Reviewed by USGSPhilippines115y ago
M6.6 earthquake 40 km ENE of Cortes, Philippines
Friday, April 18, 1913, 19:02:33 UTC · 9.459°N, 126.515°E
A magnitude 6.6 earthquake struck 40 km ENE of Cortes, Philippines on Friday, April 18, 1913, 19:02:33 UTC, at a depth of 15.0 km (shallow). It is the strongest earthquake within 300 km since an M7.7 on July 12, 1911.
- Magnitude
- 6.6
- Strong · mw
- Depth
- 15 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
128 kilotons of TNT
That is about 9 times the Hiroshima bomb. It released about 269 times the energy of a magnitude 5.0.
Tectonic setting
32 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
15 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 5 M2.5+ earthquakes within 100 km in the following 30 days; the largest was M7.2 on April 25, 1913. Most nearby activity right after a large earthquake is aftershocks, which usually become less frequent over days and weeks.
- 6.298 km E of Union, Philippines115y ago · 62 km NE of this epicenter
- 6.210 km NE of Cortes, Philippines115y ago · 31 km SW of this epicenter
- 7.270 km ENE of La Paz, Philippines115y ago · 42 km SE of this epicenter
- 6.421 km E of Union, Philippines115y ago · 38 km NW of this epicenter
- 6.616 km E of Cagdianao, Philippines115y ago · 91 km NW of this epicenter
Regional history
Past M5+ earthquakes within 300 km
USGS lists 8 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:
- 7.774 km ENE of Barcelona, PhilippinesJuly 12, 1911 · 122 km SE of this epicenter
- 7.15 km N of Capoocan, PhilippinesMarch 5, 1908 · 293 km NW of this epicenter
- 7.110 km W of Bigaan, PhilippinesJuly 20, 1907 · 132 km S of this epicenter
- 6.642 km E of Aras-asan, PhilippinesOctober 10, 1906 · 73 km S of this epicenter
- 6.475 km ENE of Sulangan, PhilippinesMay 20, 1907 · 181 km N of this epicenter
- 6.34 km SSE of Binucayan, PhilippinesApril 18, 1913 · 164 km SW of this epicenter
- 6.125 km SSE of Alburquerque, PhilippinesJuly 16, 1905 · 273 km W of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 15 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 4 recorded deaths. The most severe:
- 1870
Mindanao: Davao,Blanco
4 Nov 1870 · 300 km away
4 deathsModerate damage ($1–5M)
- 1879
Nw Mindanao: Surigao
30 Jun 1879 · 118 km away · intensity X
Extreme damage ($25M+)
- 1911M7.8
Mindanao: Talacogon,Davao,Butuan
12 Jul 1911 · 76 km away · intensity X
Severe damage ($5–24M)tsunami
- 1871
Camiguin Island: Mambajao,Catarman
20 Feb 1871 · 204 km away · intensity IX
Severe damage ($5–24M)tsunami
- 1885
E Mindanao: Surigao
22 Feb 1885 · 118 km away · intensity VIII
Severe damage ($5–24M)
- 1897M8.1
Northern Samar
18 Oct 1897 · 288 km away · intensity IX
Moderate damage ($1–5M)tsunami
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.