [...]
Complex Rupture of an Immature Fault Zone: A Simultaneous Kinematic Model of the 2019 Ridgecrest, CA Earthquakes
Published: 2019-10-24
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
The July 4, 2019 Mw6.4 and subsequent July 6, 2019 Mw7.1 Ridgecrest Sequence earthquakes ruptured orthogonal fault planes in the Little Lake Fault Zone, a low slip rate (1 mm/yr) dextral fault zone in the area linking the Eastern California Shear Zone and Walker Lane. This region accommodates nearly one fourth of plate boundary motion and has been proposed to be an incipient transform fault [...]
The 2018 Fiji Mw 8.2 and 7.9 deep earthquakes: one doublet in two slabs
Published: 2019-10-13
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
The cold Fiji-Tonga subduction zone accounts for >75% of cataloged deep earthquakes but none of the largest ten in the last century. On 19 August 2018 and 06 September 2018, a deep earthquake doublet with moment magnitude (Mw) 8.2 and 7.9 struck the Fiji area, providing a rare opportunity to interrogate the behaviors of great deep earthquakes in cold slabs. By cursory examination, the doublet [...]
Redshift of Earthquakes via Focused Blind Deconvolution of Teleseisms
Published: 2019-10-13
Subjects: Applied Mathematics, Earth Sciences, Electrical and Computer Engineering, Engineering, Geophysics and Seismology, Physical Sciences and Mathematics, Signal Processing
We present a robust factorization of the teleseismic waveforms resulting from an earthquake source into signals that originate from the source and signals that characterize the path effects. The extracted source signals represent the earthquake spectrum and its variation with azimuth. Unlike most prior work on source extraction, our method is data-driven, and it does not depend on any [...]
Making mountains on Earth and beyond
Published: 2019-10-13
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics, Tectonics and Structure
Many of Earth’s mountains are formed in orogenic belts aligned along plate margins. Their altitudes (reaching >8,000 m above sea level in the Himalayas) are the result of the balance between tectonic forces causing their uplift and erosive processes causing their destruction. The tectonic forces result, in part, from isostacy which is determined by the plasticity of the asthenosphere, but [...]
Crack to pulse transition and magnitude statistics during earthquake cycles on a self-similar rough fault
Published: 2019-10-08
Subjects: Earth Sciences, Engineering, Geophysics and Seismology, Mechanical Engineering, Physical Sciences and Mathematics, Tectonics and Structure, Tribology
Faults in nature demonstrate fluctuations from planarity at most length scales that are relevant for earthquake dynamics. These fluctuations may influence all stages of the seismic cycle; earthquake nucleation, propagation, arrest, and inter-seismic behavior. Here I show quasi-dynamic plane-strain simulations of earthquake cycles on a self-similar and finite 10 km long rough fault with [...]
Asperity failure control of stick-slip along brittle faults
Published: 2019-10-08
Subjects: Earth Sciences, Geology, Physical Sciences and Mathematics
Stick-slips are spontaneous, unstable slip events during which a natural or man-made system transitions from a strong, sticking stage to a weaker, slipping stage. Stick-slips were proposed by Brace and Byerlee (1966) as the experimental analogue of natural earthquakes. We analyze here the mechanics of stick-slips along brittle faults by conducting laboratory experiments and by modeling the [...]
Metastable olivine wedge beneath the Japan Sea imaged by seismic interferometry
Published: 2019-10-08
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
The metastable olivine wedge (MOW) within subducted slabs has long been hypothesized to host deep-focus earthquakes (>300 km). Its presence would also rule out hydrous slabs being subducted into the mantle transition zone. However, the existence and dimensions of MOW remain controversial. Here, we apply inter-source interferometry, which converts deep earthquakes into virtual seismometers, to [...]
Deep Low-Frequency Earthquakes Associated with the Eruptions of Shinmoe-dake in Kirishima Volcanoes
Published: 2019-10-06
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics, Volcanology
Deep low-frequency (DLF) earthquakes occur beneath the Kirishima volcanoes in southwest Japan at depths of 10–30 km. In this study, we aim to reveal the relationship between DLF earthquakes and volcanic activity including eruptions by relocating the hypocenters of the earthquakes using the network correlation coefficient method and detecting the earthquakes comprehensively using the matched [...]
Does a damaged fault zone mitigate the near-field landslide risk during supershear earthquakes?—Application to the 2018 magnitude 7.5 Palu earthquake.
Published: 2019-10-03
Subjects: Civil and Environmental Engineering, Earth Sciences, Engineering, Geotechnical Engineering, Physical Sciences and Mathematics
The impact of earthquakes can be severely aggravated by cascading secondary hazards. The 2018 Mw 7.5 Palu, Indonesia earthquake led to devastating tsunamis and landslides, while triggered submarine landslides possibly contributed substantially to generate the tsunami. The rupture was supershear over most of its length, but its speed was unexpectedly low, between the S-wave velocity Vs and [...]
The fingerprints of flexure in slab seismicity
Published: 2019-10-01
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
Earthquake moment tensors in east Pacific (ePac) slabs typically show downdip tensional axes (DT), whereas in the west Pacific (wPac) they typically show downdip compressional axes (DC) or have mixed orientations indicative of unbending. Prevailing conceptual models emphasise uniform stress/deformation modes, i.e. bulk stretching or shortening, as the dominant control on intermediate depth [...]