Reviewed by USGSPhilippines54y ago
M4.8 earthquake 75 km ESE of Pondaguitan, Philippines
Sunday, March 11, 1973, 02:33:53 UTC · 5.991°N, 126.756°E
A magnitude 4.8 earthquake struck 75 km ESE of Pondaguitan, Philippines on Sunday, March 11, 1973, 02:33:53 UTC, at a depth of 96.0 km (intermediate). It is the strongest earthquake within 300 km since an M6.0 on March 9, 1973.
- Magnitude
- 4.8
- Light · mb
- Depth
- 96 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 earthquakeDashed circle: 50 km aftershock search area
In context
How big was it, and why here?
Energy released
239 tons of TNT
That is about 1/63 of the Hiroshima bomb. A magnitude 5.0 releases about 2 times more energy.
Tectonic setting
69 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: intermediate
96 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 lists 3 M2.5+ earthquakes within 50 km in the following 30 days; the largest was M5.1 on March 22, 1973. 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 249 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:
- 8.11924 Mindanao, Philippines EarthquakeApril 14, 1924 · 96 km NW of this epicenter
- 8.01972 Mindanao, Philippines EarthquakeDecember 2, 1972 · 50 km N of this epicenter
- 7.947 km ESE of Kalbay, PhilippinesMarch 14, 1913 · 108 km SW of this epicenter
- 7.877 km E of Baculin, PhilippinesMay 25, 1943 · 164 km N of this epicenter
- 7.8161 km SE of Sarangani, PhilippinesApril 1, 1936 · 197 km S of this epicenter
- 7.774 km ENE of Barcelona, PhilippinesJuly 12, 1911 · 279 km N of this epicenter
- 7.6101 km SE of Sarangani, PhilippinesDecember 16, 1910 · 168 km SW of this epicenter
- 7.6223 km ESE of Sarangani, PhilippinesJanuary 30, 1969 · 161 km SE of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 26 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 3,052 recorded deaths. The most severe:
- 1856
Sangihe Pulau (Volcanic)
2 Mar 1856 · 293 km away
2,806 deathsSevere damage ($5–24M)tsunami
- 1913M7.8
Sangihe Island
14 Mar 1913 · 100 km away · intensity IX
138 deathsModerate damage ($1–5M)tsunami
- 1928M7.4
Cotabato,N Coast Of Illana Bay
19 Dec 1928 · 289 km away · intensity VII
97 deathsModerate damage ($1–5M)tsunami
- 1917M6.4
S Mindanao: Glan,Glan Padidu,Tuyan
31 Jan 1917 · 194 km away · intensity IX
7 deathsModerate damage ($1–5M)tsunami
- 1870
Mindanao: Davao,Blanco
4 Nov 1870 · 187 km away
4 deathsModerate damage ($1–5M)
- 1924M8.3
E Mindanao: Mati,Suriga
14 Apr 1924 · 63 km away · intensity IX
Severe damage ($5–24M)tsunami
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.