High-Resolution Seismic Study of Subducted Slabs

俯冲板片的高分辨率地震研究

• 批准号: 8707578
• 负责人: John Vidale
• 金额: $ 11.48万
• 依托单位: University of California-Santa Cruz
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1987
• 资助国家: 美国
• 起止时间: 1987-07-01 至 1990-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=8707578&HistoricalAwards=false
• 关键词: Resolution; Seismic; Study; Subducted; Slabs

We propose to investigate the waveforms, amplitudes, and traveltimes of body waves from earthquakes and explosions to examine the detailed velocity structure of subducting slabs in the depth range 0 to 1500. Creager and Jordon (1986) propose that penetration of subducting slabs under the Kurile Islands and other subduction zones to depths of at least 1000 km is necessary to explain travel time anomalies of deep earthquakes. Such penetration would also affect the amplitudes and waveforms of the body waves from earthquakes. Methods we have recently developed allow the calculation of the waveform and amplitude effects of high-velocity, subducting slabs. A preliminary review of available data show that we can test and refine seismic models of slabs with these new methods. We propose, as well, to refine models of slabs in the upper mantle, which empirically cause even greater waveform, amplitude and timing anomalies than the deep slabs. Our method may also help to locate where the earthquakes occur relative to the high-velocity slab (e.g., toward the top or in the middle). Reconciliation of the amplitude, waveform distortion, and timing of body waves from deep events is necessary to understand the geometry of slabs near and below the 650 km discontinuity.

我们建议调查波形，振幅和走时 地震和爆炸产生的体波， 俯冲板片在0 ~ 1500深度范围内的速度结构。 Creager和Jordon（1986年）提出，俯冲的穿透 千岛群岛和其他俯冲带下的板块 至少有1000公里是必要的，以解释旅行时间异常的 深层地震 这种穿透也会影响振幅 和地震体波的波形。 我们最近开发的方法允许计算 高速俯冲板块的波形和振幅效应。 对现有数据的初步审查表明，我们可以测试和 用这些新方法改进板的地震模型。 我们提议， 以及，完善上地幔板块的模型， 经验上导致甚至更大的波形、幅度和定时 比深层板块更大的异常 我们的方法也可以帮助定位 地震发生的位置相对于高速板块 (e.g.,在顶部或中间）。 对账 振幅，波形失真，以及来自深海的体波的时间 事件是必要的，以了解几何板附近， 在650公里的不连续面以下。