{"id":438628,"date":"2022-05-30T14:08:22","date_gmt":"2022-05-30T17:08:22","guid":{"rendered":"https:\/\/revistapesquisa.fapesp.br\/?p=438628"},"modified":"2022-05-30T14:08:22","modified_gmt":"2022-05-30T17:08:22","slug":"computer-simulations-attempt-to-explain-the-origin-of-the-serra-do-mar-and-mantiqueira-mountain-ranges","status":"publish","type":"post","link":"https:\/\/revistapesquisa.fapesp.br\/en\/computer-simulations-attempt-to-explain-the-origin-of-the-serra-do-mar-and-mantiqueira-mountain-ranges\/","title":{"rendered":"Computer simulations attempt to explain the origin of the Serra do Mar and Mantiqueira mountain ranges"},"content":{"rendered":"

Computational models reproduced the emergence of two major mountain ranges in southeastern Brazil. According to a study by researchers from the Institute of Astronomy, Geophysics, and Atmospheric Sciences (IAG) at the University of S\u00e3o Paulo (USP), the Serra do Mar and Mantiqueira mountains emerged as a result of local processes, a combination of the characteristics of Earth’s physical structure and erosion that has occurred over tens of millions of years. The Continental Rift of Southeast Brazil (CRSB), an elongated depression delimited by geological faults, was established around 60 million years ago, resulting in the formation of several sedimentary basins, including the Taubat\u00e9 and S\u00e3o Paulo basins. Their formation separated two large escarpments: the Serra do Mar near the coast, and the Mantiqueira mountains in the interior of the continent, which are more or less parallel. The process was described in detail in an article published in the scientific journal Tectonics<\/em> in January this year.<\/p>\n

The formation of the two mountain ranges was emulated using a computer program called Mandyoc, developed by geophysicists Victor Sacek from IAG and Rafael Monteiro da Silva, a PhD student advised by Sacek, who were also the authors of the article. Prior to the pair\u2019s work, geological studies attempting to explain the formation of the RCSB have never described any physical processes that validate their hypotheses. \u201cOur work used computer software to simulate the formation of Brazil\u2019s southeastern coastline since the separation of South America and Africa,\u201d explains Silva. Using this approach, the researchers found evidence that tectonic movements originating within the region would have been enough to create a fault\u2014a rupture in the earth’s crust\u2014and provoke the emergence of the RCSB. \u201cThe origins of this rift are local. The tectonic movements of the Andes, for example, which occurred thousands of kilometers away, are not required to explain it,\u201d says the geophysicist.<\/p>\n

The results of the study are based on numerical modeling and the observation of three geological characteristics of Brazil\u2019s southeast coastline: the degree of coupling between the crust (Earth\u2019s thin, solid, outermost layer) and the mantle (the thick, viscous layer located immediately below the crust); the magnitude and extent of coastal erosion; and the preexistence of zones of weakness in the continental crust. To perform hundreds of simulations\u2014each taking between three days and a week, depending on the number of simultaneous equations\u2014the group, which received funding from FAPESP, paid for processing power on the Google Cloud Platform. \u201cThere were several tens of thousands of hours of numerical simulation running on dozens of computer cores at the same time,\u201d explains Sacek.<\/p>\n

The starting point for calculating the interaction between these three factors on a geological time scale, to the order of tens of millions of years, was the separation of the African and South American continents, which began around 140\u2013130 million years ago. This simulated journey through time suggested the presence of a lower crust with relatively low viscosity, a characteristic that would have facilitated decoupling of the upper crust and contributed to the emergence of geological faults. \u201cTo illustrate the interaction between the top and bottom of the crust, we usually use the image of a peanutbutter sandwich. If the filling is less viscous, there is greater mobility and less attachment between the two \u2018slices of bread.’ Geologically speaking, this scenario increases the likelihood of faults and regions that are more susceptible to deformations,\u201d says Sacek.<\/p>\n

The USP geophysicist\u2019s group first tried to use programs developed abroad to simulate the formation of the RCSB, but they could not find any existing software with the features they needed. One of the requirements was that it had to have tools capable of solving the equations that govern the physical behavior of rocks in geological time. The only alternative was to develop their own program, Mandyoc, which is short for Mantle Dynamics Simulator Code. \u201cThe big challenge for the software was to be able to jointly simulate two processes: the earth’s internal dynamics, on a scale hundreds of kilometers deep, and the occurrence of erosion and sedimentation, phenomena that affect the crust,\u201d says Silva.<\/p>\n

