Preprints
Search for earthquake (504 results)
Active fault scarps in southern Malawi and their implications for the distribution of strain in incipient continental rifts
Published: 2019-06-18
Subjects: Earth Sciences, Geomorphology, Physical Sciences and Mathematics, Tectonics and Structure
The distribution of deformation during the early stages of continental rifting is an important constraint on our understanding of continental breakup. Incipient rifting in East Africa has been considered to be dominated by slip along rift border faults, with a subsequent transition to focussed extension on axial segments in thinned crust and/or with active magmatism. Here, we study [...]
Distributed sensing of earthquakes and ocean-solid Earth interactions on seafloor telecom cables
Published: 2019-06-07
Subjects: Earth Sciences, Environmental Sciences, Geophysics and Seismology, Physical Sciences and Mathematics, Physics
Two thirds of the surface of our planet are covered by water and are still poorly instrumented, which has prevented the earth science community from addressing numerous key scientific questions. The potential to leverage the existing fiber optic seafloor telecom cables that criss-cross the oceans, by turning them into dense arrays of seismo-acoustic sensors, remains to be evaluated. Here, we [...]
Lower crustal earthquakes in the East African Rift System: Insights from frictional properties of rock samples from the Malawi rift
Published: 2019-06-05
Subjects: Earth Sciences, Physical Sciences and Mathematics, Tectonics and Structure
Earthquakes in the southern part of the East African Rift System (EARS) occur at depths up to 45 km in the lower crust, unusually deep for an extensional regime. Typically, earthquakes in continental crust nucleate at temperatures less than 350°C, the temperature at which crystal plastic creep in quartz becomes efficient, corresponding to a depth of ~15 km with an average continental geothermal [...]
Physically consistent modeling of dike induced deformation and seismicity: Application to the 2014 Bárðarbunga dike, Iceland
Published: 2019-06-03
Subjects: Earth Sciences, Geology, Geophysics and Seismology, Physical Sciences and Mathematics, Volcanology
Dike intrusions are often associated with surface deformation and propagating swarms of earthquakes. These are understood to be manifestations of the same underlying physical process, although rarely modeled as such. We construct a physics-based model of the 2014 B\ar{\dh}arbunga dike, by far the best observed large dike ($> 0.5$ km$^3$) to date. We constrain the background stress state [...]
A shallow earthquake swarm close to hydrocarbon activities: discriminating between natural and induced causes for the 2018–19 Surrey, UK earthquake sequence
Published: 2019-05-30
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
Earthquakes induced by subsurface industrial activities are a globally emotive issue, with a growing catalogue of induced earthquake sequences. However, attempts at discriminating between natural and induced causes, particularly for anomalously shallow seismicity, can be challenging. An earthquake swarm during 2018–19 in south-east England with a maximum magnitude of ML 3.2 received great public [...]
Creep on seismogenic faults: Insights from analogue earthquake experiments
Published: 2019-05-30
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics, Tectonics and Structure
Tectonic faults display a range of slip behaviors including continuous and episodic slip covering rates of more than 10 orders of magnitude (m/s). The physical control of such kinematic observations remains ambiguous. To gain insight into the slip behavior of brittle faults we performed laboratory stick-slip experiments using a rock analogue, granular material. We realized conditions under which [...]
Teleseisms and Microseisms on an Ocean-Bottom Distributed Acoustic Sensing Array
Published: 2019-05-30
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
Sparse seismic instrumentation in the oceans limits our understanding of deep Earth dynamics and submarine earthquakes. Distributed acoustic sensing (DAS), an emerging technology that converts optical fiber to seismic sensors, allows us to leverage pre-existing submarine telecommunication cables for seismic monitoring. Here we report observations of microseism, local surface gravity waves, and a [...]
