SGER: Character and preservation of hurricane Rita storm surge sedimentation in Louisiana coastal marshes.

Character and preservation of Hurricane Rita storm surge sedimentation in Louisiana coastal marshes.Project Abstract（1）技术描述：建议研究飓风丽塔在Louisiana coastal marshes的风暴潮沉积物，以帮助回答两个具有重大社会意义的问题：如何对长期的沿海沼泽沉积物具有重要意义？海岸沼泽的风暴潮沉积物与海啸沉积物有区别吗？为了解决第一个问题，建议在风暴潮沉积物沉积后数周内对沉积物进行取样和定性，而沉积物将位于沼泽表面，可以清楚地识别，相对不受侵蚀和生物扰动的影响。同样的沉积物将在1.5年后重新调查，以确定有多少存款被纳入沼泽，并有助于长期沼泽沉积。这一贡献的重要性将通过比较风暴潮沉积与从铯-137测年获得的底层沼泽的长期平均沉积速率来确定。第二个问题将通过确定风暴潮沉积物内的内部沉积结构是否支持以下假设来解决：海啸沉积物可以通过与海啸波列一致的多个含沉积物水脉冲的内部证据来识别。这种结构在海啸沉积物中很常见，但在风暴潮沉积物中显然不存在。(2)非技术性说明：飓风引起的风暴潮沉积可能是沿海沼泽生长的一个重要但知之甚少的机制。这项研究的数据将提高我们对这种机制的理解，以及我们准确和现实地预测沼泽生长的能力。更好地了解沼泽沉积对于研究易受全球变暖引起的海平面上升影响的沿海沼泽的命运将是重要的，更好地了解风暴潮沉积物对长期沼泽沉积的潜在影响将导致对长期沼泽增长的更可靠和更现实的预测。这种预测能力对于有效保护和管理这些具有生态和商业重要性的生境至关重要。海啸沉积物的可靠识别是有效估计地震复发间隔和海啸减灾研究所必需的。该项目还将有助于整合研究和教育，因为研究生研究助理将参与实地工作和实验室工作，并将该项目作为硕士论文的基础。这一项目的成果将广泛传播，以各种方式提高科学和技术认识，使科学研究人员、决策者和广大公众都能了解。预计这一项目将产生若干会议报告和同行评审的期刊文章。

Character and preservation of Hurricane Rita storm surge sedimentation in Louisiana coastal marshes.Project Abstract(1) technical description:It is proposed to study storm surge deposits of Hurricane Rita in Louisiana coastal marshes to help answer two questions of significant societal importance: how significant to long-term coastal marsh sedimentation are episodic, but large inputs of sediment from hurricane storm surges? and, are storm surge deposits distinguishable from tsunami deposits in coastal marshes? To address the first question it is proposed to sample and characterize the storm surge deposits within weeks of deposition, while the sediments will be at the surface of the marsh, clearly identifiable and relatively undisturbed by erosion and bioturbation. The same deposits will resurveyed after 1.5 years to determine how much of the deposit is incorporated into the marsh and contributes to long-term marsh sedimentation. The significance of this contribution will be determined by comparing the storm surge sedimentation to long-term average sedimentation rates of the underlying marsh gained from cesium-137 dating. The second question will be addressed by determining if internal sedimentary structures within the storm surge deposits support the hypothesis that tsunami deposits can be identified by internal evidence of multiple pulses of sediment-laden water, consistent with a tsunami wave train. Such structures are common in tsunami deposits, but are apparently absent in storm surge deposits.(2) nontechnical description:Hurricane-derived storm surge sedimentation may be an important, but poorly understood mechanism of coastal marsh growth. Data from this study will improve our understanding of this mechanism and our ability to accurately and realistically predict marsh growth. Better understanding of marsh sedimentation will be important for studies of the fate of coastal marshes vulnerable to sea level rise caused by global warming.Better understanding of the potential impact of storm surge deposits on long-term marsh sedimentation will result in more reliable and realistic predictions of long-term marsh growth. This predictive capability will be important for the effective protection and management of these ecologically and commercially important habitats. Reliable identification of tsunami deposits is required for effective estimation of earthquake recurrence intervals and for tsunami hazard mitigation research. This project will also serve to integrate research and education, because a graduate research assistant will participate in fieldwork and laboratory work and will use the project as the basis for a master's thesis. The results of this project will be broadly disseminated to enhance scientific and technical understanding in a variety of ways, reaching scientific researchers, policy-makers and the public-at-large. It is anticipated that this project will result in several conference presentations and peer-reviewed journal articles.