Earthquake Scientists Finally Explain 9-Day Global 'Unidentified Seismic Object'

It was one year ago that 'an odd seismic signal appeared at scientific stations around the globe,' reports the Washington Post. 'A day passed, and the slow tremor still reverberated. When it continued for a third day, scientists worldwide began assembling...'

Some initially thought the seismic instruments recording the signal were broken, but that was quickly nixed. Maybe it was a new volcano emerging before their eyes, others said. One jokingly ruled out an alien party. As theories were checked off, the scientists dubbed the signal an 'Unidentified Seismic Object,' or USO... Nine days later, the vibrations greatly dissipated. But the mystery of the USO lasted much longer.

A year later, the puzzle has been solved, according to a study published in the journal Science on Thursday. It took about 70 people from 15 different countries and more than 8,000 exchanged messages (long enough for a 900-page detective novel) to crack the case. The short answer: A mega-tsunami created waves that sloshed back and forth in a fjord in Greenland, creating vibrations that traveled around the world.

Extra heat from global warming 'thinned a glacier in eastern Greenland over time so much that it could no longer support the mountain rock above it,' according to the article. A mile-long avalanche 'plunged into the Dickson Fjord, triggering a 650-foot-high tsunami — one of the highest seen in recent history.' Like the rhythmic waves in a bathtub, 'the mega-tsunami wave traveled back and forth in the inlet,' which 'radiated seismic waves globally, shaking the planet for nine days before it petered out.'

In August a German research team had studied the megatsunami, concluding that climate change was speeding the melt of Greenland's glaciers and increasing the chance of landslide-driven megatsunamis. The article reports that an author of that study said when comparing it to this one, 'The methods chosen by the teams are different, but the results agree well.'

Read more of this story at Slashdot.