Magnitude6.1

Reviewed by USGSCosta Rica104y ago

M6.1 earthquake 8 km S of San Ignacio, Costa Rica

Monday, March 24, 1924, 20:29:18 UTC · 9.727°N, 84.148°W

A magnitude 6.1 earthquake struck 8 km S of San Ignacio, Costa Rica on Monday, March 24, 1924, 20:29:18 UTC, at a depth of 25.0 km (shallow). It is the strongest earthquake within 300 km since an M6.3 on March 11, 1924.

Magnitude
6.1
Strong · mw
Depth
25 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: 100 km aftershock search area

In context

How big was it, and why here?

Energy released

20 kilotons of TNT

That is about the energy of the Hiroshima bomb. It released about 42 times the energy of a magnitude 5.0.

Tectonic setting

76 km

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

Depth: shallow

25 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 2 M2.5+ earthquakes within 100 km in the following 30 days; the largest was M6.2 on March 25, 1924. Most nearby activity right after a large earthquake is aftershocks, which usually become less frequent over days and weeks.

M3M4M5M61h6h1d3d7d14d30dMainshock M6.1
Time after the mainshock on a logarithmic scale (first hours stretched), magnitude on the vertical axis. M2.5+ events from USGS.
  1. 6.035 km ENE of Pital, Costa Rica104y ago · 92 km N of this epicenter
  2. 6.233 km WSW of Jacó, Costa Rica104y ago · 87 km W of this epicenter

Regional history

Past M5+ earthquakes within 300 km

USGS lists 15 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 700 recorded deaths. The most severe:

  1. 1910M6.4

    Cartago, San Jose

    4 May 1910 · 34 km away

    700 deathsSevere damage ($5–24M)

  2. 1854M7.3

    Costa Rica-Panama

    5 Aug 1854 · 186 km away

    Severe damage ($5–24M)tsunami

  3. 1922M6.4

    Nicaragua

    16 Feb 1922 · 275 km away

    Severe damage ($5–24M)

  4. 1888

    San Jose, Ala Juela, Heredia

    30 Dec 1888 · 25 km away · intensity VIII

    Severe damage ($5–24M)

  5. 1822M7.6

    Matina

    7 May 1822 · 128 km away · intensity VII

    Moderate damage ($1–5M)tsunami

  6. 1844M7.4

    Rivas, Greytown

    May 1844 · 179 km away

    Moderate damage ($1–5M)tsunami

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

Nearby trackers

Closest city pages