Sequence · 2023-07-02

M 6.9 · Observed seismic cluster · 132 km NW of Neiafu, Tonga

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 cluster5
M6+1
Analysis radius324 km
Observation window14 days
Largest secondary eventM 5.3
Quake Pulse · Strong sequence

What the sequence shows

After the M 6.9 reference event, Quake Pulse counts 1 M4+ event(s) in the first 24 hours and 3 in the first 7 days. Fourteen-day M4.5+ activity is about 0.5× the average equivalent derived from the previous year. The largest secondary event is M 1.6 below the reference event.

62/100Sequence score
Events in the previous 24 h2
In the first hour0
In the first 24 hours1
In the first 7 days3
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 d250Average 14-day equivalent9.6Activity / baseline ratio0.5×

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 5.3Magnitude gapM 1.6Observed duration10.3 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.

132 km NW of Neiafu, Tonga · 324 kmInteractive 3D view of earthquakes within 324 km of 132 km NW of Neiafu, Tonga.132 km NW of Neiafu, TongaM 4.5 · Fiji region · 344.8 km
132 km NW of Neiafu, Tonga324 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

21 Felt reports · PAGER GREEN · Tsunami indicator · Intermediate

64/100
Impact and context →

M4.5+ events in cluster

MagnitudeLocationDepthTime
M 6.9132 km NW of Neiafu, Tonga229.0 km2023-07-02 10:27:43 UTCView event →
M 4.5Fiji region436.5 km2023-07-02 20:23:51 UTCView event →
M 5.3Fiji region10.0 km2023-07-03 13:03:38 UTCView event →
M 4.5Fiji region10.0 km2023-07-03 18:04:56 UTCView event →
M 4.754 km SE of Hihifo, Tonga53.5 km2023-07-09 15:25:41 UTCView event →
M 4.563 km NNE of Hihifo, Tonga35.0 km2023-07-12 18:01:40 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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