Earthquakes on the Peninsula: what risk is there?

BarcelonaIn less than an hour, a series of earthquakes shook the Andalusian province of Granada again this Tuesday. Between 10:37 a.m. and 11:34 a.m., seven seismic events occurred, one of which reached a magnitude of 4.8. It appears that a seismic swarm has occurred – several earthquakes concentrated in the same area and in a short period of time – four days after a first tremor. Gójar, Churriana de la Vega, Alhendín... Each had a different epicenter, but all were felt in the provincial capital of Granada. The seismic events left three people with minor injuries – including a minor – and an uneasy atmosphere in the population, fatigued by the constant low-intensity tremors since Saturday. And although the vast majority are not perceptible and the damage is superficial, after the tragedies in Venezuela, Colombia, and Indonesia, this episode has raised some questions: can there be aftershocks? Are there more than ever and more devastating?

The associate professor of Earth Physics at the Department of Earth and Ocean Dynamics at the University of Barcelona (UB), Álvaro González, explains that seismic movements are not uncommon in southern Spain. In fact, territories such as Granada, Almeria, Murcia, and Alicante are categorized as seismic risk zones. "Andalusia has registered other similar episodes that often last for days or weeks, even months. Their evolution is difficult to anticipate, as they can gradually lose intensity or present new earthquakes of greater magnitude," he summarizes. In the case of Granada – which stands out on the seismic risk map – there is an area with active faults.

If you want to investigate the graph in more detail, open the high-resolution version in another tabFaced with this concentration of earthquakes, the Granada council has raised the emergency to phase 1 to offer more resources and strengthen coordination between authorities. It has also opted to evacuate the Alhambra museum complex – which has not suffered any damage – and public buildings for non-essential services, and has also evacuated a hundred homes about 10 kilometers away, in the municipality of Las Gabias, due to the appearance of cracks. However, the impact of this series of earthquakes has been moderate. The main damage has been to facades and furniture elements. Emergency services have responded to more than half a thousand calls to the 112 telephone number, although most of the medical assistance has been for anxiety crises.

Is this normal?

González explains that the low perception of seismic risk in Spain does not mean that the country is free from major earthquakes. The area with the highest hazard is concentrated in the southeast, but there are also areas of significant hazard in the Pyrenees. "The issue is, above all, its frequency," anticipates the expert. The State has suffered large destructive earthquakes, but episodes of magnitude 6 or 7 are much less common than in regions like Indonesia, Chile, or Colombia. Furthermore, they can be separated by several centuries. According to the National Geographic Institute, 30 major earthquakes have occurred in Spain since records began in 1048, and the most recent was in 2011 in the municipality of Lorca (Murcia). With a magnitude of 5.1, the quake left nine dead.

Earthquakes occur when blocks of rock in the subsoil abruptly shift relative to each other, releasing accumulated energy all at once. In the case of Granada, one of the hypotheses being studied is that the circulation of groundwater at great depth may favor the sliding of certain fractures. But everything is very incipient. Experts also cannot know if Tuesday's quakes are aftershocks of Saturday's early morning one or if they are linked to an adjacent fault that has reactivated. Mercedes Feriche, head of seismic prevention and risk at the Andalusian Institute of Geophysics, explains to Efe that it will be necessary to wait for the series to end – which could last weeks or months – to determine its origin. Nevertheless, experts are not alarmed and believe they should gradually lose intensity.

The low frequency of quakes may contribute to the population forgetting that a risk exists, but the network of seismometers installed in the area by the National Geographic Institute and the Andalusian Institute of Geophysics also allows for the detection of hundreds of small movements that go unnoticed. This information will allow for a detailed analysis of how the swarm will evolve: whether the number of earthquakes decreases, whether their magnitudes change, or whether larger earthquakes than those recorded up to then begin to occur. "Right now, the most probable scenario is that no larger earthquakes will occur. Although this possibility exists, it cannot be completely ruled out. The probability is approximately 1%," states González.

Are there more earthquakes than ever?

There is no evidence that there are more earthquakes generally now. There are periods with more activity and others quieter, and they can be temporarily concentrated in certain regions. What has changed is the ability to detect them and the exposure of the population. "And a higher number of destructive earthquakes does not necessarily imply that there are more earthquakes. The impact depends largely on where they occur, how much population is exposed, and the resistance of buildings," says González. A moderate earthquake in a densely populated area with vulnerable constructions can cause more damage than a much larger one in a remote region or with a high seismic preparedness.

According to the annual report of the United States Geological Survey (USGS), in 2025 they registered 138,466 earthquakes worldwide. However, in most cases, their magnitudes were weak – below 3 – or they occurred in locations far from urban areas. Thus, the USGS only highlights fourteen earthquakes, which caused significant human and economic losses. The most notable ones occurred in Myanmar and Thailand –with 1,600 dead and 3,400 injured–, in the Tibet (126 dead) and in Afghanistan (1,124 deaths and 3,251 injured). This year, the USGS has registered 17,850 earthquakes. In the same period of the year 2025, almost a thousand more were counted (18,994).