Sequence · 2020-09-01

M 6.8 · Observed seismic cluster · 86 km NW of Vallenar, Chile

Explore clusters of M4.5+ events observed around significant earthquakes. These clusters are descriptive and are not presented as earthquake predictions.

M4.5+ events in cluster28
M6+4
Analysis radius308 km
Observation window14 days
Largest secondary eventM 6.5
Quake Pulse · Major sequence

What the sequence shows

After the M 6.8 reference event, Quake Pulse counts 18 M4+ event(s) in the first 24 hours and 25 in the first 7 days. Fourteen-day M4.5+ activity is about 17.2× the average equivalent derived from the previous year. The largest secondary event is M 0.3 below the reference event.

90/100Sequence score
Events in the previous 24 h0
In the first hour4
In the first 24 hours18
In the first 7 days25
Within 14 days27
Peak one-hour count6

Local historical context

Descriptive comparison with M4.5+ events observed in the same radius during the 365 days before the sequence.

M4.5+ events / 365 d41Average 14-day equivalent1.6Activity / baseline ratio17.2×

A ratio above 1 means denser M4.5+ activity than the average equivalent derived from the previous 365 days. It is not a risk measure or a forecast.

Reference event

Largest secondary eventM 6.5Magnitude gapM 0.3Observed duration11.2 d

Earlier events are shown as context only. They are not labelled precursors and should not be interpreted as predictive signals.

Evolving sequence map

Shows M4+ cluster events according to elapsed time after the reference event.

Detailed timeline

Dots represent M4+ events retained by the sequence detector. Dot size depends on magnitude.

Sequences are descriptive groupings based on spatial and temporal proximity. Quake Pulse does not establish a causal link between every event here and does not provide earthquake forecasts.

Quake Pulse

Main-event impact

204 Felt reports · PAGER GREEN · Tsunami indicator · Shallow

71/100
Impact and context →

M4.5+ events in cluster

MagnitudeLocationDepthTime
M 6.886 km NW of Vallenar, Chile21.0 km2020-09-01 04:09:28 UTCView event →
M 5.179 km NNW of Vallenar, Chile22.9 km2020-09-01 04:20:46 UTCView event →
M 6.378 km NW of Vallenar, Chile16.2 km2020-09-01 04:30:02 UTCView event →
M 5.180 km NNW of Vallenar, Chile28.0 km2020-09-01 04:36:36 UTCView event →
M 4.875 km SW of Copiapó, Chile15.4 km2020-09-01 04:44:10 UTCView event →
M 4.577 km NW of Vallenar, Chile33.8 km2020-09-01 05:14:45 UTCView event →
M 4.687 km NW of Vallenar, Chile17.5 km2020-09-01 05:19:40 UTCView event →
M 4.979 km NW of Vallenar, Chile24.0 km2020-09-01 05:21:09 UTCView event →
M 4.888 km NNW of Vallenar, Chile17.1 km2020-09-01 05:26:21 UTCView event →
M 5.483 km NW of Vallenar, Chile19.2 km2020-09-01 05:29:39 UTCView event →
M 4.587 km NW of Vallenar, Chile21.3 km2020-09-01 05:37:07 UTCView event →
M 4.571 km NNW of Vallenar, Chile19.7 km2020-09-01 06:21:19 UTCView event →
M 4.783 km NNW of Vallenar, Chile21.1 km2020-09-01 06:28:23 UTCView event →
M 5.888 km NW of Vallenar, Chile18.1 km2020-09-01 07:01:25 UTCView event →
M 5.799 km NW of Vallenar, Chile22.0 km2020-09-01 10:31:52 UTCView event →
M 4.683 km NNW of Vallenar, Chile34.7 km2020-09-01 11:30:55 UTCView event →
M 5.099 km NW of Vallenar, Chile16.3 km2020-09-01 17:13:22 UTCView event →
M 6.594 km NW of Vallenar, Chile16.0 km2020-09-01 21:09:17 UTCView event →
M 4.8102 km NW of Vallenar, Chile15.3 km2020-09-02 03:04:27 UTCView event →
M 4.778 km NNW of Vallenar, Chile28.6 km2020-09-02 13:38:18 UTCView event →
M 4.699 km NW of Vallenar, Chile10.4 km2020-09-03 03:23:54 UTCView event →
M 4.6112 km NW of Vallenar, Chile10.0 km2020-09-03 18:41:44 UTCView event →
M 4.8107 km NW of Vallenar, Chile10.9 km2020-09-05 06:39:41 UTCView event →
M 6.340 km NW of Ovalle, Chile30.0 km2020-09-06 01:16:58 UTCView event →
M 4.788 km NW of Vallenar, Chile18.7 km2020-09-06 11:21:00 UTCView event →
M 4.590 km NW of Vallenar, Chile25.6 km2020-09-06 11:30:34 UTCView event →
M 4.6116 km NW of Vallenar, Chile10.0 km2020-09-10 20:39:14 UTCView event →
M 4.583 km NW of Vallenar, Chile20.4 km2020-09-12 09:45:30 UTCView event →

Interpretation

Explore clusters of M4.5+ events observed around significant earthquakes. These clusters are descriptive and are not presented as earthquake predictions. Historical small-earthquake detection varies through time. Long-term comparisons are most robust at higher magnitude thresholds.

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