U.S. state profile · USGS ComCat
Earthquakes in Guam
Guam has catalogued 2,456 M4+ earthquakes since 2005 (ranked 3rd of 39 U.S. states), with the strongest reaching magnitude M7.8.
Guam ranks 3rd of 39 U.S. states and territories by catalogued seismic activity - one of the most seismically active U.S. jurisdictions, averaging about 117 M4+ events a year alongside 42 significant M6+ earthquakes since 1900. Below: the full M6+ event history, magnitude and depth profile, and yearly trend.
- 2,456
- M4+ events (since 2005)
- 42
- Major M6+ (since 1900)
- M7.8
- Strongest
- ~117
- M4+ per year
The verdict
Guam is among the more seismically active places worldwide, with 2,456 M4+ earthquakes logged since 2005 and 42 major M6+ events since 1900, the strongest reaching magnitude 7.8.
- 1917
- busiest year (3 major events)
- 53 km
- average recorded event depth
- 71%
- of events are shallow (<70 km, the most damaging kind)
Average catalogued magnitude is 4.5 - most events are moderate tremors felt but rarely damaging. On the M4+ activity ladder Northern Mariana Islands sits immediately above at 3,328 events and California sits immediately below at 883.
Where Guam sits in the catalog
Rank 3rd of 39 tracked U.S. states and territories (92th percentile by M4+ count since 2005). On the M4+ activity ladder Northern Mariana Islands sits immediately above at 3,328 events and California sits immediately below at 883.
- Northern Mariana Islands - next more active (3,328 M4+)
- California - next less active (883 M4+)
Guam's M4+ count vs. every tracked state
Total catalogued M4+ events since 2005, USGS ComCat
2,456 Top 8% higher than 92% of 39 states
Each bar is a 100-wide band; taller bars hold more states. The dashed line + filled bar mark this entry. Hover or tap any bar for its full count, share, and where it sits relative to this entry.
Source USGS Comprehensive Earthquake Catalog (ComCat) · 2005-present
How Guam compares to its nearest peers
Guam ranks in the 92th percentile for M4+ frequency among all 39 tracked U.S. states and territories. Plotted here against its 12 nearest-ranked peers by how OFTEN they shake (M4+ count) against how HARD the strongest one ever hit (max recorded magnitude).
Read the chart (all 13 values)
| State | M4+ events | Strongest magnitude |
|---|---|---|
| Alaska | 8,960 | M8.2 |
| Northern Mariana Islands | 3,328 | M7.7 |
| Guam (this page) | 2,456 | M6.8 |
| California | 883 | M7.2 |
| Puerto Rico | 296 | M6.4 |
| Oregon | 263 | M6.3 |
| U.S. Virgin Islands | 221 | M6.1 |
| Hawaii | 204 | M6.9 |
| Nevada | 170 | M6.5 |
| Oklahoma | 97 | M5.8 |
| Idaho | 73 | M6.5 |
| Georgia | 67 | M6.0 |
| Texas | 52 | M5.4 |
Major (M6+) earthquakes in Guam by year
Count of significant (magnitude 6.0+) events catalogued each year
- 1997
1997: 2 major (M6+) events
2
- 1998
1998: 2 major (M6+) events
2
- 1999
1999: 1 major (M6+) events
1
- 2000
2000: 2 major (M6+) events
2
- 2001
2001: 1 major (M6+) events
1
- 2002
2002: 1 major (M6+) events
1
- 2005
2005: 1 major (M6+) events
1
- 2008
2008: 1 major (M6+) events
1
- 2010
2010: 1 major (M6+) events
1
- 2014
2014: 1 major (M6+) events
1
- 2022
2022: 1 major (M6+) events
1
- 2025
2025: 1 major (M6+) events
1
What this shows Guam's most active year for major earthquakes was 1917 (3 M6+ events). Major-quake counts track the episodic release of tectonic stress, not a smooth trend.
Magnitude distribution of major events
Breakdown of the 42 significant (M6+) earthquakes on record for Guam.
M7.0–7.9
7
16.7%
M6.0–6.9
35
83.3%
Depth of major earthquakes
Hypocentral depth of the 42 M6+ events, shallow quakes shake the surface hardest. Average depth: 53 km.
