Magnitude4.4

Reviewed by USGSPhilippines54y ago

M4.4 earthquake 145 km SE of Pondaguitan, Philippines

Tuesday, January 2, 1973, 13:03:15 UTC · 5.535°N, 127.205°E

A magnitude 4.4 earthquake struck 145 km SE of Pondaguitan, Philippines on Tuesday, January 2, 1973, 13:03:15 UTC, at a depth of 62.0 km (shallow).

Magnitude
4.4
Light · mb
Depth
62 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: 50 km aftershock search area

In context

How big was it, and why here?

Energy released

60 tons of TNT

That is about 1/251 of the Hiroshima bomb. A magnitude 5.0 releases about 8 times more energy.

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

62 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 50 km

USGS lists 2 M2.5+ earthquakes within 50 km in the following 30 days; the largest was M5.1 on January 7, 1973. Most nearby activity right after a large earthquake is aftershocks, which usually become less frequent over days and weeks.

M3M4M51h6h1d3d7d14d30dMainshock M4.4
Time after the mainshock on a logarithmic scale (first hours stretched), magnitude on the vertical axis. M2.5+ events from USGS.
  1. 5.1145 km ESE of Pondaguitan, Philippines54y ago · 20 km NE of this epicenter
  2. 4.8136 km ESE of Pondaguitan, Philippines54y ago · 39 km N of this epicenter

Regional history

Past M5+ earthquakes within 300 km

USGS lists 219 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 21 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 2,955 recorded deaths. The most severe:

  1. 1856

    Sangihe Pulau (Volcanic)

    2 Mar 1856 · 281 km away

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

  2. 1913M7.8

    Sangihe Island

    14 Mar 1913 · 122 km away · intensity IX

    138 deathsModerate damage ($1–5M)tsunami

  3. 1917M6.4

    S Mindanao: Glan,Glan Padidu,Tuyan

    31 Jan 1917 · 249 km away · intensity IX

    7 deathsModerate damage ($1–5M)tsunami

  4. 1870

    Mindanao: Davao,Blanco

    4 Nov 1870 · 258 km away

    4 deathsModerate damage ($1–5M)

  5. 1924M8.3

    E Mindanao: Mati,Suriga

    14 Apr 1924 · 133 km away · intensity IX

    Severe damage ($5–24M)tsunami

  6. 1903M7.8

    Davao Gulf

    28 Dec 1903 · 210 km away · intensity VIII

    Moderate damage ($1–5M)

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

Nearby trackers

Closest city pages