Fragile Planet?: Study Finds Earth Is Weaker Than Once Thought

CBS Local — Scientists at the University of Pennsylvania are saying that the Earth may be even more fragile than most people thought. According to new findings about the substance that makes up most of the planet’s mantle, researchers are changing their theories on how the world’s tectonic plates move under us.

The researchers say olivine, which is found throughout the Earth’s interior, is weaker than scientists had thought for years. Geologists reportedly found that the grain size of the mineral is much larger than previously estimated which leads to a weaker material. The scientists say that the finer the grain, the stronger the rock.

The findings are now painting a different picture of how researchers understand how tectonic plates form, shift, twist into volcanoes, and even trigger earthquakes. The research team says scientists have been trying to guess how strong olivine was for 40 years until their experiments opened a new door in geology.

“We need to understand the mechanical behavior of olivine, which is the most common mineral in the upper mantle of Earth,” associate professor David Goldsby said, via Science Daily.

Goldsby and his fellow scientists are hoping the findings will also help them understand how the faults in the Earth’s surface move and erode over time. “Different faults have a similar roughness, and there’s an idea published recently that says you might get those patterns because the strength of the materials on the fault surface increases with the decreasing scale of roughness,” doctoral student Christopher Thom said.

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