Sequence · 2022-09-17

M 6.5 · Observed seismic cluster · 96 km SE of Lugu, Taiwan

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 cluster21
M6+2
Analysis radius260 km
Observation window14 days
Largest secondary eventM 6.9
Quake Pulse · Major sequence

What the sequence shows

After the M 6.5 reference event, Quake Pulse counts 15 M4+ event(s) in the first 24 hours and 18 in the first 7 days. Fourteen-day M4.5+ activity is about 4.5× the average equivalent derived from the previous year. The largest secondary event is M 0.0 below the reference event.

79/100Sequence score
Events in the previous 24 h0
In the first hour2
In the first 24 hours15
In the first 7 days18
Within 14 days20
Peak one-hour count3

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 d115Average 14-day equivalent4.4Activity / baseline ratio4.5×

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 6.9Magnitude gapM 0.0Observed duration13.0 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

146 Felt reports · PAGER GREEN · Tsunami indicator · Shallow

65/100
Impact and context →

M4.5+ events in cluster

MagnitudeLocationDepthTime
M 6.596 km SE of Lugu, Taiwan10.0 km2022-09-17 13:41:17 UTCView event →
M 4.987 km E of Yujing, Taiwan10.0 km2022-09-17 13:55:41 UTCView event →
M 5.180 km E of Yujing, Taiwan10.0 km2022-09-17 14:35:13 UTCView event →
M 5.5Taiwan region10.0 km2022-09-17 14:45:27 UTCView event →
M 4.681 km E of Yujing, Taiwan10.0 km2022-09-17 15:00:09 UTCView event →
M 4.691 km E of Yujing, Taiwan18.2 km2022-09-17 18:03:29 UTCView event →
M 4.598 km S of Hualien City, Taiwan10.0 km2022-09-18 01:51:54 UTCView event →
M 4.798 km E of Yujing, Taiwan10.0 km2022-09-18 01:52:32 UTCView event →
M 4.7Taiwan10.0 km2022-09-18 02:00:08 UTCView event →
M 5.687 km E of Yujing, Taiwan11.0 km2022-09-18 05:19:17 UTCView event →
M 4.681 km E of Yujing, Taiwan10.0 km2022-09-18 05:54:40 UTCView event →
M 5.389 km E of Yujing, Taiwan10.0 km2022-09-18 06:32:01 UTCView event →
M 6.990 km E of Yujing, Taiwan10.0 km2022-09-18 06:44:13 UTCView event →
M 5.082 km E of Yujing, Taiwan10.0 km2022-09-18 06:57:34 UTCView event →
M 5.290 km E of Yujing, Taiwan10.0 km2022-09-18 08:46:29 UTCView event →
M 5.980 km SE of Lugu, Taiwan10.0 km2022-09-18 09:39:56 UTCView event →
M 5.568 km SSW of Hualien City, Taiwan9.0 km2022-09-19 02:07:42 UTCView event →
M 5.1Taiwan20.7 km2022-09-22 01:04:46 UTCView event →
M 4.591 km E of Yujing, Taiwan10.0 km2022-09-22 18:54:22 UTCView event →
M 4.566 km S of Hualien City, Taiwan10.0 km2022-09-25 15:06:31 UTCView event →
M 4.6Taiwan region10.0 km2022-09-30 14:37:20 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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