Shallow (<70 km)
30
71% of events
Intermediate (70–300 km)
12
28.6% of events
Deep (>300 km)
0
0.0% of events
Seismic hazard context
Catalogued counts on this page are history, not a building-code hazard map. Guam's latest M4+ catalog entry is dated Jul 2, 2026. For the national PGA design-basis tiers, see the seismic risk maps guide or the USGS National Seismic Hazard Model.
Strongest earthquakes in Guam
The 10 most powerful events on record (USGS, since 1900).
| Mag | Location | Depth | Date |
|---|---|---|---|
| 7.8 | 32 km S of Inarajan Village, Guam | 59.3 km | Aug 8, 1993 |
| 7.2 | 265 km S of Merizo Village, Guam | 15.0 km | Jan 28, 1931 |
| 7.1 | 261 km S of Merizo Village, Guam | 15.0 km | May 9, 1917 |
| 7.1 | 20 km SSW of Merizo Village, Guam | 85.7 km | Apr 26, 2002 |
| 7.0 | 98 km SSE of Inarajan Village, Guam | 15.0 km | Dec 9, 1909 |
| 7.0 | 69 km SSE of Inarajan Village, Guam | 37.0 km | Oct 12, 2001 |
| 7.0 | 32 km NNE of Yigo Village, Guam | 180.0 km | Oct 26, 1912 |
| 6.8 | 181 km WSW of Merizo Village, Guam | 76.0 km | May 9, 2008 |
| 6.7 | 43 km NW of Piti Village, Guam | 130.0 km | Sep 17, 2014 |
| 6.5 | 276 km SW of Merizo Village, Guam | 22.9 km | Oct 23, 1971 |
Significant earthquake record (42 events)
Every catalogued magnitude-6.0-and-above earthquake in Guam since 1900, most recent first.
| Mag | Location | Depth | Date |
|---|---|---|---|
| 6.0 | 191 km WSW of Merizo Village, Guam | 65.0 km | Nov 4, 2025 |
| 6.0 | 168 km SSW of Merizo Village, Guam | 15.0 km | Feb 13, 2022 |
| 6.7 | 43 km NW of Piti Village, Guam | 130.0 km | Sep 17, 2014 |
| 6.3 | 272 km SSE of Inarajan Village, Guam | 13.0 km | Jul 10, 2010 |
| 6.8 | 181 km WSW of Merizo Village, Guam | 76.0 km | May 9, 2008 |
| 6.3 | 63 km NNW of Yigo Village, Guam | 158.7 km | Feb 2, 2005 |
| 7.1 | 20 km SSW of Merizo Village, Guam | 85.7 km | Apr 26, 2002 |
| 7.0 | 69 km SSE of Inarajan Village, Guam | 37.0 km | Oct 12, 2001 |
| 6.2 | 166 km S of Merizo Village, Guam | 33.0 km | Dec 19, 2000 |
| 6.2 | 30 km NNW of Yigo Village, Guam | 132.2 km | Feb 26, 2000 |
| 6.0 | 45 km SSW of Merizo Village, Guam | 50.9 km | Dec 19, 1999 |
| 6.0 | 229 km SW of Merizo Village, Guam | 9.2 km | Sep 22, 1998 |
| 6.0 | 71 km N of Yigo Village, Guam | 154.1 km | May 15, 1998 |
| 6.0 | 8 km SSE of Merizo Village, Guam | 29.0 km | May 9, 1997 |
| 6.5 | 49 km N of Yigo Village, Guam | 100.8 km | Apr 23, 1997 |
| 6.0 | 41 km SE of Inarajan Village, Guam | 18.3 km | Aug 16, 1993 |
| 6.2 | 91 km ESE of Yigo Village, Guam | 21.6 km | Aug 11, 1993 |
| 7.8 | 32 km S of Inarajan Village, Guam | 59.3 km | Aug 8, 1993 |
| 6.0 | 54 km NNW of Yigo Village, Guam | 155.7 km | Feb 10, 1991 |
| 6.0 | 120 km SSW of Merizo Village, Guam | 31.9 km | May 31, 1985 |
| 6.1 | 61 km ENE of Yigo Village, Guam | 98.0 km | Sep 22, 1984 |
| 6.1 | 235 km SW of Merizo Village, Guam | 33.0 km | Sep 17, 1977 |
| 6.1 | 36 km NNW of Yigo Village, Guam | 113.0 km | Nov 1, 1975 |
| 6.2 | 294 km WSW of Merizo Village, Guam | 20.0 km | Oct 24, 1971 |
| 6.5 | 293 km WSW of Merizo Village, Guam | 15.0 km | Oct 24, 1971 |
