Reviewed by USGSPhilippines99y ago
M6.8 earthquake 2 km E of Guipos, Philippines
Friday, December 28, 1928, 14:19:43 UTC · 7.712°N, 123.345°E
A magnitude 6.8 earthquake struck 2 km E of Guipos, Philippines on Friday, December 28, 1928, 14:19:43 UTC, at a depth of 15.0 km (shallow). It is the strongest earthquake within 300 km since an M7.4 on December 19, 1928.
- 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 earthquakeColoured lines: estimated shaking intensity (USGS ShakeMap)
In context
How big was it, and why here?
Energy released
215 kilotons of TNT
That is about 14 times the Hiroshima bomb. It released about 452 times the energy of a magnitude 5.0.
Tectonic setting
424 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 has not published any M2.5+ earthquake within 100 km in the 30 days after this event.
Regional history
Past M5+ earthquakes within 300 km
USGS lists 23 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 · 252 km S of this epicenter
- 7.410 km ESE of Basak, PhilippinesDecember 19, 1928 · 149 km SE of this epicenter
- 7.25 km NW of Kadingilan, PhilippinesMarch 2, 1923 · 169 km E of this epicenter
- 6.937 km S of Daliao, PhilippinesJanuary 31, 1917 · 298 km SE of this epicenter
- 6.85 km NNW of Nalundan, PhilippinesMay 5, 1925 · 234 km N of this epicenter
- 6.8173 km SW of Palimbang, PhilippinesSeptember 11, 1915 · 299 km S of this epicenter
- 6.67 km ENE of South Upi, PhilippinesSeptember 26, 1919 · 134 km SE of this epicenter
- 6.534 km S of Daliao, PhilippinesMay 20, 1926 · 297 km SE of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 22 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 195 recorded deaths. The most severe:
- 1928M7.4
Cotabato,N Coast Of Illana Bay
19 Dec 1928 · 149 km away · intensity VII
97 deathsModerate damage ($1–5M)tsunami
- 1918M8.3
Mindanao: Cotabato
15 Aug 1918 · 252 km away · intensity X
52 deathsSevere damage ($5–24M)tsunami
- 1925M6.8
W. Luzon Island, Philippines
5 May 1925 · 190 km away · intensity IX
17 deathsModerate damage ($1–5M)tsunami
- 1897M8.7
Mindanao, Zamboanga, Sulu, Isabela
21 Sep 1897 · 241 km away · intensity IX
13 deathsSevere damage ($5–24M)tsunami
- 1917M6.4
S Mindanao: Glan,Glan Padidu,Tuyan
31 Jan 1917 · 264 km away · intensity IX
7 deathsModerate damage ($1–5M)tsunami
- 1922M6.3
Cebu Island, Mactan Island
27 Feb 1922 · 289 km away · intensity V
5 deathsModerate damage ($1–5M)tsunami
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.