scholarly journals Using Earthquake Forensics to Study Subduction from Space

Eos ◽  
2021 ◽  
Vol 102 ◽  
Author(s):  
Simon Schneider ◽  
Jonathan Weiss
Keyword(s):  
Subduction Zone ◽  
Geophysical Data ◽  
Inversion Method ◽  
Surface Motion ◽  
Data Inversion ◽  
Geodetic Measurements ◽  
Maule Earthquake ◽  
2010 Maule Earthquake

Researchers combined satellite geodetic measurements of surface motion with a new geophysical data inversion method to probe the Chilean subduction zone in the wake of the 2010 Maule earthquake.

scholarly journals Fluid and Melt Pathways in the Central Chilean Subduction Zone Near the 2010 Maule Earthquake (35–36°S) as Inferred From Magnetotelluric Data

2019 ◽  
Vol 20 (4) ◽  
pp. 1818-1835 ◽  
Author(s):  
Darcy Cordell ◽  
Martyn J. Unsworth ◽  
Daniel Diaz ◽  
Valentina Reyes‐Wagner ◽  
Claire A. Currie ◽  
...  
Keyword(s):  
Subduction Zone ◽  
Magnetotelluric Data ◽  
Maule Earthquake ◽  
2010 Maule Earthquake

2010 Maule earthquake slip correlates with pre-seismic locking of Andean subduction zone

Nature ◽  
2010 ◽  
Vol 467 (7312) ◽  
pp. 198-202 ◽  
Author(s):  
Marcos Moreno ◽  
Matthias Rosenau ◽  
Onno Oncken
Keyword(s):  
Subduction Zone ◽  
Maule Earthquake ◽  
Andean Subduction ◽  
2010 Maule Earthquake

Evolution of seismic design codes of highway bridges in Chile

2021 ◽  
pp. 875529302098801
Author(s):  
José Wilches ◽  
Hernán Santa Maria ◽  
Roberto Leon ◽  
Rafael Riddell ◽  
Matías Hube ◽  
...  
Keyword(s):  
Seismic Design ◽  
Failure Modes ◽  
Highway Bridges ◽  
Design Codes ◽  
Seismic Codes ◽  
Analysis And Design ◽  
Residual Displacements ◽  
Shear Keys ◽  
Maule Earthquake ◽  
2010 Maule Earthquake

Chile, as a country with a long history of strong seismicity, has a record of both a constant upgrading of its seismic design codes and structural systems, particularly for bridges, as a result of major earthquakes. Recent earthquakes in Chile have produced extensive damage to highway bridges, such as deck collapses, large transverse residual displacements, yielding and failure of shear keys, and unseating of the main girders, demonstrating that bridges are highly vulnerable structures. Much of this damage can be attributed to construction problems and poor detailing guidelines in design codes. After the 2010 Maule earthquake, new structural design criteria were incorporated for the seismic design of bridges in Chile. The most significant change was that a site coefficient was included for the estimation of the seismic design forces in the shear keys, seismic bars, and diaphragms. This article first traces the historical development of earthquakes and construction systems in Chile to provide a context for the evolution of Chilean seismic codes. It then describes the seismic performance of highway bridges during the 2010 Maule earthquake, including the description of the main failure modes observed in bridges. Finally, this article provides a comparison of the Chilean bridge seismic code against the Japanese and United States codes, considering that these codes have a great influence on the seismic codes for Chilean bridges. The article demonstrates that bridge design and construction practices in Chile have evolved substantially in their requirements for the analysis and design of structural elements, such as in the definition of the seismic hazard to be considered, tending toward more conservative approaches in an effort to improve structural performance and reliability for Chilean bridges.

