The Deep Roots of Geology: Tectonic History of Australia and its Margins expressed by Mantle Anisotropy

2021 ◽  
Author(s):  
Caroline Eakin
Keyword(s):  
Seismic Anisotropy ◽  
Dynamic Processes ◽  
Small Scale ◽  
Continental Margins ◽  
Continental Lithosphere ◽  
Deep Roots ◽  
Tectonic History ◽  
History Of ◽  
Mantle Anisotropy ◽  
Continental Interior

Abstract The Australian continental crust preserves a rich geological history, but it is unclear to what extent this history is expressed deeper within the mantle. Scattering of surface waves predominantly between 100-200 km depth by lateral gradients in seismic anisotropy, termed Quasi-Love waves, offer potential new insights. Across Australasia over 275 new scatterers are detected, and are found to be preferentially located near (1) the passive continental margins, and (2) the boundaries of major geological provinces within Australia. Such lateral anisotropic gradients imply pervasive fossilized lithospheric anisotropy within the continental interior, on a scale that mirrors the crustal geology at the surface, and a strong lithosphere that preserves this signal over billions of years. Along the continental margins, lateral anisotropic gradients may indicate either the edge of the thick continental lithosphere, or small-scale dynamic processes in the asthenosphere, such as edge-drive convection, tied to the transition from oceanic to continental lithosphere.

The Deep Roots of Geology: Tectonic History of Australia Preserved as Mantle Anisotropy

2021 ◽  
Author(s):  
Caroline Eakin
Keyword(s):  
Seismic Anisotropy ◽  
Small Scale ◽  
Continental Margins ◽  
Geological History ◽  
Deep Roots ◽  
Geographical Patterns ◽  
Tectonic History ◽  
History Of ◽  
Mantle Anisotropy ◽  
Continental Interior

Abstract Australia is an old stable continent with a rich geological history. Limitations in sub-surface imaging below the Moho, however, mean that is unclear to what extent, and to what depth, this rich geological history is expressed in the mantle. Scattering of surface waves at ~150km depth by lateral gradients or boundaries in seismic anisotropy, termed Quasi-Love waves, offer potential new insights. The first such analysis for Australia and Zealandia shown here detects over 300 new scatterers that display striking geographical patterns. Around two-thirds of the scatterers are coincident with either the continental margins, or major crustal boundaries within Australia, suggesting deep mantle roots to such features. Within the continental interior such lateral anisotropic gradients imply pervasive fossilized lithospheric anisotropy, on a scale that mirrors the crustal geology at the surface, and a strong lithosphere that preserves this signal over billions of years. Along the continental margins, lateral anisotropic gradients may indicate either the edge of the thick continental lithosphere, or small-scale dynamic processes in the asthenosphere, such as edge-drive convection, tied to the transition from oceanic to continental crust/lithosphere.

Tectonic History of Australia Preserved by Mantle Anisotropic Boundaries

2021 ◽  
Author(s):  
Caroline Eakin
Keyword(s):  
Seismic Anisotropy ◽  
Small Scale ◽  
Continental Margins ◽  
Surface Imaging ◽  
Geological History ◽  
Continental Lithosphere ◽  
Geographical Patterns ◽  
Tectonic History ◽  
History Of ◽  
Continental Interior

<p>Australia is an old stable continent with a rich geological history. Limitations in sub-surface imaging below the Moho, however, mean that is unclear to what extent, and to what depth, this rich geological history is expressed in the mantle. Scattering of surface waves at ~150km depth by lateral gradients or boundaries in seismic anisotropy, termed Quasi-Love waves, offer potential new insights. The first such analysis for Australia and Zealandia is performed with over 300 new scatterers detected that display striking geographical patterns. Around two-thirds of the scatterers are coincident with either the continental margins, or major crustal boundaries within Australia, suggesting deep mantle roots to such features. Within the continental interior such lateral anisotropic gradients imply pervasive fossilized lithospheric anisotropy, on a scale that mirrors the crustal geology at the surface, and a strong lithosphere that preserves this signal over billions of years. Along the continental margins, lateral anisotropic gradients may indicate either the edge of the thick continental lithosphere, or small-scale dynamic processes in the asthenosphere, such as edge-drive convection, tied to the transition from oceanic to continental crust/lithosphere.</p>

scholarly journals Quasi-Love wave scattering reveals tectonic history of Australia and its margins reflected by mantle anisotropy

