首页|Effects of Mass Wasting on the Physiochemical Properties of Fluvial Sediments in Puerto Rico Following Hurricane Maria
Effects of Mass Wasting on the Physiochemical Properties of Fluvial Sediments in Puerto Rico Following Hurricane Maria
扫码查看
点击上方二维码区域，可以放大扫码查看
原文链接
NSTL
Amer Geophysical Union
Mass wasting plays an important role in carbon cycling and sequestration by exposing fresh bedrock and delivering hillslope sediments to lowlands and fluvial systems. Chemical weathering signatures of landslide-derived fluvial sediments can be used to understand linkages between hillslope and fluvial processes and thus to characterize spatiotemporal dynamics of sediments. However, chemical signatures of fluvial sediments derived by landslides are yet to be fully understood. Here, we compare the bulk chemistry, mineralogy, and grain size of fluvial sediments collected pre- and post-Hurricane Maria in the Rio Guayanes and Rio Guayabo watersheds in southeastern Puerto Rico to help fill this knowledge gap. Comparison of the mud fraction (<63 mu m) of fluvial sediments collected before Hurricane Maria with similar mud fractions collected after the storm reveals that the post-hurricane muds exhibit a wider range and higher average weathering index values, but coarser grain size modes. We infer that small landslides triggered by Hurricane Maria transported slope materials from shallow depths, including weathered topsoil and saprolite, as opposed to previous deep-seated landslides, which likely sampled regolith and bedrock. Variances in weathering indices observed that pre- and post-hurricanes do not necessarily reflect average climate signatures, but rather reflect subtle differences in a transport mechanism, which produce significant differences in weathering indices recorded by fluvial sediments. We propose that weathering indices provide a means to understand sediment dynamics in mountainous regions, particularly for sediment transported immediately after landslides triggered by extreme events, such as precipitation and earthquakes, and also provide important data sets required for mapping potential carbon sequestration across landscapes.
mass wastingchemical index of weatheringHurricane Marialandslidesfluvial sedimentscarbon sequestrationCHEMICAL-WEATHERING RATESTRIGGERED LANDSLIDESGRAIN-SIZERIVER-BASINHILLSLOPECLIMATERAINFALLBEDROCKMOUNTAINSCHEMISTRY
Webb, N. D. S.、Regmi, N. R.、Soreghan, G. S.、Madden, A. S. Elwood、Sylvester, J.、Colon, F. Cartagena、Demirel-Floyd, C.、Madden, M. E. Elwood
NSTL
Amer Geophysical Union
