Active tectonics of plate boundary zones and the continuity of plate boundary deformation from Asia to North America
Active tectonics of plate boundary zones and the continuity of plate boundary deformation from Asia to North America
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板块边界带的活动构造及亚洲至北美板块边界变形的连续性
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发表时间：
2011
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通讯作者：
J. Freymueller
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作者：
J. Freymueller
大陆岩石圈在板块边界的普遍碎裂是规律，而不是例外。然而，在亚洲和北美西部的大部分板块边界区，大地测量学观测到的地壳运动可以很好地描述模型，使用一些刚性板块或块体，由断层，假定切割整个岩石圈。只有少数地区，主要是在青藏高原，可能是例外，因为它们显示出更连续的变形模式。这可能是由于变形广泛分布在深度，即使它主要局限于表面。变形中的亚洲和北美洲的岩石圈被分裂成几个大的刚性或非常缓慢的应变区域，很可能是板块边界带内的小板块。这些小板块中的大多数移动缓慢，使得板块的定义及其边界有时存在争议。亚洲和北美洲的板块边界带连接在一起，形成了一条宽阔的变形带，标志着整个环北方太平洋。从北太平洋附近的下加利福尼亚到西藏及更远的地区，分布变形是连续的或接近连续的。板块边界带的研究因变形的时间变化而变得复杂。尽管震后变形模型暗示了时间依赖性，但稳定变形随时间变化主导的震间周期的概念似乎仍然有效。开发一个解释地震前和地震后观测的地震周期模型仍然是一个活跃的研究领域。此外，有一些证据表明，随着时间的推移，断层滑动率的变化，特别是当一个小区域内的断层对显示耦合行为。
Pervasive fragmentation of continental lithosphere at plate boundaries is the rule, not the exception. However, over most of the plate boundary zones of Asia and western North America, crustal motions observed by geodesy can be described well by models that use a number of rigid plates or blocks, bounded by faults that are presumed to cut the entire lithosphere. Only a few areas, mostly in the Tibetan Plateau, may be exceptions to this rule because they display a more continuum-like deformation pattern. This might result from deformation that is distributed broadly at depth, even if it is mainly localized at the surface. The lithosphere of deforming Asia and North America is fragmented into several large rigid or very slowly straining regions, most likely small plates within the plate boundary zone. Most of these small plates move slowly, making the definition of the plates and their boundaries sometimes controversial. The plate boundary zones of Asia and North America are connected as part of a broad band of distributed deformation that marks the entire northern Pacific Rim. Distributed deformation is continuous or nearly so from Baja California around the north Pacific to Tibet, and beyond. Study of plate boundary zones is complicated by temporal variations in deformation. Despite the time dependence implied by postseismic deformation models, the concept of an interseismic period dominated by steady deformation with time appears to remain valid. Development of an earthquake cycle model that explains both preand post-earthquake observations remains an area of active research. In addition, there is some evidence for changes in fault slip rates over time, particularly when pairs of faults within a small area show coupled behaviour.