A Serenitatis origin for the Imbrian grooves and South Pole-Aitken thorium anomaly
International audience The northwest corner of the Moon's South Pole‐Aitken (SPA) basin contains a high abundance of thorium and a unique Imbrian aged geomorphologic unit that consists of “grooves and mounds” (referred to here as the Imbrian grooves). Because the location of these features are...
Published in: | Journal of Geophysical Research: Planets |
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ftccsdartic:oai:HAL:hal-02458520v1 2023-05-15T18:22:27+02:00 A Serenitatis origin for the Imbrian grooves and South Pole-Aitken thorium anomaly Wieczorek, Mark Zuber, Maria Department of Earth, Atmospheric and Planetary Sciences MIT, Cambridge (EAPS) Massachusetts Institute of Technology (MIT) 2001 https://hal.archives-ouvertes.fr/hal-02458520 https://hal.archives-ouvertes.fr/hal-02458520/document https://hal.archives-ouvertes.fr/hal-02458520/file/Wieczorek%20and%20Zuber,%202001a.pdf https://doi.org/10.1029/2000JE001384 en eng HAL CCSD Wiley-Blackwell info:eu-repo/semantics/altIdentifier/doi/10.1029/2000JE001384 hal-02458520 https://hal.archives-ouvertes.fr/hal-02458520 https://hal.archives-ouvertes.fr/hal-02458520/document https://hal.archives-ouvertes.fr/hal-02458520/file/Wieczorek%20and%20Zuber,%202001a.pdf doi:10.1029/2000JE001384 info:eu-repo/semantics/OpenAccess ISSN: 2169-9097 EISSN: 2169-9100 Journal of Geophysical Research. Planets https://hal.archives-ouvertes.fr/hal-02458520 Journal of Geophysical Research. Planets, Wiley-Blackwell, 2001, 106 (E11), pp.27853-27864. ⟨10.1029/2000JE001384⟩ [SDU.STU.PL]Sciences of the Universe [physics]/Earth Sciences/Planetology info:eu-repo/semantics/article Journal articles 2001 ftccsdartic https://doi.org/10.1029/2000JE001384 2021-10-09T23:11:10Z International audience The northwest corner of the Moon's South Pole‐Aitken (SPA) basin contains a high abundance of thorium and a unique Imbrian aged geomorphologic unit that consists of “grooves and mounds” (referred to here as the Imbrian grooves). Because the location of these features are almost antipodal to the Imbrium basin, where high‐thorium ejecta and seismic energy are expected to have converged, an Imbrium origin for these units has long seemed certain. By modeling the deposition of impact ejecta on the Moon, we have investigated whether the convergence of Imbrium's ejecta at its antipode could be the origin of both the Imbrian grooves and SPA thorium anomaly. As a result of the Moon's rotation, our results show that ejecta from this basin should converge more than 12° west of its antipode. Both the Imbrian grooves and thorium anomaly within SPA, however, reside slightly to the east of Imbrium's antipode. In an attempt to reconcile this disparity, the effects of a putative oblique Imbrium impact have been qualitatively investigated. While this model can distribute ejecta in the general vicinity of the Imbrian grooves, the planform of our modeled antipodal ejecta is distinctly different from that which is observed. As an alternative explanation for the origin of these features, we find that the modeled distribution of ejecta from an oblique Serenitatis impact is surprisingly similar to the planform of the Imbrian grooves, with the exception that it is offset directly to the east. This eastward offset is likely to be an artifact of our not being able to properly include the effects of the Moon's rotation in our oblique impact models. We conclude that the Imbrium grooves and SPA thorium anomaly are most consistent with having an origin from the convergence of ejecta antipodal to the Serenitatis basin. If this conclusion can be substantiated once quantitative ejecta scaling relations for oblique impacts are determined, then this implies that (1) the Serenitatis target contained a high abundance of ... Article in Journal/Newspaper South pole Archive ouverte HAL (Hyper Article en Ligne, CCSD - Centre pour la Communication Scientifique Directe) Aitken ENVELOPE(-44.516,-44.516,-60.733,-60.733) South Pole Journal of Geophysical Research: Planets 106 E11 27853 27864 |
institution |
Open Polar |
collection |
Archive ouverte HAL (Hyper Article en Ligne, CCSD - Centre pour la Communication Scientifique Directe) |
op_collection_id |
ftccsdartic |
language |
English |
topic |
[SDU.STU.PL]Sciences of the Universe [physics]/Earth Sciences/Planetology |
spellingShingle |
