Geologists discover tectonic plate’s slippery underbelly

Dynamite blasts divulge runny layer roughly 100 kilometers below surface

Tectonic plate diagram

SLIP ‘N SLIDE  A layer of slippery, partially melted rock (red) may separate the Pacific tectonic plate from the underlying mantle, reducing the amount of force required to shift the massive plate, new seismic research suggests.

Tim Stern

Using ricocheted vibrations from dynamite blasts, researchers have glimpsed a layer of gooey material sandwiched between the Pacific tectonic plate and the underlying mantle.