CycloNet : European Cyclostratigraphy Network (FWOWO40)

Earth’s weather and climate are cyclic on various timescales. Humans are most familiar with the daily variations in surface temperatures or the seasonal cycle. Over geological timescales, the Earth’s astronomical configuration with respect to the Sun also causes rhythmical climate changes, with known periodicities. Indeed, Solar System gravitational interactions influence Earth’s orientation and position determining the distribution of incoming solar radiation, as the pacing of Quaternary ice ages illustrates. Three parameters, often referred to as Milankovitch parameters, control Earth astronomical configuration: the precession and obliquity of the Earth’s axis (periods: 20 & 41 thousand years, respectively), and the eccentricity of the Earth’s orbit (multiple periods of ~100, 405 & ~2400 thousand years). This scientific network brings together geologists, astronomers, and signal processors to identify, extract and interpret astronomically driven climate changes, recorded in sedimentary geologic archives, by means of time-series analysis. Studying ancient climate signals provide detailed insights into past climate dynamics, including their chronology and pacing. By controlling the distribution of solar energy (in time and space), Milankovitch parameters influence various climate processes (temperature, precipitation, ocean, & atmosphere circulation etc.) that ultimately modify sedimentation patterns. Therefore, the identification of these astronomical cycles engraved in ancient sedimentary sequences (cyclostratigraphy) reconstructs the heartbeat of past climate states (paleoclimatology) and like a metronome, their frequencies accurately reconstruct geological timescales (astrochronology). The study of astronomical climate forcing and the application of cyclostratigraphy experienced a spectacular growth over the last decades. In 2018, the first Cyclostratigraphy Intercomparison Project (CIP) workshop constituted the first attempt to compare different methodological approaches and unite the global community around standard, uniform and reliable procedures. The results, summarized in a review paper published in Earth-Science Reviews (Sinnesael et al., 2019) concluded: [1] There is a need for further organization of the cyclostratigraphic community (e.g. to streamline different methodologies); [2] Cyclostratigraphy is a trainable skill, but currently many universities lack specific resources for training and education. Today, a regular newsletter, a dedicated free open-access journal, a scientific podcast titled CycloPod, and an educational website www.cyclostratigraphy.org connect the cyclostratigraphy community. CycloNet expands this effort into a real and sustainable scientific research network coordinated in Flanders, with partners from all around Europe, and open to the global community. CycloNet structures and officializes the European growing cyclostratigraphic community, in close cooperation with US partners in the CycloAstro project (https://sites.google.com/view/cycloastro/). At the same time, CycloNet creates a platform for streamlining and integrating new multi-disciplinary approaches. The main scientific targets for CycloNet in the next five years are: 1) Set up a diverse and sustainable community structure, relying on exchange, interaction and training. It provides a free state-of-the-art digital educational platform, for lectures to find inspiration and for students to do self-training. It organizes yearly field training courses for early-career cyclostratigraphers and mid-career geologists that want to extend their “skill set”. The latter group is targeted to witness a rapid expansion of cyclostratigraphy training in BSc and MSc programs worldwide. 2) Boost research by novel methodological approaches applying advanced signal processing techniques, driven by collaboration between cyclostratigraphers, astronomers, signal-processing engineers and climate modelers. Incorporate more prior knowledge (e.g., astronomical solutions) into cyclostratigraphic analyses, while at the same time testing astronomical models by means of geologic data. 3) Organize a second Cyclostratigraphic Intercomparison Project, in Brussels in 2023 or 2024. Set up regular meetings (online, hybrid & physical) to present results and new developments as well as detailed field studies/sampling missions to test new developments and methodologies at the outcrop.

Keywords:Cyclostratigraphy, Astrochronology, Trainability

Disciplines:Stratigraphy, Signal processing not elsewhere classified, Astronomy and space sciences not elsewhere classified, Palaeoclimatology