The deep sea holds secrets of Earth’s past, with sediment layers recording carbon cycles, climate shifts, and ecosystem upheavals. The Pacific Ocean, holding most heat and carbon, remains one of the least explored regions when it comes to long-term climate data.
Only eight Pacific High sites have been sampled using modern drilling methods, leaving legacy data as the primary source of insights. Sediment cores from these sites reveal Earth’s ancient greenhouse climates, mass extinctions, and oceanic anoxic events. However, sediment continuity is not guaranteed due to currents and internal tides that can erode layers.
Scientists argue for multi-site sampling to gather more complete and widespread records of zonal and latitudinal ocean changes over time. Technology has improved ocean drilling, enabling long, continuous core recovery from multiple holes per site.
Despite efforts, many key events remain poorly represented in Pacific cores. New proxies are being developed to study microbial communities, biomarkers, and porewaters, but fresh sediment is needed. Gaps in spatial data limit model accuracy, emphasizing the importance of gathering new cores to improve climate models.
Scientific drilling helps reconstruct circulation patterns, biological pump dynamics, and responses to warming and acidification. These insights are crucial for understanding how oceans will absorb excess CO2 and how marine life will adapt – or collapse. A global cooperation effort is necessary to advance scientific progress, including the revival of sites like Hess Rise and launching new expeditions.
The Pacific Highs serve as training grounds for ocean scientists, fostering international collaboration and hands-on experience. The study published in Paleoceanography and Paleoclimatology highlights the importance of sampling the past for predicting Earth’s future climate.
Source: https://www.earth.com/news/pacific-sediment-cores-unlock-millions-of-years-of-climate-history