Sequence · 2018-10-22

M 6.8 · Observed seismic cluster · 210 km SW of Port McNeill, Canada

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 cluster7
M6+2
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 5 M4+ event(s) in the first 24 hours and 5 in the first 7 days. Fourteen-day M4.5+ activity is about 12.0× the average equivalent derived from the previous year. The largest secondary event is M 0.3 below the reference event.

84/100Sequence score
Events in the previous 24 h1
In the first hour3
In the first 24 hours5
In the first 7 days5
Within 14 days6
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 d10Average 14-day equivalent0.4Activity / baseline ratio12.0×

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 duration9.9 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.

210 km SW of Port McNeill, Canada · 308 kmInteractive 3D view of earthquakes within 308 km of 210 km SW of Port McNeill, Canada.210 km SW of Port McNeill, CanadaM 6.5 · 237 km SW of Port McNeill, Canada · 31.8 kmM 4.5 · 186 km SW of Port McNeill, Canada · 25.1 kmM 4.9 · 232 km SW of Port McNeill, Canada · 27.3 kmM 4.6 · 224 km SW of Port McNeill, Canada · 15.6 kmM 5.2 · 217 km SW of Port McNeill, Canada · 36.6 km
210 km SW of Port McNeill, Canada308 km5 Recent earthquakes

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

170 Felt reports · PAGER GREEN · Tsunami indicator · Shallow

67/100
Impact and context →

M4.5+ events in cluster

MagnitudeLocationDepthTime
M 6.8210 km SW of Port McNeill, Canada10.0 km2018-10-22 06:16:26 UTCView event →
M 6.5237 km SW of Port McNeill, Canada10.0 km2018-10-22 06:22:48 UTCView event →
M 4.5186 km SW of Port McNeill, Canada10.0 km2018-10-22 06:31:45 UTCView event →
M 4.9232 km SW of Port McNeill, Canada10.0 km2018-10-22 06:36:07 UTCView event →
M 4.6224 km SW of Port McNeill, Canada10.0 km2018-10-22 14:00:00 UTCView event →
M 5.2217 km SW of Port McNeill, Canada10.0 km2018-10-22 16:27:00 UTCView event →
M 4.9211 km SW of Port McNeill, Canada10.0 km2018-11-01 04:22:19 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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