SHOCKWAVES AND AWE

n 15 January the Hunga-Tonga-Hunga Ha’apai volcano inTonga in the South Pacific erupted so violently it blew its island apart, leaving just two small stumps protruding from the ocean. It caused ash falls and a tsunami that wrecked many ofTonga’s other islands, cut the country off from the rest of the world for several days and caused a sonic boom that was heard round the world. This reached New Zealand, 2,000 km (1,200 miles) away, two hours after the blast, while several