Magnitude6.4

Reviewed by USGSIndonesia54y ago

M6.4 earthquake 193 km NE of Tual, Indonesia

Tuesday, April 17, 1973, 12:34:26 UTC · 4.439°S, 134.030°E

A magnitude 6.4 earthquake struck 193 km NE of Tual, Indonesia on Tuesday, April 17, 1973, 12:34:26 UTC, at a depth of 33.0 km (shallow). It is the strongest earthquake within 300 km since an M6.7 on November 8, 1970.

Magnitude
6.4
Strong · ms
Depth
33 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: 100 km aftershock search area

In context

How big was it, and why here?

Energy released

60 kilotons of TNT

That is about 4 times the Hiroshima bomb. It released about 126 times the energy of a magnitude 5.0.

Tectonic setting

27 km

from the nearest mapped plate boundary, between the Australian and Birds Head plates. Earthquakes cluster along boundaries like this one, where plates collide, pull apart or slide past each other.

Depth: shallow

33 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 3 M2.5+ earthquakes within 100 km in the following 30 days; the largest was M5.2 on May 12, 1973. Most nearby activity right after a large earthquake is aftershocks, which usually become less frequent over days and weeks.

M3M4M5M61h6h1d3d7d14d30dMainshock M6.4
Time after the mainshock on a logarithmic scale (first hours stretched), magnitude on the vertical axis. M2.5+ events from USGS.
  1. 5.2171 km SW of Nabire, Indonesia54y ago · 30 km NE of this epicenter
  2. 5.0173 km SW of Nabire, Indonesia54y ago · 61 km E of this epicenter
  3. 4.8171 km SW of Nabire, Indonesia54y ago · 31 km NE of this epicenter

Regional history

Past M5+ earthquakes within 300 km

USGS lists 61 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 7 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700. The most severe:

  1. 1938M8.6

    New Guinea

    1 Feb 1938 · 276 km away · intensity VI

    Moderate damage ($1–5M)tsunami

  2. 1938

    New Guinea: Fakfak

    13 Feb 1938 · 250 km away

    Limited damage (under $1M)tsunami

  3. 1916M8.1

    New Guinea: Irian Jaya

    13 Jan 1916 · 271 km away

  4. 1916M8.1

    New Guinea: Irian Jaya

    13 Jan 1916 · 228 km away

  5. 1943M7.6

    New Guinea: Irian Jaya: Aru Islands

    6 Nov 1943 · 181 km away

  6. 1915

    Kaimana

    23 May 1915 · 96 km away

    tsunami

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

Nearby trackers

Closest city pages