Sequence · 2018-10-10

M 6.5 · Observed seismic cluster · 154 km S of Severo-Kuril’sk, Russia

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 cluster17
M6+1
Analysis radius260 km
Observation window14 days
Largest secondary eventM 5.5
Quake Pulse · Major sequence

What the sequence shows

After the M 6.5 reference event, Quake Pulse counts 11 M4+ event(s) in the first 24 hours and 15 in the first 7 days. Fourteen-day M4.5+ activity is about 11.7× the average equivalent derived from the previous year. The largest secondary event is M 1.0 below the reference event.

80/100Sequence score
Events in the previous 24 h0
In the first hour5
In the first 24 hours11
In the first 7 days15
Within 14 days17
Peak one-hour count5

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 d38Average 14-day equivalent1.5Activity / baseline ratio11.7×

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 5.5Magnitude gapM 1.0Observed duration9.4 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

PAGER GREEN · Tsunami indicator · Shallow

52/100
Impact and context →

M4.5+ events in cluster

MagnitudeLocationDepthTime
M 6.5154 km S of Severo-Kuril’sk, Russia20.0 km2018-10-10 23:16:02 UTCView event →
M 5.2172 km S of Severo-Kuril’sk, Russia10.0 km2018-10-10 23:19:42 UTCView event →
M 5.5164 km S of Severo-Kuril’sk, Russia10.0 km2018-10-10 23:21:50 UTCView event →
M 4.8170 km S of Severo-Kuril’sk, Russia10.0 km2018-10-10 23:26:12 UTCView event →
M 4.7138 km S of Severo-Kuril’sk, Russia10.0 km2018-10-11 00:14:18 UTCView event →
M 5.4150 km S of Severo-Kuril’sk, Russia10.0 km2018-10-11 00:14:39 UTCView event →
M 5.0148 km S of Severo-Kuril’sk, Russia10.0 km2018-10-11 01:30:20 UTCView event →
M 5.2161 km S of Severo-Kuril’sk, Russia10.0 km2018-10-11 02:16:16 UTCView event →
M 4.8158 km S of Severo-Kuril’sk, Russia10.0 km2018-10-11 03:38:38 UTCView event →
M 5.2164 km S of Severo-Kuril’sk, Russia10.0 km2018-10-11 05:47:32 UTCView event →
M 5.1159 km S of Severo-Kuril’sk, Russia17.0 km2018-10-11 15:08:10 UTCView event →
M 4.5265 km SSW of Severo-Kuril’sk, Russia48.3 km2018-10-11 22:04:24 UTCView event →
M 4.5east of the Kuril Islands33.7 km2018-10-12 12:57:16 UTCView event →
M 4.8166 km S of Severo-Kuril’sk, Russia10.0 km2018-10-12 13:58:37 UTCView event →
M 4.9151 km S of Severo-Kuril’sk, Russia10.0 km2018-10-12 22:22:01 UTCView event →
M 4.691 km ESE of Ozernovskiy, Russia64.5 km2018-10-17 15:00:59 UTCView event →
M 4.6Kuril Islands57.9 km2018-10-18 07:23:43 UTCView event →
M 4.8144 km S of Severo-Kuril’sk, Russia42.6 km2018-10-20 09:51:20 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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