Reviewed by USGSIndia21y ago
M4.5 earthquake 84 km SSW of Port Blair, India
Wednesday, April 20, 2005, 07:47:49 UTC · 10.922°N, 92.586°E
A magnitude 4.5 earthquake struck 84 km SSW of Port Blair, India on Wednesday, April 20, 2005, 07:47:49 UTC, at a depth of 30.0 km (shallow). It is the strongest earthquake within 300 km since an M4.6 on April 18, 2005.
- Magnitude
- 4.5
- Light · mb
- 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 earthquake
In context
How big was it, and why here?
Energy released
85 tons of TNT
That is about 1/178 of the Hiroshima bomb. A magnitude 5.0 releases about 6 times more energy.
Tectonic setting
11 km
from the nearest mapped plate boundary, between the Caribbean and Cocos 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 50 km
USGS has not published any M2.5+ earthquake within 50 km in the 30 days after this event.
Regional history
Past M5+ earthquakes within 300 km
USGS lists 304 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 · 129 km N of this epicenter
- 6.8166 km NE of Bamboo Flat, IndiaJanuary 24, 1983 · 249 km NE of this epicenter
- 6.6Nicobar Islands, India regionDecember 26, 2004 · 228 km S of this epicenter
- 6.5152 km NNE of Bamboo Flat, IndiaSeptember 13, 2002 · 241 km N of this epicenter
- 6.5171 km S of Port Blair, IndiaApril 19, 1936 · 91 km S of this epicenter
- 6.3273 km SSE of Port Blair, IndiaOctober 21, 1916 · 208 km SE of this epicenter
- 6.3Nicobar Islands, India regionOctober 25, 1970 · 248 km SE of this epicenter
- 6.3Nicobar Islands, India regionSeptember 15, 1964 · 235 km S 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, which together caused about 2 recorded deaths. The most severe:
- 2002M6.5
Andaman Islands: Rongat, Diglipur,Ariel Bay
13 Sep 2002 · 241 km away
2 deathsModerate damage ($1–5M)tsunami
- 1941M8.0
Andaman Islands,Madras; Sri Lanka: Colombo
26 Jun 1941 · 113 km away
Extreme damage ($25M+)tsunami
- 1881M7.9
Andaman I,Nicobar I
31 Dec 1881 · 268 km away
Severe damage ($5–24M)tsunami
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.