Magnitude7.8

Reviewed by USGSPhilippines91y ago

M7.8 earthquake 161 km SE of Sarangani, Philippines

Wednesday, April 1, 1936, 02:09:27 UTC · 4.264°N, 126.379°E

A magnitude 7.8 earthquake struck 161 km SE of Sarangani, Philippines on Wednesday, April 1, 1936, 02:09:27 UTC, at a depth of 35.0 km (shallow). It is the strongest earthquake within 300 km since an M8.1 on April 14, 1924.

Magnitude
7.8
Major · mw
Depth
35 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: 200 km aftershock search areaColoured lines: estimated shaking intensity (USGS ShakeMap)

In context

How big was it, and why here?

Energy released

6.4 megatons of TNT

That is about 422 times the Hiroshima bomb. It released about 13,335 times the energy of a magnitude 5.0.

Tectonic setting

182 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

35 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 M6.7 on April 1, 1936. Most nearby activity right after a large earthquake is aftershocks, which usually become less frequent over days and weeks.

M3M4M5M6M7M81h6h1d3d7d14d30dMainshock M7.8
Time after the mainshock on a logarithmic scale (first hours stretched), magnitude on the vertical axis. M2.5+ events from USGS.
  1. 6.7217 km SE of Sarangani, Philippines91y ago · 56 km SE of this epicenter

Regional history

Past M5+ earthquakes within 300 km

USGS lists 69 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 12 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 3,003 recorded deaths. The most severe:

  1. 1856

    Sangihe Pulau (Volcanic)

    2 Mar 1856 · 118 km away

    2,806 deathsSevere damage ($5–24M)tsunami

  2. 1913M7.8

    Sangihe Island

    14 Mar 1913 · 125 km away · intensity IX

    138 deathsModerate damage ($1–5M)tsunami

  3. 1918M8.3

    Mindanao: Cotabato

    15 Aug 1918 · 300 km away · intensity X

    52 deathsSevere damage ($5–24M)tsunami

  4. 1917M6.4

    S Mindanao: Glan,Glan Padidu,Tuyan

    31 Jan 1917 · 246 km away · intensity IX

    7 deathsModerate damage ($1–5M)tsunami

  5. 1924M8.3

    E Mindanao: Mati,Suriga

    14 Apr 1924 · 249 km away · intensity IX

    Severe damage ($5–24M)tsunami

  6. 1936M7.7

    Talaud Islands

    1 Apr 1936 · 29 km away · intensity IX

    Moderate damage ($1–5M)tsunami

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

Nearby trackers

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