I think this might have been my first McPhee book. It’s three long pieces about people trying to stop geology. The Army Corps of Engineers at the Old River Control Structure in Louisiana, holding the Mississippi in its channel against a river that wants to jump into the Atchafalaya and would take New Orleans and Baton Rouge’s economy with it. Icelanders on Heimaey spraying seawater at an advancing lava flow to save their harbor, and actually stopping it. And Los Angeles building debris basins in the San Gabriels against the debris flows that come off those mountains after fire. The Iceland segment is by far the most interesting. McPhee lets the engineers explain themselves at length, and the geology wins the argument without him ever saying so.