ISROC—Inundation Signatures on ROcky Coastlines—A new Research Coordination Network targeting coastal boulder deposits

Intertidal and supratidal coastal boulder deposits (CBD) result from extreme marine inundation on rocky shores. They are important for understanding long-term coastal wave patterns, have predictive value for future events and can support coastal hazard assessment. But they are poorly studied, and their interpretation remains contentious, with debate on whether they record storms, tsunami, or both. In the case of older deposits, uncertainties about paleo-sea level contribute additional uncertainty. These ambiguities impact risk analysis: should CBD data be part of tsunami risk catalogues, or storminess indices? The hydrodynamics and climatology leading to CBD generation are also still uncertain. Two main obstacles to deeper understanding have been identified: a lack of data on CBD worldwide; and discrepant approaches that lead to difficulties in comparing data from different sites. Building community and interaction among CBD researchers, and awareness of CBD as research targets, can help grow our knowledge and tackle these obstacles.

ISROC (www.isroc.network)—Inundation Signatures on Rocky Coastlines—is an NSF-funded Research Coordination Network to define the CBD problem chain and identify research gaps by developing a broad and diverse network of researchers. The authors of this paper are the PIs and steering group. We plan to extend the community of researchers, in particular to include underrepresented groups; to facilitate development of standards and best practices for gathering and archiving CBD data; to develop cyberinfrastructure for uploading, visualizing, and analyzing data; and train the next generation of CBD researchers. To do this, we will create opportunities for cross-disciplinary collaboration and exchange. Using CBD to reconstruct coastal inundation history and extreme climatological states is a prime example of convergence research that cannot be solved by one discipline. The network includes geologists, geographers, oceanographers, engineers, hydrodynamicists, geophysicists, climatologists and paleoclimatologists. Activities include meetings, student training and exchanges; sessions in future years at major conferences in geoscience and coastal engineering; consolidation of survey/mapping approaches; building a global database; and user-friendly, fully accessible online data archiving. Understanding past inundation and how CBD form and evolve will both help to quantify present-day risk and will provide guidance for what to expect from future climate and sea level.