期刊
NATURE GEOSCIENCE
卷 9, 期 11, 页码 843-+出版社
NATURE PUBLISHING GROUP
DOI: 10.1038/NGEO2813
关键词
-
资金
- Petroleum Research Fund of the American Chemical Society
- Evolving Earth Foundation
- NSF [0623487, 1304366, 1459280, 1545859]
- Directorate For Geosciences
- Division Of Ocean Sciences [1304480, 1304366] Funding Source: National Science Foundation
- Directorate For Geosciences
- Division Of Ocean Sciences [1459280, 0623487] Funding Source: National Science Foundation
During the late Miocene epoch, about seven million years ago, large areas of the continents experienced drying, enhanced seasonality, and a restructuring of terrestrial plant and animal communities. These changes are seen throughout the subtropics, but have typically been attributed to regional tectonic forcing. Here we present a set of globally distributed sea surface temperature records spanning the past 12 million years based on the alkenone unsaturation method. We find that a sustained late Miocene cooling occurred synchronously in both hemispheres, and culminated with ocean temperatures dipping to near-modern values between about 7 and 5.4 million years ago. The period of maximum cooling coincides with evidence for transient glaciations in the Northern Hemisphere and with a steepening of the pole-to-equator temperature gradient, as well. We thus infer that late Miocene aridity and terrestrial ecosystem changes occurred in a global context of increasing meridional temperature gradients. We conclude that a global forcing mechanism, such as the previously hypothesized decline in atmospheric CO2 levels between eight and six million years ago, is required to explain the late Miocene changes in temperature, climate and ecosystems.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据