Combined effects of tectonics and glacial isostatic adjustment on intraplate deformation in central and northern Europe: Applications to geodetic baseline analyses
Combined effects of tectonics and glacial isostatic adjustment on intraplate deformation in central and northern Europe: Applications to geodetic baseline analyses
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构造和冰川均衡调整对中欧和北欧板内变形的综合影响：在大地测量基线分析中的应用
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发表时间：
2003
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通讯作者：
G. Milne
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作者：
A. Marotta;J. Mitrovica;R. Sabadini;G. Milne
我们使用一套球面、薄片、有限元模型计算来研究欧洲地区水平构造变形的模式。计算结果综合考虑了非洲-欧亚大陆辐合、大西洋洋脊推力以及东欧和地中海子域岩石圈强度变化的影响。将这10个预测结果与使用球对称、自重力、粘弹性地球冰川均衡调整模型计算的同一地区的变形进行比较。输入到GIA模型中的径向粘度剖面和冰史数据来自一个模型，该模型“最适合”由BIFROST Fennoscandian GPS网络估计的三维地壳速度。构造和GIA信号的比较包括预测地壳速度图和与永久ITRF2000和BIFROST GPS网络内站点相关的基线长度变化。我们的基线分析包括北欧和中欧的参考站点，这些站点代表了地理信息局所引起的形变的中心、边缘和外围的18个站点。尽管具有不同的几何敏感性，但与所有三个参考地点相关的基线长度变化预测都受到构造和GIA效应的显著影响。在这方面，21我们的几个构造模型得出了从Vaas、Onsala和Potsdam到55°N以下站点22的基线速率，这与观测到的趋势一致。我们发现，同时考虑GIA和24构造的影响，得到了与23 ITRF2000数据集的最佳拟合，其中后者是一个相对弱的地中海子域。在这种情况下，构造模式有助于观察到的Onsala/ 26波茨坦与南部站点之间的缩短，而没有破坏从这些参考站点和站点向北延伸的基线27的延伸；这一扩展仅由GIA流程就能很好地协调。索引术语：1208大地测量学和重力：地壳运动-板块内（8110）；3210数学地球物理：建模；8110构造物理学：大陆构造- 30一般（0905）；9335地理区域相关信息：欧洲；关键词：构造学，GIA， 31板内变形
6 [1] We use a suite of spherical, thin sheet, finite element model calculations to investigate 7 the pattern of horizontal tectonic deformation within Europe. The calculations incorporate 8 the effects of Africa-Eurasia convergence, Atlantic Ridge push forces, and changes 9 in the lithospheric strength of the East European and Mediterranean subdomains. These 10 predictions are compared to the deformation computed for the same region using a 11 spherically symmetric, self-gravitating, viscoelastic Earth model of glacial isostatic 12 adjustment. The radial viscosity profile and ice history input into the GIA model are taken 13 from a model that ‘‘best fits’’ three-dimensional crustal velocities estimated from the 14 BIFROST Fennoscandian GPS network. The comparison of the tectonic and GIA signals 15 includes predictions of both crustal velocity maps and baseline length changes associated 16 with sites within the permanent ITRF2000 and BIFROST GPS networks. Our baseline 17 analysis includes reference sites in northern and central Europe that are representative of 18 sites at the center, edge, and periphery of the GIA-induced deformation. Baseline length 19 change predictions associated with all three reference sites are significantly impacted 20 by both tectonic and GIA effects, albeit with distinct geometric sensitivities. In this regard, 21 several of our tectonic models yield baseline rates from Vaas, Onsala, and Potsdam to sites 22 below 55� N which are consistent with observed trends. We find that a best fit to the 23 ITRF2000 data set is obtained by simultaneously considering the effects of GIA plus 24 tectonics, where the latter is modeled with a relatively weak Mediterranean subdomain. In 25 this case, the tectonic model contributes to the observed shortening between Onsala/ 26 Potsdam and sites to the south, without corrupting the extension observed for baselines 27 extending from these reference sites and sites to the north; this extension is well reconciled 28 by the GIA process alone. INDEX TERMS: 1208 Geodesy and Gravity: Crustal movements— 29 intraplate (8110); 3210 Mathematical Geophysics: Modeling; 8110 Tectonophysics: Continental tectonics— 30 general (0905); 9335 Information Related to Geographic Region: Europe; KEYWORDS: tectonics, GIA, 31 intraplate deformation