Reviewed by USGSIndia region21y ago
M5.5 earthquake in Nicobar Islands, India region
Tuesday, September 13, 2005, 14:32:57 UTC · 8.073°N, 91.912°E
A magnitude 5.5 earthquake struck in Nicobar Islands, India region on Tuesday, September 13, 2005, 14:32:57 UTC, at a depth of 30.0 km (shallow). It is the strongest earthquake within 300 km since an M5.5 on August 9, 2005.
- Magnitude
- 5.5
- Moderate · mwb
- Depth
- 30 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 earthquakeDashed circle: 75 km aftershock search area
In context
How big was it, and why here?
Energy released
3 kilotons of TNT
That is about 1/6 of the Hiroshima bomb. It released about 6 times the energy of a magnitude 5.0.
Tectonic setting
12 km
from the nearest mapped plate boundary, between the Indian and Burma plates. Earthquakes cluster along boundaries like this one, where plates collide, pull apart or slide past each other.
Depth: shallow
30 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 lists 10 M2.5+ earthquakes within 75 km in the following 30 days; the largest was M5.3 on October 5, 2005. Most nearby activity right after a large earthquake is aftershocks, which usually become less frequent over days and weeks.
- 4.3Nicobar Islands, India region21y ago · 4 km S of this epicenter
- 4.4Nicobar Islands, India region21y ago · 38 km SW of this epicenter
- 5.3Nicobar Islands, India region21y ago · 26 km SE of this epicenter
- 4.2Nicobar Islands, India region21y ago · 12 km SW of this epicenter
- 4.6Nicobar Islands, India region21y ago · 58 km E of this epicenter
- 4.2Nicobar Islands, India region21y ago · 43 km W of this epicenter
- 4.6Nicobar Islands, India region21y ago · 10 km S of this epicenter
- 4.9Nicobar Islands, India region21y ago · 3 km S of this epicenter
Regional history
Past M5+ earthquakes within 300 km
USGS lists 432 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:
- 7.2284 km WNW of Sabang, IndonesiaDecember 26, 2004 · 173 km SE of this epicenter
- 7.2Nicobar Islands, India regionJuly 24, 2005 · 35 km SE of this epicenter
- 7.0190 km WNW of Sabang, IndonesiaMay 17, 1955 · 256 km SE of this epicenter
- 6.8238 km WNW of Sabang, IndonesiaJanuary 20, 1917 · 209 km SE of this epicenter
- 6.6Nicobar Islands, India regionApril 7, 1973 · 136 km SW of this epicenter
- 6.6Nicobar Islands, India regionDecember 26, 2004 · 103 km NE of this epicenter
- 6.6249 km NW of Sabang, IndonesiaMarch 5, 1921 · 204 km E of this epicenter
- 6.5253 km WNW of Sabang, IndonesiaNovember 21, 1907 · 216 km SE of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 5 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700. The most severe:
- 1881M7.9
Andaman I,Nicobar I
31 Dec 1881 · 76 km away
Severe damage ($5–24M)tsunami
- 1982M6.3
Little Nicobar Island
20 Jan 1982 · 262 km away · intensity VIII
Moderate damage ($1–5M)
- 2005M7.2
Andaman Islands, Nicobar Islands
24 Jul 2005 · 35 km away
Limited damage (under $1M)
- 1847
Little Nicobar Island
31 Oct 1847 · 210 km away · intensity X
Limited damage (under $1M)tsunami
- 1955M7.3
Little Nicobar Island
17 May 1955 · 289 km away
tsunami
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.