Modification of the lithospheric stress field by lateral variations in plate‐mantle coupling
Modification of the lithospheric stress field by lateral variations in plate‐mantle coupling
复制标题
板幔耦合横向变化对岩石圈应力场的修正
DOI：
10.1029/2009gl040484
复制
发表时间：
2009
影响因子：
5.2
通讯作者：
C. Lithgow‐Bertelloni
中科院分区：
文献类型：
--
作者：
J. Naliboff;C. Conrad;C. Lithgow‐Bertelloni
深穿透大陆根的存在下，可能会局部增加基底剪切力的大小高达4倍的分层粘度结构相比。在这里，我们研究如何在地幔岩石圈耦合的增加影响应力模式上覆弹性岩石圈。通过耦合地幔流模型的弹性岩石圈的模型，我们表明，放大地幔牵引下的岩石圈增加弹性应力的大小最多只有1.5的一个因素，在一个模式不相关的本地基底牵引的变化。这种分离可以通过弹性应力在长距离上的传输来解释，这使得它们对区域平均的基底牵引力变化敏感，但对局部变化不敏感。我们的研究结果突出了岩石圈强度的区域变化的重要性，这可以使应力模式更紧密地匹配基底剪切的区域变化。
The presence of deeply penetrating continental roots may locally increase the magnitude of basal shear tractions by up to a factor of 4 compared to a layered viscosity structure. Here we examine how these increases in mantle‐lithosphere coupling influence stress patterns in the overlying elastic lithosphere. By coupling a mantle flow model to a model for the elastic lithosphere, we show that the amplification of mantle tractions beneath cratons increases elastic stress magnitudes by at most a factor of only 1.5 in a pattern not correlated to local basal traction changes. This disconnect is explained by the transmission of elastic stresses across large distances, which makes them sensitive to regionally‐averaged changes in basal tractions, but not local variations. Our results highlight the importance of regional variations in lithospheric strength, which could allow stress patterns to more closely match regional changes in basal shear.