Broadening participation in STEM, particularly in geoscience, requires approaches that increase awareness, reduce structural barriers to participation, and foster opportunities to successfully "try on" the discipline. The Seismology Skill Building Workshop (SSBW) is a free MOOC that has developed scientific computing skills of more than 2,500 participants within a seismology context. Recent studies of the SSBW have shown its success in attracting a diverse population, including ~33% non-geoscience majors, producing large skill gains and increased intent to pursue geoscience. These results have been interpreted as due to efficacious and equitable instructional design choices, but the long-term impacts of the workshop for broadening participation in STEM were unknown.

To explore this, we designed a longitudinal survey exploring participants' subsequent actions and perspectives on the SSBW's influence. The survey was distributed to all participants, 2020-2024, who had completed the SSBW (n=751) and received 153 complete responses. We found 79% of current students and 70% of geoscience majors had engaged in post-SSBW scientific computing, coursework, or research. However, only 57% of those currently employed and 55% of non-geoscience majors had post-SSBW engagement, primarily due to lack of opportunity. Over 80% of respondents said the SSBW had a "moderate" to "very great" influence on their post-SSBW engagement. Intriguingly, over 60% of non-geoscience majors chose great to very great, compared to ~40% for geoscience majors. When asked about graduate school, 88% of all survey participants were interested or already in graduate school (85% for non-geoscience, 90% for geoscience), and only 11% of participants did not receive an offer upon applying. We also found that although confidence in scientific computing grew the most during the SSBW, it has continued to grow. Overall, these results suggest the SSBW, and other opportunities like it can impact the recruitment and retention of large numbers of students into the geosciences.