QuakeScout
Magnitude5.8

Reviewed by USGSJapan66y ago

M5.8 earthquake 114 km SE of Koshima, Japan

Wednesday, July 19, 1961, 11:58:46 UTC · 29.646°N, 131.516°E

A magnitude 5.8 earthquake struck 114 km SE of Koshima, Japan on Wednesday, July 19, 1961, 11:58:46 UTC, at a depth of 20.0 km (shallow). It is the strongest earthquake within 300 km since an M7.0 on July 18, 1961.

Magnitude
5.8
Moderate · mw
Depth
20 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: 75 km aftershock search area

In context

How big was it, and why here?

Energy released

6 kilotons of TNT

That is about 1/2 of the Hiroshima bomb. It released about 13 times the energy of a magnitude 5.0.

Tectonic setting

35 km

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

Depth: shallow

20 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 75 km

USGS lists 2 M2.5+ earthquakes within 75 km in the following 30 days; the largest was M5.8 on July 21, 1961. Most nearby activity right after a large earthquake is aftershocks, which usually become less frequent over days and weeks.

M3M4M5M61h6h1d3d7d14d30dMainshock M5.8
Time after the mainshock on a logarithmic scale (first hours stretched), magnitude on the vertical axis. M2.5+ events from USGS.
  1. 5.7123 km SE of Nishinoomote, Japan66y ago · 38 km NE of this epicenter
  2. 5.8123 km SE of Nishinoomote, Japan66y ago · 34 km NE of this epicenter

Regional history

Past M5+ earthquakes within 300 km

USGS lists 99 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:

  1. 8.01941 Hyuganada EarthquakeNovember 18, 1941 · 279 km N of this epicenter
  2. 7.958 km ESE of Takanabe, JapanNovember 2, 1931 · 254 km N of this epicenter
  3. 7.9108 km NW of Naze, JapanJune 15, 1911 · 269 km W of this epicenter
  4. 7.678 km S of Naze, JapanJune 16, 1938 · 297 km SW of this epicenter
  5. 7.518 km NNE of Nichinan, JapanFebruary 26, 1961 · 233 km N of this epicenter
  6. 7.4152 km ESE of Koshima, JapanFebruary 1, 1916 · 38 km SE of this epicenter
  7. 7.422 km N of Nishinoomote, JapanJuly 13, 1923 · 150 km N of this epicenter
  8. 7.229 km ESE of Takanabe, JapanApril 13, 1913 · 267 km N of this epicenter

History · NOAA

Deadliest earthquakes in this area

NOAA’s significant-earthquake database lists 14 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 81 recorded deaths. The most severe:

  1. 1914M7.1

    Sakurijima

    12 Jan 1914 · 230 km away

    63 deaths$19 million damagetsunami

  2. 1911M8.0

    Ryukyu Islands

    15 Jun 1911 · 235 km away

    12 deathsSevere damage ($5–24M)tsunami

  3. 1961M7.3

    Miyazaki

    26 Feb 1961 · 219 km away

    2 deathsModerate damage ($1–5M)tsunami

  4. 1941M7.4

    Shikoku

    18 Nov 1941 · 268 km away

    2 deathsLimited damage (under $1M)tsunami

  5. 1939M6.6

    Seikaido, Japan

    20 Mar 1939 · 299 km away

    1 deathLimited damage (under $1M)tsunami

  6. 1931M7.5

    Kyushu

    2 Nov 1931 · 262 km away

    1 deathtsunami

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

Nearby trackers

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