Quake Pulse logoQuake Pulse
Sequence · 2003-11-17

M 7.8 · Observed seismic cluster · Rat Islands, Aleutian Islands, Alaska

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 cluster81
M6+1
Analysis radius468 km
Observation window14 days
Largest secondary eventM 5.8
Quake Pulse · Major sequence

What the sequence shows

After the M 7.8 reference event, Quake Pulse counts 54 M4+ event(s) in the first 24 hours and 75 in the first 7 days. Fourteen-day M4.5+ activity is about 40.1× the average equivalent derived from the previous year. The largest secondary event is M 2.0 below the reference event.

90/100Sequence score
Events in the previous 24 h0
In the first hour12
In the first 24 hours54
In the first 7 days75
Within 14 days83
Peak one-hour count12

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 d54Average 14-day equivalent2.1Activity / baseline ratio40.1×

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 2.0Observed duration13.8 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.

1 hour24 hours7 days14 days
Rat Islands, Aleutian Islands, Alaska · 468 kmInteractive 3D view of earthquakes within 468 km of Rat Islands, Aleutian Islands, Alaska.Rat Islands, Aleutian Islands, AlaskaM 5.4 · Rat Islands, Aleutian Islands, Alaska · 34.9 kmM 5.2 · Rat Islands, Aleutian Islands, Alaska · 119.4 kmM 5.1 · Rat Islands, Aleutian Islands, Alaska · 27.2 kmM 4.9 · Rat Islands, Aleutian Islands, Alaska · 25.1 kmM 4.8 · Rat Islands, Aleutian Islands, Alaska · 114.0 kmM 4.5 · Rat Islands, Aleutian Islands, Alaska · 51.5 kmM 5.5 · Rat Islands, Aleutian Islands, Alaska · 73.8 kmM 4.5 · Rat Islands, Aleutian Islands, Alaska · 72.2 kmM 5.1 · Rat Islands, Aleutian Islands, Alaska · 111.3 kmM 4.7 · Rat Islands, Aleutian Islands, Alaska · 53.7 kmM 5.0 · Rat Islands, Aleutian Islands, Alaska · 84.9 kmM 5.0 · Rat Islands, Aleutian Islands, Alaska · 21.0 kmM 5.1 · Rat Islands, Aleutian Islands, Alaska · 29.2 kmM 4.8 · Rat Islands, Aleutian Islands, Alaska · 108.3 kmM 4.7 · Rat Islands, Aleutian Islands, Alaska · 71.9 kmM 4.6 · Rat Islands, Aleutian Islands, Alaska · 91.4 kmM 4.7 · Rat Islands, Aleutian Islands, Alaska · 126.2 kmM 5.1 · Rat Islands, Aleutian Islands, Alaska · 20.9 kmM 4.6 · Rat Islands, Aleutian Islands, Alaska · 32.9 kmM 4.6 · Rat Islands, Aleutian Islands, Alaska · 82.4 kmM 4.7 · Rat Islands, Aleutian Islands, Alaska · 81.2 kmM 4.5 · Rat Islands, Aleutian Islands, Alaska · 42.0 kmM 5.1 · Rat Islands, Aleutian Islands, Alaska · 9.7 kmM 4.6 · Rat Islands, Aleutian Islands, Alaska · 54.7 kmM 4.6 · Rat Islands, Aleutian Islands, Alaska · 47.8 kmM 4.7 · Rat Islands, Aleutian Islands, Alaska · 40.4 kmM 5.0 · Rat Islands, Aleutian Islands, Alaska · 63.7 kmM 4.9 · Rat Islands, Aleutian Islands, Alaska · 22.2 kmM 5.1 · Rat Islands, Aleutian Islands, Alaska · 88.7 kmM 4.6 · Rat Islands, Aleutian Islands, Alaska · 90.1 kmM 5.0 · Rat Islands, Aleutian Islands, Alaska · 36.6 kmM 4.7 · Rat Islands, Aleutian Islands, Alaska · 108.7 kmM 4.9 · Rat Islands, Aleutian Islands, Alaska · 3.6 kmM 4.7 · Rat Islands, Aleutian Islands, Alaska · 8.1 kmM 4.6 · Rat Islands, Aleutian Islands, Alaska · 97.4 kmM 4.6 · Rat Islands, Aleutian Islands, Alaska · 86.6 kmM 4.5 · Rat Islands, Aleutian Islands, Alaska · 60.8 kmM 4.5 · Rat Islands, Aleutian Islands, Alaska · 85.5 kmM 4.5 · Rat Islands, Aleutian Islands, Alaska · 74.3 kmM 4.5 · Rat Islands, Aleutian Islands, Alaska · 73.1 kmM 4.7 · 157 km WNW of Adak, Alaska · 237.3 kmM 4.8 · Rat Islands, Aleutian Islands, Alaska · 110.6 kmM 4.9 · Rat Islands, Aleutian Islands, Alaska · 93.1 kmM 4.5 · Rat Islands, Aleutian Islands, Alaska · 53.0 kmM 4.7 · Rat Islands, Aleutian Islands, Alaska · 17.6 kmM 4.7 · Rat Islands, Aleutian Islands, Alaska · 11.7 kmM 4.6 · Rat Islands, Aleutian Islands, Alaska · 84.2 kmM 4.5 · Rat Islands, Aleutian Islands, Alaska · 72.1 kmM 4.8 · Rat Islands, Aleutian Islands, Alaska · 24.8 kmM 4.6 · Rat Islands, Aleutian Islands, Alaska · 75.0 kmM 5.5 · Rat Islands, Aleutian Islands, Alaska · 37.0 kmM 4.8 · Rat Islands, Aleutian Islands, Alaska · 11.8 kmM 4.8 · 297 km W of Adak, Alaska · 106.7 kmM 4.7 · Rat Islands, Aleutian Islands, Alaska · 63.5 km
Rat Islands, Aleutian Islands, Alaska468 km54 Recent earthquakes

