Reviewed by USGSPhilippines54y ago
M4.7 earthquake 98 km E of Pondaguitan, Philippines
Saturday, March 10, 1973, 05:19:56 UTC · 6.201°N, 127.056°E
A magnitude 4.7 earthquake struck 98 km E of Pondaguitan, Philippines on Saturday, March 10, 1973, 05:19:56 UTC, at a depth of 70.0 km (intermediate). It is the strongest earthquake within 300 km since an M4.7 on March 10, 1973.
- Magnitude
- 4.7
- Light · mb
- Depth
- 70 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
169 tons of TNT
That is about 1/89 of the Hiroshima bomb. A magnitude 5.0 releases about 3 times more energy.
Tectonic setting
30 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
70 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 2 M2.5+ earthquakes within 50 km in the following 30 days; the largest was M4.8 on March 11, 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 248 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 · 109 km NW of this epicenter
- 8.01972 Mindanao, Philippines EarthquakeDecember 2, 1972 · 50 km NW of this epicenter
- 7.947 km ESE of Kalbay, PhilippinesMarch 14, 1913 · 148 km SW of this epicenter
- 7.877 km E of Baculin, PhilippinesMay 25, 1943 · 132 km N of this epicenter
- 7.8161 km SE of Sarangani, PhilippinesApril 1, 1936 · 228 km S of this epicenter
- 7.774 km ENE of Barcelona, PhilippinesJuly 12, 1911 · 254 km N of this epicenter
- 7.6101 km SE of Sarangani, PhilippinesDecember 16, 1910 · 206 km SW of this epicenter
- 7.6223 km ESE of Sarangani, PhilippinesJanuary 30, 1969 · 174 km S of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 24 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 149 recorded deaths. The most severe:
- 1913M7.8
Sangihe Island
14 Mar 1913 · 140 km away · intensity IX
138 deathsModerate damage ($1–5M)tsunami
- 1917M6.4
S Mindanao: Glan,Glan Padidu,Tuyan
31 Jan 1917 · 228 km away · intensity IX
7 deathsModerate damage ($1–5M)tsunami
- 1870
Mindanao: Davao,Blanco
4 Nov 1870 · 203 km away
4 deathsModerate damage ($1–5M)
- 1924M8.3
E Mindanao: Mati,Suriga
14 Apr 1924 · 70 km away · intensity IX
Severe damage ($5–24M)tsunami
- 1903M7.8
Davao Gulf
28 Dec 1903 · 147 km away · intensity VIII
Moderate damage ($1–5M)
- 1936M7.7
Talaud Islands
1 Apr 1936 · 199 km away · intensity IX
Moderate damage ($1–5M)tsunami
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.