M5.0 earthquake in South Sandwich Islands region

Sunday, December 28, 2014, 05:05:13 UTC · 56.326°S, 27.089°W

A magnitude 5.0 earthquake struck in South Sandwich Islands region on Sunday, December 28, 2014, 05:05:13 UTC, at a depth of 113.0 km (intermediate). It is the strongest earthquake within 300 km since an M5.5 on December 18, 2014.

Magnitude: 5.0; Moderate · mb
Depth: 113 km; Intermediate
Felt reports: 0; Max intensity I
Est. shaking: —; No ShakeMap
PAGER alert: None; Not issued
Tsunami: No flag; USGS feed

Outlined circle: this earthquakeDashed circle: 75 km aftershock search area

In context

How big was it, and why here?

Energy released

477 tons of TNT

That is about 1/32 of the Hiroshima bomb. Each whole step in magnitude is about 32 times more energy.

Tectonic setting

99 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: intermediate

113 km

Intermediate-depth earthquakes usually break inside a plate that is sinking into the mantle. Shaking spreads over a wide area but is gentler at the epicenter than a shallow quake of the same size.

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 PAGER estimate is available for this event.

After the main event

Aftershocks within 75 km

USGS lists 1 M2.5+ earthquake within 75 km in the following 30 days; the largest was M5.1 on January 23, 2015. Most nearby activity right after a large earthquake is aftershocks, which usually become less frequent over days and weeks.

Time after the mainshock on a logarithmic scale (first hours stretched), magnitude on the vertical axis. M2.5+ events from USGS.

5.1South Sandwich Islands region11y ago · 25 km E of this epicenter

Regional history

Past M5+ earthquakes within 300 km

USGS lists 1,123 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:

1929M8.1
South Sandwich Islands
27 Jun 1929 · 176 km away
1961M7.7
South Sandwich Islands
5 Sep 1961 · 186 km away
1961M7.7
South Sandwich Islands
8 Sep 1961 · 14 km away

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

Nearby trackers