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Sequence · 2018-09-28

M 7.5 · Observed seismic cluster · 72 km N of Palu, Indonesia

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 cluster50
M6+1
Analysis radius420 km
Observation window14 days
Largest secondary eventM 5.8
Quake Pulse · Major sequence

What the sequence shows

After the M 7.5 reference event, Quake Pulse counts 35 M4+ event(s) in the first 24 hours and 45 in the first 7 days. Fourteen-day M4.5+ activity is about 35.5× the average equivalent derived from the previous year. The largest secondary event is M 1.7 below the reference event.

98/100Sequence score
Events in the previous 24 h9
In the first hour11
In the first 24 hours35
In the first 7 days45
Within 14 days49
Peak one-hour count11

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 d36Average 14-day equivalent1.4Activity / baseline ratio35.5×

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 5.8Magnitude gapM 1.7Observed duration12.3 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.

1 hour24 hours7 days14 days
72 km N of Palu, Indonesia · 420 kmInteractive 3D view of earthquakes within 420 km of 72 km N of Palu, Indonesia.72 km N of Palu, IndonesiaM 5.8 · 99 km N of Palu, Indonesia · 28.4 kmM 5.7 · Minahasa, Sulawesi, Indonesia · 71.9 kmM 4.6 · 113 km ENE of Palu, Indonesia · 99.1 kmM 5.8 · 16 km SSE of Palu, Indonesia · 88.5 kmM 5.3 · 49 km WSW of Palu, Indonesia · 103.6 kmM 4.6 · 27 km WSW of Poso, Indonesia · 157.8 kmM 4.6 · 94 km SW of Palu, Indonesia · 158.1 kmM 5.4 · 24 km N of Palu, Indonesia · 47.8 kmM 5.2 · 39 km N of Palu, Indonesia · 32.8 kmM 4.9 · 53 km WSW of Poso, Indonesia · 148.8 kmM 5.6 · 14 km NNE of Palu, Indonesia · 58.8 kmM 5.2 · 69 km SSE of Palu, Indonesia · 140.7 kmM 4.6 · 48 km NNW of Palu, Indonesia · 33.6 kmM 4.7 · 58 km NNE of Palu, Indonesia · 29.5 kmM 5.2 · 49 km N of Palu, Indonesia · 22.7 kmM 4.7 · 47 km ESE of Palu, Indonesia · 102.3 kmM 4.9 · 95 km N of Palu, Indonesia · 23.3 kmM 4.5 · 32 km SSE of Palu, Indonesia · 103.1 kmM 5.7 · 108 km N of Palu, Indonesia · 39.4 kmM 5.2 · 56 km S of Palu, Indonesia · 129.4 kmM 4.6 · 109 km NNW of Palu, Indonesia · 42.9 kmM 4.7 · 94 km N of Palu, Indonesia · 23.3 kmM 4.6 · 72 km ENE of Palu, Indonesia · 92.0 kmM 4.5 · 64 km SSE of Palu, Indonesia · 134.6 kmM 4.6 · 36 km ENE of Palu, Indonesia · 62.1 kmM 5.4 · 115 km NNW of Palu, Indonesia · 50.0 kmM 4.9 · 24 km NNE of Palu, Indonesia · 50.2 kmM 5.0 · 46 km S of Palu, Indonesia · 118.6 kmM 4.6 · 61 km W of Poso, Indonesia · 134.6 kmM 4.5 · 61 km W of Poso, Indonesia · 134.9 kmM 5.0 · 67 km WSW of Poso, Indonesia · 152.5 kmM 4.5 · 75 km SW of Poso, Indonesia · 177.8 kmM 4.8 · 75 km SSE of Palu, Indonesia · 147.8 kmM 4.8 · 19 km NW of Poso, Indonesia · 142.7 kmM 5.1 · 64 km WSW of Poso, Indonesia · 144.4 km
72 km N of Palu, Indonesia420 km35 Recent earthquakes

