Arid
DOI10.1002/jgrf.20101
Mechanisms of dust emission from Pleistocene loess deposits, Nebraska, USA
Sweeney, Mark R.1; Mason, Joseph A.2
通讯作者Sweeney, Mark R.
来源期刊JOURNAL OF GEOPHYSICAL RESEARCH-EARTH SURFACE
ISSN2169-9003
EISSN2169-9011
出版年2013
卷号118期号:3页码:1460-1471
英文摘要

Saltation bombardment is commonly believed to be the primary mechanism by which large quantities of dust can be generated. Direct entrainment of silt, on the other hand, is thought to generate minimal quantities of dust. If so, loess landscapes should rarely be major sources of dust unless disturbed by human activity. To test the mechanisms by which loess can be eroded by the wind, we used the Portable In-Situ Wind Erosion Lab (PI-SWERL). PI-SWERL tests were conducted on benches that were carved into loess at field locations. Coarse to fine loess was also collected and tested in a controlled setting using (1) dry, unconsolidated loess and (2) crusted loess. Results indicate that in most cases, the threshold friction velocity for silt is less than that for sand and that most dust generation occurs by direct entrainment of dust. Saltation, even in coarse loess, was nonexistent to intermittent. In a few cases, saltation of sand or soil aggregates preceded dust generation or enhanced emissions after direct entrainment began. Emission fluxes of loess are potentially high in both proximal and distal settings, suggesting that loess is easily entrainable if vegetation density is low. We hypothesize that an arid and windy climate of the late Pleistocene, paired with lower vegetation density, facilitated large-scale erosion of Peoria Loess in Nebraska to generate wind-aligned ridges and troughs. More broadly, our results indicate that loess landscapes have the potential to be major sources as well as sinks of dust.


英文关键词loess dust direct entrainment PI-SWERL aggregates
类型Article
语种英语
国家USA
收录类别SCI-E
WOS记录号WOS:000325978500020
WOS关键词CENTRAL GREAT-PLAINS ; WIND EROSION ; COLUMBIA PLATEAU ; DUNE ACTIVITY ; PEORIA-LOESS ; SOIL ; SALTATION ; DESERT ; ACCUMULATION ; TRANSPORT
WOS类目Geosciences, Multidisciplinary
WOS研究方向Geology
资源类型期刊论文
条目标识符http://119.78.100.177/qdio/handle/2XILL650/178440
作者单位1.Univ S Dakota, Dept Earth Sci, Vermillion, SD 57069 USA;
2.Univ Wisconsin, Dept Geog, Madison, WI 53706 USA
推荐引用方式
GB/T 7714
Sweeney, Mark R.,Mason, Joseph A.. Mechanisms of dust emission from Pleistocene loess deposits, Nebraska, USA[J],2013,118(3):1460-1471.
APA Sweeney, Mark R.,&Mason, Joseph A..(2013).Mechanisms of dust emission from Pleistocene loess deposits, Nebraska, USA.JOURNAL OF GEOPHYSICAL RESEARCH-EARTH SURFACE,118(3),1460-1471.
MLA Sweeney, Mark R.,et al."Mechanisms of dust emission from Pleistocene loess deposits, Nebraska, USA".JOURNAL OF GEOPHYSICAL RESEARCH-EARTH SURFACE 118.3(2013):1460-1471.
条目包含的文件
条目无相关文件。
个性服务
推荐该条目
保存到收藏夹
导出为Endnote文件
谷歌学术
谷歌学术中相似的文章
[Sweeney, Mark R.]的文章
[Mason, Joseph A.]的文章
百度学术
百度学术中相似的文章
[Sweeney, Mark R.]的文章
[Mason, Joseph A.]的文章
必应学术
必应学术中相似的文章
[Sweeney, Mark R.]的文章
[Mason, Joseph A.]的文章
相关权益政策
暂无数据
收藏/分享

除非特别说明,本系统中所有内容都受版权保护,并保留所有权利。