Arrival-angle anomalies across the USArray Transportable Array
Arrival-angle anomalies across the USArray Transportable Array
复制标题
USArray 可移动阵列的到达角异常
DOI：
10.1016/j.epsl.2013.12.046
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发表时间：
2014
影响因子：
5.3
通讯作者：
V. Hjörleifsdóttir
中科院分区：
文献类型：
--
作者：
A. Foster;G. Ekström;V. Hjörleifsdóttir
我们构建复合地图的面波到达角异常使用集群地震和阵列方法测量波前几何。这导致在2006年至2010年期间覆盖USAray可移动阵列的整个足迹的到达角的观测。在传播方向上的到达角偏差带指示在阵列内部和外部均存在非均匀速度结构。我们比较观察到的模式预测使用两个全球层析模型，地幔模型S362ANI和表面波色散模型GDM52的到达角。我们使用射线理论为基础的预测方法和测量的合成数据计算使用光谱元素的方法。这两种模型和所有的预测方法产生类似的平均到达角和长波长模式的异常，这是类似的观测。预测的短波长特征通常与观测结果不一致。谱元方法产生了一些复杂性，这是不使用基于射线理论的方法获得的，这种预测的复杂性是类似的字符观察到的模式，但不匹配。
We construct composite maps of surface-wave arrival-angle anomalies using clustered earthquakes and an array method for measuring wave-front geometry. This results in observations of arrival angles covering the entire footprint of the USArray Transportable Array during 2006–2010. Bands of arrival-angle deviations in the propagation direction indicate the presence of heterogeneous velocity structure both inside and outside of the array. We compare the observed patterns to arrival angles predicted using two global tomographic models, the mantle model S362ANI and the surface-wave-dispersion model GDM52. We use both ray-theory-based prediction methods and measurements on synthetic data calculated using a spectral-element method. Both models and all prediction methods produce similar mean arrival angles and long-wavelength patterns of anomalies which are similar to the observations. Predicted short-wavelength features generally do not agree with the observations. The spectral-element method produces some complexity that is not obtained using the ray-theory-based methods; this predicted complexity is similar in character to the observed patterns, but does not match them.