date: 2016-12-20T10:35:04Z pdf:PDFVersion: 1.6 pdf:docinfo:title: Aus eins mach zwei: Geodynamische Modelle beschreiben Südamerikas Trennung von Afrika xmp:CreatorTool: Adobe InDesign CS6 (Macintosh) dc:description: The South American continent as we know it formed during the break-up of West Gondwana between 150 and 110 million years ago, when the South Atlantic Rift system evolved into the South Atlantic ocean. Using state-of-the-art global tectonic reconstructions in conjunction with numerical and analytical modelling, we investigate the geodynamics of rift systems as they evolve into an ocean basin. We find that rifts initially stretch very slowly along the future splitting zone, but then move apart very quickly before the onset of rupture. In case of the split between South America and Africa, the divergence rate increased from initially 5 to 7 millimetres per year to over 40 millimetres per year within few million years. Intriguingly, abrupt rift acceleration did not only occur during the splitting of West Gondwana, but also during the separation of Australia and Antarctica, North America and Greenland, Africa and South America, in the North Atlantic or the South China Sea. We elucidate the underlying process by reproducing the rapid transition from slow to fast extension using analytical and numerical modelling with constant force boundary conditions. The mechanical models suggest that the two-phase velocity behaviour is caused by a rift-intrinsic strength?velocity feedback similar to a rope that snaps when pulled apart. This mechanism provides an explanation for several previously unexplained rapid absolute plate motion changes, offering new insights into the balance of plate driving forces through time. Keywords: access_permission:modify_annotations: true access_permission:can_print_degraded: true subject: The South American continent as we know it formed during the break-up of West Gondwana between 150 and 110 million years ago, when the South Atlantic Rift system evolved into the South Atlantic ocean. Using state-of-the-art global tectonic reconstructions in conjunction with numerical and analytical modelling, we investigate the geodynamics of rift systems as they evolve into an ocean basin. We find that rifts initially stretch very slowly along the future splitting zone, but then move apart very quickly before the onset of rupture. In case of the split between South America and Africa, the divergence rate increased from initially 5 to 7 millimetres per year to over 40 millimetres per year within few million years. Intriguingly, abrupt rift acceleration did not only occur during the splitting of West Gondwana, but also during the separation of Australia and Antarctica, North America and Greenland, Africa and South America, in the North Atlantic or the South China Sea. We elucidate the underlying process by reproducing the rapid transition from slow to fast extension using analytical and numerical modelling with constant force boundary conditions. The mechanical models suggest that the two-phase velocity behaviour is caused by a rift-intrinsic strength?velocity feedback similar to a rope that snaps when pulled apart. This mechanism provides an explanation for several previously unexplained rapid absolute plate motion changes, offering new insights into the balance of plate driving forces through time. dc:creator: S. description: The South American continent as we know it formed during the break-up of West Gondwana between 150 and 110 million years ago, when the South Atlantic Rift system evolved into the South Atlantic ocean. Using state-of-the-art global tectonic reconstructions in conjunction with numerical and analytical modelling, we investigate the geodynamics of rift systems as they evolve into an ocean basin. We find that rifts initially stretch very slowly along the future splitting zone, but then move apart very quickly before the onset of rupture. In case of the split between South America and Africa, the divergence rate increased from initially 5 to 7 millimetres per year to over 40 millimetres per year within few million years. Intriguingly, abrupt rift acceleration did not only occur during the splitting of West Gondwana, but also during the separation of Australia and Antarctica, North America and Greenland, Africa and South America, in the North Atlantic or the South China Sea. We elucidate the underlying process by reproducing the rapid transition from slow to fast extension using analytical and numerical modelling with constant force boundary conditions. The mechanical models suggest that the two-phase velocity behaviour is caused by a rift-intrinsic