Dr. Moses Strauss Department of Marine Geosciences, The Leon H. Charney School of Marine Sciences, University of Haifa, Carmel, 31905, Israel.
GEOMAR Helmholtz Centre for Ocean Research Kiel, Kiel, Germany.
Sci Rep. 2019 Jun 20;9(1):8842. doi: 10.1038/s41598-019-45308-7.
The Tethys Ocean was compartmentalized into the Mediterranean Sea and Indian Ocean during the early Miocene, yet the exact nature and timing of this disconnection are not well understood. Here we present two new neodymium isotope records from isolated carbonate platforms on both sides of the closing seaway, Malta (outcrop sampling) and the Maldives (IODP Site U1468), to constrain the evolution of past water mass exchange between the present day Mediterranean Sea and Indian Ocean via the Mesopotamian Seaway. Combining these data with box modeling results indicates that water mass exchange was reduced by ~90% in a first step at ca. 20 Ma. The terminal closure of the seaway then coincided with the sea level drop caused by the onset of permanent glaciation of Antarctica at ca. 13.8 Ma. The termination of meridional water mass exchange through the Tethyan Seaway resulted in a global reorganization of currents, paved the way to the development of upwelling in the Arabian Sea and possibly led to a strengthening of South Asian Monsoon.
特提斯洋在中新世早期被分隔为地中海和印度洋，但这一分隔的确切性质和时间尚不清楚。在这里，我们从关闭海峡两侧的孤立碳酸盐台地（露头采样）和马尔代夫（IODP 站点 U1468）提供了两个新的钕同位素记录，以限制现今地中海和印度洋之间通过美索不达米亚海峡的过去水体交换的演化。将这些数据与箱式模型结果相结合表明，在大约 2000 万年前的第一步中，水体交换减少了约 90%。然后，海峡的最终关闭与大约 1380 万年前南极洲永久性冰盖开始导致的海平面下降同时发生。通过特提斯海峡的经向水体交换的终止导致了全球海流的重新组合，为阿拉伯海上升流的发展铺平了道路，并可能导致南亚季风的加强。
