Bayesian noise-reduction in Arabia/Somalia and Nubia/Arabia finite rotations since ~20 Ma: Implications for Nubia/Somalia relative motion
Knowledge of Nubia/Somalia relative motion since the Early Neogene is of particular importance in the Earth Sciences, because it (i) impacts on inferences on African dynamic topography; and (ii) allows us to link plate kinematics within the Indian realm with those within the Atlantic basin. The cont...
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ftanucanberra:oai:digitalcollections.anu.edu.au:1885/70787 2023-05-15T13:36:32+02:00 Bayesian noise-reduction in Arabia/Somalia and Nubia/Arabia finite rotations since ~20 Ma: Implications for Nubia/Somalia relative motion Iaffaldano, Giampiero Hawkins, Rhys Sambridge, Malcolm 2015-12-13T22:16:17Z http://hdl.handle.net/1885/70787 unknown American Geophysical Union 1525-2027 http://hdl.handle.net/1885/70787 Geochemistry, Geophysics, Geosystems. G3 Journal article 2015 ftanucanberra 2015-12-28T23:35:00Z Knowledge of Nubia/Somalia relative motion since the Early Neogene is of particular importance in the Earth Sciences, because it (i) impacts on inferences on African dynamic topography; and (ii) allows us to link plate kinematics within the Indian realm with those within the Atlantic basin. The contemporary Nubia/Somalia motion is well known from geodetic observations. Precise estimates of the past-3.2-Myr average motion are also available from paleo-magnetic observations. However, little is known of the Nubia/Somalia motion prior to ∼3.2 Ma, chiefly because the Southwest Indian Ridge spread slowly, posing a challenge to precisely identify magnetic lineations. This also makes the few observations available particularly prone to noise. Here we reconstruct Nubia/Somalia relative motions since ∼20 Ma from the alternative plate-circuit Nubia-Arabia-Somalia. We resort to trans-dimensional hierarchical Bayesian Inference, which has proved effective in reducing finite-rotation noise, to unravel the Arabia/Somalia and Arabia/Nubia motions. We combine the resulting kinematics to reconstruct the Nubia/Somalia relative motion since ∼20 Ma. We verify the validity of the approach by comparing our reconstruction with the available record for the past ∼3.2 Myr, obtained through Antarctica. Results indicate that prior to ∼11 Ma the total motion between Nubia and Somalia was faster than today. Furthermore, it featured a significant strike-slip component along the Nubia/Somalia boundary. It is only since ∼11 Ma that Nubia diverges away from Somalia at slower rates, comparable to the present-day one. Kinematic changes of some 20% might have occurred in the period leading to the present-day, but plate-motion steadiness is also warranted within the uncertainties. Key Points Bayesian inference to reduce finite-rotation noise Reconstruction of Nubia/Somalia motion since ∼20 Ma Nubia/Somalia relative motion changed at ∼11 Ma Article in Journal/Newspaper Antarc* Antarctica Australian National University: ANU Digital Collections Indian |
institution |
Open Polar |
collection |
Australian National University: ANU Digital Collections |
op_collection_id |
ftanucanberra |
language |
unknown |
description |
Knowledge of Nubia/Somalia relative motion since the Early Neogene is of particular importance in the Earth Sciences, because it (i) impacts on inferences on African dynamic topography; and (ii) allows us to link plate kinematics within the Indian realm with those within the Atlantic basin. The contemporary Nubia/Somalia motion is well known from geodetic observations. Precise estimates of the past-3.2-Myr average motion are also available from paleo-magnetic observations. However, little is known of the Nubia/Somalia motion prior to ∼3.2 Ma, chiefly because the Southwest Indian Ridge spread slowly, posing a challenge to precisely identify magnetic lineations. This also makes the few observations available particularly prone to noise. Here we reconstruct Nubia/Somalia relative motions since ∼20 Ma from the alternative plate-circuit Nubia-Arabia-Somalia. We resort to trans-dimensional hierarchical Bayesian Inference, which has proved effective in reducing finite-rotation noise, to unravel the Arabia/Somalia and Arabia/Nubia motions. We combine the resulting kinematics to reconstruct the Nubia/Somalia relative motion since ∼20 Ma. We verify the validity of the approach by comparing our reconstruction with the available record for the past ∼3.2 Myr, obtained through Antarctica. Results indicate that prior to ∼11 Ma the total motion between Nubia and Somalia was faster than today. Furthermore, it featured a significant strike-slip component along the Nubia/Somalia boundary. It is only since ∼11 Ma that Nubia diverges away from Somalia at slower rates, comparable to the present-day one. Kinematic changes of some 20% might have occurred in the period leading to the present-day, but plate-motion steadiness is also warranted within the uncertainties. Key Points Bayesian inference to reduce finite-rotation noise Reconstruction of Nubia/Somalia motion since ∼20 Ma Nubia/Somalia relative motion changed at ∼11 Ma |
format |
Article in Journal/Newspaper |
author |
Iaffaldano, Giampiero Hawkins, Rhys Sambridge, Malcolm |
spellingShingle |
Iaffaldano, Giampiero Hawkins, Rhys Sambridge, Malcolm Bayesian noise-reduction in Arabia/Somalia and Nubia/Arabia finite rotations since ~20 Ma: Implications for Nubia/Somalia relative motion |
author_facet |
Iaffaldano, Giampiero Hawkins, Rhys Sambridge, Malcolm |
author_sort |
Iaffaldano, Giampiero |
title |
Bayesian noise-reduction in Arabia/Somalia and Nubia/Arabia finite rotations since ~20 Ma: Implications for Nubia/Somalia relative motion |
title_short |
Bayesian noise-reduction in Arabia/Somalia and Nubia/Arabia finite rotations since ~20 Ma: Implications for Nubia/Somalia relative motion |
title_full |
Bayesian noise-reduction in Arabia/Somalia and Nubia/Arabia finite rotations since ~20 Ma: Implications for Nubia/Somalia relative motion |
title_fullStr |
Bayesian noise-reduction in Arabia/Somalia and Nubia/Arabia finite rotations since ~20 Ma: Implications for Nubia/Somalia relative motion |
title_full_unstemmed |
Bayesian noise-reduction in Arabia/Somalia and Nubia/Arabia finite rotations since ~20 Ma: Implications for Nubia/Somalia relative motion |
title_sort |
bayesian noise-reduction in arabia/somalia and nubia/arabia finite rotations since ~20 ma: implications for nubia/somalia relative motion |
publisher |
American Geophysical Union |
publishDate |
2015 |
url |
http://hdl.handle.net/1885/70787 |
geographic |
Indian |
geographic_facet |
Indian |
genre |
Antarc* Antarctica |
genre_facet |
Antarc* Antarctica |
op_source |
Geochemistry, Geophysics, Geosystems. G3 |
op_relation |
1525-2027 http://hdl.handle.net/1885/70787 |
_version_ |
1766080270408089600 |