Revision 1

Accepted · first revision · record

Title: Is an earthquake's final magnitude determined in its first seconds?
Plain: A small and a giant earthquake may start out looking identical. Whether the first seconds of shaking already reveal how big the quake will get decides how useful early warning can be.
Precise: Using global catalogs of source time functions, determine whether the moment-rate function in the first few seconds statistically predicts the final moment magnitude $M_w$ for large events (weak or strong determinism), or whether growth is universal until arrest. An answer is a statistically significant discrimination of final $M_w$ from early moment rate, with stated scatter, or proof of indistinguishability.
Settled by: Analysis of near-field and teleseismic source time functions of many $M \ge 7$ events with uniform processing.
Kind: well-posed
Answer type: yes-no
References: (empty)
Literature status: contested
Status note: Meier and coauthors (Science, 2017) reported universal initial moment-rate growth for large subduction earthquakes, while other source-time-function studies report weak determinism; contested as of 2025.
Posed since: (empty)