Detailed timeline

Dots represent M4+ events retained by the sequence detector. Dot size depends on magnitude.

0 h24 h7 d14 d

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

Shallow

49/100
Impact and context →

M4.5+ events in cluster

MagnitudeLocationDepthTime
M 7.8Rat Islands, Aleutian Islands, Alaska33.0 km2003-11-17 06:43:06 UTCView event →
M 5.4Rat Islands, Aleutian Islands, Alaska33.0 km2003-11-17 06:51:00 UTCView event →
M 5.2Rat Islands, Aleutian Islands, Alaska33.0 km2003-11-17 06:54:16 UTCView event →
M 5.1Rat Islands, Aleutian Islands, Alaska33.0 km2003-11-17 07:00:13 UTCView event →
M 4.9Rat Islands, Aleutian Islands, Alaska33.0 km2003-11-17 07:03:37 UTCView event →
M 4.8Rat Islands, Aleutian Islands, Alaska33.0 km2003-11-17 07:05:26 UTCView event →
M 4.5Rat Islands, Aleutian Islands, Alaska15.7 km2003-11-17 07:09:56 UTCView event →
M 5.5Rat Islands, Aleutian Islands, Alaska33.0 km2003-11-17 07:12:42 UTCView event →
M 4.5Rat Islands, Aleutian Islands, Alaska34.9 km2003-11-17 07:16:42 UTCView event →
M 5.1Rat Islands, Aleutian Islands, Alaska33.0 km2003-11-17 07:17:09 UTCView event →
M 4.7Rat Islands, Aleutian Islands, Alaska33.0 km2003-11-17 07:18:34 UTCView event →
M 5.0Rat Islands, Aleutian Islands, Alaska33.0 km2003-11-17 07:35:32 UTCView event →
M 5.0Rat Islands, Aleutian Islands, Alaska33.0 km2003-11-17 07:38:12 UTCView event →
M 5.1Rat Islands, Aleutian Islands, Alaska33.0 km2003-11-17 07:56:37 UTCView event →
M 4.8Rat Islands, Aleutian Islands, Alaska33.0 km2003-11-17 08:05:23 UTCView event →
M 4.7Rat Islands, Aleutian Islands, Alaska33.0 km2003-11-17 08:06:33 UTCView event →
M 4.6Rat Islands, Aleutian Islands, Alaska33.0 km2003-11-17 08:40:40 UTCView event →
M 4.7Rat Islands, Aleutian Islands, Alaska33.0 km2003-11-17 08:51:02 UTCView event →
M 5.1Rat Islands, Aleutian Islands, Alaska33.0 km2003-11-17 08:51:42 UTCView event →
M 4.6Rat Islands, Aleutian Islands, Alaska33.0 km2003-11-17 09:05:48 UTCView event →
M 4.6Rat Islands, Aleutian Islands, Alaska33.0 km2003-11-17 09:23:57 UTCView event →
M 4.7Rat Islands, Aleutian Islands, Alaska33.0 km2003-11-17 09:25:10 UTCView event →
M 4.5Rat Islands, Aleutian Islands, Alaska11.9 km2003-11-17 09:35:49 UTCView event →
M 5.1Rat Islands, Aleutian Islands, Alaska33.0 km2003-11-17 09:37:13 UTCView event →
M 4.6Rat Islands, Aleutian Islands, Alaska33.0 km2003-11-17 09:54:38 UTCView event →
M 4.6Rat Islands, Aleutian Islands, Alaska33.0 km2003-11-17 10:20:31 UTCView event →
