Active Tectonics of Interior Alaska: Seismicity, Gps Geodesy, and Local Geomorphology
Active Tectonics of Interior Alaska: Seismicity, Gps Geodesy, and Local Geomorphology
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阿拉斯加内陆的活动构造：地震活动、GPS 大地测量学和当地地貌学
DOI：
10.1029/179gm06
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发表时间：
2013
期刊：
影响因子：
--
通讯作者：
R. Hansen
中科院分区：
文献类型：
--
作者：
N. Ruppert;K. Ridgway;J. Freymueller;Ryan S. Cross;R. Hansen
阿拉斯加内陆是一个活跃的变形景观，是一个广阔的变形区的一部分，该变形区在会聚板块边界内侧延伸数百公里。本章提供了一个概述的地震活动性，构造地貌学和地壳运动的GPS测量在阿拉斯加内陆和周边地区的最新研究。虽然合并后的数据集没有指向一个单一的机制，阿拉斯加内陆的变形，我们认为，北美和两个地壳块，白令和兰格尔之间的相互作用，是负责广泛的扩散带变形的特点，这一地区。我们认为，变形带沿着北北东走向，左侧地震带的德纳里断层以北和沿着苏西特纳地震带南部的代表白令块体和北美板块之间的分布边界的东部范围。双差地震重定位记录了地震结构的细节，并有助于确定阿拉斯加内陆地壳的孕震部分。频率-震级和应力分析提供了该地区断层参数和地震行为的见解。河道形态和流剖面扰动有助于确定阿拉斯加内陆活跃的地表变形。全球定位系统的测量结果表明，该地区的相对运动与稳定的板块内部所预期的不同，并且包括多个变形源的影响。研究结果表明，阿拉斯加内陆有三种主要的构造类型：右旋走滑断层、左旋走滑地震带和逆冲断层。
Interior Alaska is an actively deforming landscape that is part of a broad zone of deformation extending hundreds of kilometers inboard of the convergent plate boundary. This chapter provides an overview of recent studies on the seismicity, tectonic geomorphology, and crustal motions from GPS measurements in interior Alaska and the surrounding regions. Although the combined data sets do not point to one single mechanism of deformation for interior Alaska, we suggest that the interactions between North America and two crustal blocks, the Bering and Wrangell, are responsible for the broad diffuse belt of deformation that characterizes this region. We propose that the deformation zone extending along the NNE-striking, left-lateral seismic zones north of the Denali fault and along the Susitna seismic zone south of the fault represents the eastern extent of the distributed boundary between the Bering block and the North American plate. Double-difference earthquake relocations document the fine details of seismic structures and help define the seismogenic part of the crust in interior Alaska. Frequency―magnitude and stress analysis provide insights into faulting parameters and earthquake behavior in the region. Stream channel morphologies and stream profile perturbations help define active surface deformation in interior Alaska. GPS measurements show that the relative motions across the region are different than what would be expected for a stable plate interior, and include the effects of multiple deformation sources. Results from the study show that three dominant types of structures characterize interior Alaska: right-lateral strike-slip faults, left-lateral strike-slip seismic zones, and thrust faults.