strength?velocity feedback similar to a rope that snaps when pulled apart. This mechanism provides an explanation for several previously unexplained rapid absolute plate motion changes, offering new insights into the balance of plate driving forces through time. dcterms:created: 2016-12-20T10:33:02Z Last-Modified: 2016-12-20T10:35:04Z dcterms:modified: 2016-12-20T10:35:04Z dc:format: application/pdf; version=1.6 title: Aus eins mach zwei: Geodynamische Modelle beschreiben Südamerikas Trennung von Afrika xmpMM:DocumentID: uuid:375e45d1-4a2c-4dea-b3e8-0f8d6624473f Last-Save-Date: 2016-12-20T10:35:04Z pdf:docinfo:creator_tool: Adobe InDesign CS6 (Macintosh) access_permission:fill_in_form: true pdf:docinfo:keywords: pdf:docinfo:modified: 2016-12-20T10:35:04Z meta:save-date: 2016-12-20T10:35:04Z pdf:encrypted: false dc:title: Aus eins mach zwei: Geodynamische Modelle beschreiben Südamerikas Trennung von Afrika modified: 2016-12-20T10:35:04Z cp:subject: The South American continent as we know it formed during the break-up of West Gondwana between 150 and 110 million years ago, when the South Atlantic Rift system evolved into the South Atlantic ocean. Using state-of-the-art global tectonic reconstructions in conjunction with numerical and analytical modelling, we investigate the geodynamics of rift systems as they evolve into an ocean basin. We find that rifts initially stretch very slowly along the future splitting zone, but then move apart very quickly before the onset of rupture. In case of the split between South America and Africa, the divergence rate increased from initially 5 to 7 millimetres per year to over 40 millimetres per year within few million years. Intriguingly, abrupt rift acceleration did not only occur during the splitting of West Gondwana, but also during the separation of Australia and Antarctica, North America and Greenland, Africa and South America, in the North Atlantic or the South China Sea. We elucidate the underlying process by reproducing the rapid transition from slow to fast extension using analytical and numerical modelling with constant force boundary conditions. The mechanical models suggest that the two-phase velocity behaviour is caused by a rift-intrinsic strength?velocity feedback similar to a rope that snaps when pulled apart. This mechanism provides an explanation for several previously unexplained rapid absolute plate motion changes, offering new insights into the balance of plate driving forces through time. pdf:docinfo:subject: The South American continent as we know it formed during the break-up of West Gondwana between 150 and 110 million years ago, when the South Atlantic Rift system evolved into the South Atlantic ocean. Using state-of-the-art global tectonic reconstructions in conjunction with numerical and analytical modelling, we investigate the geodynamics of rift systems as they evolve into an ocean basin. We find that rifts initially stretch very slowly along the future splitting zone, but then move apart very quickly before the onset of rupture. In case of the split between South America and Africa, the divergence rate increased from initially 5 to 7 millimetres per year to over 40 millimetres per year within few million years. Intriguingly, abrupt rift acceleration did not only occur during the splitting of West Gondwana, but also during the separation of Australia and Antarctica, North America and Greenland, Africa and South America, in the North Atlantic or the South China Sea. We elucidate the underlying process by reproducing the rapid transition from slow to fast extension using analytical and numerical modelling with constant force boundary conditions. The mechanical models suggest that the two-phase velocity behaviour is caused by a rift-intrinsic strength?velocity feedback similar to a rope that snaps when pulled apart. This mechanism provides an explanation for several previously unexplained rapid absolute plate motion changes, offering new insights into the balance of plate driving forces through time. Content-Type: application/pdf pdf:docinfo:creator: Brune X-Parsed-By: org.apache.tika.parser.DefaultParser creator: S. meta:author: S. dc:subject: meta:creation-date: 2016-12-20T10:33:02Z created: Tue Dec 20 11:33:02 CET 2016 access_permission:extract_for_accessibility: true access_permission:assemble_document: true xmpTPg:NPages: 6 Creation-Date: 2016-12-20T10:33:02Z access_permission:extract_content: true access_permission:can_print: true meta:keyword: Author: S. producer: Adobe PDF Library 10.0.1 access_permission:can_modify: true pdf:docinfo:producer: Adobe PDF Library 10.0.1 pdf:docinfo:created: 2016-12-20T10:33:02Z