scholarly journals Density contrast matters for drop fragmentation thresholds at low Ohnesorge number

2019 ◽  
Vol 4 (10) ◽  
Author(s):  
Florence Marcotte ◽  
Stéphane Zaleski
Keyword(s):  
Density Contrast ◽  
Ohnesorge Number ◽  
Fragmentation Thresholds

scholarly journals Dynamics of retracting surfactant-laden ligaments at intermediate Ohnesorge number

2020 ◽  
Vol 5 (8) ◽  
Author(s):  
Cristian R. Constante-Amores ◽  
Lyes Kahouadji ◽  
Assen Batchvarov ◽  
Seungwon Shin ◽  
Jalel Chergui ◽  
...  
Keyword(s):  
Ohnesorge Number

Lithosphere flexure estimation of an non-uniform flexural rigidity plate：A quantitative modeling approach

2021 ◽  
Author(s):  
Mingju Xu ◽  
Zhaocai Wu ◽  
Fei Ji ◽  
Aiguo Ruan ◽  
Chunfeng Li
Keyword(s):  
Differential Equation ◽  
Partial Differential Equation ◽  
Flexural Rigidity ◽  
Density Contrast ◽  
Surface Load ◽  
Model Errors ◽  
Mantle Material ◽  
Partial Differential ◽  
Estimation Errors ◽  
Tectonic Plates

<p>Lithosphere motion is one of the fundamental processes in Earth tectonics. To understand the processes involving the nature of tectonic evolution and dynamics, it is critical to figure out the lithosphere flexure of tectonic plates. Over long-term (> 10<sup>5</sup> yr) geological timescales, the lithosphere can be modelled as flexing like a thin, elastic plate, using the partial differential equation for flexure of an orthotropic plate. The partial differential equation is used indirectly to form theoretical admittance and coherence curves, which are then compared against the observed admittance and coherence to invert a non-uniform flexural rigidity (or effective elastic thickness, <em>T<sub>e</sub></em>) plate. The non-uniform flexural rigidity lithosphere flexure amplitude can be estimated after that.</p><p>In this presentation, we use the classic lithosphere model with applied surface load at ground and internal load at Moho, but assume that the compensation material is denser than the mantle material beneath Moho. The density contrast between compensation material and mantle material beneath Moho is set to be 200 kg/m<sup>3</sup> referring to the density contrast of the uppermost and bottom lithosphere mantle. In such a lithosphere model, errors of lithosphere flexure estimation are mainly contributed by the errors of<em> T<sub>e</sub> </em>and Moho recovering. Synthetic modelling is then performed to analyze the incoming influence deriving from<em> T<sub>e</sub></em> and Moho errors.</p><p>The synthetic modelling reflects 1) the lithosphere flexure estimation errors are not sensitive to the errors of <em>T<sub>e </sub></em>recovering, even an error of about 10 km of <em>T<sub>e </sub></em>only result in an error within 1km of lithosphere flexure, 2) the influence of Moho errors to lithosphere flexure errors will be magnified in regions where <em>T<sub>e</sub> </em>is low, as lithosphere flexure errors over 1km mainly occur in regions where <em>T<sub>e</sub></em> is lower than 8km.</p>

Contribution of satellite altimetry in modelling Moho density contrast in oceanic areas

2019 ◽  
Vol 13 (1) ◽  
pp. 33-40 ◽  
Author(s):  
M. Abrehdary ◽  
L. E. Sjöberg ◽  
D. Sampietro
Keyword(s):  
Satellite Altimetry ◽  
Density Contrast ◽  
Contrast Model ◽  
Bathymetric Data ◽  
Crustal Model ◽  
Marine Gravity ◽  
Study Results ◽  
Vening Meinesz ◽  
Satellite Altimetry Data

Abstract The determination of the oceanic Moho (or crust-mantle) density contrast derived from seismic acquisitions suffers from severe lack of data in large parts of the oceans, where have not yet been sufficiently covered by such data. In order to overcome this limitation, gravitational field models obtained by means of satellite altimetry missions can be proficiently exploited, as they provide global uniform information with a sufficient accuracy and resolution for such a task. In this article, we estimate a new Moho density contrast model named MDC2018, using the marine gravity field from satellite altimetry in combination with a seismic-based crustal model and Earth’s topographic/bathymetric data. The solution is based on the theory leading to Vening Meinesz-Moritz’s isostatic model. The study results in a high-accuracy Moho density contrast model with a resolution of 1° × 1° in oceanic areas. The numerical investigations show that the estimated density contrast ranges from 14.2 to 599.7 kg/m3 with a global average of 293 kg/m3. In order to evaluate the accuracy of the MDC2018 model, the result was compared with some published global models, revealing that our altimetric model is able to image rather reliable information in most of the oceanic areas. However, the differences between this model and the published results are most notable along the coastal and polar zones, which are most likely due to that the quality and coverage of the satellite altimetry data are worsened in these regions.

Decorrelative Mollifier Gravimetry

2021 ◽  
Author(s):  
Willi Freeden
Keyword(s):  
Inverse Problems ◽  
Density Contrast ◽  
Disturbing Potential ◽  
Book Series ◽  
Inverse Gravimetry ◽  
Constructive Approximation ◽  
Vening Meinesz ◽  
Inverse Gravimetry Problem

<p>The lecture highlights arguments that, coming from multiscale mathematics, have fostered the advancement of gravimetry, as well as those that, generated by gravimetric problems, have contributed to the enhancement in constructive approximation and numerics. Inverse problems in gravimetry are delt with multiscale mollifier decorrelation strategies. Two examples are studied in more detail: (i) Vening Meinesz multiscale surface mollifier regularization to determine locally the Earth's disturbing potential from deflections of vertical, (ii) Newton multiscale volume mollifier regularization of the inverse gravimetry problem to derive locally the density contrast distribution from functionals of the Newton integral and to detect fine particulars of geological relevance. All in all, the Vening Meinesz medal  lecture is meant as an  \lq \lq appetizer'' served to enjoy the tasty meal "Mathematical Geoscience Today'' to be shared by geoscientists and mathematicians in the field of gravimetry. It provides innovative concepts and locally relevant applications presented in a monograph to be published by Birkhäuser in the book series “Geosystems Mathematics” (2021).</p>

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