The air pressure rose by 3 hPA. After an hour the air pressure was back to normal.

On Saturday, a submarine volcano erupted near the island nation of Tonga in the Pacific Ocean. This volcanic eruption could even be seen from space. The air above the volcano was pushed away, creating a powerful air pressure wave.

This shock wave was even measurable in the Netherlands. It caused the air pressure to increase in a short time. The increase was reported by meteorologists across the country. The KNMI also reported a clear increase via Twitter.

The shock wave lost little power during its journey through the atmosphere. In nearby New Zealand, the air pressure rose by six hectopascals. In the Netherlands, the shock wave caused an increase of three hPA.

What is air pressure?

Without us realizing it, air exerts pressure on all organisms and objects on Earth. Air weighs about 1.3 grams per litre. In a high-pressure area, the air pressure is higher than in a low-pressure area. Meteorologists use a barometer to measure air pressure. The air pressure is stated in hectopascals (hPA).

Exceptional situation

It is exceptional that a shock wave is generated during a volcanic eruption. Shock waves have not been measured in many other volcanic eruptions. Seawater may have entered the magma chamber. This caused a large pressure build-up, resulting in the extreme explosion.