August 29, 2012 Earthquake Archive

Archive context

What this daily record shows

This page preserves a selection from the worldwide earthquake list compiled for August 29, 2012. Separate agencies sometimes published different preliminary magnitudes or depths for the same event, so closely timed entries may represent multiple estimates rather than separate earthquakes.

Historical data notice. These entries reproduce the values recorded in the archive. They are not a live feed, and later agency catalogs may contain revised solutions. Use the overview map for current activity.

The Southern California boom

People along the Southern California coast reported a brief, loud boom and rattling around 19:45 UTC. The archive initially opened a placeholder so observations could be collected, but its magnitude, depth and coordinates were explicitly not measured earthquake values.

Subsequent checks found no corresponding earthquake solution. Contemporary reporting ultimately associated the disturbance with aircraft activity offshore. Accounts commonly described a short pressure-like jolt, rattling windows and doors, and little or no sustained ground motion. Those reports remain useful as an example of why a felt disturbance should not be classified as an earthquake before instrumental confirmation.

The placeholder is excluded from the earthquake table below because it was not a verified seismic event.

Browse complete daily lists Worldwide list guide →

Notable entries

Largest and most discussed events

These highlights summarize the strongest listed events and the principal felt reports without treating early estimates as final.

21:07 UTC • Northern Xinjiang, China

Magnitude 6.3 agency solutions

Multiple agencies listed a shallow event at M6.3. Archived observations from Urumqi described prolonged building movement and residents going outside.

22:43 UTC • North Pacific Ocean

Magnitude 5.9 oceanic event

The list recorded a M5.9 solution at 10 km depth in the North Pacific Ocean.

15:31 UTC • South Atlantic Ocean

Magnitude 5.8 event

Three agency entries agreed on a M5.8 event and an initial depth of 10 km.

22:37 UTC • Kermadec region

Multiple Kermadec solutions

Agency estimates ranged from M4.8 to M5.3, illustrating routine variation among early solutions.

13:00 UTC • Offshore Chiapas

Magnitude 5.1–5.2

Solutions placed this event offshore from Chiapas, Mexico. One archived observation described weak shaking and disturbed water containers.

10:01 UTC • South of Fiji

Deep regional earthquake

Agencies reported values from M4.9 to M5.3 at roughly 152–164 km depth.

Selected chronology

August 29, 2012 event list

A compact preservation of representative entries from the much longer source table. Duplicate agency solutions are grouped where practical.

Historical archive only. Agency names identify the source recorded at the time; no live status is implied.

Source	Location	UTC time	M	Depth
EMSC	Canary Islands, Spain region	23:45	3.2	19 km
GEOFON	North Pacific Ocean	22:43	5.9	10 km
EMSC / GEOFON / USGS	South of the Kermadec Islands	22:37	4.8–5.3	10–22 km
USGS / GEOFON / EMSC	Northern Xinjiang, China	21:07	6.3	10–20 km
EMSC / GEOFON / USGS	Santa Cruz Islands	20:03	4.7–4.8	30–40 km
EMSC	Greece	19:24	3.0	5 km
GEOFON / EMSC / USGS	Fox Islands, Aleutian Islands	18:07	4.3–4.7	39–56 km
EMSC / GEOFON / USGS	South Atlantic Ocean	15:31	5.8	10 km
EMSC / USGS / GEOFON	Offshore Chiapas, Mexico	13:00	5.1–5.2	59–74 km
EMSC / GEOFON	Banda Sea	13:43	4.1	413 km
EMSC / GEOFON / USGS	South of the Fiji Islands	10:01	4.9–5.3	152–164 km
USGS / EMSC / GEOFON	Nias region and northern Sumatra, Indonesia	09:20	4.7–5.0	10–37 km
GEOFON / USGS / EMSC	Tajikistan	08:13	4.2–4.4	52 km
GEOFON / EMSC / USGS	Java, Indonesia	06:48	4.5–4.6	48–60 km
EMSC / GEOFON / USGS	Tajikistan and Afghanistan–Tajikistan border region	02:06–02:07	4.7	10–17 km
GEONET	Canterbury, New Zealand	00:10	4.0	10 km

Archive FAQ

Questions about this record

Is this a live earthquake list?

No. It is a historical record for August 29, 2012. Current activity should be checked through the overview map and official seismic agencies.

Why are some events listed more than once?

Different monitoring networks independently calculated locations, magnitudes and depths. Their initial solutions can vary.

Was the Southern California boom an earthquake?

No instrumentally confirmed earthquake was associated with the reports. The archive's final assessment attributed the disturbance to offshore aircraft activity.

Why is the California placeholder omitted from the table?

Its original magnitude, depth and coordinates were artificial fields used to collect observations, not measured data.

Can historical magnitudes change?

Yes. Agencies routinely review waveforms and revise earthquake parameters after preliminary publication.

How should felt reports be interpreted?

They describe individual observations and can help characterize effects, but they do not by themselves establish magnitude, location or cause.