Well-being loss: a comprehensive metric for household disaster resilience
Published: 2019-05-16
Subjects: Civil and Environmental Engineering, Earth Sciences, Engineering, Environmental Studies, Physical Sciences and Mathematics, Risk Analysis, Social and Behavioral Sciences
Natural disaster risk assessments typically consider environmental hazard and physical damage, neglecting to quantify how asset losses affect households’ well-being. However, for a given asset loss, a wealthy household might easily recover, while a poor household might suffer from major, long-lasting impacts. Ignoring such differential impacts can lead to inequitable interventions and exacerbate [...]
Shallow slow slip events along the Nankai Trough detected by the GNSS-A
Published: 2019-05-16
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics, Tectonics and Structure
Various slow earthquakes (SEQs), including tremors, very-low-frequency events, and slow slip events (SSEs), occur along megathrust zones. In a shallow plate boundary region, although many SEQs have been observed along pan-Pacific subduction zones, SSEs with a duration on the order of a year or with a large slip have not yet been detected due to difficulty in offshore observation. We try to [...]
Extension at the coast of the Makran subduction zone (Iran)
Published: 2019-05-14
Subjects: Earth Sciences, Physical Sciences and Mathematics, Tectonics and Structure
In the Makran subduction zone, earthquake focal mechanisms and geodetic data indicate that the deforming prism currently experiences N-S compression. However, paleostress inversions performed on normal faults observed along the coast reveal local stress components consistent with N-S extension. Previously proposed mechanisms such as gravitational collapse are not in line with N-S compression and [...]
Holocene sedimentary record and coastal evolution in the Makran subduction zone (Iran)
Published: 2019-05-14
Subjects: Earth Sciences, Geomorphology, Other Earth Sciences, Physical Sciences and Mathematics, Sedimentology
The Makran coast displays evidence of surface uplift since at least the Late Pleistocene, but it remains uncertain whether this displacement is accommodated by creep on the subduction interface, or in a series of large earthquakes. Here, we address this problem by looking at the short term (Holocene) history of continental vertical displacements recorded in the geomorphology and sedimentary [...]
A Novel Hybrid Finite Element-Spectral Boundary Integral Scheme for Modeling Earthquake Cycles: Application to Rate and State Faults with Low-Velocity Zones
Published: 2019-05-13
Subjects: Applied Mechanics, Earth Sciences, Engineering, Geophysics and Seismology, Mechanical Engineering, Physical Sciences and Mathematics
We present a novel hybrid finite element (FE) - spectral boundary integral (SBI) scheme that enables efficient simulation of earthquake cycles. This combined FE-SBI approach captures the benefits of finite elements in modelling problems with nonlinearities, as well as the computational superiority of SBI. The domain truncation enabled by this scheme allows us to utilize high-resolution finite [...]
Complex earthquake behavior on simple faults
Published: 2019-05-10
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
While power-law distributions in seismic moment and interevent times are ubiquitous in regional catalogs, the statistics of individual faults remains controversial. Continuum fault models typically produce characteristic earthquakes or a narrow range of sizes, leading to the view that the regional statistics originates from interaction of multiple faults. I present theoretical arguments and [...]
Fracturing and crystal plastic behaviour of garnet under seismic stress in the dry lower continental crust (Musgrave Ranges, Central Australia)
Published: 2019-05-08
Subjects: Earth Sciences, Physical Sciences and Mathematics
Garnet is a high strength mineral compared to other common minerals, such as quartz and feldspar, in the felsic crust. In felsic mylonites, garnet typically occurs as porphyroclasts that mostly evade intracrystalline deformation, except under relatively high temperature conditions. The microstructure of garnet in felsic lower-crustal rocks of the Musgrave Ranges (Central Australia) records both [...]
Dating and morpho-stratigraphy of uplifted marine terraces in the Makran subduction zone (Iran)
Published: 2019-05-03
Subjects: Earth Sciences, Geomorphology, Physical Sciences and Mathematics, Tectonics and Structure
The western part of the Makran subduction zone (Iran) is currently experiencing active surface uplift, as attested by the presence of emerged marine terraces along the coast. To better understand the uplift recorded by these terraces, we investigated seven localities along the Iranian Makran and we performed radiocarbon, 230Th/U and optically stimulated luminescence (OSL) dating of the layers of [...]