The
Challenger Deep is the deepest known point in the
Earth's
seabed hydrosphere, with a depth of by direct measurement from submersibles, and slightly more by
sonar bathymetry (see below). It is in the
Pacific Ocean, at the southern end of the
Mariana Trench near the
Mariana Islands group. The Challenger Deep is a relatively small slot-shaped depression in the bottom of a considerably larger crescent-shaped
oceanic trench, which itself is an unusually
deep feature in the ocean floor. Its bottom is about long and wide, with gently sloping sides. The closest land to the Challenger Deep is
Fais Island (one of the outer islands of
Yap), southwest, and
Guam, to the northeast. It is located in the ocean territory of the
Federated States of Micronesia, from its border with ocean territory associated with Guam.