Brazil Tsunami Evidence From 1755 Quake

More than 271 years ago, an earthquake that wrecked Lisbon sent a wave across the Atlantic towards the beaches of Pernambuco, a state in north-eastern Brazil. Scientists now think that sea may have pushed up to four kilometres (2.5 miles) inland, but the evidence is a computer model and one sandy layer.

This is research from 2020 to 2022, not a new measurement, so we present it as context as of Sunday, 8 November 2026. For readers in the United States, it is a reminder that one Atlantic earthquake can reach three continents.

The sea may have pushed up to four kilometres inland on Pernambuco’s coast in 1755, but the evidence is a computer model and one sandy layer.

What Happened in 1755

The Lisbon earthquake struck on Saturday, 1 November 1755, with its source in the Atlantic off south-west Portugal. No seismometers existed then, so scientists still debate its exact size.

The tsunami it caused crossed the ocean, and the US Geological Survey (USGS), the American government geoscience agency, notes reports of the wave reaching Brazil. USGS also studies the 1755 case when it models tsunami hazard for the American East Coast.

What the Study Measured

A team from the State University of Rio de Janeiro (UERJ) and Portuguese colleagues surveyed Brazil’s north-eastern coast and published a paper in the Journal of South American Earth Sciences in 2022. The paper has a permanent web address, called a DOI, listed in the sources below.

The team combined three tools: colonial-era letters, computer simulations and sediment samples. Only one site showed a coarse marine sand layer inside the dunes, which the authors read as a sign of a high-energy sea flood.

The simulations show flooding up to 4 km inland, mainly along rivers near Itamaracá island. That figure is a modelled limit under chosen assumptions, not a measured shoreline.

Why It Matters

Brazil sits far from the big plate boundaries, so local quakes are rare and the main risk is a distant Atlantic event. A 1755-type event would affect coasts well beyond Portugal.

Travellers planning a stay in Recife can read the Recife guide for November for current conditions. For how modern alerts work, see our reports on Ecuador, where a quake brought no tsunami alert, and Panama, where a 7.7 quake did.

What Is Not Known

The sand layer’s exact age is uncertain, so its link to 1755 stays tentative. Whether one study site speaks for the whole coast is open.

Reliable damage and casualty figures for Brazil in 1755 are not established in the sources we checked. We found no newer paper, official hazard map or evacuation plan tied to this research.

What It Means for You

If you plan to visit or live in Recife or Itamaracá, this is history, not a warning. Follow official civil defence alerts as you would anywhere on a coast.

For US readers, the lesson is scale: the risk today is low and well studied. Treat this as context, not a reason to change plans.

Frequently Asked Questions

Did a tsunami really hit Brazil in 1755?

Researchers think so, based on colonial letters, computer models and one sand layer on the north-east coast. The evidence is suggestive rather than conclusive.

How far inland did the water go?

Simulations show up to about 4 km (2.5 miles) near Itamaracá island, mostly along rivers. That is a modelled estimate, not a measured shoreline.

Could a tsunami from Europe hit Recife again?

It is possible in principle but rare, and nobody can predict the timing. Nothing in the research points to an imminent threat.