eTextbook: Oceanography: An Invitation to Marine Science - Ebooks

What is the definition of Oceanography?

The scientific study of the ocean, its associated life-forms, and its bordering lands.

What is Marine Science?

The process of applying the scientific method to the ocean, its surroundings, and the life-forms within it.

What is a galaxy?

A huge, rotating aggregation of stars, dust, gas, and other debris held together by gravity.

What astronomical event is responsible for synthesizing heavy elements?

A supernova, which is the explosive collapse of a massive star.

What is density stratification?

The process by which gravity pulls heavier elements toward the center of a planet, while lighter ones rise to the surface.

What process formed Earth's early atmosphere and oceans?

Outgassing, the volcanic venting of volatile substances including water vapor.

What is biosynthesis?

The early evolution of living organisms from simple organic building blocks.

Who was the Greek scholar that first calculated the circumference of the Earth?

Eratosthenes of Cyrene, around $230\,\text{B.C.E.}$.

What are latitude lines?

Lines drawn parallel to the equator used to measure distance north or south.

What are longitude lines?

Lines drawn from pole to pole used to measure distance east or west of the prime meridian.

Who led the first expeditions devoted entirely to scientific oceanography on the HMS Endeavour?

Captain James Cook.

What invention allowed for the accurate determination of longitude at sea?

The chronometer, invented by John Harrison.

Which expedition ($1872 \text{--} 1876$) was the first dedicated entirely to marine science?

The HMS Challenger expedition.

What is the lithosphere?

The cool, rigid outer layer of Earth, consisting of the crust and the uppermost mantle.

What is the asthenosphere?

The hot, plastic, and slowly flowing layer of the upper mantle below the lithosphere.

What is the principle of buoyancy?

The ability of an object to float in a fluid by displacing a volume of fluid equal to its own weight.

What is the theory of continental drift?

The proposal that Earth's continents move gradually over the surface of the planet.

What is seafloor spreading?

The process by which new ocean floor is created at mid-ocean ridges and moves away from the center.

What occurs at subduction zones?

One tectonic plate descends into the mantle beneath another plate.

What is paleomagnetism?

The study of the fossil magnetic field preserved in rocks as they form.

What are the three types of tectonic plate boundaries?

Divergent, convergent, and transform boundaries.