对地球长期自转稳定性的一种解释。

An Explanation for Earth's Long-Term Rotational Stability.

作者信息

Richards MA, Ricard Y, Lithgow-Bertelloni C, Spada G, Sabadini R

机构信息

M. A. Richards, Department of Geology and Geophysics, University of California, Berkeley, CA 94720, USA. Y. Ricard, Departement de Geologie, Ecole Normale Superieure, Lyon, France. C. Lithgow-Bertelloni, Department of Terrestrial Magnetism, Carnegie Institution of Washington, Washington, DC 20015-1305, USA. G. Spada, Dipartimento di Fisica, Settore Geofisica, Universita di Bologna, Bologna, Italy. R. Sabadini, Dipartimento di Scienze della Terra, Sezione Geofisica, Universita di Milano, Milano, Italy.

出版信息

Science. 1997 Jan 17;275(5298):372-5. doi: 10.1126/science.275.5298.372.

DOI:10.1126/science.275.5298.372

PMID:8994030

Abstract

Paleomagnetic data show less than approximately 1000 kilometers of motion between the paleomagnetic and hotspot reference frames-that is, true polar wander-during the past 100 million years, which implies that Earth's rotation axis has been very stable. This long-term rotational stability can be explained by the slow rate of change in the large-scale pattern of plate tectonic motions during Cenozoic and late Mesozoic time, provided that subducted lithosphere is a major component of the mantle density heterogeneity generated by convection. Therefore, it is unnecessary to invoke other mechanisms, such as sluggish readjustment of the rotational bulge, to explain the observed low rate of true polar wander.

摘要

古地磁数据表明，在过去1亿年里，古地磁参考系与热点参考系之间的运动距离不到约1000公里，也就是说，真极移距离很短，这意味着地球自转轴一直非常稳定。这种长期的旋转稳定性可以用新生代和中生代晚期板块构造运动大规模格局变化速率缓慢来解释，前提是俯冲的岩石圈是由对流产生的地幔密度不均一性的主要组成部分。因此，没有必要援引其他机制，如旋转凸起的缓慢重新调整，来解释观测到的真极移低速率。