Specifics of the Caledonian Collision in the Ol’khon Region (Lake Baikal, Russia)

2021 ◽  
Vol 62 (4) ◽  
pp. 389-400
Author(s):  
V.A. Makrygina
Keyword(s):  
Subduction Zone ◽  
Oceanic Crust ◽  
Lake Baikal ◽  
Siberian Craton ◽  
Island Arc ◽  
Geophysical Data ◽  
Igneous Rocks ◽  
Fold Belt ◽  
Adjacent Part

Abstract —Analysis of geochemical, geochronological, and new geophysical data on metasedimentary and igneous rocks of the Ol’khon region has made it possible to substantiate: (1) the absence of products of the Caledonian suprasubduction magmatism from the adjacent part of the Siberian craton and (2) the presence of a product of this magmatism in the Anga–Talanchan island arc, namely, the Krestovsky massif with gabbro-diorite to granite phases. This suggests subduction of the Paleoasian oceanic crust under the island arc before the collision. The geophysical data showed a steep sinking of the Siberian craton margin. This sinking and the supposed contrary movement and rotation of the Siberian craton prevented the appearance of a subduction zone beneath the craton during the collision but caused the wide development of fault plates in the fold belt at the late collision stage. The residue of oceanic crust slab was pressed out along the fault planes near the surface and formed a row of gabbro-pyroxenite massifs of the Birkhin Complex in the fold belt, where syncollisional granitic melts (Sharanur Complex) formed at the same time. The interaction of two contrasting melts gave rise to the Tazheran and Budun alkaline syenite massifs and alkaline metasomatites of the Birkhin and Ulanganta gabbroid massifs.

scholarly journals Illuminating subduction zone rheological properties in the wake of a giant earthquake

2019 ◽  
Vol 5 (12) ◽  
pp. eaax6720 ◽  
Author(s):  
Jonathan R. Weiss ◽  
Qiang Qiu ◽  
Sylvain Barbot ◽  
Tim J. Wright ◽  
James H. Foster ◽  
...  
Keyword(s):  
Subduction Zone ◽  
Subduction Zones ◽  
Three Dimensional ◽  
Surface Strain ◽  
Postseismic Deformation ◽  
Crust And Upper Mantle ◽  
Plate Convergence ◽  
Maule Earthquake ◽  
History Of ◽  
Dependent Viscosity

Deformation associated with plate convergence at subduction zones is accommodated by a complex system involving fault slip and viscoelastic flow. These processes have proven difficult to disentangle. The 2010 Mw 8.8 Maule earthquake occurred close to the Chilean coast within a dense network of continuously recording Global Positioning System stations, which provide a comprehensive history of surface strain. We use these data to assemble a detailed picture of a structurally controlled megathrust fault frictional patchwork and the three-dimensional rheological and time-dependent viscosity structure of the lower crust and upper mantle, all of which control the relative importance of afterslip and viscoelastic relaxation during postseismic deformation. These results enhance our understanding of subduction dynamics including the interplay of localized and distributed deformation during the subduction zone earthquake cycle.

Microwave Biomedical Data Inversion Using the Finite-Difference Contrast Source Inversion Method

2009 ◽  
Vol 57 (5) ◽  
pp. 1528-1538 ◽  
Author(s):  
Colin Gilmore ◽  
Aria Abubakar ◽  
Wenyi Hu ◽  
Tarek M. Habashy ◽  
Peter M. van den Berg
Keyword(s):  
Finite Difference ◽  
Inversion Method ◽  
Biomedical Data ◽  
Source Inversion ◽  
Data Inversion ◽  
Contrast Source Inversion

scholarly journals GRID-SITES: Gridded Solar Iterative Temperature Emission Solver for Fast DEM Inversion

Solar Physics ◽  
2019 ◽  
Vol 294 (10) ◽  
Author(s):  
James Pickering ◽  
Huw Morgan
Keyword(s):  
Emission Measure ◽  
Inversion Method ◽  
Multiple Channels ◽  
Differential Emission Measure ◽  
The Core ◽  
Data Inversion ◽  
Core Method ◽  
Input Dataset ◽  
Order Of Magnitude ◽  
General Measurement

Abstract The increasing size of solar datasets demands highly efficient and robust analysis methods. This paper presents an approach that can increase the computational efficiency of differential emission measure (DEM) inversions by an order of magnitude or higher, with the efficiency factor increasing with the size of the input dataset. The method, named the Gridded Solar Iterative Temperature Emission Solver (Grid-SITES) is based on grouping pixels according to the similarity of their intensities in multiple channels, and solving for one DEM per group. This is shown to be a valid approach, given a sufficiently high number of grid bins for each channel. The increase in uncertainty arising from the quantisation of the input data is small compared to the general measurement and calibration uncertainties. In this paper, we use the Solar Iterative Temperature Emission Solver (SITES) as the core method for the DEM inversion, although Grid-SITES provides a general framework which may be used with any DEM inversion method, or indeed any large multi-dimensional data inversion problem. The method is particularly efficient for processing larger images, offering a factor of 30 increase in speed for a 10 megapixel image. For a time series of observations, the gridded results can be passed sequentially to each new image, with new populated bins added as required. This process leads to increasing efficiency with each new image, with potential for a ${\approx\,}100$≈100 increase in efficiency dependent on the size of the images.

