Sequence · 2018-09-16

M 6.5 · Observed seismic cluster · south of the Fiji Islands

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 cluster6
M6+1
Analysis radius260 km
Observation window14 days
Largest secondary eventM 5.0
Quake Pulse · Notable sequence

What the sequence shows

After the M 6.5 reference event, Quake Pulse counts 4 M4+ event(s) in the first 24 hours and 5 in the first 7 days. Fourteen-day M4.5+ activity is about 1.4× the average equivalent derived from the previous year. The largest secondary event is M 1.5 below the reference event.

55/100Sequence score
Events in the previous 24 h0
In the first hour1
In the first 24 hours4
In the first 7 days5
Within 14 days5
Peak one-hour count1

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 d93Average 14-day equivalent3.6Activity / baseline ratio1.4×

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 5.0Magnitude gapM 1.5Observed duration6.8 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.

south of the Fiji Islands · 260 kmInteractive 3D view of earthquakes within 260 km of south of the Fiji Islands.south of the Fiji IslandsM 4.7 · south of the Fiji Islands · 30.7 kmM 4.7 · south of the Fiji Islands · 34.9 kmM 4.5 · south of the Fiji Islands · 41.2 kmM 5.0 · south of the Fiji Islands · 19.9 km
south of the Fiji Islands260 km4 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

2 Felt reports · PAGER GREEN · Very deep

44/100
Impact and context →

M4.5+ events in cluster

MagnitudeLocationDepthTime
M 6.5south of the Fiji Islands576.0 km2018-09-16 21:11:48 UTCView event →
M 4.7south of the Fiji Islands613.3 km2018-09-16 21:30:23 UTCView event →
M 4.7south of the Fiji Islands581.3 km2018-09-17 00:08:23 UTCView event →
M 4.5south of the Fiji Islands596.5 km2018-09-17 07:27:55 UTCView event →
M 5.0south of the Fiji Islands568.9 km2018-09-17 09:32:40 UTCView event →
M 4.7south of the Fiji Islands540.9 km2018-09-23 15:43:26 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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