RUI: Using an Elastic Dislocation Model to Test an Alternative Hypothesis Regarding the Cascadia Subduction Zone

RUI：使用弹性位错模型来检验有关卡斯卡迪亚俯冲带的替代假设

• 批准号: 0308565
• 负责人: David Verdonck
• 金额: $ 1.6万
• 依托单位: SUNY College at Geneseo
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-09-01 至 2004-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0308565&HistoricalAwards=false
• 关键词: RUI; Using; Elastic; Dislocation; Model

VerdonckEAR-0208019In most models of Cascadia subduction, lithology and heat flow models constrain the downdip extent of coupling between the subducting and overriding plates. Recent seismological studies suggest that some of the previous assumptions made regarding lithology may be unjustified. A preliminary model suggests that active surface deformation can be the result of deep coupling in addition to the shallow region that is indicated by currently accepted models. An exploratory model is being developed that tests the hypothesis that the Cascadia subduction zone is locked deeper than currently thought. Traditional two dimensional dislocation modeling is being employed as a first step, possibly followed by more advanced models.Three seismic hazards pose a threat to western Oregon and Washington state: large megathrust earthquakes; moderate size earthquakes on crustal faults; and large intraplate earthquakes within the subducted slab. All three of these hazards may be influenced by the location and extent of coupling between the subducting Juan de Fuca and overriding North America plates. Reducing the uncertainty regarding the downdip limit of this locked region will allow for better assessment of the potential for damaging earthquakes near the highly populated urban areas of the Pacific Northwest.

在卡斯卡迪亚俯冲的大多数模型中，岩性和热流模型限制了俯冲板块和覆盖板块之间耦合的下倾程度。最近的地震学研究表明，以前关于岩性的一些假设可能是不合理的。初步的模型表明，活跃的表面变形可以是深耦合的结果，除了浅区域，这是目前公认的模型。目前正在开发一个探索模型，以检验卡斯卡迪亚俯冲带被锁定在比目前认为的更深的地方的假设。 传统的二维位错模型作为第一步被采用，随后可能是更先进的models.Three地震灾害构成了威胁西部俄勒冈州和华盛顿州：大型巨型逆冲断层地震;中等规模的地震地壳断层;和大型板内地震俯冲板。所有这三种危险都可能受到胡安·德富卡俯冲板块和北美板块之间耦合的位置和程度的影响。减少这一锁定区域下倾极限的不确定性，将有助于更好地评估太平洋西北部人口稠密的城市地区附近发生破坏性地震的可能性。