Preprints
Search for earthquake (526 results)
Ambient noise image Campi Flegrei 2011-2013
Published: 2018-03-26
Subjects: Earth Sciences, Environmental Monitoring, Environmental Sciences, Physical Sciences and Mathematics, Tectonics and Structure, Volcanology
Earthquakes at Campi Flegrei have been low-magnitude and sparse for more than thirty years, denying onshore monitoring observations of their usual source for structural constraint: seismic tomography. Here, we used ambient seismic noise recorded between 2011 and 2013 to reconstruct period-dependent Rayleigh-wave velocity maps of caldera-wide structures and volcanic reservoirs. The lowest [...]
Evaluating models of Coulomb stress transfer: Is variable fault geometry important?
Published: 2018-03-21
Subjects: Earth Sciences, Physical Sciences and Mathematics, Tectonics and Structure
To determine the importance of receiver fault geometry in Coulomb stress calculations a new methodology is presented to model faults with variable geometry. Although most models use planar faults, it is known that these are inaccurate representations of faults observed in the field. The central Italian Apennines are chosen as a straightforward tectonic system with well‐exposed normal faults to [...]
Kinematics of the active West Andean fold-and-thrust belt (Central Chile): structure and long-term shortening rate
Published: 2018-03-19
Subjects: Earth Sciences, Geomorphology, Geophysics and Seismology, Physical Sciences and Mathematics, Tectonics and Structure
West-verging thrusts, synthetic with the Nazca - South America subduction interface, have been recently discovered at the western front of the Andes. At ~33°30’S, the active San Ramón fault stands as the most frontal of these west-verging structures, and represents a major earthquake threat for Santiago, capital city of Chile. Here we elaborate a detailed 3D structural map and a precise [...]
Slow-slip events in semi-brittle serpentinite fault zones
Published: 2018-03-14
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
Slow-slip events are earthquake-like events only with much lower slip rates. While peak coseismic velocities can reach tens of meters per second, slow-slip is on the order of 1E-7 m/s and may last for days to weeks. Under the rate-and-state model of fault friction, slow-slip is produced only when the asperity size is commensurate with the critical nucleation size, a function of frictional [...]
Probing earthquake dynamics through seismic radiated energy rate: illustration with the M7.8 2015 Nepal earthquake
Published: 2018-02-25
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
Dynamic characterizations of earthquakes focus on whole-event representations, that is whether the total radiation of seismic waves is more or less energetic. Denolle et al (2015) and Yin et al. (2018) suggest to use the source spectrogram in order to analyze the radiation during the rupture itself. Here, we take a retrospective view on these studies to better establish the methodology of source [...]
Structure and kinematics of the Sumatran Fault System in North Sumatra (Indonesia)
Published: 2018-02-24
Subjects: Earth Sciences, Geology, Physical Sciences and Mathematics
Lithospheric-scale faults related to oblique subduction are responsible for some of the most hazardous earthquakes reported worldwide. The mega-thrust in the Sunda sector of the Sumatran oblique subduction has been intensively studied, especially after the infamous 2004 Mw 9.1 earthquake, but its onshore kinematic complement within the Sumatran subduction, the transform Sumatran Fault System, has [...]
Active deformation of Malawi Rift’s North Basin hinge zone modulated by reactivation of pre-existing Precambrian shear zone fabric
Published: 2018-02-19
Subjects: Earth Sciences, Geology, Geophysics and Seismology, Physical Sciences and Mathematics, Tectonics and Structure
Key Points: 1. Filtered aeromagnetic data elucidates the relationship between earthquake surface ruptures and buried faults along the North Basin hinge-zone, Malawi Rift. 2. Fault segments align with basement shear zone fabric. 3. Strain accommodation in the North Basin hinge zone is modulated by reactivation of the underlying Precambrian shear zone fabric. Abstract: We integrated temporal [...]
