High Resolution Imaging of the Mantle of North America with 3D Wavefield Imaging

技术说明本项目将使用一种称为平面波偏移的新型三维地震波成像方法分析Earthscope便携式阵列（TA）的数据。 这种方法产生了可以说是迄今为止从TA产生的最高分辨率图像。 它是通过一种源自地震反射法的技术来实现这一点的，地震反射法是石油和天然气勘探中使用的主要技术。 该项目将利用这项技术来解决三个主要的科学问题。 (1)法拉隆板块的几何形状是什么，北美已经被覆盖了至少1亿年？ (2)我们在以前的工作中成像的上地幔倾斜界面是否是地幔流动过程的标志？ (3)这些高分辨率的图像告诉了我们关于地球区域的什么性质？的地幔称为过渡带，位于两个全球性的不连续性之间的深度为410和660公里？ 该项目将通过四种方法解决这些问题。 (1)使用石油和天然气行业中解释地震反射数据常用的工具进行3D可视化。 (2)应用正演模拟方法来评价我们成像结果的可靠性，并检验方法（1）中提出的更详细的假设。 (3)将我们的结果与其他科学家的不同方法进行比较。 (4)更广泛的意义和重要性Earthscope的USAray元件的建立是为了提供数据，以提供对塑造北美大陆的过程的新理解。 地震成像技术是解决这一重大问题的主要方法。 该项目对于提供迄今为止用这些数据获得的最高分辨率图像并将其与其他人的相关工作以真实几何关系联系起来非常重要。 这有可能极大地改变我们对北美地质学许多元素的看法，因为我们能够看到以前不可能看到的东西。 这对石油和天然气行业产生了广泛的影响，因为这是一项基础工作，可以影响对塑造北美地质的地质过程的理解。 我们还计划制作一些可用于各级科学教育的数据产品。

Technical DescriptionThis project will analyze data from the Earthscope Transportable Array (TA) using a novel three-dimensional, seismic wave imaging method called plane wave migration. This method has produced what is arguably the highest resolution image produced from the TA to date. It accomplishes this with a technology derived from the seismic reflection method, which is the primary technology used in oil and gas exploration. The project will use this technology to address three main scientific questions. (1) What is the geometry of the Farallon Plate that North America has been overriding for at least 100 million years? (2) Are dipping interfaces in the upper mantle we have imaged in previous work markers of mantle flow processes? (3) What do these high resolution images tell us about the nature of the region of Earth?s mantle called the transition zone that lies between two global discontinuities at depths of 410 and 660 km? The project will address these questions through four approaches. (1) 3D visualization using tools commonly available for interpretation seismic reflection data in the oil and gas industry. (2) Application of forward modeling methods to appraise the reliability of our imaging results and to test more detailed hypotheses that will arise form approach (1). (3) Comparison of our results with different approaches produced by other scientists. (4) Further technical developments of the imaging technology that will be applied in the project.Broader significance and importanceThe USArray element of Earthscope was built to provide the data to provide a new understanding of the processes that have shaped the North American continent. Seismic imaging technologies were the main approach to addressing this large issue. This project is important for providing the highest resolution images yet obtained with these data and relating them in true geometry to related work by others. This has the potential to dramatically change our perspectives on many elements of North American geology by being able to see what was previously not possible. This has broad impacts for the oil and gas industry as fundamental work that can impact understanding of geologic processes that shape North American geology. We also plan to produce a number of data products that can be used for science education at all levels.