Sequence · 2023-07-16

M 7.2 · Observed seismic cluster · 2023 Sand Point, Alaska Earthquake

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 cluster9
M6+1
Analysis radius372 km
Observation window14 days
Largest secondary eventM 5.8
Quake Pulse · Major sequence

What the sequence shows

After the M 7.2 reference event, Quake Pulse counts 4 M4+ event(s) in the first 24 hours and 6 in the first 7 days. Fourteen-day M4.5+ activity is about 8.1× the average equivalent derived from the previous year. The largest secondary event is M 1.4 below the reference event.

86/100Sequence score
Events in the previous 24 h0
In the first hour2
In the first 24 hours4
In the first 7 days6
Within 14 days9
Peak one-hour count2

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 d29Average 14-day equivalent1.1Activity / baseline ratio8.1×

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 5.8Magnitude gapM 1.4Observed duration12.2 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.

2023 Sand Point, Alaska Earthquake · 372 kmInteractive 3D view of earthquakes within 372 km of 2023 Sand Point, Alaska Earthquake.2023 Sand Point, Alaska EarthquakeM 5.8 · 81 km SSW of Sand Point, Alaska · 26.4 kmM 4.5 · 114 km S of Sand Point, Alaska · 8.4 kmM 4.5 · 117 km S of Sand Point, Alaska · 10.7 kmM 4.7 · 91 km SSW of Sand Point, Alaska · 26.0 km
2023 Sand Point, Alaska Earthquake372 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

165 Felt reports · PAGER GREEN · Tsunami indicator · Shallow

75/100
Impact and context →

M4.5+ events in cluster

MagnitudeLocationDepthTime
M 7.22023 Sand Point, Alaska Earthquake25.0 km2023-07-16 06:48:21 UTCView event →
M 5.881 km SSW of Sand Point, Alaska35.0 km2023-07-16 06:51:20 UTCView event →
M 4.5114 km S of Sand Point, Alaska42.4 km2023-07-16 07:03:23 UTCView event →
M 4.5117 km S of Sand Point, Alaska40.5 km2023-07-16 07:51:40 UTCView event →
M 4.791 km SSW of Sand Point, Alaska42.3 km2023-07-16 11:22:56 UTCView event →
M 4.8113 km S of False Pass, Alaska47.8 km2023-07-17 21:59:04 UTCView event →
M 4.6Alaska Peninsula42.5 km2023-07-18 11:06:33 UTCView event →
M 4.559 km SSW of Sand Point, Alaska42.4 km2023-07-24 12:04:19 UTCView event →
M 4.787 km SSW of Sand Point, Alaska37.0 km2023-07-26 15:29:17 UTCView event →
M 4.6Alaska Peninsula6.0 km2023-07-28 11:32:26 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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