2021 ◽  
Vol 2 (1) ◽  
Author(s):  
Caroline M. Eakin
Keyword(s):  
Wave Scattering ◽  
Seismic Anisotropy ◽  
Love Waves ◽  
Small Scale ◽  
Continental Margins ◽  
Tectonic History ◽  
Seismic Surface Waves ◽  
History Of ◽  
Mantle Anisotropy ◽  
Continental Interior

AbstractThe Australian continental crust preserves a rich geological history, but it is unclear to what extent this history is expressed deeper within the mantle. Here an investigation of Quasi-Love waves is performed to detect scattering of seismic surface waves at mantle depths (between 100–200 km) by lateral gradients in seismic anisotropy. Across Australasia 275 new observations of Quasi-Love waves are presented. The inferred scattering source and lateral anisotropic gradients are preferentially located either near the passive continental margins, or near the boundaries of major geological provinces within Australia. Pervasive fossilized lithospheric anisotropy within the continental interior is implied, on a scale that mirrors the crustal geology at the surface, and a strong lithosphere that has preserved this signal over billions of years. Along the continental margins, lateral anisotropic gradients may indicate either the edge of the thick continental lithosphere, or small-scale dynamic processes in the asthenosphere below.

scholarly journals SEISMIC ANISOTROPY PARAMETERS OF TRANSVERSE WAVES BY GAJIGABUL EARTHQUAKE WHICH OCCURRED 10 FEBRUARY 2014 ML = 5,8

2016 ◽  
Author(s):  
С.Э. Казымова ◽  
И.Э. Казымов
Keyword(s):  
Spatial Analysis ◽  
Seismic Anisotropy ◽  
Three Dimensional ◽  
Digital Signal ◽  
Dynamic Processes ◽  
Small Scale ◽  
Transverse Waves ◽  
Anisotropy Parameters ◽  
Birefringence Effect ◽  
Dimensional Graph

В статье представлен анализ параметров расщепленных поперечных волн от глубокого (h = 56 км) землетрясения, произошедшего в пределах Нижнекуринской впадины 10 февраля 2014 г. с Ml = 5,8. Пространственный анализ волновых форм ведется с использованием 3‑хкомпонентных цифровых записей сигнала. Для выделенных участков 3‑хкомпонентной записи в программе «DIMAS» строится трехмерный график траектории движения частиц и проекции траектории движения на плоскости NE, NZ, EZ. Установлен эффект двулучепреломления, когда поперечная волна расщепляется на две (S1 и S2), каждая из которых имеет свою поляризацию и скорость для широкополосных трехкомпонентных записей (BHE, BHN, BHZ) 4‑х сейсмических станций («QUB», «GAN», «LKR», «GOB»). Это дает возможность изучения мелкомасштабных деформаций для лучшего понимания динамических процессов и свойств среды с глубиной In the article presents an analysis of the parameters of split shear waves from deep (h = 56 km) the earthquake occurred within the Lower Kura depression February 10, 2014 with Ml = 5,8. Spatial analysis of waveforms is conducted with use 3‑component digital signal records. For selected areas of 3‑component records in the program «DIMAS» construct a three-dimensional graph of the trajectory of particle motion and trajectory of the projection on the plane NE, NZ, EZ. Established the birefringence effect, ie, shear wave splits into two (S1 and S2), each of which has its polarization and the rate for broadband three component records (BHE, BHN, BHZ) of 4 seismic stations («QUB», «GAN», «LKR», «GOB»). This makes it possible to study small-scale deformations for a better understanding of dynamic processes and properties with depth media

