Reviewed by USGSIndia region22y ago
M6.6 earthquake in Nicobar Islands, India region
Sunday, December 26, 2004, 09:20:01 UTC · 8.879°N, 92.375°E
A magnitude 6.6 earthquake struck in Nicobar Islands, India region on Sunday, December 26, 2004, 09:20:01 UTC, at a depth of 16.1 km (shallow). It is the strongest earthquake within 300 km since an M7.2 on December 26, 2004.
- Magnitude
- 6.6
- Strong · mwc
- Depth
- 16 km
- Shallow
- Felt reports
- 0
- Did You Feel It?
- Est. shaking
- V
- Moderate (ShakeMap)
- PAGER alert
- None
- Not issued
- Tsunami
- No flag
- USGS feed
Outlined circle: this earthquakeDashed circle: 100 km aftershock search area
In context
How big was it, and why here?
Energy released
120 kilotons of TNT
That is about 8 times the Hiroshima bomb. It released about 251 times the energy of a magnitude 5.0.
Tectonic setting
82 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
16 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 100 km
USGS lists 82 M2.5+ earthquakes within 100 km in the following 30 days; the largest was M6.2 on December 29, 2004. Most nearby activity right after a large earthquake is aftershocks, which usually become less frequent over days and weeks.
- 4.3274 km S of Port Blair, India21y ago · 55 km NE of this epicenter
- 4.0Nicobar Islands, India region21y ago · 77 km SE of this epicenter
- 4.2Nicobar Islands, India region21y ago · 96 km SE of this epicenter
- 4.3252 km S of Port Blair, India21y ago · 98 km NE of this epicenter
- 3.9Nicobar Islands, India region21y ago · 76 km SE of this epicenter
- 4.3Nicobar Islands, India region22y ago · 19 km W of this epicenter
- 4.5Nicobar Islands, India region22y ago · 93 km SE of this epicenter
- 4.5Nicobar Islands, India region22y ago · 80 km SW of this epicenter
Regional history
Past M5+ earthquakes within 300 km
USGS lists 206 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 · 228 km S of this epicenter
- 7.0190 km WNW of Sabang, IndonesiaMay 17, 1955 · 281 km SE of this epicenter
- 6.8238 km WNW of Sabang, IndonesiaJanuary 20, 1917 · 240 km SE of this epicenter
- 6.6Nicobar Islands, India regionApril 7, 1973 · 239 km SW of this epicenter
- 6.6249 km NW of Sabang, IndonesiaMarch 5, 1921 · 215 km SE of this epicenter
- 6.5253 km WNW of Sabang, IndonesiaNovember 21, 1907 · 272 km S of this epicenter
- 6.5171 km S of Port Blair, IndiaApril 19, 1936 · 143 km N of this epicenter
- 6.3273 km SSE of Port Blair, IndiaOctober 21, 1916 · 145 km E of this epicenter
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:
- 1881M7.9
Andaman I,Nicobar I
31 Dec 1881 · 40 km away
Severe damage ($5–24M)tsunami
- 1982M6.3
Little Nicobar Island
20 Jan 1982 · 280 km away · intensity VIII
Moderate damage ($1–5M)
- 1847
Little Nicobar Island
31 Oct 1847 · 223 km away · intensity X
Limited damage (under $1M)tsunami
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.