Reviewed by USGSIndia21y ago
M4.7 earthquake 232 km SSE of Port Blair, India
Monday, February 28, 2005, 00:35:29 UTC · 9.871°N, 93.853°E
A magnitude 4.7 earthquake struck 232 km SSE of Port Blair, India on Monday, February 28, 2005, 00:35:29 UTC, at a depth of 23.9 km (shallow). It is the strongest earthquake within 300 km since an M4.7 on February 27, 2005.
- Magnitude
- 4.7
- Light · mb
- Depth
- 24 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: 50 km aftershock search area
In context
How big was it, and why here?
Energy released
169 tons of TNT
That is about 1/89 of the Hiroshima bomb. A magnitude 5.0 releases about 3 times more energy.
Tectonic setting
30 km
from the nearest mapped plate boundary, between the Sunda and Burma plates. Earthquakes cluster along boundaries like this one, where plates collide, pull apart or slide past each other.
Depth: shallow
24 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 50 km
USGS lists 6 M2.5+ earthquakes within 50 km in the following 30 days; the largest was M4.8 on March 5, 2005. Most nearby activity right after a large earthquake is aftershocks, which usually become less frequent over days and weeks.
- 4.6226 km SSE of Port Blair, India21y ago · 11 km NE of this epicenter
- 4.4234 km SSE of Port Blair, India21y ago · 36 km SW of this epicenter
- 4.6195 km SSE of Port Blair, India21y ago · 37 km NW of this epicenter
- 4.5192 km SE of Port Blair, India21y ago · 45 km N of this epicenter
- 4.2252 km SSE of Port Blair, India21y ago · 24 km S of this epicenter
- 4.8188 km SSE of Port Blair, India21y ago · 45 km NW of this epicenter
Regional history
Past M5+ earthquakes within 300 km
USGS lists 457 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:
- 8.043 km N of Bamboo Flat, IndiaJune 26, 1941 · 279 km NW of this epicenter
- 6.6Nicobar Islands, India regionDecember 26, 2004 · 196 km SW of this epicenter
- 6.6249 km NW of Sabang, IndonesiaMarch 5, 1921 · 276 km S of this epicenter
- 6.5171 km S of Port Blair, IndiaApril 19, 1936 · 125 km W of this epicenter
- 6.3273 km SSE of Port Blair, IndiaOctober 21, 1916 · 64 km SW of this epicenter
- 6.3Nicobar Islands, India regionOctober 25, 1970 · 86 km S of this epicenter
- 6.3Nicobar Islands, India regionSeptember 15, 1964 · 141 km SW of this epicenter
- 6.3253 km E of Port Blair, IndiaMarch 28, 1971 · 259 km NE of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 4 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700. The most severe:
- 1941M8.0
Andaman Islands,Madras; Sri Lanka: Colombo
26 Jun 1941 · 266 km away
Extreme damage ($25M+)tsunami
- 1881M7.9
Andaman I,Nicobar I
31 Dec 1881 · 217 km away
Severe damage ($5–24M)tsunami
- 2005M7.2
Andaman Islands, Nicobar Islands
24 Jul 2005 · 284 km away
Limited damage (under $1M)
- 1847
Little Nicobar Island
31 Oct 1847 · 283 km away · intensity X
Limited damage (under $1M)tsunami
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.