Explore clusters of M4.5+ events observed around significant earthquakes. These clusters are descriptive and are not presented as earthquake predictions.
After the M 6.5 reference event, Quake Pulse counts 0 M4+ event(s) in the first 24 hours and 2 in the first 7 days. Fourteen-day M4.5+ activity is about 0.8× the average equivalent derived from the previous year. The largest secondary event is M 1.7 below the reference event.
Descriptive comparison with M4.5+ events observed in the same radius during the 365 days before the sequence.
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.
Earlier events are shown as context only. They are not labelled precursors and should not be interpreted as predictive signals.
Shows M4+ cluster events according to elapsed time after the reference event.
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.
2 Felt reports · PAGER GREEN · Intermediate
| Magnitude | Location | Depth | Time | |
|---|---|---|---|---|
| M 6.5 | 207 km WSW of Haveluloto, Tonga | 246.0 km | 2021-04-25 22:28:02 UTC | View event → |
| M 4.5 | 266 km WNW of Haveluloto, Tonga | 517.9 km | 2021-04-27 17:25:07 UTC | View event → |
| M 4.5 | south of the Fiji Islands | 595.6 km | 2021-04-29 15:58:28 UTC | View event → |
| M 4.8 | 238 km WSW of Haveluloto, Tonga | 351.9 km | 2021-05-03 16:07:54 UTC | View event → |
| M 4.6 | Fiji region | 566.0 km | 2021-05-03 19:29:38 UTC | View event → |
| M 4.5 | 246 km SSW of Vaini, Tonga | 105.4 km | 2021-05-04 02:20:07 UTC | View event → |
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.
Guides, explainers and practical reading to go beyond the live data.
Magnitude is only one part of the story. Depth, distance, local ground conditions and building vulnerability help explain why shaking can differ so much from one earthquake to another.
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Earthquake-resistant design is not about making buildings immovable. It is about controlling forces, deformation and failure so people have a much better chance of staying safe.
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Early-warning systems detect an earthquake after it starts and try to send an alert before the strongest shaking arrives. The difference between warning and prediction matters.
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