M 4.7Rat Islands, Aleutian Islands, Alaska33.0 km2003-11-17 10:28:34 UTCView event →
M 5.0Rat Islands, Aleutian Islands, Alaska40.5 km2003-11-17 10:49:30 UTCView event →
M 4.9Rat Islands, Aleutian Islands, Alaska33.0 km2003-11-17 10:50:38 UTCView event →
M 5.1Rat Islands, Aleutian Islands, Alaska33.0 km2003-11-17 11:04:25 UTCView event →
M 4.6Rat Islands, Aleutian Islands, Alaska24.2 km2003-11-17 11:12:16 UTCView event →
M 5.0Rat Islands, Aleutian Islands, Alaska33.0 km2003-11-17 11:12:35 UTCView event →
M 4.7Rat Islands, Aleutian Islands, Alaska33.0 km2003-11-17 11:22:01 UTCView event →
M 4.9Rat Islands, Aleutian Islands, Alaska33.0 km2003-11-17 11:44:34 UTCView event →
M 4.7Rat Islands, Aleutian Islands, Alaska33.0 km2003-11-17 11:53:14 UTCView event →
M 4.6Rat Islands, Aleutian Islands, Alaska33.0 km2003-11-17 12:05:59 UTCView event →
M 4.6Rat Islands, Aleutian Islands, Alaska33.0 km2003-11-17 13:03:16 UTCView event →
M 4.5Rat Islands, Aleutian Islands, Alaska33.0 km2003-11-17 13:22:58 UTCView event →
M 4.5Rat Islands, Aleutian Islands, Alaska33.0 km2003-11-17 13:30:28 UTCView event →
M 4.5Rat Islands, Aleutian Islands, Alaska33.0 km2003-11-17 13:48:55 UTCView event →
M 4.5Rat Islands, Aleutian Islands, Alaska33.0 km2003-11-17 14:05:44 UTCView event →
M 4.7157 km WNW of Adak, Alaska221.9 km2003-11-17 16:52:29 UTCView event →
M 4.8Rat Islands, Aleutian Islands, Alaska33.0 km2003-11-17 16:53:04 UTCView event →
M 4.9Rat Islands, Aleutian Islands, Alaska33.0 km2003-11-17 18:28:43 UTCView event →
M 4.5Rat Islands, Aleutian Islands, Alaska33.0 km2003-11-17 18:34:32 UTCView event →
M 4.7Rat Islands, Aleutian Islands, Alaska33.0 km2003-11-17 18:46:28 UTCView event →
M 4.7Rat Islands, Aleutian Islands, Alaska33.0 km2003-11-17 18:48:28 UTCView event →
M 4.6Rat Islands, Aleutian Islands, Alaska33.0 km2003-11-17 18:52:59 UTCView event →
M 4.5Rat Islands, Aleutian Islands, Alaska33.0 km2003-11-17 20:05:40 UTCView event →
M 4.8Rat Islands, Aleutian Islands, Alaska33.0 km2003-11-17 23:37:10 UTCView event →
M 4.6Rat Islands, Aleutian Islands, Alaska33.0 km2003-11-17 23:41:42 UTCView event →
M 5.5Rat Islands, Aleutian Islands, Alaska33.0 km2003-11-18 02:12:22 UTCView event →
M 4.8Rat Islands, Aleutian Islands, Alaska33.0 km2003-11-18 02:28:56 UTCView event →
M 4.8297 km W of Adak, Alaska8.3 km2003-11-18 02:29:01 UTCView event →
M 4.7Rat Islands, Aleutian Islands, Alaska33.0 km2003-11-18 05:13:44 UTCView event →
M 4.5Rat Islands, Aleutian Islands, Alaska33.0 km2003-11-18 07:48:27 UTCView event →
