Humans as geologic agents: A deep-time perspective
Humans as geologic agents: A deep-time perspective
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DOI：
10.1130/g21108.1
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发表时间：
2005-03
期刊：
影响因子：
5.8
通讯作者：
B. Wilkinson
中科院分区：
文献类型：
--
作者：
B. Wilkinson
人类在各种建设活动中移动越来越多的岩石和沉积物，农田土壤流失的平均速率可能超过形成速率高达一个数量级，但要认识到人类作为全球侵蚀代理人的实际重要性，就必须了解仅由自然过程对陆地表面施加的史前剥蚀速率。构成大陆和海洋沉积岩的大量风化碎屑提供了这样一个信息来源，并表明过去5亿年地球历史的平均剥蚀使大陆表面每百万年下降几十米。相比之下，建筑和农业活动目前导致足够的沉积物和岩石的运输，使所有无冰的大陆表面每百万年下降几百米。人类现在在移动沉积物方面的作用比地球表面所有其他自然过程的总和要重要一个数量级。土地利用的时间趋势与全球人口之间的关系表明，人类在公元第一个千年的后半期成为侵蚀的主要因素。
Humans move increasingly large amounts of rock and sediment during various construction activities, and mean rates of cropland soil loss may exceed rates of formation by up to an order of magnitude, but appreciating the actual importance of humans as agents of global erosion necessitates knowledge of prehistoric denudation rates imposed on land surfaces solely by natural processes. Amounts of weathering debris that compose continental and oceanic sedimentary rocks provide one such source of information and indicate that mean denudation over the past half-billion years of Earth history has lowered continental surfaces by a few tens of meters per million years. In comparison, construction and agricultural activities currently result in the transport of enough sediment and rock to lower all ice-free continental surfaces by a few hundred meters per million years. Humans are now an order of magnitude more important at moving sediment than the sum of all other natural processes operating on the surface of the planet. Relationships between temporal trends in land use and global population indicate that humans became the prime agents of erosion sometime during the latter part of the first millennium A.D.