A magnitude 6.0 earthquake near Benavente killed at least 30 people and left 13,000 homeless, devastating towns in Portugal's Lower Tagus Valley.
Key Facts
- Moment Magnitude
- 6.0
- Mercalli Intensity
- IX (Violent)
- Death Toll
- At least 30 people
- Injured
- 75 people
- Displaced
- 13,000 people
- Destruction in Samora Correia & Muge
- 90% destroyed
By the Numbers
Location
Cause → Event → Consequence
Beneath the Lower Tagus Valley lies a system of normal faults that were reactivated during the Eocene as reverse faults. Movement along one of these buried faults triggered the earthquake, a seismically active zone near Lisbon that has historically produced significant seismic events.
On 23 April 1909 at 17:39 GMT, a magnitude 6.0 earthquake struck the Lisbon region of Portugal with its epicenter near Benavente. The shaking reached Mercalli intensity IX, causing severe structural damage across the Lower Tagus Valley and minor damage and fires as far away as Lisbon.
At least 30 people were killed and 75 injured, while approximately 13,000 were left homeless. The towns of Samora Correia and Muge suffered the most severe destruction, with 90 percent of their built environment destroyed. Lisbon experienced minor structural damage, fires, and several injuries.
Human Cost
Each dot represents approximately 10,000 deaths. Total estimated: 30 (earthquake)