Towards a universal rule in the recurrence interval scaling of repeating earthquakes?
Kate Huihsuan Chen and Ruey-Juin Rau: Department of Earth Sciences, National Cheng Kung University, Tainan, Taiwan;
Robert M. Nadeau: Berkeley Seismological Laboratory, University of California, Berkeley, California, U.S.A.
Geophysical Research Letters (GRL) paper 10.1029/2007GL030554, 2007, http://dx.doi.org/10.1029/2007GL030554
6. Abrupt climate change clues in tropical African sediments
Tropical Africa, affected by both Indian and Atlantic monsoons, is responsible for much of the heat and water vapor that drives deep atmospheric convection. Noting that the relationship between this region's climate and global climate change is not well understood, Tierney et al. compare records of past climate events in tropical Africa with global paleoclimate records. The authors studied a sediment core from Lake Tanganyika, a lake on Tanzania's western border. In the Southern Hemisphere's winter, Indian Ocean monsoons interact with local winds, making southern lake habitats favorable for silica-bearing diatoms. During summer, these winds slacken as the low-pressure Intertropical Convergence Zone (ITCZ) moves southward, making lake habitats favorable for cyanobacteria. The authors analyze the concentrations of biogenic silica found in the core and notice that during known abrupt climate shifts in the Northern Hemisphere, the lake contained fewer diatoms, perhaps influenced by weakened monsoons and t
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American Geophysical Union