Earth's Origin and Evolution Quiz

The Earth formed approximately 4.6 billion years ago from a spinning nebula.

Gravitational compression and radioactive decay heated the early Earth.

The Earth's core is primarily composed of iron and nickel due to density.

Early Earth's atmosphere was primarily composed of lighter gases that escaped.

The process that separated materials in the mantle to form different crusts

Stable oceanic and continental crust formed 3.8 billion years ago.

About 95% of the universe is hydrogen and helium.

Most Earth's elements originated in stars before the solar system.

Hydrogen and helium, abundant in the universe, are scarce on Earth due to their escape into space.

Water, formed by hydrogen reacting with oxygen, is Earth's unique chemical characteristic and earned it the nickname "blue planet."

Planets formed from small solid bodies called planetesimals that aggregated over time, according to this early 20th-century hypothesis.

Planets formed from a spinning disk of gas and dust (solar nebula) with a temperature gradient, explaining variations between planets.

Earth formed in two stages: initial accretion of 80% followed by differentiation of core, then the remaining 20% accretion.

Meteorites provide clues to the composition of planetesimals, with heavier elements condensing first and lighter ones like water later.

The solar nebula had a temperature gradient, explaining the decreasing iron content of planets as they are farther from the sun.

Earth's iron and nickel content suggests a two-stage accretion process, where initial accretion and differentiation happened followed by later accretion.

The elevated regions on the moon's surface, characterized by heavily cratered terrain and rocks rich in plagioclase feldspar.

Dark, flat plains on the moon's surface formed by ancient volcanic eruptions, composed of basaltic rocks.

The process where a planet's interior separates into layers of different densities, with heavier materials sinking to the core and lighter materials forming the crust.

The process of impact events that form craters on planetary surfaces, providing evidence of past bombardment.

Events where molten rock (basalt) from the moon's interior erupted onto the surface, forming the Maria.

Elements and compounds that easily vaporize or change state at relatively low temperatures, such as water and carbon dioxide.

Varying in density and composition, from Earth's breathable atmosphere to Venus's dense CO2 atmosphere, and Mars's thin CO2 atmosphere.

Abundant liquid water on the surface, due to its size and distance from the sun, making it suitable for life.

The earliest form of Earth's crust, composed of granite or diorite, which existed around 4.3 to 4.4 billion years ago.

The process by which gases from Earth's interior are released into the atmosphere.

Helium in the atmosphere comes from radioactive decay of uranium in the Earth's crust, while atmospheric argon comes from potassium 40 decay.

Oxygen in the early atmosphere was not from outgassing but from a separate process: photosynthesis.

The breaking down of molecules by high-energy ultraviolet radiation, leading to the formation of oxygen and ozone in the early atmosphere.

Ozone (O3) filters out harmful ultraviolet radiation from the sun, making Earth habitable.

The early atmosphere was mainly composed of methane, ammonia, and some water vapor, with no molecular oxygen.

Oxygen accumulated in the atmosphere after all methane and ammonia were converted to carbon dioxide and nitrogen by reactions with oxygen.

The speed at which seawater has formed throughout Earth's history, tied to the rate of atmospheric water vapor production and chemical fractionation of the Earth.

The release rates of these elements into the atmosphere provide evidence for a long-term accumulation of seawater.

Isotopic evidence suggests the presence of an ocean as far back as 4.4 billion years ago, indicating the early stages of atmospheric and seawater outgassing were complete.

The factors that determine the average global temperature, including solar output, orbital variations, reflectivity, and atmospheric transparency.

The proportion of incoming solar radiation that is reflected back from a surface, expressed as a percentage, affecting the global temperature.

The upper layer of the ocean where sunlight penetrates, absorbing solar radiation and distributing heat via oceanic currents.

The trapping of long-wavelength infrared radiation in the atmosphere by gases like CO2, methane, and water vapor, causing an increase in global temperature.

The boundary between Earth's crust and the mantle, marked by a significant change in seismic wave velocities.

The bottom of the lithosphere is marked by a zone with low seismic wave velocity and reduced rigidity, indicating a change in material properties.

The speed at which seismic waves travel through the Earth, providing information about the composition and state of Earth's layers.

A material's resistance to deformation under stress, reflecting its stiffness and ability to withstand forces.

A zone characterized by low seismic wave velocity and reduced rigidity, indicating a change in material properties.

Low wave velocity suggests a less rigid material, often a zone of partial melting or transition from solid to more fluid-like.

There is a decrease in rigidity at the base of the lithosphere, indicating a transition to a more pliable state.

Low seismic velocity is often caused by partial melting or a transition from solid to more fluid-like material, affecting wave propagation.

It represents a key transition zone within the Earth, separating the rigid lithosphere from the more fluid-like asthenosphere.