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The current theory of continental drift provides a good model forunderstanding terrestrial processes through history. However, whileplate tectonics is able to successfully shed light on processes upto 3 billion years ago, the theory isn't sufficient in explainingthe dynamics of the earth and crust formation before that point andthrough to the earliest formation of planet, some 4.6 billion yearsago. This is the conclusion of Tomas Naaeraa of the Nordic Center forEarth Evolution at the Natural History Museum of Denmark, a part ofthe University of Copenhagen. His new doctoral dissertation hasjust been published by the esteemed international scientificjournal, Nature. "Using radiometric dating, one can observe that the 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 a good modelfor understanding the processes at play during the earliestepisodes of the Earths's history, those beyond 3 billion years ago. There was another crust dynamic and crust formation that occurredunder other processes," explains Tomas Naeraa, who has been a PhDstudent at the Natural History Museum of Denmark and the GeologicalSurvey 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. TomasNaeraa can now demonstrate that the half-century old model nolonger suffices. "Plate tectonics theory can be applied to about 3 billion years ofthe Earth's history. However, the Earth is older, up to 4.567billion years old. We can now demonstrate that there has been asignificant shift in the Earth's dynamics. Thus, the Earth, under the first third of its history, developedunder conditions other than what can be explained using the platetectonics model," explains Tomas Naeraa. Tomas is currentlyemployed as a project researcher at GEUS. Central research topic for 30 years Since 2006, the 40-year-old Tomas Naeraa has conducted studies ofrocks 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. Naeraa's instructor, Professor Minik Rosing of the Natural HistoryMuseum of Denmark considers Naeraa'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 and initiated byother factors, we need to find out what controlled climate and theenvironments in which life began and evolved 4 billion years ago. This fundamental understanding can be of great significance for theunderstanding of future climate change," says Minik Rosing, whoadds that: "An enormous job waits ahead, and Naeraas' dissertationis an epochal step." Tomas Naeraas' dissertation, "Hafnium isotope evidence for a transition of continental growth3.2 Gyr ago" was published in Nature May 31. I am an expert from custom-posterprinting.com, while we provides the quality product, such as China Bus Stop Shelter Advertising , China Vehicle Wrap Printing, Plastic Membership Card Printing,and more.
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