Life Sciences Commons^™

Middle Miocene Ice Sheet Dynamics, Deep‐Sea Temperatures, And Carbon Cycling: A Southern Ocean Perspective, Amelia E. Shevenell, James P. Kennett, David W. Lea

Marine Science Faculty Publications

Relative contributions of ice volume and temperature change to the global ∼1‰ δ¹⁸O increase at ∼14 Ma are required for understanding feedbacks involved in this major Cenozoic climate transition. A 3‐ma benthic foraminifer Mg/Ca record of Southern Ocean temperatures across the middle Miocene climate transition reveals ∼2 ± 2°C cooling (14.2–13.8 Ma), indicating that ∼70% of the increase relates to ice growth. Seawater δ¹⁸O, calculated from Mg/Ca and δ¹⁸O, suggests that at ∼15 Ma Antarctica's cryosphere entered an interval of apparent eccentricity‐paced expansion. Glaciations increased in intensity, revealing a central role for internal climate …