Anomalous earthquakes on volcano ring-fault structures

Rolling bearings are vital components in rotary machinery, and their operating condition affects the entire mechanical systems. As one of the most important denoising methods for nonlinear systems, local projection (LP) denoising method can be used to reduce noise effectively. Afterwards, high-order polynomials are utilized to estimate the centroid of the neighborhood to better preserve complete geometry of attractors; thus, high-order local projection (HLP) can improve noise reduction performance. This paper proposed an adaptive high-order local projection (AHLP) denoising method in the field of fault diagnosis of rolling bearings to deal with different kinds of vibration signals of faulty rolling bearings. Optimal orders can be selected corresponding to vibration signals of outer ring fault (ORF) and inner ring fault (IRF) rolling bearings, because they have different nonlinear geometric structures. The vibration signal model of faulty rolling bearing is adopted in numerical simulations, and the characteristic frequencies of simulated signals can be well extracted by the proposed method. Furthermore, two kinds of experimental data have been processed in application researches, and fault frequencies of ORF and IRF rolling bearings can be both clearly extracted by the proposed method. The theoretical derivation, numerical simulations, and application research can indicate that the proposed novel approach is promising in the field of fault diagnosis of rolling bearing.

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Analogue modelling of fault structures: 2. Inversion

Marine and Petroleum Geology ◽

10.1016/0264-8172(92)90094-u ◽

1992 ◽

Vol 9 (2) ◽

pp. 222-223

Author(s):

Albert W. Bally

Keyword(s):

Analogue Modelling ◽

Fault Structures

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Novel Bathymetry of Lake Afdera Reveals Fault Structures and Volcano-Tectonic Features of an Incipient Transform Zone (Afar, Ethiopia)

Frontiers in Earth Science ◽

10.3389/feart.2021.706643 ◽

2021 ◽

Vol 9 ◽

Author(s):

Jean-Charles Schaegis ◽

Valentin Rime ◽

Tesfaye Kidane ◽

Jon Mosar ◽

Ermias Filfilu Gebru ◽

...

Keyword(s):

Afar Depression ◽

Nodal Basin ◽

Bathymetric Data ◽

The North ◽

Transfer Zones ◽

Fault Structures ◽

Bathymetric Map ◽

Endorheic Lake ◽

Tectonic Features ◽

Transfer Zone

Lake Afdera is a hypersaline endorheic lake situated at 112 m below sea-level in the Danakil Depression. The Danakil Depression is located in the northern part of the Ethiopian Afar and features an advanced stage of continental rifting. The remoteness and inhospitable environment explain the limited scientific research and knowledge about this lake. Bathymetric data were acquired during 2 weeks expeditions in January/February 2016 and 2017 using an easily deployable echosounder system mounted on an inflatable motorized boat. This study presents the first complete bathymetric map of the lake Afdera. Bathymetric results show that the lake has an average depth of 20.9 m and a total volume of 2.4 km3. The maximum measured depth is 80 m, making Lake Afdera the deepest known lake in Afar and the lowest elevation of the Danakil Depression. Comparison with historical reports shows that the lake level did not fluctuate significantly during the last 50 years. Two distinct tectonic basins to the north and the south are recognized. Faults of different orientations control the morphology of the northern basin. In contrast, the southern basin is affected by volcano-tectonic processes, unveiling a large submerged caldera. Comparison between the orientation of faults throughout the lake with the regional fault pattern indicates that the lake is part of two transfer zones: the major Alayta–Afdera Transfer Zone and the smaller Erta Ale–Tat’Ali Transfer Zone. The interaction between these Transfer Zones and the rift axis forms the equivalent of a developing nodal basin which explains the lake’s position as the deepest point of the depression. This study provides evidence for the development of an incipient transform fault on the floor of the Afar depression.

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Research on Automatic Construction Method of Three-Dimensional Complex Fault Model

Minerals ◽

10.3390/min11080893 ◽

2021 ◽

Vol 11 (8) ◽

pp. 893

Author(s):

Chi Zhang ◽

Xiaolin Hou ◽

Mao Pan ◽

Zhaoliang Li

Keyword(s):

Three Dimensional ◽

Geological Structure ◽

Fault Model ◽

Construction Method ◽

Model Construction ◽

Automatic Construction ◽

Complex Fault ◽

Resource Exploration ◽

Fault Structures ◽

Manual Interaction

Three-dimensional complex fault modeling is an important research topic in three-dimensional geological structure modeling. The automatic construction of complex fault models has research significance and application value for basic geological theories, as well as engineering fields such as geological engineering, resource exploration, and digital mines. Complex fault structures, especially complex fault networks with multilevel branches, still require a large amount of manual participation in the characterization of fault transfer relationships. This paper proposes an automatic construction method for a three-dimensional complex fault model, including the generation and optimization of fault surfaces, automatic determination of the contact relationship between fault surfaces, and recording of the model. This method realizes the automatic construction of a three-dimensional complex fault model, reduces the manual interaction in model construction, improves the automation of fault model construction, and saves manual modeling time.

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