![]() But the vast majority of earthquake lights (85 percent) occurred in association with a quake within a tectonic plate at sites of continental rifting, a category that represents just five percent of all earthquakes. Worldwide, roughly 95 percent of seismic activity occurs at the boundaries between two or more tectonic plates. "And eventually, when we started to look at them, we found a really striking pattern." "We built a pretty large database of earthquakes with earthquake lights that happened around the world," says Thériault, a geologist with the Quebec Ministry of Natural Resources. Today, in a study published in Seismological Research Letters, a team of scientists by Robert Thériault used an alternate strategy to figuring out the answer-they analyzed the geologic circumstances of 65 earthquakes starting in the year 1600 that produced reports of light to see what these events had in common. But it's extremely hard to test either of these hypotheses, because earthquakes are so unpredictable, and the conditions are so difficult to replicate in a lab. Others have suggested that tectonic stress temporarily allows rocks to conduct electromagnetic energy, triggering changes in the magnetic charge of the ionosphere, the uppermost level of the atmosphere. Some have proposed that tectonic movement of rocks that include quartz could generate a pizoelectric field that produces flashes of light. Over the past few decades, a variety of hypothesis have been offered. They've since been captured with greater frequency and even on video, like this clip taken 30 minutes before an earthquake that hit China's Sichuan Province in 2008:īut for scientists, accepting that earthquake lights exist presents a new problem: How do you explain them? It wasn't until a series of photographs of strange lights snapped during a 1965 earthquake in Nagano, Japan-including the one below-that scientists acknowledged the validity of the phenomenon. ![]() The lights sometimes appeared for just a few seconds, but other times they hovered in the sky for minutes or hours at a time.įor much of modern history, these reports were considered apocryphal. Among the dozens of earthquakes that reportedly produced strange lights, their qualities varied widely: People reported seeing white flares, or floating orbs, or rainbow-colored flickering flames. They were spotted in 1930, during an earthquake in Idu, Japan, visible up to 70 miles away from the epicenter. Just after an 1888 quake that hit New Zealand, for instance, there were reports of “luminous appearances” and "an extraordinary glow" visible for several hours. ![]() For centuries, eyewitnesses have occasionally reported seeing an inexplicable phenomenon minutes before, during or after an earthquake: strange bright lights in the sky. ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |