Table 1 Scenarios to explain Late Oligocene trends in SST and deep sea δ18O.
From: Strength and variability of the Oligocene Southern Ocean surface temperature gradient
Scenario | Antarctic proximal SST | Subtropical SST | Deep ocean δ18O | Evaluation |
|---|---|---|---|---|
Observations from the Late Oligocene proxy data | Cooling | Stable/slight warming | Decreasing | Target |
1. pCO2 decrease | Cooling | Cooling | Increasing | Failure |
2. Antarctic Ice Sheet expansion | Cooling | Stable/slight cooling | Increasing | Failure |
3. Deepening of oceanic gateways and Antarctic ice loss | Cooling | Stable | Decreasing | Success |