[SDU.STU.PL]Sciences of the Universe [physics]/Earth Sciences/Planetology Wieczorek, Mark Zuber, Maria A Serenitatis origin for the Imbrian grooves and South Pole-Aitken thorium anomaly |
topic_facet |
[SDU.STU.PL]Sciences of the Universe [physics]/Earth Sciences/Planetology |
description |
International audience The northwest corner of the Moon's South Pole‐Aitken (SPA) basin contains a high abundance of thorium and a unique Imbrian aged geomorphologic unit that consists of “grooves and mounds” (referred to here as the Imbrian grooves). Because the location of these features are almost antipodal to the Imbrium basin, where high‐thorium ejecta and seismic energy are expected to have converged, an Imbrium origin for these units has long seemed certain. By modeling the deposition of impact ejecta on the Moon, we have investigated whether the convergence of Imbrium's ejecta at its antipode could be the origin of both the Imbrian grooves and SPA thorium anomaly. As a result of the Moon's rotation, our results show that ejecta from this basin should converge more than 12° west of its antipode. Both the Imbrian grooves and thorium anomaly within SPA, however, reside slightly to the east of Imbrium's antipode. In an attempt to reconcile this disparity, the effects of a putative oblique Imbrium impact have been qualitatively investigated. While this model can distribute ejecta in the general vicinity of the Imbrian grooves, the planform of our modeled antipodal ejecta is distinctly different from that which is observed. As an alternative explanation for the origin of these features, we find that the modeled distribution of ejecta from an oblique Serenitatis impact is surprisingly similar to the planform of the Imbrian grooves, with the exception that it is offset directly to the east. This eastward offset is likely to be an artifact of our not being able to properly include the effects of the Moon's rotation in our oblique impact models. We conclude that the Imbrium grooves and SPA thorium anomaly are most consistent with having an origin from the convergence of ejecta antipodal to the Serenitatis basin. If this conclusion can be substantiated once quantitative ejecta scaling relations for oblique impacts are determined, then this implies that (1) the Serenitatis target contained a high abundance of ... |
author2 |
Department of Earth, Atmospheric and Planetary Sciences MIT, Cambridge (EAPS) Massachusetts Institute of Technology (MIT) |
format |
Article in Journal/Newspaper |
author |
Wieczorek, Mark Zuber, Maria |
author_facet |
Wieczorek, Mark Zuber, Maria |
author_sort |
Wieczorek, Mark |
title |
A Serenitatis origin for the Imbrian grooves and South Pole-Aitken thorium anomaly |
title_short |
A Serenitatis origin for the Imbrian grooves and South Pole-Aitken thorium anomaly |
title_full |
A Serenitatis origin for the Imbrian grooves and South Pole-Aitken thorium anomaly |
title_fullStr |
A Serenitatis origin for the Imbrian grooves and South Pole-Aitken thorium anomaly |
title_full_unstemmed |
A Serenitatis origin for the Imbrian grooves and South Pole-Aitken thorium anomaly |
title_sort |
serenitatis origin for the imbrian grooves and south pole-aitken thorium anomaly |
publisher |
HAL CCSD |
publishDate |
2001 |
url |
https://hal.archives-ouvertes.fr/hal-02458520 https://hal.archives-ouvertes.fr/hal-02458520/document https://hal.archives-ouvertes.fr/hal-02458520/file/Wieczorek%20and%20Zuber,%202001a.pdf https://doi.org/10.1029/2000JE001384 |
long_lat |
ENVELOPE(-44.516,-44.516,-60.733,-60.733) |
geographic |
Aitken South Pole |
geographic_facet |
Aitken South Pole |
genre |
South pole |
genre_facet |
South pole |
op_source |
ISSN: 2169-9097 EISSN: 2169-9100 Journal of Geophysical Research. Planets https://hal.archives-ouvertes.fr/hal-02458520 Journal of Geophysical Research. Planets, Wiley-Blackwell, 2001, 106 (E11), pp.27853-27864. ⟨10.1029/2000JE001384⟩ |
op_relation |
info:eu-repo/semantics/altIdentifier/doi/10.1029/2000JE001384 hal-02458520 https://hal.archives-ouvertes.fr/hal-02458520 https://hal.archives-ouvertes.fr/hal-02458520/document https://hal.archives-ouvertes.fr/hal-02458520/file/Wieczorek%20and%20Zuber,%202001a.pdf doi:10.1029/2000JE001384 |
op_rights |
info:eu-repo/semantics/OpenAccess |
op_doi |
https://doi.org/10.1029/2000JE001384 |
container_title |
Journal of Geophysical Research: Planets |
container_volume |
106 |
container_issue |
E11 |
container_start_page |
27853 |
op_container_end_page |
27864 |
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