The Northern Appalachian Anomaly: A modern asthenospheric upwelling

Menke, William; Skryzalin, Peter; Levin, Vadim; Harper, Thomas; Darbyshire, Fiona et Dong, Ted (2016). « The Northern Appalachian Anomaly: A modern asthenospheric upwelling ». Geophysical Research Letters, 43.

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Résumé

The Northern Appalachian Anomaly (NAA) is an intense, laterally localized (400km diameter) low-velocity anomaly centered in the asthenosphere beneath southern New England. Its maximum shear velocity contrast, at 200km depth, is about 10%, and its compressional-to-shear velocity perturbation ratio is about unity, values compatible with it being a modern thermal anomaly. Although centered close to the track of the Great Meteor hot spot, it is not elongated parallel to it and does not crosscut the cratonic margin. In contrast to previous explanations, we argue that the NAA's spatial association with the hot spot track is coincidental and that it is caused by small-scale upwelling associated with an eddy in the asthenospheric flow field at the continental margin. That the NAA is just one of several low-velocity features along the eastern margin of North America suggests that this process may be globally ubiquitous.

Type:	Article de revue scientifique
Mots-clés ou Sujets:	Asthenosphere, Great Meteor hot spot, Northern Appalachian Anomaly, Seismic tomography, Upwelling
Unité d'appartenance:	Centres institutionnels > Centre de recherche en géochimie et géodynamique (GEOTOP) Faculté des sciences > Département des sciences de la Terre et de l'atmosphère
Déposé par:	Marie Larocque
Date de dépôt:	26 oct. 2016 15:31
Dernière modification:	01 juin 2017 23:10
Adresse URL :	http://archipel.uqam.ca/id/eprint/9024

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