Reviewed by USGS50y ago
M5.1 earthquake western Indian-Antarctic Ridge
Tuesday, November 2, 1976, 04:37:25 UTC · 48.960°S, 124.476°E
A magnitude 5.1 earthquake struck western Indian-Antarctic Ridge on Tuesday, November 2, 1976, 04:37:25 UTC, at a depth of 33.0 km (shallow). It is the strongest earthquake within 300 km since an M5.6 on November 28, 1975.
- Magnitude
- 5.1
- Moderate · mb
- Depth
- 33 km
- Shallow
- Felt reports
- 0
- Did You Feel It?
- Est. shaking
- —
- No ShakeMap
- PAGER alert
- None
- Not issued
- Tsunami
- No flag
- USGS feed
Outlined circle: this earthquake
In context
How big was it, and why here?
Energy released
674 tons of TNT
That is about 1/22 of the Hiroshima bomb. It released about 1 times the energy of a magnitude 5.0.
Tectonic setting
2 km
from the nearest mapped plate boundary, between the Australian and Antarctic plates. Earthquakes cluster along boundaries like this one, where plates collide, pull apart or slide past each other.
Depth: shallow
33 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 PAGER estimate is available for this event.
After the main event
Aftershocks within 75 km
USGS has not published any M2.5+ earthquake within 75 km in the 30 days after this event.
Regional history
Past M5+ earthquakes within 300 km
USGS lists 10 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:
- 6.0western Indian-Antarctic RidgeOctober 19, 1927 · 71 km SW of this epicenter
- 6.0western Indian-Antarctic RidgeNovember 13, 1956 · 86 km W of this epicenter
- 5.9western Indian-Antarctic RidgeNovember 15, 1972 · 66 km W of this epicenter
- 5.9western Indian-Antarctic RidgeJune 13, 1958 · 127 km SE of this epicenter
- 5.6western Indian-Antarctic RidgeNovember 28, 1975 · 203 km E of this epicenter
- 5.5western Indian-Antarctic RidgeJune 26, 1974 · 16 km S of this epicenter
- 5.4western Indian-Antarctic RidgeJune 22, 1974 · 120 km SE of this epicenter
- 5.2western Indian-Antarctic RidgeMay 8, 1974 · 211 km W of this epicenter