Preparing Seismic Applications for Exascale Using Scientific Workflows

<p><span dir="ltr" role="presentation">Scientific workflows are key to supporting the execution of large-scale simulations in many scientific </span><span dir="ltr" role="presentation">domains, including solid earth geophysics. Although many different workflow tools exist, they share </span><span dir="ltr" role="presentation">common features, enabling application developers to express their simulations as a series of linked </span><span dir="ltr" role="presentation">software elements with data dependencies and then execute the workflow efficiently on distributed </span><span dir="ltr" role="presentation">resources.</span></p> <p><span dir="ltr" role="presentation">To illustrate the use and benefits of scientific workflows in seismic applications, this talk will describe </span><span dir="ltr" role="presentation">CyberShake, a probabilistic seismic hazard analysis (PSHA) platform developed by the Southern </span><span dir="ltr" role="presentation">California Earthquake Center (SCEC). CyberShake uses 3D physics-based wave propagation </span><span dir="ltr" role="presentation">simulations with reciprocity to calculate ground motions for events from an earthquake rupture forecast </span><span dir="ltr" role="presentation">(ERF). Typically, CyberShake considers over 500,000 events per site of interest, and then combines </span><span dir="ltr" role="presentation">the individual ground motions with probabilities from the ERF to produce site-specific PSHA curves. </span><span dir="ltr" role="presentation">CyberShake has integrated modules from another SCEC workflow application, the Broadband Platform </span><span dir="ltr" role="presentation">(BBP), enabling CyberShake simulations to include both low-frequency deterministic and high-</span><span dir="ltr" role="presentation">frequency stochastic content. This talk will discuss the workflow framework that CyberShake utilizes </span><span dir="ltr" role="presentation">to support campaigns requiring hundreds of thousands of node-hours over months of wall clock time, </span><span dir="ltr" role="presentation">and the lessons learned through 15 years of CyberShake simulations.</span></p> <p><span dir="ltr" role="presentation">This talk will also reflect on the growth and development of workflow-based simulations and explore </span><span dir="ltr" role="presentation">the challenges faced by applications in the exascale era, such as managing massive volumes of data, </span><span dir="ltr" role="presentation">taking full advantage of exascale systems, and the emergence of AI-informed simulations. The talk </span><span dir="ltr" role="presentation">will discuss ways in which workflow technologies may help mitigate these challenges as we move our </span><span dir="ltr" role="presentation">science forward.</span></p>