Abyssal Manganese Nodule Recording of Global Cooling and Tibetan Plateau Uplift Impacts on Asian Aridification

• Published in: Geophysical research letters 2022-02, Vol.49 (3), p.n/a
• Main Authors: Jiang, X. D., Zhao, X., Zhao, X. Y., Chou, Y.‐M., Roberts, A. P., Hein, J. R., Yu, J. M., Sun, X. M., Shi, X. F., Cao, W., Liu, Q. S.
• Format: Article
• Language: English
• Subjects: Abyssal zone; Aridification; Asian aridification; Atmospheric particulates; Biogeochemical cycles; Biological activity; Blooms; Cooling; Dust; Dust storms; Eolian dust; Ferromanganese nodules; Fossils; Geochemistry; Global cooling; Latitude; Magnetism; Manganese; manganese nodules; Microbial activity; Microorganisms; Miocene; northwest Pacific Ocean; Oceans; Plateaus; Pliocene; Primary production; Productivity; rock magnetism; Uplift; Westerlies
• ISSN: 0094-8276; 1944-8007
• DOI: 10.1029/2021GL096624

The impact of central Asian aridification on the low latitude North Pacific Ocean since the late Miocene remains unclear. To address this question, we systematically studied an abyssal manganese nodule from the northwestern Pacific Ocean, which is expected to be sensitive to eolian dust sourced from central Asia. Geochemical variations and the fossilized remains of magnetotactic bacteria within the studied nodule manifest two prominent Asian aridification events at ∼8–7 Ma and 3.6–0 Ma. These results suggest that central Asian aridification impacted both primary productivity and abyssal microbial activity in the NW Pacific Ocean via eolian dust inputs. In contrast to the Pliocene aridification event, the late Miocene event was associated with a primary productivity bloom that is not evident in coeval global primary productivity records, which indicates that the ∼8–7 Asian aridification event was likely due to NE Tibetan Plateau uplift rather than to global cooling. Plain Language Summary Central Asian aridification since the late Miocene has had a significant influence on climate, temperature, and North Pacific Ocean productivity through eolian dust inputs transported by westerlies. However, it is unclear whether the low latitude of NW Pacific Ocean responded to this aridification. We systematically analyzed the geochemistry and magnetism of a NW Pacific manganese nodule, and find that Asian aridification since, the late Miocene impacted biogeochemical cycling and abyssal microbial activity in the NW Pacific Ocean via eolian dust input. Our results imply that these two prominent Asian aridification events at around 8–7 Ma and ca. 3.6 Ma can be attributed to the NE Tibetan Plateau uplift and global cooling, respectively. Key Points A manganese nodule from the NW Pacific carries a paleoclimatic record of Asian aridification since the Late Miocene Asian aridification impacted biogeochemical cycling and abyssal microbial activity in the NW Pacific Ocean Major Asian aridification events at ∼8–7 Ma and ∼3.6–0 Ma may be attributed to NE Tibetan Plateau uplift and global cooling, respectively