Japanese scientists hope to reach the Earths mantle in massive borehole project
Japanese scientists have announced a plan to drill through the Earth’s crust and reach the mantle. The major initiative would be a first for humankind. Despite multiple previous attempts and multiple boreholes of significant depth, we’ve never managed to drill far enough to see what lies beneath the Earth’s rocky crust. Instead, our knowledge of the mantle is mostly based on indirect observations, like the speed at which seismic waves propagate through the planet’s internal geometry. A 2007 investigation into a unique area between Cape Verde and the Caribbean Sea, where the crust of the Earth is missing and the mantle is directly exposed, yielded some fascinating rock samples and scientific data, but not the same information that scientists hope to gather by drilling into the molten layer directly.
The new project, led by the Japan Agency for Marine-Earth Science and Technology (JAMSTEC), will begin by conducting a two-week study off the coast of Hawaii. If this location isn’t suitable, the research team plans to investigate areas offshore from Costa Rica and Mexico. All of the drilling sites are in the ocean because the Earth’s crust is roughly twice as thick on land as it is over water. Even so, this is no small task. Chikyu’s drill will have to pass through 2.5 miles of water and 3.7 miles of crust to reach the mantle, which accounts for ~85% of the Earth’s volume.
We already know that the mantle is comprised of different material than the Earth’s crust. Mantle material has a higher ratio of magnesium to iron than Earth’s crust, but contains less silicon and aluminum than our planet’s surface does. We also know that the mantle slowly circulates thanks to convection currents. As the graph below shows, hot spots deep in the region where the mantle meets the Earth’s core lead to an upwelling of heat several thousand kilometers away.
https://www.extremetech.com/extreme/247370-drill-baby-drill-japanese-scientists-hope-reach-earths-mantle-massive-drilling-project
= new reply since forum marked as read
sheesh...it's simple.
