Reviewed by USGSTonga39y ago
M4.4 earthquake 195 km E of Neiafu, Tonga
Wednesday, October 7, 1987, 02:14:09 UTC · 18.406°S, 172.154°W
A magnitude 4.4 earthquake struck 195 km E of Neiafu, Tonga on Wednesday, October 7, 1987, 02:14:09 UTC, at a depth of 33.0 km (shallow).
- Magnitude
- 4.4
- Light · mb
- Depth
- 33 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
60 tons of TNT
That is about 1/251 of the Hiroshima bomb. A magnitude 5.0 releases about 8 times more energy.
Tectonic setting
52 km
from the nearest mapped plate boundary, between the Tonga and Pacific plates. Earthquakes cluster along boundaries like this one, where plates collide, pull apart or slide past each other.
Depth: shallow
33 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 435 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:
- 8.11919 Tonga EarthquakeApril 30, 1919 · 32 km W of this epicenter
- 7.8146 km ESE of Hihifo, TongaDecember 26, 1975 · 240 km N of this epicenter
- 7.6199 km ESE of Hihifo, TongaApril 2, 1977 · 190 km N of this epicenter
- 7.4103 km ESE of Neiafu, TongaFebruary 27, 1921 · 108 km SW of this epicenter
- 7.385 km ESE of Neiafu, TongaJanuary 2, 1907 · 142 km SW of this epicenter
- 7.3201 km ENE of Neiafu, TongaOctober 6, 1987 · 52 km N of this epicenter
- 7.2108 km SE of Neiafu, TongaDecember 19, 1906 · 140 km SW of this epicenter
- 7.0206 km SE of Hihifo, TongaJune 17, 1978 · 146 km N of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 9 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700. The most severe:
- 1919M8.1
Tonga Islands
30 Apr 1919 · 39 km away
Limited damage (under $1M)tsunami
- 1865M8.0
Tonga Islands
18 Nov 1865 · 187 km away
Limited damage (under $1M)tsunami
- 1977M7.6
Apia
2 Apr 1977 · 190 km away · intensity VI
Limited damage (under $1M)tsunami
- 1902M7.8
Tonga Islands
9 Feb 1902 · 263 km away
- 1975M7.8
Samoa Islands
26 Dec 1975 · 240 km away · intensity V
tsunami
- 1913M7.6
Tonga Islands
26 Jun 1913 · 263 km away
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.