Since communication with the Pacific state of Tonga is still difficult at best, the full extent of the disaster can only be estimated slowly. It is certain that after the eruption of the Hunga Tonga-Hunga Ha'apai on 15 January, a huge ash cloud fell on the archipelago, which destroyed the harvests and made the drinking water supplies at least partially undrinkable. Tsunamis, which are said to have been up to 15 meters high in some places, also damaged many houses and infrastructure considerably. On the basis of satellite images and various measurement data, however, the picture of the heaviest volcanic eruption of the last 30 years is becoming increasingly clear. As reported by the British National Centre for Earth Observation (NERC), the ash clouds even reached the stratopause of our atmosphere at an altitude of more than 50 kilometres during the eruption.
The so -called umbrella of the outcast ashes spread mainly in 35 kilometers, but in the central area the force of the outbreak chased the material up to 55 kilometers. This even achieved stratopause or atmospheric layers of it: no other known volcanic eruption has been measured. However, the large mass of the expectoration remained in deeper layers and spread sideways, which led to strong ash rain on the surrounding islands. Overall, the Hunga Tonga released about one cubic kilometer material, about twice as much as Mount St. Helens during its outbreak in 1980.
Based on satellite data, scientists estimate that 400,000 tonnes of sulphur dioxide were released into the atmosphere. This cloud began to drift westward with the prevailing winds and spread across the globe. Nevertheless, experts suspect that the amount is not enough to have a lasting influence on the climate in the coming years. The eruption of Pinatubo in the Philippines in 1991, for example, released 50 times more sulfur dioxide and subsequently caused slightly lower global average temperatures. A similar effect is not expected this time.
On the other hand, the island created by Hunga Tonga only in the recent past has suffered severely. According to satellite images, she disappeared back into the sea as a result of the explosion. Only the two older edges, which already existed before the 2009 eruptions as the two smaller islands Hunga Tonga and Hunga Ha'apai, remained. This gave the island a shorter life than geologists had suspected in the meantime.
