Reviewed by USGSPhilippines54y ago
M4.6 earthquake 21 km E of Mangili, Philippines
Saturday, April 7, 1973, 18:17:10 UTC · 5.969°N, 125.879°E
A magnitude 4.6 earthquake struck 21 km E of Mangili, Philippines on Saturday, April 7, 1973, 18:17:10 UTC, at a depth of 178.0 km (intermediate). It is the strongest earthquake within 300 km since an M4.9 on March 31, 1973.
- Magnitude
- 4.6
- Light · mb
- Depth
- 178 km
- Intermediate
- 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
120 tons of TNT
That is about 1/126 of the Hiroshima bomb. A magnitude 5.0 releases about 4 times more energy.
Tectonic setting
161 km
from the nearest mapped plate boundary, between the Philippine Sea and Sunda plates. Earthquakes this far from a boundary happen on faults inside a plate, often less frequently but sometimes strongly.
Depth: intermediate
178 km
Intermediate-depth earthquakes usually break inside a plate that is sinking into the mantle. Shaking spreads over a wide area but is gentler at the epicenter than a shallow quake of the same size.
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 241 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:
- 8.31918 Mindanao, Philippines EarthquakeAugust 15, 1918 · 214 km W of this epicenter
- 8.11924 Mindanao, Philippines EarthquakeApril 14, 1924 · 80 km NE of this epicenter
- 8.01972 Mindanao, Philippines EarthquakeDecember 2, 1972 · 101 km NE of this epicenter
- 7.947 km ESE of Kalbay, PhilippinesMarch 14, 1913 · 47 km S of this epicenter
- 7.877 km E of Baculin, PhilippinesMay 25, 1943 · 219 km NE of this epicenter
- 7.8161 km SE of Sarangani, PhilippinesApril 1, 1936 · 198 km S of this epicenter
- 7.6101 km SE of Sarangani, PhilippinesDecember 16, 1910 · 145 km S of this epicenter
- 7.6223 km ESE of Sarangani, PhilippinesJanuary 30, 1969 · 217 km SE of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 29 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 3,104 recorded deaths. The most severe:
- 1856
Sangihe Pulau (Volcanic)
2 Mar 1856 · 259 km away
2,806 deathsSevere damage ($5–24M)tsunami
- 1913M7.8
Sangihe Island
14 Mar 1913 · 73 km away · intensity IX
138 deathsModerate damage ($1–5M)tsunami
- 1928M7.4
Cotabato,N Coast Of Illana Bay
19 Dec 1928 · 198 km away · intensity VII
97 deathsModerate damage ($1–5M)tsunami
- 1918M8.3
Mindanao: Cotabato
15 Aug 1918 · 214 km away · intensity X
52 deathsSevere damage ($5–24M)tsunami
- 1917M6.4
S Mindanao: Glan,Glan Padidu,Tuyan
31 Jan 1917 · 97 km away · intensity IX
7 deathsModerate damage ($1–5M)tsunami
- 1870
Mindanao: Davao,Blanco
4 Nov 1870 · 126 km away
4 deathsModerate damage ($1–5M)
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.