Ones measured above sea level which is Mount Belinda 1,370 meters above the other one is South Sandwich Trench 8,428 meters below sea level. Below sea level because you subtract the above sea level by below sea level you still end up with below sea level. 3,529 kilometers below sea level how i did this i subtracted 8,428 by 1,370 and 7,058 than divided that by 2 to get to the center of both