A series of unusual “mini-tsunamis” known locally as rissagues swept into Ibiza on Monday morning, sending seawater across a popular beach, promenade and nearby restaurants and forcing the cancellation of a planned evening concert in San Antonio.

The sudden sea-level changes affected Platja de s’Arenal in Sant Antoni de Portmany, where holidaymakers and locals were caught off guard as water moved inland across the beachfront.

Seawater Floods Ibiza’s Beachfront

Footage from the area showed seawater pushing across the sand and onto the promenade, with people scrambling to move their belongings as the water advanced.

The flooding also reached bars, restaurants and other businesses along the waterfront, while coolers, containers and temporary structures installed for an evening event were swept around by the water.

The phenomenon was particularly noticeable because the water did not arrive as a towering breaking wave. Instead, the sea level rose and moved inland gradually enough for people to walk through the flooded areas.

Concert Cancelled After Water Reaches Event Area

The flooding also disrupted plans for an evening concert in San Antonio.

A stage and other equipment had already been installed for a tribute concert celebrating a famous Spanish rock band, but the area was left surrounded by seawater.

San Antonio Town Hall subsequently announced that the 10pm concert would be cancelled for safety reasons.

What Causes a “Mini-Tsunami”?

Despite the dramatic name, a rissaga is not a conventional tsunami.

Traditional tsunamis are generally associated with underwater earthquakes or other major disturbances beneath the sea. Rissagues, by contrast, are caused by rapid changes in atmospheric pressure and weather conditions, which can trigger sudden oscillations in sea level.

The phenomenon is particularly well known in the Balearic Islands and can create dangerous conditions around low-lying coastlines and ports.

During Monday's episode, the first major change was recorded shortly before 8am, with a sea-level variation of around 86 centimetres (2.8 feet) reported in the affected area.

Ibiza Wasn't the Only Island Affected

The unusual sea-level changes were not limited to Ibiza.

Parts of Mallorca and Menorca also experienced similar conditions. In Mallorca, seawater reached areas including Puerto Alcudia, Andratx, Sóller and Port Adriano, while authorities in Menorca's Ciutadella monitored the possibility of sea-level oscillations of up to 1.2 metres.

The Balearic authorities had warned about the possibility of rissagues, with ports considered among the areas most vulnerable to sudden changes in sea level.

No Immediate Injuries Reported

Despite the dramatic scenes, no immediate injuries were reported following the Ibiza flooding.

The relatively slow movement of the water gave people time to move away from the affected areas, although the incident demonstrated how quickly coastal conditions can change.

The main immediate risks were to people close to the shoreline, boats, waterfront businesses and temporary event infrastructure.

A Familiar Phenomenon in the Balearics

Rissagues are not new to the islands.

A major episode in July 2018 caused flooding along coastal roads, beach bars and restaurant terraces in parts of Mallorca. Boats were also pulled from their moorings as sea levels changed rapidly.

The latest event is another reminder that even during Ibiza's peak summer season, extreme and unusual weather can quickly disrupt life along the island's coastline.

For visitors, the incident also highlights why official weather and sea-level warnings should be taken seriously, particularly when spending time around beaches, marinas and waterfront venues.