Sequence · 2021-09-08

M 7.0 · Observed seismic cluster · Acapulco, Mexico

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 radius340 km
Observation window14 days
Largest secondary eventM 4.9
Quake Pulse · Major sequence

What the sequence shows

After the M 7.0 reference event, Quake Pulse counts 4 M4+ event(s) in the first 24 hours and 4 in the first 7 days. Fourteen-day M4.5+ activity is about 8.7× the average equivalent derived from the previous year. The largest secondary event is M 2.1 below the reference event.

84/100Sequence score
Events in the previous 24 h0
In the first hour1
In the first 24 hours4
In the first 7 days4
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 d15Average 14-day equivalent0.6Activity / baseline ratio8.7×

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 4.9Magnitude gapM 2.1Observed duration12.3 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.

Acapulco, Mexico · 340 kmInteractive 3D view of earthquakes within 340 km of Acapulco, Mexico.Acapulco, MexicoM 4.9 · 5 km WSW of Los Órganos de San Agustín, Mexico · 12.9 kmM 4.7 · 2 km WNW of Texca, Mexico · 12.6 kmM 4.5 · 24 km S of Acapulco de Juárez, Mexico · 39.1 kmM 4.6 · 2 km SW of Tuncingo, Mexico · 14.1 km
Acapulco, Mexico340 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

665 Felt reports · PAGER RED · Tsunami indicator · Shallow

100/100
Impact and context →

M4.5+ events in cluster

MagnitudeLocationDepthTime
M 7.0Acapulco, Mexico20.0 km2021-09-08 01:47:47 UTCView event →
M 4.95 km WSW of Los Órganos de San Agustín, Mexico10.0 km2021-09-08 02:18:01 UTCView event →
M 4.72 km WNW of Texca, Mexico10.0 km2021-09-08 02:58:19 UTCView event →
M 4.524 km S of Acapulco de Juárez, Mexico10.0 km2021-09-08 05:42:56 UTCView event →
M 4.62 km SW of Tuncingo, Mexico19.8 km2021-09-08 09:50:19 UTCView event →
M 4.612 km SSW of Cruz Grande, Mexico10.0 km2021-09-20 09:36:32 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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