| Title: |
Climate Response to Orbital Forcing Across the Oligocene-Miocene Boundary |
| Authors: |
Zachos, James C.; Shackleton, Nicholas J.; Revenaugh, Justin S.; Pälike, Heiko; Flower, Benjamin P. |
| Source: |
Science ; volume 292, issue 5515, page 274-278 ; ISSN 0036-8075 1095-9203 |
| Publisher Information: |
American Association for the Advancement of Science (AAAS) |
| Publication Year: |
2001 |
| Description: |
Spectral analyses of an uninterrupted 5.5-million-year (My)–long chronology of late Oligocene–early Miocene climate and ocean carbon chemistry from two deep-sea cores recovered in the western equatorial Atlantic reveal variance concentrated at all Milankovitch frequencies. Exceptional spectral power in climate is recorded at the 406-thousand-year (ky) period eccentricity band over a 3.4-million-year period [20 to 23.4 My ago (Ma)] as well as in the 125- and 95-ky bands over a 1.3-million-year period (21.7 to 23.0 Ma) of suspected low greenhouse gas levels. Moreover, a major transient glaciation at the epoch boundary (∼23 Ma), Mi-1, corresponds with a rare orbital congruence involving obliquity and eccentricity. The anomaly, which consists of low-amplitude variance in obliquity (a node) and a minimum in eccentricity, results in an extended period (∼200 ky) of low seasonality orbits favorable to ice-sheet expansion on Antarctica. |
| Document Type: |
article in journal/newspaper |
| Language: |
English |
| DOI: |
10.1126/science.1058288 |
| Availability: |
https://doi.org/10.1126/science.1058288; https://www.science.org/doi/pdf/10.1126/science.1058288 |
| Accession Number: |
edsbas.941B3C5D |
| Database: |
BASE |