Alkalinity generation in coastal sediments

The ocean stores the largest pool of CO2 on Earth. This storage capacity is regulated by the seawater's alkalinity content (excess of bases over acids). A higher oceanic alkalinity content increases the solubility of CO2 in seawater, and this process controls atmospheric CO2 concentrations and Earth's climate on a timescale of hundreds to thousands of years. Marine sediments account for ~40% of the ocean's alkalinity input, thereby playing an essential role in our climate. Sedimentary alkalinity production occurs through three main pathways: carbonate dissolution, denitrification, and sulphate reduction. These processes can interact, and increasing the rate of one may decrease the rate of another. However, the interactions are poorly understood, limiting our ability to predict the net release of alkalinity from the sediment and, ultimately, the ocean's CO2 uptake capacity. In this project, we aim to shed light on how alkalinity-generating processes in the sediment interact, focusing on how environmental conditions impact this dynamic. Over a yearly cycle, we will track how the sedimentary alkalinity release changes according to seasonal patterns and between different sediment types and communities of benthic animals. This study has the potential to significantly advance our understanding of the processes regulating sedimentary alkalinity production, particularly the role of interaction effects, and thereby contribute to more accurate climate predictions.

Cruises

Plan code Principal Investigator Duration Shared campaigns