| 6.5 | 276 km SW of Merizo Village, Guam | 22.9 km | Oct 23, 1971 |
| 6.0 | 20 km SW of Merizo Village, Guam | 30.0 km | Sep 16, 1970 |
| 6.2 | 148 km SW of Merizo Village, Guam | 17.9 km | Mar 4, 1970 |
| 6.0 | 134 km E of Yigo Village, Guam | 15.0 km | Jan 13, 1959 |
| 6.2 | 283 km SW of Merizo Village, Guam | 15.0 km | Aug 2, 1950 |
| 6.2 | 121 km SSW of Merizo Village, Guam | 25.0 km | Jun 12, 1946 |
| 6.0 | 70 km SE of Inarajan Village, Guam | 35.0 km | Jan 30, 1937 |
| 6.2 | 40 km E of Yigo Village, Guam | 35.0 km | Dec 13, 1936 |
| 6.4 | 46 km ENE of Yigo Village, Guam | 70.0 km | Oct 29, 1936 |
| 6.2 | 254 km S of Merizo Village, Guam | 15.0 km | Mar 15, 1932 |
| 7.2 | 265 km S of Merizo Village, Guam | 15.0 km | Jan 28, 1931 |
| 6.0 | 206 km SW of Merizo Village, Guam | 20.0 km | May 1, 1929 |
| 6.3 | 146 km WSW of Merizo Village, Guam | 15.0 km | Nov 24, 1917 |
| 7.1 | 261 km S of Merizo Village, Guam | 15.0 km | May 9, 1917 |
| 6.4 | 279 km S of Merizo Village, Guam | 15.0 km | May 6, 1917 |
| 7.0 | 32 km NNE of Yigo Village, Guam | 180.0 km | Oct 26, 1912 |
| 7.0 | 98 km SSE of Inarajan Village, Guam | 15.0 km | Dec 9, 1909 |
Peak-magnitude sample from the same roster
A Guam-keyed shuffle of states with a recorded max magnitude. Layout order flips by state so sibling pages do not open the same block first.
Other states in this catalog sample
A second Guam-keyed shuffle of the full 38-state roster (not ABS-gap nearest neighbors).
Frequently asked questions
How many earthquakes hit Guam? ▼
What was the largest earthquake in Guam? ▼
How does Guam rank for earthquakes? ▼
Where does this data come from? ▼
Understand the data
About Guam's figures
2,456 M4+ events since 2005 · strongest M7.8 · average M4.5 · 42 M6+ significant events since 1900 · latest M4+ catalog stamp Jul 2, 2026. Computed from the USGS Comprehensive Earthquake Catalog (ComCat); state assignment uses USGS place-name geocoding. See the methodology and USGS ComCat.
Disclaimer: PlainQuake is informational only, not an emergency service or engineering advice. See our full disclaimer.
What Guam's numbers mean
Guam ranks 3rd of 39 U.S. states and territories - one of the most seismically active U.S. jurisdictions.
- See Guam's computed risk level alongside every other state, using the same USGS-derived methodology. Open the risk calculator
- 71% of Guam's catalogued major earthquakes are shallow (under 70km) - shallow events generally produce stronger surface shaking than deep ones of the same magnitude. How depth affects shaking
- Compare Guam against every other U.S. state by count and maximum magnitude. See the full state ranking
Figures reflect the USGS ComCat catalog (M4+ since 2005, M6+ significant events since 1900) - not a real-time hazard assessment. For official guidance, see the USGS Earthquake Hazards Program.
According to the US Geological Survey Earthquake Hazards Program, PlainQuake's figures are rendered directly from 315,341 recorded M4+ earthquakes and 14,428 significant M6+ events (USGS ComCat, 2005-present) -- no figure is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of 2026-07-19.