N. Cubas

N. Cubas
Sorbonne Université | UPMC · Institut des Sciences de la Terre Paris (iSTeP)

PhD

About

35
Publications
5,464
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474
Citations
Introduction
N. Cubas currently works at the Institut des Sciences de la Terre Paris (iSTeP), Sorbonne University (Pierre and Marie Curie University). N. does research in seismo-tectonics.
Additional affiliations
September 2014 - present
Sorbonne Université
Position
  • Professor (Assistant)
September 2013 - present
Institut de Physique du Globe de Paris
Position
  • PostDoc Position
September 2009 - June 2013
California Institute of Technology
Position
  • PostDoc Position

Publications

Publications (35)
Article
Full-text available
Strike-slip faults are generally described as continuous structures, while they are actually formed of successive segments separated by geometrical complexities. Although this along-strike segmentation is known to affect the overall dynamics of earthquakes, the physical processes governing the scale of this segmentation remain unclear. Here, we use...
Article
Full-text available
Tectonics and climate-driven surface processes govern the evolution of Earth’s surface topography. Topographic change in turn influences lithospheric deformation, but the elementary scale at which this feedback can be effective is unclear. Here we show that it operates in a single weather-driven erosion event. In 2009, typhoon Morakot delivered ~ 3...
Article
Full-text available
The long‐term erosion of steep landscapes is punctuated by dramatic erosional events that can remove significant amount of sediments within a timescale shorter than a seismic cycle. However, the role of such large erosional events on seismicity is poorly understood. We use QDYN, a quasi‐dynamic numerical model of earthquake cycles to investigate th...
Article
Full-text available
What controls the location and segmentation of mega-earthquakes in subduction zones is a long-standing problem in Earth sciences. Prediction of earthquake rupture extent mostly relies on interplate coupling models based on Global Navigation Satellite Systems providing patterns of slip deficit between tectonic plates. We here investigate if and how...
Article
Full-text available
The local topographic slope of the accretionary prism is often used together with the critical taper theory to determine the effective friction on subduction megath-rust. In this context, extremely small topographic slopes associated with extremely low effective basal friction (µ ≤ 0.05) can be interpreted either as seismically locked portions of m...
Article
We used teleseismic receiver function analysis to image the crustal structure beneath 24 broadband seismic stations densely deployed along two profiles traversing different structural units across the western Afar margin. Our high-resolution receiver function results image pronounced spatial variations in the crustal structure along the profiles an...
Article
Full-text available
Fragments of subducted slow-spreading oceanic lithosphere are exposed continuously in the Liguro-Piemont domain of the Western Alps. By combining new and literature petrological data, interpolated maps of maximum temperatures, maximum Si contents of phengite as a proxy for peak pressure and thermodynamic modelling, we provide a detailed framework o...
Preprint
Full-text available
What controls the location and segmentation of mega-earthquakes in subduction zones is a long-standing problem in earth sciences. Prediction of earthquake ruptures mostly relies on interplate coupling models based on Global Navigation Satellite Systems providing patterns of slip deficit between tectonic plates. We here investigate if and how the se...
Preprint
Full-text available
The local topographic slope of the accretionary prism is often used together with the critical taper theory to determine the effective friction on subduction megathrust. In this context, extremely small topographic slopes associated with extremely low effective basal friction (μ ≤ 0.05) can be interpreted either as seismically locked portions of me...
Article
Full-text available
Western Makran is one of the few subduction zones left with a largely unconstrained seismogenic potential. According to the sparse GPS stations, the subduction is accumulating some strain to be released during future earthquakes. To enhance the seismic hazard assessment, we here propose to study the finite deformation of the western Makran accretio...
Preprint
Full-text available
The long-term erosion of steep landscapes is punctuated by dramatic erosional events that can remove significant amount of sediments within a time-scale shorter than a seismic cycle. However, the role of such large erosional events on seismicity is poorly understood. We use QDYN, a quasi-dynamic numerical model of earthquake cycles to investigate t...
Article
The Amazon Fan provides a natural laboratory to study the generation of overpressure, due to rapid late Cenozoic burial that has resulted in gravitational collapse above shale detachments. Here we examine collapse systems for the first time using the techniques of petroleum systems analysis. We propose an integrated methodology based on numerical m...
Article
Full-text available
At subduction zones, transient aseismic slip occurs either as afterslip following a large earthquake or as episodic slow slip events during the interseismic period. Afterslip and slow slip events are usually considered as distinct processes occurring on separate fault areas governed by different frictional properties. Continuous GPS (Global Positio...
Article
Full-text available
Although patterns of interseismic strain accumulation above subduction zones are now routinely characterised using geodetic measurements, their physical origin, persistency through time, and relationships to seismic hazard and long-term deformation are still debated. Here, we use GPS and morphological observations from southern Mexico to explore po...
Article
Full-text available
The very large slip up to the subduction front of the 2011 Tohoku-Oki (Japan) earthquake has challenged our classic view of the megathrust undergoing only aseismic slip at shallow depth. Furthermore, the enhancement of tsunamis during frontal rupturing has increased concern about tsunami risks. Recent seismic reflection images from the Sumatra subd...
