Reviewed by USGSIndonesia21y ago
M4.5 earthquake 187 km W of Banda Aceh, Indonesia
Wednesday, April 20, 2005, 00:52:24 UTC · 5.252°N, 93.665°E
A magnitude 4.5 earthquake struck 187 km W of Banda Aceh, Indonesia on Wednesday, April 20, 2005, 00:52:24 UTC, at a depth of 30.0 km (shallow). It is the strongest earthquake within 300 km since an M4.6 on April 19, 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 earthquakeDashed circle: 50 km aftershock search area
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
113 km
from the nearest mapped plate boundary, between the Burma and Indian plates. Earthquakes this far from a boundary happen on faults inside a plate, often less frequently but sometimes strongly.
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 lists 2 M2.5+ earthquakes within 50 km in the following 30 days; the largest was M6.1 on May 18, 2005. Most nearby activity right after a large earthquake is aftershocks, which usually become less frequent over days and weeks.
Regional history
Past M5+ earthquakes within 300 km
USGS lists 447 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 · 200 km NW of this epicenter
- 7.0190 km WNW of Sabang, IndonesiaMay 17, 1955 · 177 km N of this epicenter
- 6.975 km WSW of Banda Aceh, IndonesiaAugust 23, 1936 · 116 km E of this epicenter
- 6.95 km W of Banda Aceh, IndonesiaApril 2, 1964 · 182 km E of this epicenter
- 6.968 km WSW of Sabang, IndonesiaApril 4, 1983 · 128 km NE of this epicenter
- 6.8238 km WNW of Sabang, IndonesiaJanuary 20, 1917 · 198 km N of this epicenter
- 6.7171 km W of Meulaboh, IndonesiaDecember 9, 1929 · 161 km SE of this epicenter
- 6.77 km SSE of Reuleuet, IndonesiaApril 12, 1967 · 292 km E of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 16 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 9 recorded deaths. The most severe:
- 1936M7.3
Banda Aceh,Lhok Sukon,Lhoksemawe
23 Aug 1936 · 148 km away · intensity VIII
9 deathsModerate damage ($1–5M)tsunami
- 1964M7.0
Banda Aceh
2 Apr 1964 · 236 km away · intensity VII
Severe damage ($5–24M)tsunami
- 1837M7.3
Banda Atjeh
29 Sep 1837 · 260 km away
Moderate damage ($1–5M)tsunami
- 1983M6.6
Sumatera: Banda Aceh
4 Apr 1983 · 128 km away · intensity VII
$1 million damage
- 1982M6.3
Little Nicobar Island
20 Jan 1982 · 192 km away · intensity VIII
Moderate damage ($1–5M)
- 1847
Little Nicobar Island
31 Oct 1847 · 231 km away · intensity X
Limited damage (under $1M)tsunami
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.