Hurricanes alter 10 Be concentrations in tropical river sediment but do not change regional erosion rate estimates
Hurricanes alter 10 Be concentrations in tropical river sediment but do not change regional erosion rate estimates
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飓风改变了热带河流沉积物中 10 Be 的浓度，但不改变区域侵蚀率估计
DOI：
10.1002/esp.5310
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发表时间：
2022
影响因子：
3.3
通讯作者：
Caffee, Marc
中科院分区：
文献类型：
--
作者：
Quock, Melinda;Schmidt, Amanda H.;Corbett, Lee B.;Bierman, Paul R.;Hidy, Alan J.;Caffee, Marc
热带岛屿，包括许多岛弧内的岛屿，经常遭受热带气旋等极端风暴的干扰。为了测试此类风暴是否会影响宇宙成因核素浓度，使其不反映长期侵蚀率，我们在五级飓风玛丽亚（2017 年）前后测量了加勒比海安山岩岛多米尼加河流沉积物样本中的大气和原位 10Be。风暴前和风暴后浓度的总体在统计上无法区分（对于原位 10Be，n= 7 对，对于流星 10Be，n= 11 对）。前后样本对中 10Be 浓度相对于该对平均值的变化范围为 -138% 到 +73%。这些新数据表明，极端风暴对多米尼加近地表侵蚀深度和数量的影响在空间上存在差异。我们的数据支持 Niemi 等人的计算。 (2005) 和 Yanites 等人。 （2009）建议在受质量运动和极端风暴影响的小型（<~100km2）流域中，应谨慎对待基于宇宙成因核素的侵蚀率的流域比较。与全球类似的陡峭和潮湿地区相比，多米尼加原位10Be确定的侵蚀率（几何平均值 = 0.102 mm y−1，n= 12）较低，并且与质量运动的空间密度呈正相关。
Tropical islands, including many in island arcs, are subjected to recurring disturbances from extreme storms such as tropical cyclones. To test whether such storms influence cosmogenic nuclide concentrations such that they do not reflect long‐term rates of erosion, we measured meteoric andin situ10Be in river sediment samples from Dominica, an andesitic island in the Caribbean, before and after category five Hurricane Maria (in 2017). Populations of before‐ and after‐storm concentrations are statistically indistinguishable (n= 7 pairs forin‐situ10Be,n= 11 pairs for meteoric10Be).10Be concentrations vary from −138% to +73% within before–after sample pairs relative to the mean of the pair. These new data suggest that the effects of extreme storms on the depth and amount of near‐surface erosion on Dominica vary spatially. Our data support the calculations of Niemi et al. (2005) and Yanites et al. (2009) suggesting that basin‐by‐basin comparisons of erosion rates based on cosmogenic nuclides should be approached with caution in small (<~100 km2) watersheds affected by mass movements and extreme storms. Erosion rates determined fromin‐situ10Be on Dominica (geometric mean = 0.102 mm y−1,n= 12) are low compared to similarly steep and wet areas globally and correlate positively with the spatial density of mass movements.