Chapter
Although patterns of interseismic strain accumulation above subduction zones are now routinely characterised using geodetic measurements, their physical origin, persistency through time, and relationships to seismic hazard and long-term deformation are still debated. Here, we use GPS and morphological observations from southern Mexico to explore po...
Conference Paper
The 2004 Sumatra and 2011 Japan earthquakes took the community by surprise because they ruptured frontal sections of megathrust thought to slip aseismically. Studying the deformation of accretionary prisms can help in characterizing the specific structures associated to frontal propagation and determining the mechanical properties leading to this b...
Article
Full-text available
The Sumatra subduction zone is one of the most seismically active subduction zones. Although there have been three Mw≥8.4 earthquakes in the region, including the disastrous 2004 Mw=9.2 Sumatra-Andaman earthquake, a 500 km long patch around Mentawai Islands is still locked and could produce a large megathrust earthquake. If the rupture propagates t...
Article
Full-text available
We use numerical modeling to investigate fault properties that explain key features of the 2011 Mw 9.0 Tohoku-Oki earthquake as well as the overall regional behavior of the NE Japan Megathrust. In particular, we study the possibility that slip near the trench resulted from thermal pressurization on a shallow patch of the megathrust, and investigate...
Conference Paper
A better understanding of the relation between the structural geology and the morphology of forearc wedges with frictional properties could provide insights on earthquake mechanics. Therefore, we study, with simple mechanical analysis allowing for inverse studies, the three subduction zones that produced the major earthquakes of the 21st century :...
Article
Full-text available
We examine the fundamental mechanism of frontal accretion in a sand wedge from the occurrence of a forward thrust ramp evolving into a fault-bend fold to the jump of deformation to a new frontal ramp ahead. We use inverse problem theory to extract quantitative information on friction parameters from the systematic comparison of experimental observa...
Article
Full-text available
We analyze the mechanical properties needed to account for the large shallow slip during the 2011 Tohoku-Oki earthquake and the activation of landward normal faulting within the forearc. We show that the morphology and internal structure of the forearc follows closely the prediction of the critical Coulomb wedge in horizontal compression, implying...
Conference Paper
Observations following the Tohoku-Oki earthquake suggested the concurrent activation of normal faulting at the rear and of reverse faulting at the toe of the wedge (Ito et al., 2011). The objective of this talk is to justify these observations with a mechanical analysis. The protototype considered consists of the triangular wedge with the decollem...
Conference Paper
A number of unusual features were observed during the Tohoku-Oki earthquake: the maximum slip occurred along the shallower portion of the megathrust where aseismic creep is thought to be the dominant mode of slip; most of the ground shaking came from the deeper portion of the rupture which released a small fraction of the moment; the shallow portio...
Conference Paper
In this study, focused on the 2010 Mw 8.8 Maule earthquake and the 2011 Tohoku-Oki Mw 9.0, we estimate megathrust frictional properties from mechanical analyses of the forearc structure and morphology and then use dynamic simulations to analyze how the frictional properties relate to the mode of fault slip (seismic or aseismic) during the earthquak...
Article
The 2011 Mw 9.1 Tohoku-Oki earthquake had unusually large slip (over 50 m) concentrated in a relatively small region, with local stress drop inferred to be 5–10 times larger than that found for typical megathrust earthquakes. Here we conduct a detailed analysis of foreshocks and aftershocks (Mw 5.5–7.5) sampling this megathrust zone for possible cl...
Conference Paper
Determining the spatio-temporal variations of frictional properties is a key issue in order to advance our understanding of earthquake dynamics. This study aims to characterize these variations for the 2010 Maule Mw 8.8 earthquake area based on the analysis of the forearc morphology and dynamic earthquake simulation. Two different mechanical approa...
Conference Paper
Some recent studies have pointed out to a possible correlation between forearc morphology and seismic asperities on megathrust. One possible cause for this correlation would be that the effective friction along megathrust depends on the mode of slip: it would be lower in seismic asperities area due to dynamic weakening during seismic rupture, and l...
Article
Full-text available
The quasi-static deformation of dry sand is widely used as an analogue to the brittle deformation of the upper crust. The quantitative comparison of analogue to natural tectonics, or to mechanical predictions, requires identifying sources of biases and estimating the intrinsic variability of the experimental results. We develop experimental and sta...
Conference Paper
Some recent studies have pointed out to a possible correlation between forearc topography and seismic asperities on megathrust. This correlation suggests that the morpho-tectonic zones could reveal spatial variations in frictional properties of megathrusts of relevance to their seismic behavior : a seaward accretionary prism thought to overly a sha...
Article
This research aims to develop and validate simple procedures, accounting for mechanical equilibrium and maximum rock strength, to select the dominant mode of folding and to predict sequences of thrusting in fold-and-thrust belts and accretionary wedges. An inverse analysis of sandbox experiments is proposed to validate the procedures, leading to an...
Article
Full-text available
The main objective is to determine the three stages of the life of a thrust in an accretionary wedge which are the onset of thrusting along its ramp, the development with the construction of the relief, and the arrest because of the onset of another thrusting event. A simple kinematics is proposed for the geometry of the developing thrust fold base...