Ü-Net: Deep-Learning Schemes for Ground Penetrating Radar Data Inversion

2020 ◽  
Vol 25 (2) ◽  
pp. 287-292
Author(s):  
Longhao Xie ◽  
Qing Zhao ◽  
Chunguang Ma ◽  
Binbin Liao ◽  
Jianjian Huo
Keyword(s):  
Neural Network ◽  
Dielectric Constant ◽  
Data Compression ◽  
Ground Penetrating Radar ◽  
Quantitative Imaging ◽  
Inversion Method ◽  
Output Unit ◽  
Data Inversion ◽  
Ground Penetrating ◽  
Constant Distribution

Electromagnetic (EM) inversion is a quantitative imaging technique that can describe the dielectric constant distribution of a target based on the EM signals scattered from it. In this paper, a novel deep neural network (DNN) based methodology for ground penetrating radar (GPR) data inversion, known as the Ü-net is introduced. The proposed Ü-net consists of three parts: a data compression unit, U-net, and an output unit. The novel inversion approach, based on supervised learning, uses a neural network to generate the dielectric constant distribution from GPR data. The GPR data can be compressed and reshaped the size using data compression unit. The U-net maps the object features to the dielectric constant distribution. The output unit meshes the dielectric constant distribution more finely. A novel feature of the proposed methodology is the application of instance normalization (IN) to the DNN EM inversion method and a comparison of its performance to batch normalization (BN). The validity of this technique is confirmed by numerical simulations. The Mean-Square Error of the test data sets is 0.087. These simulations prove that the instance normalization is suitable for GPR data inversion. The proposed approach is promising for achieving quality dielectric constant images in real-time.

Assessing disaster capitalism in post-disaster processes in Chile: neoliberal reforms and the role of the corporate class

2020 ◽  
Vol 29 (6) ◽  
pp. 831-847
Author(s):  
Vicente Sandoval ◽  
Claudia Gonzalez-Muzzio ◽  
Carlos Villalobos ◽  
Juan Pablo Sarmiento ◽  
Gabriela Hoberman
Keyword(s):  
Private Sector ◽  
Private Funding ◽  
Content Type ◽  
Neoliberal Reforms ◽  
Maule Earthquake ◽  
Disaster Capitalism ◽  
2010 Maule Earthquake ◽  
Cross Case Analysis ◽  
Post Disaster

PurposeThis paper examines disaster capitalism in Chile, that is, the relationships between disasters and neoliberalism. It looks at two post-disaster dimensions: disasters as windows of opportunity to introduce political reforms and disasters as occasions for the corporate class to capitalize on such disasters.Design/methodology/approachTwo indices, disaster capitalism (DC) and post-disaster private involvement (PDPI), are proposed for cross-case analysis. They are based on legal records, institutional reports and economic data. The DC assesses the introduction of reforms following disasters, while PDPI evaluates the share of public-private funding used for recovery. Both indices are applied here to two disasters in Chile: the 2010 Maule earthquake, and the 2008 Chaitén volcanic eruption.FindingsResults show that the highly neoliberal Chilean context leaves limited space for new neoliberal reforms. Although recovery is implemented predominantly through the private sector, the state still assumes greater responsibility for recovery costs. Results also detect poor levels of participation from the private sector in accounting their efforts and making them publicly available. Likewise, the research suggests that neoliberal reforms become more likely after disasters. However, the preexisting politico-economic context matters. Finally, there is clearly a need for data systematization in post-disaster recovery.Originality/valueIn the Chilean context, the indices proved beneficial as a strategy for data collection and a method for scrutinizing the implications of neoliberal policy implemented in the wake of disasters, as well as in evaluating the role of the corporate class during recovery.

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