Sequence · 2026-03-21

M 6.6 · Observed seismic cluster · northern Mid-Atlantic Ridge

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 cluster4
M6+1
Analysis radius276 km
Observation window14 days
Largest secondary eventM 5.2
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 2 in the first 7 days. Fourteen-day M4.5+ activity is about 6.0× the average equivalent derived from the previous year. The largest secondary event is M 1.4 below the reference event.

65/100Sequence score
Events in the previous 24 h0
In the first hour0
In the first 24 hours1
In the first 7 days2
Within 14 days3
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 d5Average 14-day equivalent0.2Activity / baseline ratio6.0×

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 5.2Magnitude gapM 1.4Observed duration9.1 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.

northern Mid-Atlantic Ridge · 276 kmInteractive 3D view of earthquakes within 276 km of northern Mid-Atlantic Ridge.northern Mid-Atlantic RidgeM 4.6 · northern Mid-Atlantic Ridge · 9.5 km
northern Mid-Atlantic Ridge276 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

PAGER GREEN · Tsunami indicator · Shallow

49/100
Impact and context →

M4.5+ events in cluster

MagnitudeLocationDepthTime
M 6.6northern Mid-Atlantic Ridge10.0 km2026-03-21 12:16:46 UTCView event →
M 4.6northern Mid-Atlantic Ridge10.0 km2026-03-22 05:26:15 UTCView event →
M 5.1northern Mid-Atlantic Ridge10.0 km2026-03-23 01:41:37 UTCView event →
M 5.2northern Mid-Atlantic Ridge10.0 km2026-03-30 14:43:32 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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