Quotable (#215)

A life-gripped planet:

By controlling the chemical state of the atmosphere, life has also altered the rocks it comes into contact with, and so oxygenated the crust and mantle of Earth. This changes the material properties of the rocks, how they bend and break, squish, fold, and melt under various forces and conditions. All the clay minerals produced by Earth’s biosphere soften Earth’s crust—the crust of a lifeless planet is harder—helping to lubricate the plate tectonic engine. The wetness of Earth seems to explain why plate tectonics has persisted on Earth and not on its dry twin, Venus. One of the more extreme claims of the Gaia camp, at present neither proven nor refuted, is that the influence of life over the eons has helped Earth hold on to her life‐giving water, while Venus and Mars, lifeless through most of their existence, lost theirs. If so, then life may indeed be responsible for Earth’s plate tectonics. One of the original architects of plate tectonic theory, Norm Sleep from Stanford, has become thoroughly convinced that life is deeply implicated in the overall physical dynamics of Earth, including the “nonliving” interior domain. In describing the cumulative, long-term influence of life on geology, continent building, and plate tectonics, he wrote, “The net effect is Gaian. That is, life has modified Earth to its advantage.” The more we study Earth, the more we see this. Life has got Earth in its clutches. Earth is a biologically modulated planet through and through. In a nontrivial way, it is a living planet.

Quotable (#154)

In the end, the magnitude-9.0 Tohoku earthquake and subsequent tsunami killed more than eighteen thousand people, devastated northeast Japan, triggered the meltdown at the Fukushima power plant, and cost an estimated two hundred and twenty billion dollars. The shaking earlier in the week turned out to be the foreshocks of the largest earthquake in the nation’s recorded history. But for Chris Goldfinger, a paleoseismologist at Oregon State University and one of the world’s leading experts on a little-known fault line, the main quake was itself a kind of foreshock: a preview of another earthquake still to come. …

From Kathryn Schulz’s Pulitzer Prize-winning story about extreme quake risk.