M 5.8Rat Islands, Aleutian Islands, Alaska33.0 km2003-11-18 07:50:10 UTCView event →
M 5.0Rat Islands, Aleutian Islands, Alaska33.0 km2003-11-18 09:21:40 UTCView event →
M 4.6Rat Islands, Aleutian Islands, Alaska33.0 km2003-11-18 09:47:37 UTCView event →
M 4.8Rat Islands, Aleutian Islands, Alaska33.0 km2003-11-18 11:34:29 UTCView event →
M 5.2Rat Islands, Aleutian Islands, Alaska33.0 km2003-11-18 11:55:01 UTCView event →
M 4.6Rat Islands, Aleutian Islands, Alaska33.0 km2003-11-18 15:40:51 UTCView event →
M 4.5Rat Islands, Aleutian Islands, Alaska33.0 km2003-11-18 16:22:34 UTCView event →
M 4.6Rat Islands, Aleutian Islands, Alaska33.0 km2003-11-18 20:01:35 UTCView event →
M 4.6Rat Islands, Aleutian Islands, Alaska33.0 km2003-11-18 20:27:46 UTCView event →
M 4.6Andreanof Islands, Aleutian Islands, Alaska76.0 km2003-11-19 02:27:35 UTCView event →
M 4.7Rat Islands, Aleutian Islands, Alaska33.0 km2003-11-19 19:25:48 UTCView event →
M 4.6Rat Islands, Aleutian Islands, Alaska33.0 km2003-11-20 06:07:07 UTCView event →
M 4.8Rat Islands, Aleutian Islands, Alaska33.0 km2003-11-20 14:29:05 UTCView event →
M 4.6Rat Islands, Aleutian Islands, Alaska33.0 km2003-11-20 17:52:04 UTCView event →
M 4.5Rat Islands, Aleutian Islands, Alaska33.0 km2003-11-20 21:06:44 UTCView event →
M 4.6Rat Islands, Aleutian Islands, Alaska33.0 km2003-11-20 21:23:55 UTCView event →
M 4.7Rat Islands, Aleutian Islands, Alaska33.0 km2003-11-21 00:56:31 UTCView event →
M 4.5Rat Islands, Aleutian Islands, Alaska33.0 km2003-11-21 05:41:20 UTCView event →
M 4.6Rat Islands, Aleutian Islands, Alaska33.0 km2003-11-21 22:17:32 UTCView event →
M 4.5Rat Islands, Aleutian Islands, Alaska33.0 km2003-11-22 12:20:13 UTCView event →
M 5.0Rat Islands, Aleutian Islands, Alaska33.0 km2003-11-24 09:05:45 UTCView event →
M 4.8Rat Islands, Aleutian Islands, Alaska33.0 km2003-11-25 07:23:43 UTCView event →
M 5.0Rat Islands, Aleutian Islands, Alaska33.0 km2003-11-26 10:34:10 UTCView event →
M 4.844 km NW of Atka, Alaska69.9 km2003-11-27 00:32:44 UTCView event →
M 4.8Rat Islands, Aleutian Islands, Alaska33.0 km2003-11-28 00:17:53 UTCView event →
M 5.1Rat Islands, Aleutian Islands, Alaska33.0 km2003-11-28 12:38:35 UTCView event →
M 5.4Rat Islands, Aleutian Islands, Alaska33.0 km2003-11-30 00:10:04 UTCView event →
M 4.5Rat Islands, Aleutian Islands, Alaska33.0 km2003-12-01 02:55:45 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.

Blog

Latest from the blog

Guides, explainers and practical reading to go beyond the live data.

View all articles →