Case Study : Mariana Trench

Location :

The Mariana Trench is located in the

western Pacific east of the Philippines

and an average of approximately 124

miles (200 kilometers) east of the

Mariana Islands.

About Mariana Trench :

The Mariana Trench is the deepest point on Earth. The Mariana Trench is a crescent-

shaped scar in the Earth’s crust that measures more than 1, 500 miles (2, 550

kilometers) long and 43 miles (69 kilometers) wide on average. The distance between

the surface of the ocean and the trench’s deepest point – the Challenger Deep, which

lies about 200 miles (322 kilometers) southwest of the U.S. territory of Guam – is

nearly 7 miles (11 kilometers). The pressure at the deepest part of Mariana Trench is

over 8 tons per square inch.

Formation of Mariana Trench :

1) The oceanic crust, the Philippine

Plate, is much heavier than the

continental crust, the Eurasian

Plate.

2) When these plates collide into

each other, the Philippine Plate,

which is much denser and heavier,

sinks into the molten mantle, while

the lighter, Eurasian Plate rides

up over the top.

3) The forces driving the two plates

together are really intense, so the

subducted oceanic plate creates a

trench where it drags the edge of

the edge of the continental crust

down as it descends underneath.

Uses of Mariana Trench

Mariana Trench is proposed as a site for nuclear waste disposal, in the hope that

tectonic plate subduction occurring at the site might eventually push the nuclear

waste deep into the Earth’s mantle. However, ocean dumping of nuclear waste is

prohibited by international law. Furthermore, plate subduction zones are associated

with very large mega thrust earthquakes, the effects of which are unpredictable and

possibly adverse to the safety of long-term disposal.

The Mariana Trench is often used as a North-South passage by submarines as it is

part of a long system of trenches that circle the Pacific Ocean, connected with the

Japan and Kuril Trenches.

Trenches are becoming much more focused in the scientific community. Geologists now

think these seismically active zones could play a central role in some earthquakes.