Reviewed by USGSPhilippines102y ago
M6.8 earthquake 5 km NNW of Nalundan, Philippines
Tuesday, May 5, 1925, 10:06:14 UTC · 9.798°N, 123.044°E
A magnitude 6.8 earthquake struck 5 km NNW of Nalundan, Philippines on Tuesday, May 5, 1925, 10:06:14 UTC, at a depth of 15.0 km (shallow). It is the strongest earthquake within 300 km since an M6.8 on March 12, 1915.
- Magnitude
- 6.8
- Strong · mw
- Depth
- 15 km
- Shallow
- Felt reports
- 0
- Did You Feel It?
- Est. shaking
- VII
- Very strong (ShakeMap)
- PAGER alert
- None
- Not issued
- Tsunami
- No flag
- USGS feed
Outlined circle: this earthquakeDashed circle: 100 km aftershock search areaColoured lines: estimated shaking intensity (USGS ShakeMap)
In context
How big was it, and why here?
Energy released
256 kilotons of TNT
That is about 17 times the Hiroshima bomb. It released about 537 times the energy of a magnitude 5.0.
Tectonic setting
374 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: 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 1 M2.5+ earthquake within 100 km in the following 30 days; the largest was M6.2 on May 5, 1925. 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 11 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:
- 7.15 km N of Capoocan, PhilippinesMarch 5, 1908 · 245 km NE of this epicenter
- 6.829 km NNW of Roxas City, PhilippinesMarch 12, 1915 · 231 km N of this epicenter
- 6.815 km WNW of Santa Fe, PhilippinesAugust 29, 1922 · 297 km NW of this epicenter
- 6.55 km SSW of Mantalongon, PhilippinesOctober 11, 1906 · 65 km NE of this epicenter
- 6.410 km W of Wao, PhilippinesJuly 13, 1922 · 290 km SE of this epicenter
- 6.325 km WSW of Jabonga, PhilippinesApril 28, 1913 · 253 km E of this epicenter
- 6.26 km S of Bangad, PhilippinesApril 23, 1922 · 259 km N of this epicenter
- 6.125 km SSE of Alburquerque, PhilippinesJuly 16, 1905 · 117 km SE of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 25 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 22 recorded deaths. The most severe:
- 1925M6.8
W. Luzon Island, Philippines
5 May 1925 · 67 km away · intensity IX
17 deathsModerate damage ($1–5M)tsunami
- 1922M6.3
Cebu Island, Mactan Island
27 Feb 1922 · 124 km away · intensity V
5 deathsModerate damage ($1–5M)tsunami
- 1879
Nw Mindanao: Surigao
30 Jun 1879 · 269 km away · intensity X
Extreme damage ($25M+)
- 1897M7.9
Masbate Island
13 May 1897 · 266 km away · intensity VIII
Severe damage ($5–24M)tsunami
- 1902M7.3
Mindanao: Lanao, Cotabato
21 Aug 1902 · 260 km away · intensity X
Severe damage ($5–24M)tsunami
- 1743
Leyte
Sep 1743 · 208 km away
Severe damage ($5–24M)
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.