Detailed timeline

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

0 h24 h7 d14 d

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

40 Felt reports · PAGER RED · Shallow

90/100
Impact and context →

M4.5+ events in cluster

MagnitudeLocationDepthTime
M 7.572 km N of Palu, Indonesia20.0 km2018-09-28 10:02:45 UTCView event →
M 5.899 km N of Palu, Indonesia10.0 km2018-09-28 10:14:20 UTCView event →
M 5.7Minahasa, Sulawesi, Indonesia10.0 km2018-09-28 10:16:48 UTCView event →
M 4.6113 km ENE of Palu, Indonesia10.0 km2018-09-28 10:24:45 UTCView event →
M 5.816 km SSE of Palu, Indonesia10.0 km2018-09-28 10:25:04 UTCView event →
M 5.349 km WSW of Palu, Indonesia10.0 km2018-09-28 10:26:11 UTCView event →
M 4.627 km WSW of Poso, Indonesia10.0 km2018-09-28 10:37:10 UTCView event →
M 4.694 km SW of Palu, Indonesia10.0 km2018-09-28 10:38:28 UTCView event →
M 5.424 km N of Palu, Indonesia10.0 km2018-09-28 10:39:03 UTCView event →
M 5.239 km N of Palu, Indonesia10.0 km2018-09-28 10:47:44 UTCView event →
M 4.953 km WSW of Poso, Indonesia10.0 km2018-09-28 10:49:04 UTCView event →
M 5.614 km NNE of Palu, Indonesia10.0 km2018-09-28 10:50:25 UTCView event →
M 5.269 km SSE of Palu, Indonesia10.0 km2018-09-28 11:06:50 UTCView event →
M 4.648 km NNW of Palu, Indonesia10.0 km2018-09-28 11:36:27 UTCView event →
M 4.758 km NNE of Palu, Indonesia10.0 km2018-09-28 12:05:04 UTCView event →
M 5.249 km N of Palu, Indonesia10.0 km2018-09-28 12:27:33 UTCView event →
M 4.747 km ESE of Palu, Indonesia10.0 km2018-09-28 12:39:33 UTCView event →
M 4.995 km N of Palu, Indonesia10.0 km2018-09-28 13:10:26 UTCView event →
M 4.532 km SSE of Palu, Indonesia10.0 km2018-09-28 13:28:51 UTCView event →
M 5.7108 km N of Palu, Indonesia10.0 km2018-09-28 13:35:30 UTCView event →
M 5.256 km S of Palu, Indonesia10.0 km2018-09-28 13:39:44 UTCView event →
M 4.6109 km NNW of Palu, Indonesia10.0 km2018-09-28 13:56:50 UTCView event →
M 4.794 km N of Palu, Indonesia10.0 km2018-09-28 14:10:08 UTCView event →
M 4.672 km ENE of Palu, Indonesia10.0 km2018-09-28 14:10:49 UTCView event →
M 4.564 km SSE of Palu, Indonesia10.0 km2018-09-28 14:16:04 UTCView event →
M 4.636 km ENE of Palu, Indonesia10.0 km2018-09-28 14:24:40 UTCView event →
M 5.4115 km NNW of Palu, Indonesia10.0 km2018-09-28 14:26:00 UTCView event →
M 4.924 km NNE of Palu, Indonesia10.0 km2018-09-28 15:28:13 UTCView event →
M 5.046 km S of Palu, Indonesia10.0 km2018-09-28 15:35:42 UTCView event →
M 4.661 km W of Poso, Indonesia10.0 km2018-09-28 17:05:45 UTCView event →
M 4.561 km W of Poso, Indonesia10.0 km2018-09-28 20:41:01 UTCView event →
M 5.067 km WSW of Poso, Indonesia10.0 km2018-09-28 21:24:01 UTCView event →
M 4.575 km SW of Poso, Indonesia10.0 km2018-09-28 22:17:50 UTCView event →
M 4.875 km SSE of Palu, Indonesia10.0 km2018-09-29 02:32:50 UTCView event →
M 4.819 km NW of Poso, Indonesia10.0 km2018-09-29 06:36:12 UTCView event →
M 5.164 km WSW of Poso, Indonesia10.0 km2018-09-29 07:40:11 UTCView event →
M 5.160 km W of Poso, Indonesia10.0 km2018-09-29 10:30:18 UTCView event →
M 4.854 km SE of Palu, Indonesia10.0 km2018-09-30 14:38:42 UTCView event →
M 4.654 km SE of Palu, Indonesia10.0 km2018-09-30 15:01:26 UTCView event →
M 5.2102 km NNW of Palu, Indonesia10.0 km2018-10-01 05:43:34 UTCView event →
M 4.725 km NNW of Palu, Indonesia10.0 km2018-10-01 17:39:01 UTCView event →
M 5.225 km N of Palu, Indonesia10.0 km2018-10-01 23:46:38 UTCView event →
M 5.162 km WSW of Poso, Indonesia10.0 km2018-10-02 04:59:26 UTCView event →
M 4.816 km SSE of Palu, Indonesia14.6 km2018-10-02 21:06:56 UTCView event →
M 4.649 km W of Poso, Indonesia10.0 km2018-10-04 18:27:22 UTCView event →
M 4.540 km SSE of Palu, Indonesia10.0 km2018-10-04 22:08:34 UTCView event →
M 4.811 km E of Palu, Indonesia10.0 km2018-10-08 21:15:46 UTCView event →
M 5.228 km SSW of Palu, Indonesia10.0 km2018-10-08 21:16:05 UTCView event →
M 4.625 km W of Poso, Indonesia10.0 km2018-10-08 21:59:54 UTCView event →
M 4.9183 km WNW of Gorontalo, Indonesia10.0 km2018-10-10 17:34:23 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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