The Earth Is Pulsating Every 26 Seconds, and Seismologists Don t Agree About Why

摘要

Every 26 seconds, the Earth shakes. Not a lot - certainly not enough that you'd feel it -but just enough that seismologists on multiple continents get a measurable little blip on their detectors. Though this pulse has been observed for decades, researchers don't agree on what's causing it. The pulse - or microseism, in geologist lingo - was first documented in the early 1960s by researcher Jack Oliver at the Lamont Geological Observatory (now known as the Lamont-Doherty Earth Observatory). Oliver figured out that the pulse was coming from somewhere "in the southern or equatorial Atlantic Ocean," and that it was stronger in the Northern Hemisphere's summer months. In 1980, Gary Holcomb, a geologist with the U.S. Geological Survey, used new tech to look at the microseism: digital seismometers. But both his and Oliver's work would mostly be forgotten to time, while the constant seismic drumbeat would go on, unnoticed, beneath our feet.