M5.8 earthquake in Mariana Islands region

Sunday, July 17, 1927, 08:48:28 UTC · 12.927°N, 141.604°E

A magnitude 5.8 earthquake struck in Mariana Islands region on Sunday, July 17, 1927, 08:48:28 UTC, at a depth of 25.0 km (shallow). It is the strongest earthquake within 300 km since an M6.0 on July 17, 1925.

Magnitude: 5.8; Moderate · 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 earthquake

In context

How big was it, and why here?

Energy released

7 kilotons of TNT

That is about 1/2 of the Hiroshima bomb. It released about 14 times the energy of a magnitude 5.0.

Tectonic setting

182 km

from the nearest mapped plate boundary, between the Philippine Sea and Mariana plates. Earthquakes this far from a boundary happen on faults inside a plate, often less frequently but sometimes strongly.

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 75 km

USGS has not published any M2.5+ earthquake within 75 km in the 30 days after this event.

Regional history

Past M5+ earthquakes within 300 km

USGS lists 5 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 6 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700. The most severe:

1849M7.5
Guam
25 Jan 1849 · 219 km away · intensity IX
Severe damage ($5–24M)tsunami
1892M7.5
Guam
16 May 1892 · 219 km away · intensity VIII
Moderate damage ($1–5M)tsunami
1825
Ladrones Island
Apr 1825 · 219 km away · intensity VIII
Moderate damage ($1–5M)tsunami
1834
Agana
May 1834 · 219 km away
Moderate damage ($1–5M)
1903
Guam
10 Feb 1903 · 219 km away · intensity VII
Limited damage (under $1M)tsunami
1809
Guam
1809 · 219 km away
tsunami

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

Nearby trackers