Earth Science: An Illustrated Guide

These flashcards cover key concepts from an Earth Science textbook, focusing on Earth's structure, history, rocks, atmospheric and oceanic processes, and surface shaping.

Inertia

The planet Earth attempts to speed through space in a straight line, while the Sun's gravitational force tries to pull it in. _ prevents Earth from falling into the Sun, resulting in Earth's orbit.

ellipsoid

Earth is nearly an not a perfect sphere.

time zones

The world is divided into standard __ based on the prime (or Greenwich) meridian at 0° longitude.

Degrees of longitude

___ are measured as angles from the center of Earth and divided into minutes and seconds.

terrestrial

The inner planets Mercury, Venus, Earth, and Mars have rocky surfaces and are known as __ planets.

photosphere

The is the "surface" of the Sun and has temperatures that vary from 7,800–16,000°F.

umbra

During a solar eclipse, the part of the Moon's shadow where the Sun is completely blotted out is called the ___.

mantle

A crust of relatively light rocks rests on the __.

magnetic

Earth's magnetic field consists of imaginary flux lines (lines of magnetic force) that curve around Earth between its north and south __ poles.

sporadic

Meteors enter the atmosphere at a constant rate of about six per hour and these are known as __ showers.

Meteorites

__ are lumps of stone or metal that have fallen onto Earth from space.

nucleosynthesis

Stars passed through cycles of heating, expansion, cooling, and contraction, generating heavier elements in their cores by processes of stellar __.

superposition

The principle of __ states that in an undisturbed sequence of strata the lowest stratum is the oldest and the highest is the youngest.

angular unconformity

An __ marks the boundary between tilted and horizontal sedimentary rock layers.

Paleomagnetic

A known sequence of past changes in polarization recorded in rocks enables scientists to date rocks and fossils formed tens of millions of years ago using __ dating.

Cambrian

The fine-grained Burgess shale of southwest Canada preserves a rich sample of life below the waves from the __ period.

Pangaea

By the Permian period, all continents lay jammed together as the supercontinent __.

eons

Earth history is divided into four major units of time known as __.

Major

_ continents were drifting and the ocean floor was rifting and being subducted under continents by Proterozoic times.

Pacific

New land in North America was gradually added as the continental North American Plate overrode the oceanic Farallon and __ plates.

nonconformity

A section through part of Earth’s crust may reveal tilting, folding, faulting, igneous intrusions, and a __—an unconformity where sedimentary rock overlies granite or another igneous or metamorphic rock.

eclipse

A (an) __ occurs when one heavenly body blocks the light shining from a second onto a third.

The Ocean

_ is the continuous expanse of seawater that covers 71 percent of the planet. It also refers to its major subdivisions contained within ocean basins.

sedimentary, metamorphic, igneous

There are two main types of rock, known as and , with the third type being rocks made from sediment.

Pleistocene

There were major temperature fluctuations in the ___ epoch and cold phases saw ice sheets advancing south through North America.