FROM THE DEPARTMENT OF EARTH-SHATTERING KABOOMS: In 2021, a deadly volcano erupted with no warning. Here’s why. “Nyiragongo’s last two eruptions, in 1977 and 2002, were both presaged by days of distinct seismic rumblings strong enough to be felt by people living nearby. But before the eruption on May 22, 2021, even the sensitive monitoring stations near the volcano seemed to detect no clear warning signs of magma on the move underground.”