Magnitude7.2

Reviewed by USGSPhilippines103y ago

M7.2 earthquake 70 km E of Aras-asan, Philippines

Saturday, August 30, 1924, 03:04:59 UTC · 8.982°N, 126.942°E

A magnitude 7.2 earthquake struck 70 km E of Aras-asan, Philippines on Saturday, August 30, 1924, 03:04:59 UTC, at a depth of 15.0 km (shallow). It is the strongest earthquake within 300 km since an M8.1 on April 14, 1924.

Magnitude
7.2
Major · mw
Depth
15 km
Shallow
Felt reports
0
Did You Feel It?
Est. shaking
VI
Strong (ShakeMap)
PAGER alert
None
Not issued
Tsunami
No flag
USGS feed

Outlined circle: this earthquakeDashed circle: 200 km aftershock search areaColoured lines: estimated shaking intensity (USGS ShakeMap)

In context

How big was it, and why here?

Energy released

919 kilotons of TNT

That is about 61 times the Hiroshima bomb. It released about 1,928 times the energy of a magnitude 5.0.

Tectonic setting

3 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 200 km

USGS lists 1 M2.5+ earthquake within 200 km in the following 30 days; the largest was M6.5 on September 14, 1924. Most nearby activity right after a large earthquake is aftershocks, which usually become less frequent over days and weeks.

M3M4M5M6M71h6h1d3d7d14d30dMainshock M7.2
Time after the mainshock on a logarithmic scale (first hours stretched), magnitude on the vertical axis. M2.5+ events from USGS.
  1. 6.5149 km E of Union, Philippines103y ago · 117 km NE of this epicenter

Regional history

Past M5+ earthquakes within 300 km

USGS lists 30 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:

History · NOAA

Deadliest earthquakes in this area

NOAA’s significant-earthquake database lists 19 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 4 recorded deaths. The most severe:

  1. 1870

    Mindanao: Davao,Blanco

    4 Nov 1870 · 278 km away

    4 deathsModerate damage ($1–5M)

  2. 1879

    Nw Mindanao: Surigao

    30 Jun 1879 · 182 km away · intensity X

    Extreme damage ($25M+)

  3. 1924M8.3

    E Mindanao: Mati,Suriga

    14 Apr 1924 · 280 km away · intensity IX

    Severe damage ($5–24M)tsunami

  4. 1911M7.8

    Mindanao: Talacogon,Davao,Butuan

    12 Jul 1911 · 103 km away · intensity X

    Severe damage ($5–24M)tsunami

  5. 1871

    Camiguin Island: Mambajao,Catarman

    20 Feb 1871 · 250 km away · intensity IX

    Severe damage ($5–24M)tsunami

  6. 1885

    E Mindanao: Surigao

    22 Feb 1885 · 182 km away · intensity VIII

    Severe damage ($5–24M)

NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.

Nearby trackers

Closest city pages