VERTICAL DEPTHS OF THE WORLD'S DEEPEST DRILLED HOLES:

Kola drill hole, the Kola Peninsula, Russia. Depth: 12,262 m Bertha Rogers drill hole, Oklahoma, USA. Depth: 9,583 m KTB drill hole, Bavaria, Germany. Depth: 9,101 m

Y R A B LI O T H P E C N IE C S / K I N T U P S At a depth of 12,262 m, the rock was so soft that the Kola drilling was halted.