Eruption!

Anak Krakatau has been much in the news over the past few days, erupting repeatedly since the fourth of September. The name itself is rather appropriate because Anak Krakatau means “Child of Krakatau”, having risen from the remains of the much larger volcano that erupted so spectacularly in 1883. In fact, Anak Krakatau only began emerging above the sea in 1927, eventually growing into the volcano we know today.

That 1883 eruption has a little story behind it for me. When I was in secondary school, our English language teacher told us about Krakatau and its enormous eruption in 1883. There were several huge explosions on the 27th of August that were heard thousands of kilometres away. The sound travelled so far that people on Rodrigues Island in the Indian Ocean, nearly 5,000 kilometres away, reportedly heard what they thought was cannon fire. The eruption also sent vast quantities of ash and volcanic material high into the atmosphere, producing unusually vivid sunsets around the world for months afterwards.

Our teacher then suggested that we ask our grandparents whether they had heard the explosions or seen those spectacular sunsets when they were young. It sounded like a perfectly reasonable suggestion at the time, except for one small flaw, at least in my case. None of my grandparents had been born before 1883! And even if they had been, they would have been far too young to remember an event that happened so far away. So I never got to ask them whether they had heard the great explosions or seen skies turning red, orange and yellow because of a volcano in the Dutch East Indies. But for some reason, that little classroom exercise stayed in my memory.

And now, more than half a century later, Krakatau has suddenly come back into my thoughts. Three days ago, I read about the temporary closure of the Soekarno-Hatta Airport in Jakarta, some 150 kilometres away, because of volcanic ash from Anak Krakatau. Then more reports began appearing about the scale of the eruptions. At one stage, ash plumes were reaching as high as 15,000 metres, or almost 50,000 feet, and the volcanic ash disrupted flights at eight airports. Almost 3,000 flights were reportedly affected, involving some 340,000 passengers. The airports have since reopened, although aviation authorities continue to monitor the situation because volcanic ash is obviously something aircraft operators do not take lightly.

The eruption itself has also been rather persistent. There was a continuous explosive phase from the fourth of September that lasted about 25 hours, followed by further eruptions over the next few days. These produced bursts of ash and lava, with some of the plumes drifting towards Sumatra and others towards Java. For the moment, the authorities have kept Anak Krakatau at a high alert level with people being advised to stay at least three kilometres from the crater. There has been no indication of an impending tsunami in the Sunda Strait, although the authorities are keeping a close watch on sea conditions because of what happened in 2018 when part of Anak Krakatau collapsed into the sea and generated a devastating tsunami.

Then I came across another interesting fact. Anak Krakatau isn't the only Indonesian volcano that has been erupting. Several others have been showing significant activity at around the same time, including Mount Semeru in East Java, Mount Ibu in North Maluku, Mount Ili Lewotolok and Mount Lewotobi Laki-laki in East Nusa Tenggara and Mount Sinabung in North Sumatra. Truly, Indonesia is one of the most volcanically active countries in the world, sitting along the Pacific Ring of Fire. So perhaps it shouldn't be too surprising to have several volcanoes erupting simultaneously. 

The six volcanoes are also at different levels of activity, so it would be misleading to suggest that all of them pose the same degree of danger. Some are producing regular ash plumes while others have more significant hazards for communities living nearby. Anak Krakatau has attracted the most international attention because of its famous name and the fact that its ash has affected aviation over such a wide area, while the others are mainly a concern for people living in their immediate surroundings.

All this has made me think again about that English lesson so many years ago. At the time, Krakatau was simply an interesting story in a school textbook and our teacher's suggestion to ask our grandparents seemed like an ordinary homework exercise. I couldn't do it because my grandparents were not even born yet! And I certainly never imagined that I would still remember that lesson more than half a century later.

Yet here I am, reading the news about Anak Krakatau erupting again, seeing reports about volcanic ash closing airports and wondering what it must have been like in 1883 when the original Krakatau exploded with such force that its sound travelled thousands of kilometres and its dust helped create strange sunsets around the world. I suppose some lessons from school stay with us for reasons that have nothing much to do with the lesson itself. I don't remember what else we studied in that particular English class, but I certainly remember Krakatau and the rather impossible homework assignment that came with it.