Week 2 (Slide 15-17) Flashcards
Define “Milankovitch Cycles.”
Milankovitch Cycles are long-term changes in Earth’s orbit and orientation, including axial tilt, precession, and orbital eccentricity, which influence Earth’s climate over thousands of years.
How does the axial tilt of Earth affect its climate over long periods?
Changes in Earth’s axial tilt, ranging from 22.1° to 24.5°, alter the intensity and distribution of sunlight, contributing to variations in climate, including glacial and interglacial cycles.
What is precession in the context of Earth’s motion?
A) The gradual change in the Earth’s axial tilt
B) The change in the distance between Earth and the Sun
C) The wobbling of Earth’s axis, like a spinning top
D) The movement of tectonic plates
C) The wobbling of Earth’s axis, like a spinning top
True or False: The Earth’s orbit around the sun is a perfect circle, causing consistent solar intensity throughout the year.
False – Earth’s orbit is slightly elliptical (eccentric), which causes variations in solar intensity, contributing to climate cycles over long periods.
Yes or No
Are Milankovitch Cycles considered a recent discovery?
No – While understanding of these cycles has deepened with modern science, Milutin Milankovitch first proposed them in the early 20th century, and they are now well-established as climate change drivers.
Explain how changes in Earth’s orbital eccentricity can influence climate.
Earth’s orbit fluctuates between being more circular and slightly elliptical over thousands of years. When the orbit is more elliptical, there are greater differences in solar radiation received, affecting seasonal and long-term climate patterns.
Which of the following provides evidence for Milankovitch Cycles?
A) Ice cores and ocean sediments
B) Volcanic rock formations
C) Fossilized plants
D) Desert dunes
A
How might changes in the Sun’s output over time affect Earth’s climate?
Although controversial, variations in the Sun’s energy output could influence Earth’s climate, potentially contributing to warming or cooling phases over long timescales.
Define “precession” in astronomical terms.
Precession is the gradual wobble in Earth’s rotational axis, which changes the orientation of the axis over thousands of years, influencing seasonal variations and climate.
True or False: The movement of tectonic plates has no impact on Earth’s climate.
False – The movement of tectonic plates, such as the formation of mountain ranges or the closing of the Isthmus of Panama, can alter ocean currents and atmospheric circulation, significantly affecting climate.
Describe how the movement of the Indian subcontinent and the closing of the Isthmus of Panama have impacted Earth’s climate.
The collision of the Indian subcontinent with Asia created the Himalayas, altering atmospheric circulation and monsoon patterns. The closing of the Isthmus of Panama about 10 million years ago redirected ocean currents, strengthening the Gulf Stream and impacting climate patterns globally.