Tectonic history of the Dent Blanche

2017 ◽  
Vol 9 (2.1) ◽  
pp. 1-73 ◽  
Author(s):  
Paola Manzotti ◽  
Michel Ballèvrei
Keyword(s):  
Tectonic History ◽  
History Of

Craft Beer's Unlikely Alchemist

2019 ◽  
Vol 19 (4) ◽  
pp. 78-90
Author(s):  
Theresa McCulla
Keyword(s):  
San Francisco ◽  
Assembly Line ◽  
The United States ◽  
Risk Tolerance ◽  
Small Scale ◽  
Intellectual Curiosity ◽  
Brewing Industry ◽  
Washing Machine ◽  
Craft Beer ◽  
History Of

In 1965, Frederick (Fritz) Maytag III began a decades-long revitalization of Anchor Brewing Company in San Francisco, California. This was an unexpected venture from an unlikely brewer; for generations, Maytag's family had run the Maytag Washing Machine Company in Iowa and he had no training in brewing. Yet Maytag's career at Anchor initiated a phenomenal wave of growth in the American brewing industry that came to be known as the microbrewing—now “craft beer”—revolution. To understand Maytag's path, this article draws on original oral histories and artifacts that Maytag donated to the Smithsonian Institution's National Museum of American History via the American Brewing History Initiative, a project to document the history of brewing in the United States. The objects and reflections that Maytag shared with the museum revealed a surprising link between the birth of microbrewing and the strategies and culture of mass manufacturing. Even if the hallmarks of microbrewing—a small-scale, artisan approach to making beer—began as a backlash against the mass-produced system of large breweries, they relied on Maytag's early, intimate connections to the assembly-line world of the Maytag Company and the alchemy of intellectual curiosity, socioeconomic privilege, and risk tolerance with which his history equipped him.

Study of Diabetic Mellitus and Knowledge of Lotion Foot Care on the Community

2018 ◽  
Vol 9 (3) ◽  
Author(s):  
Hariyadi DM ◽  
Athiyah U ◽  
Hendradi E ◽  
Rosita N ◽  
Erawati T ◽  
...  
Keyword(s):  
Blood Glucose ◽  
T Test ◽  
Small Scale ◽  
Scale Production ◽  
Foot Care ◽  
Diabetic Mellitus ◽  
Glucose Levels ◽  
Blood Glucose Levels ◽  
Before And After ◽  
History Of

The prevention of Diabetic Mellitus (DM) and its complications is the main aim of this study, in addition to the training of lotion foot care application and the development of small scale industry. The research team delivered knowledge in the form of training on Diabetic Mellitus, healthy food, treatment and prevention of complications, and small-scale production of cosmetic products. The aim of this study was to determine the correlation between training on diabetic and lotion foot care application as preventive measures against diabetic complications on the patient's blood glucose levels in the community of residents in Banyuurip Jaya, Surabaya. It was expected from this training that the knowledge of the residents increases and people living with diabetic undergo lifestyle changes and therefore blood sugar levels can be controlled. The parameters measured in this research were blood glucose levels, the anti diabetic drug types consumed, and compliance on diabetics. This study used the data taken from 60 patients with DM over a period of one month. Questionnaires and log books was used to retrieve data and changes in blood glucose levels in diabetic patients. The results showed the demographic data of patients with type 2 diabetic of 85% female and 15% male, with the range of patients aged of 61-70 years of 46.67% and had history of diabetic (90%). The history of drugs consumed by respondents was anti diabetic drugs such as metformin (40%), glimepiride (33.37%) and insulin (6.67%). In addition, the increased knowledge of DM patients after being given the training compared to before training was shown in several questions in the questionnaire. A statistical analysis using t-test analyzed a correlation between training provided in order to enhance understanding of the patient, as well as correlation with blood glucose levels. A paired T-test showed that there was a relationship between the knowledge of trainees before and after training (p less than 0.05). An interesting result was that there was no relationship between blood glucose levels before and after training provided (p> 0.05).

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