Modeling and Interpretation of Ultraprecise Crustal Deformation Measurements

超精密地壳形变测量的建模和解释邓肯卡尔阿格纽该项目正在开发模型，以了解在过去十年中在南加州使用精确应变仪观察到的形变信号;这些可以测量从几秒钟到几个月的时间范围内地面的微小变化。这些模型和解释方法将用于其他地方，例如理解EarthScope的板块边界观测站（PBO）观测的信号，数据来自加州南部的三个站点：（1）Pinyon Flat天文台（PFO），我们在那里操作三个长基线应变仪，两个长基线倾斜仪和许多相关的传感器;（2）Durmid Hill（DHL），我们在靠近圣安德烈亚斯断层的地方操作一台长基线应变仪，（3）Glendale，洛杉矶（GVS），我们在2002年秋天完成了一台长基线应变仪。因此，对它们进行建模可以测试通常的简单模型在解释地震和其他构造变化引起的变形方面的充分性。这些信号包括两种类型的DHL（假潮和火车）附近的表面负荷，这两个弹性半空间的应变直接矛盾的意见。它们还包括地球潮汐，在DHL和GVS都显示出明显的扭曲，分别来自横向变化的弹性结构和崎岖的地形。我们还模拟了不太了解的信号，例如DHL看到的短期应变变化，我们将其解释为附近圣安德烈亚斯断层的蠕变事件，以及与兰德斯和赫克托矿地震有关的变化。

Modeling and Interpretation of UltrapreciseCrustal Deformation MeasurementsDuncan Carr AgnewThis project is developing models to understand deformation signals observed over the last decade with precise strainmeters in southern California; these can measure very small changes in the ground over a range of periods from seconds to many months. The models and interpretive methods will be used elsewhere, for example to understand the signals to be be observed by the Plate Boundary Observatory (PBO) component of EarthScope.The data come from three sites in southern California: (1) Pinyon Flat Observatory (PFO) at which we operate three long-base strainmeters, two long-base tiltmeters, and many related sensors; (2) Durmid Hill (DHL), where we operate a single long-base strainmeter close to the San Andreas fault, and (3) Glendale, Los Angeles (GVS), where we completed a single long-base strainmeter in the fall of 2002.Some signals come from known sources, so that modeling them tests how adequate the usual simple models are for interpreting deformations from earthquakes and other tectonic changes. These signals include two types of surface loading near DHL (seiches and trains); for both of these the strains for an elastic halfspace directly contradict the observations. They also include the earth tides, which show significant distortions at both DHL and GVS, from laterally varying elastic structure and rugged topography respectively.We are also modelling less-understood signals, such as short-term strain changes seen at DHL, which we interpret as creep events on the San Andreas fault nearby, and changes related to the Landers and Hector Mine earthquakes.