Geological Perspective on Global Warming

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What principle is one of the cornerstones of geology, based on the premise that present-day processes have operated throughout geologic time?

Catastrophism

Uniformitarianism (correct)

Evolution

Pangaea Theory

How have geologists been able to assign ages in years to the subdivisions of the geologic time scale?

Using radiometric dating techniques (correct)

Through carbon dating techniques

By studying volcanic eruptions

Through analyzing fossil records

What resulted from the work of many 19th-century geologists who pieced together information from numerous rock exposures?

Development of the geologic time scale (correct)

Assignment of absolute ages to Earth's history

Identification of Earth's subsystems

Discovery of radioactivity

What principle allows us to use present-day processes as the basis for interpreting the past and predicting potential future events?

Uniformitarianism Signup and view all the answers

What did Hubble observe about the velocity of galaxies moving away from Earth?

It increases proportionally to distance Signup and view all the answers

What larger cycle has resulted in numerous glacial advances and retreats during the past 1.8 million years?

Global warming and cooling Signup and view all the answers

Which geological era is characterized by the appearance of life in the oceans and the colonization of land by plants and fungi?

Mesozoic Signup and view all the answers

How does the Doppler effect relate to the observed redshift in the spectral lines of galaxies?

It causes the spectral lines to shift towards longer wavelengths Signup and view all the answers

Which period on the Geologic Time Scale is known for the extinction of dinosaurs and the rise of mammals?

Cretaceous Signup and view all the answers

What is the analogy used in the text to explain how galaxies move apart from each other?

Raisins uniformly distributing within a loaf of rising bread Signup and view all the answers

What process occurs when stars undergo nuclear reactions?

Conversion of lighter elements into heavier elements by nuclear fission. Signup and view all the answers

Based on the text, what happens to the velocity between galaxies as their distance increases?

It increases proportionally Signup and view all the answers

What happens to the composition of the universe over time?

It gradually increases in heavier elements due to nuclear fusion in stars. Signup and view all the answers

How does the motion of raisins in a rising loaf of bread relate to the expanding universe?

Raisins move apart, representing the galaxies receding from each other in the universe. Signup and view all the answers

What is the term used for Earth's earliest eon, encompassing the time from Earth’s formation to around 4 billion years ago?

Precambrian Signup and view all the answers

What is the estimated composition of the universe when it is one trillion years old?

20% hydrogen, 60% helium, and 20% all other elements. Signup and view all the answers

Which combination of layers form plates?

The crust and asthenosphere Signup and view all the answers

What is a scientific theory based on?

A large body of supporting evidence Signup and view all the answers

What phenomenon is thought to result in plate movement?

Convection cells Signup and view all the answers

What led scientists to conclude the occurrence of the Big Bang approximately 14 billion years ago?

An expanding universe and opaque background radiation Signup and view all the answers