The Moon Decided to Get a Better Look at Beautiful Torrevieja — and the Sea Put on a Meteotsunami

On August 28, the coast of southern Alicante province experienced a rather unusual natural spectacle for several hours. In Torrevieja and Guardamar, the sea visibly pulled back from the shoreline, prompting lifeguards to raise red flags and ban swimming. At Acequión beach in Torrevieja, the water retreated by several metres. Proyecto Mastral recorded the unusual change in sea level and warned that further oscillations could occur during the day.

But Torrevieja was only one episode in a much broader event.

A few days earlier, on August 24 in Santa Pola, the sea suddenly retreated along parts of Playa Lisa and Gran Playa, exposing sections of seabed normally hidden beneath the water, before moving back towards the shore. The water reached the first line of buildings and Blasco Ibáñez Avenue, prompting police to temporarily close part of the road.

In Dénia, the situation was even more interesting for yacht owners: the sea level changed by approximately half a metre in just five minutes, while strong currents developed around the harbour, making navigation more difficult.

In Xàbia, observers recorded the water retreating by approximately 10 metres.

Then, on August 28, the phenomenon reached La Manga. In the southern area, the sea retreated by around 3–5 metres, while in the northern section, within the municipality of San Javier, it reached approximately 7 metres. A red flag was also raised there for several hours.

So this was no longer simply one strange beach in Torrevieja. The Mediterranean was visibly changing its behaviour at different points along the coast over several days.

Who pushed the sea?

Specialists call the phenomenon a meteotsunami, or rissaga. Despite the rather dramatic name, this is not a tsunami caused by an earthquake. AEMET links such events to atmospheric waves and rapid changes in air pressure.

Oceanographer Francisco López Castejón explains it in almost household terms: when atmospheric pressure rises sharply, the air exerts greater pressure on the sea surface, temporarily lowering the water level. The water then returns. According to him, such phenomena are well known in the Mediterranean, while the current episode stood out mainly because of its speed: the change occurred over roughly 12 hours.

Another specialist, Juan Beneyto of Inforatge, links the oscillations to rapid pressure changes and contrasts between air masses — in particular, the arrival of cooler air over an atmosphere that still retained the heat of summer.

And what about the Moon?

This is where nature gives us a pleasant opportunity to argue the case.

August 28 was a full moon. The Moon and the Sun genuinely influence tides, so the tidal background of those days cannot simply be ignored.

But specialists have not said that the full moon caused the meteotsunami. The rapid movement of the water is primarily attributed to atmospheric effects.

In other words, the Moon may well have been on stage. But there is currently no good reason to name it the prime suspect.

The sea went away — people reached for their phones. Lifeguards reached for the red flags

In Torrevieja and Guardamar, lifeguards preferred not to conduct an experiment to find out how far the sea might return. Eulen, the company responsible for beach safety, recommended clearing the bathing areas because of the possibility of a sudden rise in water level and the development of currents.

In Pilar de la Horadada and Orihuela Costa, a fall in sea level was also observed, but the yellow flag remained in place and beachgoers were simply urged to exercise caution.

In Dénia, the warning was no longer merely theoretical: strong currents actually made it harder for yachts to manoeuvre.

We have found no reports of serious injuries directly resulting from the August 28 episode in Torrevieja and Guardamar. And López Castejón, commenting on the La Manga episode, does not consider it particularly dangerous provided people behave sensibly: the important thing is not to enter the water when it starts coming back, because that is when currents can develop.

And there is one final detail.

AEMET recalls that strong sea-level oscillations had already been recorded in July 2017 in Santa Pola, La Marina de Elche, Torrevieja and El Campello.

So apparently the Mediterranean has not invented anything new.

It simply decides, from time to time, to move the boundaries of its property by several metres.

Following it when it retreats — especially under a red flag — is still a bad idea.