Ocean Planet: An ANZIC workshop report focused on future research challenges and opportunities for collaborative international scientific ocean drilling

The ANZIC Ocean Planet Workshop (14-16 April 2019) and focused Working Group sessions represent a multidisciplinary community effort that defines scientific themes and challenges for the next phase of marine research using the capabilities of current and anticipated platforms of the International Ocean Discovery Program (IODP). Attended by 75 mostly early- and mid-career participants from Australia, New Zealand, Japan, and the United States, the workshop featured nine keynote presentations. Working groups identified important themes and challenges that are fundamental to understanding the Earth system. This research relies upon ocean-going research platforms to recover geological, geobiological, and microbiological information preserved in sediment and rock beneath the seafloor and to monitor subseafloor environments through the global ocean. The workshop program was built around five scientific themes: Biosphere Frontiers, Earth Dynamics, Core to Crust, Global Climate, Natural Hazards, and Ocean Health through Time. Workshop sessions focused on these themes and developed 19 associated scientific challenges. Underpinning these are legacy samples and data, technology, engineering, education, public outreach, big data, and societal impact. Although all challenges are important, the asterisks that follow denote those of particular relevance and interest to ANZIC. Ocean Health through Time comprises the ocean’s response to natural perturbations in biogeochemical cycles*; the lateral and vertical influence of human disturbance on the ocean floor; and the drivers and proxies of evolution, extinction, and recovery of life*. Global Climate entails coupling between the climate system and the carbon cycle; the drivers, rates, and magnitudes of sea level change in a dynamic world*; the extremes, variations, drivers, and impacts of Earth’s hydrologic cycle*; and cryosphere dynamics*. Biosphere Frontiers addresses the habitable limits for life*; the composition, complexity, diversity, and mobility of subseafloor communities*; the sensitivity of ecosystems to environmental changes; and how the signatures of life are preserved through time and space*. Earth Dynamics: Core to Crust encompasses the controls on the lifecycle of ocean basins and continents*; how the core and mantle interact with Earth’s surface*; the rates, magnitudes, and pathways of physico-chemical transfer among the geosphere, hydrosphere, and biosphere*; and the composition, structure, and dynamics of Earth’s upper mantle. Natural Hazards involves the mechanisms and periodicities of destructive earthquakes*; the impacts of submarine and coastal volcanism; the consequences of submarine slope failures on coastal communities and critical infrastructure*; and the magnitudes, frequencies, and impacts of natural disasters*. The ANZIC Ocean Planet Workshop will contribute to formulating the next science framework for scientific ocean drilling which in turn will guide the focused planning of specific drilling, logging, and monitoring projects