\u201cThe program is a mathematically robust tool, which can be used to numerically test different hypotheses,\u201d says Claudio Riccomini, a geologist from USP\u2019s Institute of Geosciences (IG) who did not participate in Sacek and Silva’s research. Jamison Assun\u00e7\u00e3o, a PhD student at IAG, and Agustina Pesce, a geophysicist from the National University of San Juan in Argentina, also helped create Mandyoc.<\/p>\n

The article authors now intend to use the software to model the deformation of the rift in a more specific period of time: the last 36 million years. \u201cThis set of events is relevant to oil prospecting, for example, since it is likely to have reached the marine regions adjacent to the southeast coast of Brazil, in the Santos and Campos basins,\u201d explains Riccomini. Mandyoc is an open-source program and is available to download for free from the Github collaborative platform. Later this year, the IAG geophysicists plan to publish a scientific paper with a complete description of the program’s functionalities.<\/p>\n

Projects<\/strong>
\n1.<\/strong> Evolution of the Amazon River basin: The uplift of the Andes, climate, and other geodynamic processes (n\u00ba. 17\/24870-5<\/a>); Grant Mechanism<\/strong> Regular Research Grant; Principal Investigator<\/strong> Victor Sacek (USP); Investment<\/strong> R$142,098.05.
\n2.<\/strong> Evolution of the stress field in the lithosphere: A numerical approach (n\u00ba. 17\/10554-4<\/a>); Grant Mechanism<\/strong> Doctoral (PhD) Fellowship; Supervisor<\/strong> Victor Sacek (USP); Beneficiary<\/strong> Rafael Monteiro da Silva; Investment<\/strong> R$179,976.72.<\/p>\n

Scientific article<\/strong>
\nSILVA, R. M. & SACEK, V. Influence of surface processes on postrift faulting during divergent margins evolution<\/a>. Tectonics<\/strong>. Jan. 19, 2022.<\/p>\n","protected":false},"excerpt":{"rendered":"A study by geophysicists from UNESP suggests the mountain ranges were formed by local processes, not influenced by the Andes","protected":false},"author":690,"featured_media":438633,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"_exactmetrics_skip_tracking":false,"_exactmetrics_sitenote_active":false,"_exactmetrics_sitenote_note":"","_exactmetrics_sitenote_category":0,"footnotes":""},"categories":[159],"tags":[219,240],"coauthors":[3491],"class_list":["post-438628","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-science","tag-computation","tag-geology"],"acf":[],"_links":{"self":[{"href":"https:\/\/revistapesquisa.fapesp.br\/en\/wp-json\/wp\/v2\/posts\/438628","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/revistapesquisa.fapesp.br\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/revistapesquisa.fapesp.br\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/revistapesquisa.fapesp.br\/en\/wp-json\/wp\/v2\/users\/690"}],"replies":[{"embeddable":true,"href":"https:\/\/revistapesquisa.fapesp.br\/en\/wp-json\/wp\/v2\/comments?post=438628"}],"version-history":[{"count":1,"href":"https:\/\/revistapesquisa.fapesp.br\/en\/wp-json\/wp\/v2\/posts\/438628\/revisions"}],"predecessor-version":[{"id":438637,"href":"https:\/\/revistapesquisa.fapesp.br\/en\/wp-json\/wp\/v2\/posts\/438628\/revisions\/438637"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/revistapesquisa.fapesp.br\/en\/wp-json\/wp\/v2\/media\/438633"}],"wp:attachment":[{"href":"https:\/\/revistapesquisa.fapesp.br\/en\/wp-json\/wp\/v2\/media?parent=438628"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/revistapesquisa.fapesp.br\/en\/wp-json\/wp\/v2\/categories?post=438628"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/revistapesquisa.fapesp.br\/en\/wp-json\/wp\/v2\/tags?post=438628"},{"taxonomy":"author","embeddable":true,"href":"https:\/\/revistapesquisa.fapesp.br\/en\/wp-json\/wp\/v2\/coauthors?post=438628"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}