An underwater eruption in the same area in 2009 /
The volcanic eruption that hit Tonga was so powerful it was felt 18,000 kilometres away in Malaga, on Spain's Costa del Sol.
The explosion in Polynesia generated a shock wave that was recorded by the Aemet observatory in Malaga, according to its director, José María Sánchez-Laulhé.
The increase of two millibars in atmospheric pressure was not noticeable to the general population.
“In observatories, pressure oscillations have been recorded due to the shock wave, very clear peaks of several millibars can be seen. Due to the explosion in Tonga island, all the weather barographs in the world have recorded them,” said Sánchez-Laulhé.
The oscillation however was very small and similar changes can be recorded as day turns to night or as storms approach, he added.
The government of Tonga has called the event an “unprecedented disaster". Some smaller islands have seen every home on them destroyed after being hit by a tsunami and then covered by volcanic ash on Saturday 15 January.
At least three people have died including a British woman. Transport is disrupted with flights temporarily halted and sea transport routes challenged. An aid operation to remote islands is now underway.