Communicating Unnatural Disasters
Published: 2018-01-02
Subjects: Earth Sciences, Engineering, Environmental Studies, Physical Sciences and Mathematics, Risk Analysis, Social and Behavioral Sciences
Off the back of the 2017 hurricanes we extend the notion of human-influenced meteo-hydro hazards to include deeper geophysical events. We question where to place Human responsibility in a changing world, and we outline ways to bridge the gaps between scientist’s technical knowledge and ‘meaning’ as it is understood by people at risk. This short Op-ed has been rejected by Science after two rounds [...]
Topographic modulation of fault kinematics in the Himalaya and Tibet
Published: 2017-12-21
Subjects: Earth Sciences, Physical Sciences and Mathematics, Tectonics and Structure
In many locations in the Himalaya and Tibet, extensional stepovers on strike-slip faults occur beneath pre-existing topographic highs. An influential physical model of orogens, explaining contemporaneous high-elevation normal faulting and low-elevation reverse faulting, holds that horizontal tectonic compression is invariant across the orogen while vertical stress varies with topography, [...]
The spectrum of slip behaviours of a granular fault gouge analogue governed by rate and state friction.
Published: 2017-12-13
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
The exact principles of earthquake recurrence and magnitude are currently unknown which is why earthquake hazard assessment relies on statistical models combined with numerical simulations. A component of seismic and aseismic slip is the frictional character of a fault. We shear fused glass beads with a narrow particle size distribution of 300-400µm at stresses of 5-20kPa and with low shear rates [...]
Synchronization of great subduction megathrust earthquakes: Insights from scale model analysis
Published: 2017-12-04
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
The size of great subduction megathrust earthquakes is controlled mainly by the number of adjacent asperities failing synchronously and the resulting rupture length. Here we investigate experimentally the long-term recurrence behavior of a pair of asperities coupled by quasi-static stress transfer over hundreds of seismic cycles. We statistically analyze long (c. 500 ka) time-series of M8-9 [...]
The crisis of a paradigm. A methodological interpretation of Tohoku and Fukushima catastrophe
Published: 2017-12-04
Subjects: Earth Sciences, Environmental Studies, Geophysics and Seismology, Physical Sciences and Mathematics, Social and Behavioral Sciences, Tectonics and Structure
The 2011 Japanese disaster often presented as a ‘new Chernobyl’ accumulated the effects of earthquake, tsunami and of the subsequent nuclear accident at Fukushima. In the light of this disaster, we review methodological rea- sons both from geophysical and philosophical perspectives that lead the scientific and technological communities to flawed conclusions, prime cause of the disaster. The [...]
Ice shelf rift propagation and the mechanics of wave-induced fracture
Published: 2017-11-28
Subjects: Earth Sciences, Glaciology, Physical Sciences and Mathematics
Distant storms, tsunamis, and earthquakes generate waves on floating ice shelves. Previous studies, however, have disagreed about whether the resulting wave-induced stresses may cause ice shelf rift propagation. Most ice shelf rifts show long periods of dormancy suggesting that they have low background stress concentrations and may therefore be susceptible to wave-induced stresses. Here, I [...]
Lithospheric flexure and rheology determined by climate cycle markers in the Corinth Rift
Published: 2017-11-28
Subjects: Earth Sciences, Geology, Geomorphology, Physical Sciences and Mathematics, Tectonics and Structure
Geomorphic strain markers accumulating the effects of many earthquake cycles help to constrain the mechanical behaviour of continental rift systems as well as the related seismic hazards. In the Corinth Rift (Greece), the unique record of onshore and offshore markers of Pleistocene ~100-ka climate cycles provides an outstanding possibility to constrain rift mechanics over a range of timescales. [...]
The role of coseismic Coulomb stress changes in shaping the hard-link between normal fault segments
Published: 2017-11-27
Subjects: Earth Sciences, Geology, Geomorphology, Geophysics and Seismology, Physical Sciences and Mathematics, Tectonics and Structure
The mechanism and evolution of fault linkage is important in the growth and development of large faults. Here we investigate the role of coseismic stress changes in shaping the hard-links between parallel normal fault segments (or faults), by comparing numerical models of the Coulomb stress change from simulated earthquakes on two en echelon fault segments to natural observations of hard-linked [...]