MARIANAS TRENCH

SONAR

Device that sends out an acoustic pulse in water and measures distances in terms of time for the echo of pulse to return

SEAFLOOR SPREADING

Process that creates new sea floor as plates move away from each other at the mid-ocean ridges

WATER PRESSURE

Weight of water pressing on an object, more than pressure than air, depends on depth of the fluid

MUD VOLCANOES

What could possibly be the reason why there are no earthquakes in the Marianas Trench?

CHALLENGER DEEP

Deepest part of the Marianas Trench: 35,800 feet

GUAM

Largest and southernmost island in the Marianas Islands administered as a territory of the United States

JAMES CAMERON

1st human to reach the 6.8-mile-deep (11 kilometer deep) Marianas Trench solo

DON WALSH

American Navy personnel who went to the deepest part of ocean in the Trieste along with Jacque Picard.

HMS CHALLENGER

British navy ship that collected samples and measurements across Atlantic, Indian and Pacific oceans and laid foundation for modern science of oceanography

OCEANIC RIDGE

Continuous elevated zone on the floor of all the major ocean basins and varying in width from 1000-4000km; the rifts at the crests represent divergent plate boundaries

PLATE TECTONICS

Theory stating that the earth's surface is broken into plates that move.

MARIANAS TRENCH

Deepest portion of world's oceans located in the Western Pacific. This is location where floor of Pacific Ocean descends back into the Earth. The deepest portion of this area is called the Challenger Deep and plunges to a depth of 7 miles.

SUBDUCTION

Geological process in which one edge of a crustal plate is forced sideways and downward into the mantle below another plate (San Andreas Fault).

HYDROTHERMAL VENT

Geysers on the seafloor, created where tectonic plates move apart, spewing hot and mineral-rich water (plumes) into cold ocean depths.

OCEANOGRAPHER

Scientist who studies Earth's oceans (NOAA research vessel)