|
"Using radiometric dating, one can observe that Earth's oldestcontinents were created in geodynamic environments which weremarkedly different than current environments characterised by platetectonics. Therefore, plate tectonics as we know it today is not agood model for understanding the processes at play during theearliest episodes of Earths's history, those beyond 3 billion yearsago. There was another crust dynamic and crust formation thatoccurred under other processes," explains Tomas Næraa,who has been a PhD student at the Natural History Museum of Denmarkand the Geological Survey of Denmark and Greenland -- GEUS. Plate tectonics is a theory of continental drift and sea floorspreading. A wide range of phenomena from volcanism, earthquakesand undersea earthquakes (and pursuant tsunamis) to variations inclimate and species development on Earth can be explained by theplate tectonics model, globally recognized during the 1960's. TomasNæraa can now demonstrate that the half-century old model nolonger suffices. "Plate tectonics theory can be applied to about 3 billionyears of the Earth's history. However, the Earth is older, up to4.567 billion years old. We can now demonstrate that there has beena significant shift in the Earth's dynamics. Thus, the Earth, underthe first third of its history, developed under conditions otherthan what can be explained using the plate tectonics model,"explains Tomas Næraa. Tomas is currently employed as aproject researcher at GEUS. Central research topic for 30 years Since 2006, the 40-year-old Tomas Næraa has conducted studiesof rocks sourced in the 3.85 billion year-old bedrock of the Nuukregion in West Greenland. Using isotopes of the element hafnium(Hf), he has managed to shed light upon a research topic that haspuzzled geologists around the world for 30 years. Næraa'sinstructor, Professor Minik Rosing of the Natural History Museum ofDenmark considers Næraa's dissertation a seminal work: "We have come to understand the context of the Earth's andcontinent's origins in an entirely new way. Climate and nutrientcycles which nourish all terrestrial organisms are driven by platetectonics. So, if the Earth's crust formation was controlled andinitiated by other factors, we need to find out what controlledclimate and the environments in which life began and evolved 4billion years ago. This fundamental understanding can be of greatsignificance for the understanding of future climate change,"says Minik Rosing, who adds that: "An enormous job waitsahead, and Næraas' dissertation is an epochal step.". We are high quality suppliers, our products such as China Lp Gas Regulator , China Gas Cylinder Regulators for oversee buyer. To know more, please visits Brass Gas Valve.
Related Articles -
China Lp Gas Regulator, China Gas Cylinder Regulators,
|
