The earthquake on March 31, 1761, was one of the most significant seismic events to impact the Iberian Peninsula. With an estimated magnitude of 8.5, the quake not only generated physical destruction but also had profound psychological and social implications for the people living in the affected areas. The epicenter was located off the coast, and the tremors were felt strongly in cities like Lisbon, which had only recently begun to rebuild after the catastrophic earthquake of 1755. The earlier quake had destroyed much of Lisbon, leading to extensive architectural and urban planning initiatives aiming to improve building safety and urban resilience.

During the earthquake, the tremors were accompanied by a series of aftershocks that continued to unsettle the population. Many residents were particularly worried about the potential for tsunamis and additional quakes given the region's seismic history. Panic ensued as people rushed into the streets, fearing for their lives as buildings swayed dangerously. Many structures built since the previous earthquake were put to the test, and the effectiveness of new building codes was closely scrutinized.

The second quake contributed to changing attitudes toward seismic risks in Lisbon and surrounding areas. It fueled scientific curiosity and led to early research into earthquake science, although the field was still in its infancy. Various thinkers and scientists began to study the link between geological phenomena and human habitation, fostering a growing interest in how to mitigate such disasters in the future.