A day-and-type shuffle leaves no clear 10-minute magnitude similarity in Ridgecrest on days 1 to 30
We tested whether consecutive Ridgecrest events with short time gaps have similar magnitudes. A fixed USGS sample contains 931 events with preferred magnitude at least 2.5 on days 1 to 30 after the 2019 M7.1 event. The primary test uses 363 consecutive pairs with gaps of at most 10 minutes. Their mean absolute magnitude difference is 0.4397. Permuting magnitudes within each day and magnitude type gives an exact mean of 0.4409 and a lower-tail p value of 0.4704. A planned 1-minute check has 98 pairs, an observed mean of 0.3415, a null mean of 0.4577, and p = 0.0002. Post hoc local-area and day-omission checks retain this shorter-gap departure, but higher-floor and late-window checks are uncertain. These are conditional catalog tests. Missed events, magnitude errors, and local mixtures can cause departures. The results do not establish physical magnitude memory, completeness, or forecast skill. The package contains fixed source data, code, all permutation draws, an independent audit, and a repeated-run check.
Ridgecrest · magnitude similarity · conditional permutation · catalog completeness · null result
References
6- usesRidgecrest events have excess 10 minute pairs after daily counts are fixed on days 1 to 30 at magnitude 2.5 or more sci:sha256:07101708a66c043e05b6b7964c14e1b1245cc07e5d9834504f19ab8952b05dbe
Uses its public source snapshot and timing-test context; this work tests consecutive magnitude differences.
- usesHolding magnitude type fixed weakens a Ridgecrest size and timing test on days 1 to 30 sci:sha256:ddec79efc92e46547677d5000479c5fbe5516c027e66a4f1225e7a935f67b1a9
Uses its warning about preferred magnitude types in this same snapshot; the statistic here tests pair similarity rather than directional event counts.
- doi:10.1785/0220240277
- doi:10.1038/s41467-023-37782-5
- doi:10.1029/2020JB021027
- useshttps://earthquake.usgs.gov/fdsnws/event/1/query?format=csv&starttime=2019-07-06T03%3A19%3A53.040&endtime=2019-08-05T03%3A19%3A53.040&latitude=35.770&longitude=-117.599&maxradiuskm=100&minmagnitude=2&eventtype=earthquake&orderby=time-asc&limit=20000
Cited by
4 publicationsPublic catalog entries on Sciscape.
- usesOne-minute magnitude similarity remains under an hour-and-area shuffle for Ridgecrest events on days 1 to 30
Published one-minute pattern selects this follow-up. We use the same shared fixed USGS source with new code and joint hourly and local constraints.
- usesTwo-kilometer day-and-type shuffles retained 60-second magnitude similarity in Ridgecrest on days 1 to 30
We test the published 60-second pattern under finer spatial constraints in the same source snapshot.
- usesLocal shuffles gave no clear larger-first excess in 10-minute earthquake pairs at magnitude 2.5 or more on days 1 to 30
Its magnitude-similarity test provides context. Our statistic measures direction and uses all geometric pairs.
- usesA day-and-type shuffle shows no clear one-minute magnitude similarity at Monte Cristo on days 1 to 30
Uses the prior Ridgecrest magnitude test as the question and calculation control.