قالب وردپرس درنا توس
Home / Science / A huge earthquake in Bolivia has revealed extensive mountain ranges below the surface of the earth

A huge earthquake in Bolivia has revealed extensive mountain ranges below the surface of the earth



Classical science fiction author Jules Verne once envisioned an entire subterranean landscape inside the planet, complete with lost prehistoric species and plant life. The book was aptly titled Journey to the Center of the Earth.

We may not really find dinosaurs down there, but recent research shows features in the underworld that resemble structures on the surface. Far from a bubbling, hot mess, there are mountains that can compete high up.

Princeton University geophysics in the US and the Chinese Academy of Sciences used the echoes of a massive earthquake that shook Bolivia two decades ago to assemble the whole topography deep beneath the surface.

On June 9, 1

994, a magnitude 8.2 earthquake shook a sparsely populated Amazon region in the South American nation. For decades, nothing so powerful was seen, until shocks were felt in Canada.

"Earthquakes of this magnitude are rare," says geoscientist Jessica Irving.

It was not only big was deep, with a focal point estimated at a depth of just under 650 kilometers. Unlike earthquakes that grind through the crust, the energy of these monsters can shake the entire mantle like a bowl of jelly.

The tremor was one of the first to be measured in a modern seismic network and provided researchers with unprecedented shots of waves hopping through the interior of our planet.

Just as the sound waves of an ultrasound can reveal differences in the density of tissue within a body, so can the giant waves pulsing through the molten intestines of the earth while their crusts shudder and rub against themselves To get a picture of what's down there Recently, geoscientists used signatures in these waves to determine the rigidity of the planet's core.

In this case, researchers used the intensity of the earthquake of 1994 to detect the wave scattering during the transition between layers of boundaries.

"We know that almost all objects have a surface roughness and therefore scatter light, so we can see these objects – the scattering waves carry the surface roughness information," says geoscientist Wenbo Wu of the California Institute of Technology.

"In this study, we examined scattered seismic waves that propagated within the earth to limit the roughness of the 660-kilometer boundary of the Earth."

At this depth there is a subdivision between the more rigid lower parts of the mantle and an upper zone, which is not so much under pressure, creating a discontinuity characterized by the appearance of various minerals

The deepest hole we have ever dug is only 12 kilometers deep. Without a Jules-Verne-scale tunnel plunging down there, we had no idea what this transitional zone would look like. Until now.

Based on these important waves flowing through the border, the researchers have hit the meeting point between the upper and lower parts of the mantle to form a zigzagged mountain range that makes everything on the surface a pity. [19659003] "In other words, at the 660-kilometer border there is a stronger topography than the Rocky Mountains or the Appalachians," says Wu.

This serrated line has a significant impact on the formation of the Earth. The bulk of our planet consists mostly of a cloak. If we know how it mixes and changes through heat transfer, we know how it evolves over time.

Various evidence for the evidence has produced competing models of the flow and migration of minerals in the pressurized rock. Some say it is well mixed, others suggest interference at the boundary.

Knowing the details of this subterranean mountain could determine the fate of various models describing the history of the planet's ever-changing geology.

"What's exciting These results provide new information to understand the fate of old tectonic plates that have descended into the mantle and where ancient mantle material could still be found," says Irving.

It might not be easy to explore. And forget the mastodons and the huge insects. But the lost world under our feet still contains references to our past when we know where to look.

This research was published in Science .


Source link