A Seismic Study of the Taiwan Orogen

台湾造山带地震研究

• 批准号: 0106786
• 负责人: Wang-Ping Chen
• 金额: $ 10.98万
• 依托单位: University of Illinois at Urbana-Champaign
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-07-15 至 2004-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0106786&HistoricalAwards=false
• 关键词: Seismic; Study; Taiwan; Orogen

Abstract for proposal EAR0106786 (PH # 9x)Title: A Seismic Study of the Taiwan OrogenPI's: Wang-Ping Chen, Department of Geology and Mid-America Earthquake Center, University of Illinois, Urbana, IL 61801This is a seismic study of the Taiwan orogen, an important case of active collision zone that has been a focus of international research for the last 20 years. Since the devastating Chi-Chi earthquake sequence of 1999, seismicity increased remarkably in and around Taiwan. Hundreds of large- to moderate-sized earthquakes have been well recorded by arrays of state-of-the-art instruments, providing high-resolution data to investigate active arc-continent collision.We plan to study about 300 earthquakes, including precise determinations of epicenters, focal depths, fault plane solutions, and seismic moments, in order to address some key questions in active collision. The young age and fast convergence of the collision zone are particularly favorable for resolving: 1) if spatial variations reflect time-progression of collision; and 2) if reactivation of pre-existing, extensional structures is important in the early stages of collision. We will focus on these topics and cast our interpretation in the context of geological and geophysical information gathered from various sources.In addition, we will study diffuse deformation to the east of the suture zone, in the interior of the western Philippine Sea. Recent marine data showed a surprisingly old age (early Cretaceous) for the colliding edge of the Philippine Sea. This region, underlain by oceanic lithosphere, is often assumed to be mechanically strong, thus behaving as the driving edge of the collision. The proposed work will constrain the thickness of the strongest part of the colliding oceanic lithosphere, and potentially provide clues to the anomalously shallow depth of the old sea floor.

建议摘要EAR0106786(PH#9x)标题：台湾造山带的地震研究。伊利诺伊大学地质与中美地震中心陈王平，伊利诺伊大学，Urbana，IL 61801这是台湾造山带的地震研究，台湾造山带是近20年来国际研究的焦点。自1999年集集大地震发生以来，台湾及周边地区的地震活动显著增加。一系列最先进的仪器已经记录了数百次大中型地震，为研究活动的弧陆碰撞提供了高分辨率的数据。我们计划研究大约300次地震，包括震中、震源深度、断层面解和地震矩的精确确定，以解决活动碰撞中的一些关键问题。碰撞带的年轻和快速收敛特别有利于解决：1)空间变化是否反映了碰撞的时间进展；2)如果先前存在的伸展构造在碰撞早期阶段的重新激活是重要的。我们将专注于这些主题，并在从各种来源收集的地质和地球物理信息的背景下进行解释。此外，我们还将研究缝合带以东的弥漫变形，即菲律宾西部海的内陆。最近的海洋数据显示，菲律宾海碰撞边缘的年龄令人惊讶地老了(白垩纪早期)。这一被大洋岩石圈覆盖的区域通常被认为是机械强度很强的区域，因此是碰撞的驱动边缘。这项拟议的工作将限制碰撞的大洋岩石圈最强烈部分的厚度，并可能为了解旧海底异常浅的深度提供线索。