نتایج جستجو برای: mantle boundary as in all gravity

تعداد نتایج: 17669882  

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه پیام نور - دانشگاه پیام نور استان تهران - دانشکده حقوق 1389

abstract the third millennium has started, but the world is facing with serious challenges in achieving international security and peace. various human rights violations have lead the states to find means to protect human rights. also article 55 of the united nations charter introduces the respect to human rights and fundamental freedom as the most suitable ways to realize peace and security. ...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه امام رضا علیه السلام - دانشکده ادبیات و زبانهای خارجی 1392

cognitive studies of translation process have recently been awarded a great deal of attention. there exists a psychological angle to almost all translation activities. the present study, thus, deals with analysing the relationships between iranian prospective translators tolerance for ambiguity (ta) and their willingness to translate (wtt). the research was conducted as a mixed methods study, d...

2014
Yongliang Bai Simon E. Williams R. Dietmar Müller Zhan Liu Maral Hosseinpour

Crustal thickness is a critical parameter for understanding the processes of continental rifting and breakup and the evolution of petroleum systems within passive margins. However, direct measurements of crustal thickness are sparse and expensive, highlighting the need for methodologies using gravity anomaly data, jointly with other geophysical data, to estimate crustal thickness. We evaluated ...

2004
A. V. Vezolainen V. S. Solomatov A. T. Basilevsky J. W. Head

[1] Three-dimensional models of the uplift of Beta Regio caused by a mantle plume satisfy constraints on gravity, topography, rheology, and the uplift rate substantially better than two-dimensional models. In particular, the uplift time of Beta Regio is reduced to an acceptable 800 million years. Three-dimensional models give the plume formation depth around 3000 km, which approximately corresp...

2010
Bradford H. Hager Thomas H. Jordan STEVEN SAMUEL SHAPIRO

We examine, as a function of depth, the relationship between a tectonic regionalization and upper-mantle shear-wave heterogeneity represented by a recent seismic tomographic model. We perform Monte Carlo simulations that incorporate the spectral properties of both the regions and the seismic signal. Our results indicate that ridges can be readily distinguished from older oceans to a depth of ab...

2018
Joseph S Byrnes Leif Karlstrom

Eruptive phenomena at all scales, from hydrothermal geysers to flood basalts, can potentially be initiated or modulated by external mechanical perturbations. We present evidence for the triggering of magmatism on a global scale by the Chicxulub meteorite impact at the Cretaceous-Paleogene (K-Pg) boundary, recorded by transiently increased crustal production at mid-ocean ridges. Concentrated pos...

2003
L. V. Potts T. Leftwich H. R. Kim H. Han R. B. von Frese

Introduction: The internal structures of terrestrial planets are commonly constrained by seismic data and geochemical considerations. We suggest that these constraints may be augmented by gravity drilling that focuses on interpreting satellite altitude free-air gravity observations for boundary undulations of the internal density layers related to mass flow. This approach involves separating th...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه تحصیلات تکمیلی علوم پایه زنجان - دانشکده ریاضی 1393

in this thesis, a structured hierarchical methodology based on petri nets is used to introduce a task model for a soccer goalkeeper robot. in real or robot soccer, goalkeeper is an important element which has a key role and challenging features in the game. goalkeeper aims at defending goal from scoring goals by opponent team, actually to prevent the goal from the opponent player’s attacks. thi...

2004
Thorne Lay Edward J. Garnero Quentin Williams

Seismological detections of complex structures in the lowermost mantle boundary layer (the D′′ region) motivate a conceptual model of a compositionally stratified thermo-chemical boundary layer (TCBL) within which lateral temperature variations (sustained by large-scale mid-mantle flow) cause variations of partial melt fraction. Partial melt fractions of from 0 to 30% in the TCBL occur due to t...

2004
Thorne Lay Edward J. Garnero

The past two decades have witnessed tremendous progress in seismological, geodynamical, geomagnetic, and mineral physics efforts to quantify deep Earth processes. Our understanding of structures and processes in the lowermost mantle has advanced accordingly, and there is now widespread agreement that some form of major thermo-chemical boundary layer (TCBL) exists on the mantle side of the core-...

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید