Solid Earth (SE) sciences address fundamental problems in understanding the Earth. Exascale computing will allow advances on, at least, three fronts:
1. On explicitly solving problems that, traditionally, have been parameterized because are unaffordable in terms of size, model resolution, complex physical couplings, and huge amounts of data involved.
2. On solving currently affordable problems but with much less computing time. This is critical in scenarios of early warning and emergency management.
3. Introducing a probabilistic framework through a large ensemble of model realizations, model data assimilation, and uncertainty quantification.
SE sciences have significant scientific and socioeconomic implications, including geohazards, hydrocarbon and energy resource exploration, or containment of underground waste and carbon sequestration. From a social point of view, it is important to foster scientific, engineering, and information technology innovation for a better risk management of geohazards. This is relevant to support the preparation of EU policies on risk mitigation and adaptation and assist in the development of civil protection capabilities to protect EU citizens from geohazards.
The Center of Excellence for Exascale in Solid Earth (ChEESE; GA No 823844) has run from November 2018 to March 2021. ChEESE has prepared 10 Community flagship codes in the areas of computational seismology, tsunamis, volcanology and magnetohydrodynamics for the present pre-exascale and the upcoming exascale hardware architectures. The flagship applications have been used together with workflows to implement 12 Pilot Demonstrators (PDs) addressing exascale capability and capacity challenges in the area of SE. The 8 PDs reaching a TRL equal or higher than 5 during the second half of the project have also been used to enable and validate services on critical aspects of geohazards such as urgent computing during emergency situations, probabilistic hazard assessment, early warning, and Earth’s subsurface imaging. This has been done in close collaboration with members of the Industry and Users Board (IUB), which have also furnished the appropriate use-cases and requirements to perform 14 test cases and 6 live exercises in which services ran in operational mode. ChEESE has also been very successful in integrating the community around HPC and leveraging the growth of an ecosystem of “child” projects and initiatives that benefit from (and synergize with) the CoE.