Certain words can shake the blogosphere in much the same way earthquakes stir the planet.

A new study of word frequencies in political blogs finds that equations describing earthquake evolution fit the eruption of topics onto political blogs.

News tends to move quickly through the public consciousness, noted physicist Peter Klimek of the Medical University of Vienna and colleagues in a paper posted on arXiv.org. Readers usually absorb a story, discuss it with their friends, and then forget it. But some events send lasting reverberations through society, changing opinions and even governments.

“It...