Reviewed by USGSGuam91y ago
M6.4 earthquake 46 km ENE of Yigo Village, Guam
Thursday, October 29, 1936, 18:39:01 UTC · 13.743°N, 145.261°E
A magnitude 6.4 earthquake struck 46 km ENE of Yigo Village, Guam on Thursday, October 29, 1936, 18:39:01 UTC, at a depth of 70.0 km (intermediate). It is the strongest earthquake within 300 km since an M7.0 on May 18, 1913.
- Magnitude
- 6.4
- Strong · mw
- Depth
- 70 km
- Intermediate
- 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
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
126 km
from the nearest mapped plate boundary, between the Mariana and Pacific plates. Earthquakes this far from a boundary happen on faults inside a plate, often less frequently but sometimes strongly.
Depth: intermediate
70 km
Intermediate-depth earthquakes usually break inside a plate that is sinking into the mantle. Shaking spreads over a wide area but is gentler at the epicenter than a shallow quake of the same size.
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 1 M2.5+ earthquake within 100 km in the following 30 days; the largest was M5.9 on November 12, 1936. Most nearby activity right after a large earthquake is aftershocks, which usually become less frequent over days and weeks.
Regional history
Past M5+ earthquakes within 300 km
USGS lists 12 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:
- 7.0176 km ESE of San Jose Village, Northern Mariana IslandsMay 18, 1913 · 205 km E of this epicenter
- 7.098 km SSE of Inarajan Village, GuamDecember 9, 1909 · 152 km S of this epicenter
- 7.032 km NNE of Yigo Village, GuamOctober 26, 1912 · 34 km W of this epicenter
- 6.3146 km WSW of Merizo Village, GuamNovember 24, 1917 · 227 km SW of this epicenter
- 6.0206 km SW of Merizo Village, GuamMay 1, 1929 · 290 km SW of this epicenter
- 5.973 km E of Yigo Village, GuamJune 11, 1932 · 41 km SE of this epicenter
- 5.9144 km SSW of Merizo Village, GuamMarch 2, 1933 · 223 km SW of this epicenter
- 5.9119 km SSW of Merizo Village, GuamOctober 10, 1928 · 198 km SW of this epicenter
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:
- 1849M7.5
Guam
25 Jan 1849 · 214 km away · intensity IX
Severe damage ($5–24M)tsunami
- 1909M8.0
Guam
9 Dec 1909 · 141 km away · intensity VIII
Moderate damage ($1–5M)tsunami
- 1892M7.5
Guam
16 May 1892 · 214 km away · intensity VIII
Moderate damage ($1–5M)tsunami
- 1825
Ladrones Island
Apr 1825 · 214 km away · intensity VIII
Moderate damage ($1–5M)tsunami
- 1834
Agana
May 1834 · 214 km away
Moderate damage ($1–5M)
- 1903
Guam
10 Feb 1903 · 214 km away · intensity VII
Limited damage (under $1M)tsunami
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.