Ocean-lithosphere dynamics

The oceanic lithosphere, with a life cycle of roughly 200 million years, is a fundamental component of the global plate tectonic system. Its formation, transformation, and eventual recycling are closely linked to the movement of energy and matter within the Earth. These processes not only shape the structure of our planet but also influence the formation of natural resources and the occurrence of major natural hazards, including earthquakes, tsunamis, and volcanic activity.

Continental shelves and passive margins—formed during the breakup of continents and the opening of ocean basins—play a crucial role in both economic and environmental contexts. They host valuable natural resources and provide important storage potential for CO₂, while also being associated with hazards such as submarine landslides and related tsunamis. Active continental margins, particularly subduction zones, are among the most significant sources of geohazards worldwide, generating powerful earthquakes, tsunamis, and volcanic eruptions. In addition, the opening and closing of ocean basins and gateways strongly influence global ocean circulation patterns, thereby impacting Earth’s climate over long timescales.

Over the past decades, extensive marine research—supported by numerous expeditions—has significantly advanced our understanding of oceanic geodynamics. Studies have explored the structure and formation of oceanic crust at mid-ocean ridges and hotspots, the evolution of transform fault systems, and the complex processes occurring in subduction zones. Research in island arc and back-arc regions has shed light on volcanic activity, crust formation, and the development of mineral resources. Furthermore, investigations into continental breakup and large igneous provinces, as well as the evolution of oceanic gateways, have provided key insights into the links between tectonics, ocean circulation, and climate.

Despite these advances, many fundamental questions remain. Future research aims to build on existing knowledge by leveraging modern research infrastructure, advanced instrumentation, and innovative data acquisition and analysis methods. Key research directions include:

• Understanding and predicting natural hazards: Long-term monitoring of the ocean floor and sub-seafloor is essential to better understand the interactions between tectonic processes, mantle dynamics, seismic activity, and volcanic systems. High-resolution, long-duration datasets will improve our ability to assess and eventually anticipate geohazards such as earthquakes, tsunamis, volcanic eruptions, and submarine landslides. These efforts will also contribute to evaluating the potential for CO₂ storage in subseafloor formations.
• Exploring the life cycle of oceanic lithosphere: While many aspects of the plate tectonic cycle are well understood, key questions remain regarding the global cycling of materials and energy, as well as the formation of economically important resources. In particular, the role of mid-ocean ridges, mantle plumes, and large igneous provinces—and their interactions with oceans and climate—requires further investigation through improved and higher-resolution data.
• Investigating the transition from land to sea: Coastal and nearshore regions are increasingly important research areas, as they are highly dynamic and directly affect large populations worldwide. Understanding groundwater systems, sediment dynamics, and the impacts of geohazards in these environments is essential. Rapid-response research following major events, combined with long-term monitoring and geological archives, will enhance our understanding and support the development of mitigation strategies.
• Assessing natural resources in the deep ocean: The exploration of marine mineral resources, particularly seafloor massive sulfide deposits, has gained renewed importance. Alongside evaluating their economic potential, research also focuses on the environmental impacts of potential deep-sea mining, especially on fragile ocean ecosystems. Systematic studies, supported by advanced research infrastructure, are essential to balance resource use with environmental protection.

Together, these research efforts contribute to a deeper understanding of Earth’s dynamic systems and support the development of strategies to address global challenges related to natural hazards, climate change, and sustainable resource management.