Sequence · 2023-09-08

M 6.6 · Observed seismic cluster · south of the Kermadec 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 cluster7
M6+1
Analysis radius276 km
Observation window14 days
Largest secondary eventM 5.6
Quake Pulse · Strong sequence

What the sequence shows

After the M 6.6 reference event, Quake Pulse counts 1 M4+ event(s) in the first 24 hours and 4 in the first 7 days. Fourteen-day M4.5+ activity is about 1.2× the average equivalent derived from the previous year. The largest secondary event is M 1.0 below the reference event.

67/100Sequence score
Events in the previous 24 h1
In the first hour0
In the first 24 hours1
In the first 7 days4
Within 14 days7
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 d152Average 14-day equivalent5.8Activity / baseline ratio1.2×

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 5.6Magnitude gapM 1.0Observed duration13.3 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.

south of the Kermadec Islands · 276 kmInteractive 3D view of earthquakes within 276 km of south of the Kermadec Islands.south of the Kermadec IslandsM 4.9 · south of the Kermadec Islands · 169.4 km
south of the Kermadec Islands276 km1 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

22 Felt reports · PAGER GREEN · Tsunami indicator · Intermediate

60/100
Impact and context →

M4.5+ events in cluster

MagnitudeLocationDepthTime
M 6.6south of the Kermadec Islands79.0 km2023-09-08 09:09:57 UTCView event →
M 4.9south of the Kermadec Islands10.0 km2023-09-09 02:38:46 UTCView event →
M 4.6south of the Kermadec Islands10.0 km2023-09-09 12:24:16 UTCView event →
M 4.8south of the Kermadec Islands10.0 km2023-09-10 16:30:18 UTCView event →
M 4.6south of the Kermadec Islands82.8 km2023-09-10 22:36:53 UTCView event →
M 5.0Kermadec Islands, New Zealand55.1 km2023-09-16 02:01:54 UTCView event →
M 4.5south of the Kermadec Islands110.3 km2023-09-20 09:20:34 UTCView event →
M 5.6Kermadec Islands, New Zealand34.0 km2023-09-21 15:20:31 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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