Reviewed by USGSIndonesia58y ago
M6.4 earthquake 187 km N of Tobelo, Indonesia
Thursday, February 20, 1969, 10:30:20 UTC · 3.405°N, 128.233°E
A magnitude 6.4 earthquake struck 187 km N of Tobelo, Indonesia on Thursday, February 20, 1969, 10:30:20 UTC, at a depth of 47.5 km (shallow). It is the strongest earthquake within 300 km since an M6.4 on February 20, 1969.
- Magnitude
- 6.4
- Strong · mw
- Depth
- 48 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: 100 km aftershock search area
In context
How big was it, and why here?
Energy released
64 kilotons of TNT
That is about 4 times the Hiroshima bomb. It released about 135 times the energy of a magnitude 5.0.
Tectonic setting
59 km
from the nearest mapped plate boundary, between the Philippine Sea and Sunda plates. Earthquakes cluster along boundaries like this one, where plates collide, pull apart or slide past each other.
Depth: shallow
48 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 3 M2.5+ earthquakes within 100 km in the following 30 days; the largest was M6.2 on March 5, 1969. 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 137 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:
- 7.8161 km SE of Sarangani, PhilippinesApril 1, 1936 · 227 km NW of this epicenter
- 7.790 km NE of Tobelo, IndonesiaSeptember 8, 1966 · 117 km S of this epicenter
- 7.6101 km SE of Sarangani, PhilippinesDecember 16, 1910 · 283 km NW of this epicenter
- 7.6223 km ESE of Sarangani, PhilippinesJanuary 30, 1969 · 171 km NW of this epicenter
- 7.564 km NNW of Ternate, IndonesiaJune 25, 1907 · 258 km SW of this epicenter
- 7.5210 km SSE of Sarangani, PhilippinesAugust 17, 1912 · 251 km W of this epicenter
- 7.5273 km N of Tobelo, IndonesiaOctober 23, 1914 · 92 km N of this epicenter
- 7.3146 km SE of Pondaguitan, PhilippinesSeptember 24, 1957 · 253 km NW of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 7 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700. The most severe:
- 1936M7.7
Talaud Islands
1 Apr 1936 · 228 km away · intensity IX
Moderate damage ($1–5M)tsunami
- 1910M6.7
Sulawesi-N. Moluccas Islands
18 Dec 1910 · 152 km away · intensity VIII
Limited damage (under $1M)tsunami
- 1907M7.9
Djailolo Gilolo
25 Jun 1907 · 300 km away
- 1957M7.6
Philippines
24 Sep 1957 · 247 km away
- 1910M7.5
Talaud Islands
16 Dec 1910 · 276 km away
- 1969M7.5
Talaud Islands, Mindanao, Visayan
30 Jan 1969 · 181 km away
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.