Geology: Deep-sea hiatuses track the vigor of Cenozoic ocean bottom currents

The deep-sea stratigraphic record is full of gaps. These hiatuses track changes in ocean circulation and chemistry, but determining their timing and causes has been limited by sparse data and incomplete knowledge of ocean gateway evolution in earlier studies. We combine a significantly expanded, age-calibrated deep-sea stratigraphic database with a global tectonic and paleo–water depth model to investigate the distribution of >400 Cenozoic hiatuses longer than ~0.2 m.y. We find that only a small number of hiatuses are due to carbonate dissolution. The majority of hiatuses were, by implication, caused by mechanical erosion and redistribution of sediments by bottom currents into regions of increased sedimentation such as contourite drifts. We link peaks in regional hiatuses to changes in ocean circulation and intensification of deep-water formation. Widespread hiatuses in the South Atlantic, South Pacific, and southern Indian oceans between ca. 34 Ma and 30 Ma are attributed to the coeval widening and deepening of the Drake Passage and the opening of the deep Tasman Gateway. A peak in hiatuses in the Atlantic in the early Miocene is linked to the initiation of a proto–Atlantic Meridional Overturning Circulation driven by the complete opening of the deep Drake Passage and the progressive closure of the Tethys seaway. A long-term 30% decline in hiatus frequency since ca. 14 Ma is synchronous with post–Miocene Climate Optimum cooling, suggesting the slowing of abyssal circulation. Our synthesis of deep-sea hiatuses could be used to track the fate of deep-sea sediments and to ground-truth deep-ocean circulation models.

Adriana Dutkiewicz, Dietmar Müller; Deep-sea hiatuses track the vigor of Cenozoic ocean bottom currents. Geology 2022; doi: https://doi.org/10.1130/G49810.1

Download the open-access paper here:

The input data for individual drilling sites used in the paper can be downloaded here

Media pieces:

Cosmos: When the Earth warms, the ocean speeds up

IFLScience: Global Heating Means Faster Ocean Currents, 66 Million Years Of Data Suggests

Vista Al Mar: El calentamiento global acelera las corrientes en el océano profundo

Notimerica: El calentamiento acelera las corrientes en los abismos oceánicos

CHRONICA: El calentamiento acelera las corrientes en los abismos oceánicos

Gamingsym: Die globale Erwärmung beschleunigt Strömungen im Abgrund des Ozeans

Nachwelt: Die globale Erwärmung beschleunigt Strömungen im Abgrund des Ozeans

Focus Technica: Missing Link: Global Warming Speeds Up Currents in the Ocean’s Abyss

Fishingwire: GLOBAL WARMING SPEEDS UP CURRENTS IN THE OCEAN’S ABYSS

CNBETA: 缺失环节:研究发现全球变暖加速了深海环流

 779 total views,  3 views today

Share