Magnitude6.9

Reviewed by USGS12y ago

M6.9 earthquake in South Sandwich Islands region

Sunday, June 29, 2014, 07:52:55 UTC · 55.470°S, 28.367°W

A magnitude 6.9 earthquake struck in South Sandwich Islands region on Sunday, June 29, 2014, 07:52:55 UTC, at a depth of 8.0 km (shallow). The USGS PAGER alert is green: low likelihood of casualties and damage. It is the strongest earthquake within 300 km since an M6.9 on September 6, 2004.

Tsunami flagUSGS sets this flag for large events in oceanic regions so tsunami warning centers review them. It does not by itself mean a tsunami occurred. Check tsunami.gov and local authorities for official messages.

Magnitude
6.9
Strong · mww
Depth
8 km
Shallow
Felt reports
0
Did You Feel It?
Est. shaking
V
Moderate (ShakeMap)
PAGER alert
Green
Impact estimate
Tsunami
Flag
Check tsunami.gov

Outlined circle: this earthquakeDashed circle: 100 km aftershock search area

In context

How big was it, and why here?

Energy released

338 kilotons of TNT

That is about 22 times the Hiroshima bomb. It released about 708 times the energy of a magnitude 5.0.

Tectonic setting

49 km

from the nearest mapped plate boundary, between the Sandwich and South American plates. Earthquakes cluster along boundaries like this one, where plates collide, pull apart or slide past each other.

Depth: shallow

8 km

Shallow earthquakes (under 70 km) produce the strongest surface shaking for their size, so they are the ones most likely to cause damage near the epicenter.

Did You Feel It?

Where it was felt

No “Did You Feel It?” reports have been published for this event yet. If you felt it, you can add your report on the USGS website.

I felt it — report to USGS ↗

USGS PAGER estimate

Who was exposed to shaking

USGS publishes PAGER impact estimates for significant earthquakes, usually within an hour. No populated area was estimated to feel noticeable shaking.

After the main event

Aftershocks within 100 km

USGS lists 141 M2.5+ earthquakes within 100 km in the following 30 days; the largest was M6.0 on June 29, 2014. Most nearby activity right after a large earthquake is aftershocks, which usually become less frequent over days and weeks.

Regional history

Past M5+ earthquakes within 300 km

USGS lists 861 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:

History · NOAA

Deadliest earthquakes in this area

NOAA’s significant-earthquake database lists 3 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700. The most severe:

  1. 1929M8.1

    South Sandwich Islands

    27 Jun 1929 · 63 km away

  2. 1961M7.7

    South Sandwich Islands

    5 Sep 1961 · 293 km away

  3. 1961M7.7

    South Sandwich Islands

    8 Sep 1961 · 111 km away

NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.

Nearby trackers

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