Quantifying the effects of an extreme earthquake on a large river system

量化极端地震对大型河流系统的影响

基本信息

批准号：
1053504
负责人：
A Joshua West
金额：
$ 29.48万
依托单位：
University of Southern California
依托单位国家：
美国
项目类别：
Continuing Grant
财政年份：
2011
资助国家：
美国
起止时间：
2011-05-01 至 2016-04-30
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=1053504&HistoricalAwards=false
关键词：
Quantifying effects extreme earthquake large

项目摘要

This project will assemble the first integrated picture of how key chemical and physical characteristics of a major river system are affected by extreme disturbance from a large earthquake, using as a basis for study the response of the Min Jiang, or Yangtze River, to the 2008 8.0 Mw earthquake in Wenchuan, China. This earthquake triggered widespread landslides in the Min Jiang catchment area, and our preliminary data indicate that these landslides significantly changed the amount and composition of sediment carried by the river, and the chemistry of the river water. In our research, which seizes the opportunity presented by this rare natural experiment, we will collaborate with colleagues from the UK, Germany, and China to combine (i) compilation and interpretation of hydrometric data from the Chinese Hydrologic Bureau, (ii) fieldwork to collect representative samples, and (iii) new analyses targeted to explore key geochemical signatures in material carried by the river. The results of our measurements will be compared to data collected before the earthquake. In particular, we will explore differences before and after the earthquake in (i) the amount of suspended sediment carried by the river; (ii) the 10Be concentration in riverbed sediments; (iii) the dissolved major element composition of river waters; and (iv) the concentration and flux of particulate organic carbon transported as part of river sediment. In rivers around the world, measurements of sediment concentrations, and of the chemical properties of sediment and river water, have been routinely used to understand some of the most important processes at the Earth?s surface such as 1) physical erosion and sediment mobilization that pose widespread engineering hazards and 2) mineral weathering and organic carbon transport that play central roles in the global carbon cycle. It is commonly assumed that measurements made at any one point in time on a river reflect what is going on over much longer periods of time. If very large disturbances that happen only very rarely ? such as an extreme earthquake ? have significant effects on these measured parameters, then our quantitative understanding of important processes like erosion, sediment mobilization, and the global carbon cycle may be incomplete. The 2008 Wenchuan earthquake in Sichuan, China, provides an ideal and rare opportunity to explore whether this is the case, because the large-magnitude earthquake had such a significant effect in triggering landslides in the headwaters of the Yangtze River, and because we can take advantage of extensive data that were collected on the Yangtze prior to the earthquake. Our research will seize this opportunity by building an international collaboration that will apply a range of approaches to studying this river system.

该项目将首次综合展示主要河流水系的关键化学和物理特征如何受到大地震极端干扰的影响，并以此为基础研究岷江或长江对 2008 年地震的响应中国汶川发生8.0兆瓦地震。此次地震引发了岷江流域大范围的山体滑坡，我们的初步数据表明，这些山体滑坡显着改变了河流携带的泥沙数量和成分，以及河水的化学成分。在我们的研究中，抓住这一罕见的自然实验带来的机会，我们将与来自英国、德国和中国的同事合作，结合（i）中国水文局水文测量数据的汇编和解释，（ii）实地考察，收集代表性样本，以及（iii）新的分析，旨在探索河流携带的物质中的关键地球化学特征。我们的测量结果将与地震前收集的数据进行比较。我们将特别探讨地震前后在以下方面的差异：（i）河流携带的悬浮泥沙量； (ii) 河床沉积物中的 10Be 浓度； (iii) 河水溶解的主要元素组成； (iv) 作为河流沉积物一部分输送的颗粒有机碳的浓度和通量。在世界各地的河流中，沉积物浓度以及沉积物和河水的化学性质的测量通常用于了解地球表面的一些最重要的过程，例如 1) 物理侵蚀和沉积物流动造成广泛的工程危害；2）矿物风化和有机碳迁移在全球碳循环中发挥着核心作用。人们普遍认为，在河流上任何一个时间点进行的测量都反映了更长时间内发生的情况。如果非常大的干扰很少发生？比如极端地震？如果对这些测量参数有重大影响，那么我们对侵蚀、沉积物流动和全球碳循环等重要过程的定量理解可能是不完整的。 2008年中国四川汶川地震为探讨是否确实如此提供了一个理想且难得的机会，因为这次大地震对引发长江源头的山体滑坡影响如此之大，而且因为我们可以采取利用地震前在长江上收集的大量数据。我们的研究将抓住这个机会，建立国际合作，应用一系列方法来研究这个河流系统。

项目成果

期刊论文数量（2）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

Earthquakes drive focused denudation along a tectonically active mountain front

地震导致沿构造活跃的山前集中剥蚀

DOI：
10.1016/j.epsl.2017.04.040
发表时间：
2017-08-15
期刊：
Earth and Planetary Science Letters
影响因子：
5.3
作者：
Gen K. Li;A. West;A. Densmore;Zhangdong Jin;Fei Zhang;Jin Wang;M. Clark;Robert G. Hilton
通讯作者：
Robert G. Hilton

Competing Effects of Mountain Uplift and Landslide Erosion Over Earthquake Cycles

地震周期中山体抬升和滑坡侵蚀的竞争效应