Magnitude4.6

Reviewed by USGSCosta Rica37y ago

M4.6 earthquake 4 km S of Puntarenas, Costa Rica

Tuesday, April 3, 1990, 11:52:06 UTC · 9.938°N, 84.842°W

A magnitude 4.6 earthquake struck 4 km S of Puntarenas, Costa Rica on Tuesday, April 3, 1990, 11:52:06 UTC, at a depth of 33.0 km (shallow). It is the strongest earthquake within 300 km since an M4.9 on March 27, 1990.

Magnitude
4.6
Light · mb
Depth
33 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

120 tons of TNT

That is about 1/126 of the Hiroshima bomb. A magnitude 5.0 releases about 4 times more energy.

Tectonic setting

73 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

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 50 km

USGS lists 1 M2.5+ earthquake within 50 km in the following 30 days; the largest was M4.8 on April 16, 1990. Most nearby activity right after a large earthquake is aftershocks, which usually become less frequent over days and weeks.

M3M4M51h6h1d3d7d14d30dMainshock M4.6
Time after the mainshock on a logarithmic scale (first hours stretched), magnitude on the vertical axis. M2.5+ events from USGS.
  1. 4.814 km NNW of Miramar, Costa Rica36y ago · 31 km N of this epicenter

Regional history

Past M5+ earthquakes within 300 km

USGS lists 234 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 41 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 1,781 recorded deaths. The most severe:

  1. 1930

    Managua

    31 Mar 1930 · 282 km away

    1,000 deaths$15 million damage

  2. 1910M6.4

    Cartago, San Jose

    4 May 1910 · 92 km away

    700 deathsSevere damage ($5–24M)

  3. 1952

    Costa Rica

    30 Dec 1952 · 152 km away

    29 deaths

  4. 1973M6.5

    Tilaran, Arenal, Rio Chiquito

    14 Apr 1973 · 83 km away

    26 deathsUnder $1 million damage

  5. 1955M5.8

    Costa Rica

    1 Sep 1955 · 38 km away

    10 deathsModerate damage ($1–5M)

  6. 1941M7.6

    Costa Rica-Panama

    5 Dec 1941 · 227 km away · intensity IV

    6 deathsModerate damage ($1–5M)tsunami

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

Nearby trackers

Closest city pages