Country profile · USGS ComCat
Earthquakes in Portugal
Portugal has catalogued 434 M4+ earthquakes since 2005 (ranked 47th of 187 countries), with the strongest reaching magnitude M7.8.
Portugal ranks 47th of 187 countries by catalogued seismic activity - a moderately seismically active country, averaging about 21 M4+ events a year alongside 11 significant M6+ earthquakes since 1900. The record is episodic - 27% of those M6+ events fall in 1969 alone.
- 434
- M4+ events (since 2005)
- 11
- Major M6+ (since 1900)
- M7.8
- Strongest
- ~21
- M4+ per year
The verdict
Portugal is moderately seismically active, above the global median, with 434 M4+ earthquakes logged since 2005 and 11 major M6+ events since 1900, the strongest reaching magnitude 7.8.
- 1969
- busiest year (3 major events)
- 16 km
- average recorded event depth
- 100%
- of events are shallow (<70 km, the most damaging kind)
Average catalogued magnitude is 4.5 - most events are moderate M4-5 tremors that are felt but rarely cause damage. On the M4+ activity ladder Svalbard and Jan Mayen sits immediately above at 435 events and Tanzania sits immediately below at 368.
ComCat country tape
Event tape PORTUGAL · Portugal M4+ · 47th/187
Portugal · 434 M4+ · max M7.8 · 11 M6+
- PCT 434
- VS-PEER 47th/187
- COMCAT M7.8
- TAPE 11
- EPIC near Svalbard and Jan Mayen
- YOY 100% shallow
Stamps derive from this country's USGS ComCat row (M4+ book, rank, peak magnitude, M6+ record, ladder neighbour, depth/peak year), not a hazard forecast. PlainQuake is informational only - not professional advice and not a substitute for official USGS guidance. See our disclaimer. Verify with USGS ComCat → · Read with methodology → · How earthquakes are measured → · Reading earthquake data → · All country catalog rows → · Countries ranked →
Observed impact record
What ComCat observed after earthquakes in Portugal
USGS recorded Modified Mercalli Intensity (MMI) for 4 events in this catalogued record; their average observed intensity was MMI 6.4. These are only events with an observation, not an estimate of future shaking or a safety rating.
- MMI observations
- 4
- Average observed MMI
- 6.4
- PAGER alerts / tsunami flags
- 0 / 0
Source: USGS Comprehensive Earthquake Catalog (ComCat) GeoJSON impact fields. Missing MMI, alert, and tsunami values remain unreported rather than being treated as zero.
Where Portugal sits in the catalog
Rank 47th of 187 tracked countries (75th percentile by M4+ count since 2005). On the M4+ activity ladder Svalbard and Jan Mayen sits immediately above at 435 events and Tanzania sits immediately below at 368.
- Svalbard and Jan Mayen - next more active (435 M4+)
- Tanzania - next less active (368 M4+)
Portugal's M4+ count vs. every tracked country
Total catalogued M4+ events since 2005, USGS ComCat
434 Top 25% higher than 75% of 187 countries
Each bar is a 500-wide band; taller bars hold more countries. 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
Major (M6+) earthquakes in Portugal by year
Count of significant (magnitude 6.0+) events catalogued each year
- 1909 1
1909: 1 major (M6+) events
1
- 1939 1
1939: 1 major (M6+) events
1
- 1964 1
1964: 1 major (M6+) events
1
- 1969
1969: 3 major (M6+) events
3
- 1980 1
1980: 1 major (M6+) events
1
- 1998 1
1998: 1 major (M6+) events
1
- 2007
2007: 3 major (M6+) events
3
What this shows Portugal's most active year for major earthquakes was 1969 (3 M6+ events). Major-quake counts are irregular, they track the episodic release of tectonic stress, not a smooth trend.
3 of 434 catalogued M4+ events since 2005 reached M6.0 or higher.
Magnitude distribution of major events
Breakdown of the 11 significant (M6+) earthquakes on record for Portugal.
M7.0-7.9
1
9.1%
M6.0-6.9
10
90.9%
Depth of major earthquakes
Hypocentral depth of the 11 M6+ events, shallow quakes shake the surface hardest. Average depth: 16 km.
Shallow (<70 km)
11
100.0% of events
Intermediate (70–300 km)
0
0.0% of events
Deep (>300 km)
0
0.0% of events
Strongest earthquakes in Portugal
The 10 most powerful events on record (USGS, since 1900).
| Mag | Location | Depth | Date |
|---|---|---|---|
| 7.8 | 188 km SW of Sagres, Portugal | 14.5 km | Feb 28, 1969 |
| 6.7 | 29 km NE of Ribeira Seca, Portugal | 10.0 km | Jan 1, 1980 |
| 6.7 | 99 km SE of Senhora do Rosário, Portugal | 10.0 km | May 8, 1939 |
| 6.6 | 91 km SSE of Olhão, Portugal | 28.5 km | Mar 15, 1964 |
| 6.3 | 74 km SE of Povoação, Portugal | 14.0 km | Apr 5, 2007 |
| 6.2 | 12 km N of Horta, Portugal | 10.0 km | Jul 9, 1998 |
| 6.2 | 169 km WSW of Sagres, Portugal | 10.0 km | Feb 28, 1969 |
| 6.1 | 82 km SE of Senhora do Rosário, Portugal | 8.0 km | Apr 7, 2007 |
| 6.0 | 181 km SW of Sagres, Portugal | 20.0 km | Feb 12, 2007 |
| 6.0 | 272 km W of Sagres, Portugal | 45.0 km | Sep 6, 1969 |
Significant earthquake record (11 events)
Every catalogued magnitude-6.0-and-above earthquake in Portugal since 1900, most recent first.
| Mag | Location | Depth | Date |
|---|---|---|---|
| 6.1 | 82 km SE of Senhora do Rosário, Portugal | 8.0 km | Apr 7, 2007 |
| 6.3 | 74 km SE of Povoação, Portugal | 14.0 km | Apr 5, 2007 |
| 6.0 | 181 km SW of Sagres, Portugal | 20.0 km | Feb 12, 2007 |
| 6.2 | 12 km N of Horta, Portugal | 10.0 km | Jul 9, 1998 |
| 6.7 | 29 km NE of Ribeira Seca, Portugal | 10.0 km | Jan 1, 1980 |
| 6.0 | 272 km W of Sagres, Portugal | 45.0 km | Sep 6, 1969 |
| 6.2 | 169 km WSW of Sagres, Portugal | 10.0 km | Feb 28, 1969 |
| 7.8 | 188 km SW of Sagres, Portugal | 14.5 km | Feb 28, 1969 |
| 6.6 | 91 km SSE of Olhão, Portugal | 28.5 km | Mar 15, 1964 |
| 6.7 | 99 km SE of Senhora do Rosário, Portugal | 10.0 km | May 8, 1939 |
| 6.0 | 2 km SW of Alcochete, Portugal | 10.0 km | Apr 23, 1909 |
Other countries in this catalog sample
A Portugal-keyed shuffle of the full 186-country roster, not the six nearest by count.
Peak-magnitude sample from the same roster
A second Portugal-keyed shuffle of countries with a recorded max magnitude.
Showing 6 of 186 countries with a recorded max magnitude.
According to the US Geological Survey Earthquake Hazards Program, PlainQuake's figures are rendered directly from 317,293 recorded M4+ earthquakes and 14,444 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 2026-08-26.