Focal Mechanisms Explained: What are those “beach balls”?

Whole-channel inclusion: IRIS Earthquake Science is an honest teaching channel (title sample + 3 transcripts read: The sampled video with a transcript (Lesson 4 on Well Logs) is a substantive technical lecture consistent with genuine teaching, supporting the 'whole' channel verdict.); this title passed a strict title check (sonnet) after a labelling pass.

A 7-minute video from IRIS Earthquake Science: “Focal Mechanisms Explained: What are those “beach balls”?”.

Video by IRIS Earthquake Science, played through YouTube's embedded player.