U3L2 Climate Change Over Time Flashcards
What happened during the Great Oxygenation Event?
Aquatic bacteria known as cyanobacteria developed the ability to photosynthesize roughly 2.3 billion years ago. By taking in carbon dioxide and releasing oxygen during photosynthesis, cyanobacteria changed the composition of the atmosphere. This addition of oxygen gas occurred over the course of hundreds of millions of years, as part of what is known as the Great Oxygenation Event.
How did the Great Oxygenation Event cause Earth’s temperature to drop?
Earth’s atmosphere had been rich in methane, which is a potent heat-trapping molecule, or greenhouse gas. As oxygen displaced the methane in the atmosphere, Earth’s temperature dropped, leading to the longest glaciation period on record.
What is the definition of feedback?
Ability of change in a system to lead to further changes
Who do ice cores help scientists learn about the climate of Earth billions of years ago?
Air bubbles and particles trapped in the ice provide evidence of the conditions of the atmosphere long ago.
How long was the Great Oxygenation Event?
Hundreds of millions of years
The addition of oxygen cause which organisms to die?
The addition of oxygen also killed off most other microbes. These were anaerobic, meaning they could not use oxygen.
Earth’s orbit changes from nearly circular to slightly oval on a ________ cycle
100,000-year
Earth rotates on its axis at a tilt, which varies between a __ and __ degree tilt every 41,000 years
22;24
What is the Milankovitch Cycle?
The combination of these cycles in Earth’s orbit, tilt, and wobble has resulted in periodic changes in the distance of Earth from the sun and the angle of the sunlight hitting Earth. These three cycles, known as the Milankovitch Cycles, have an impact on seasons and periodic cycles of change in temperature over a long period of time.
How can studying sedimentary rock help scientists find out what was happening billions of years ago?
As oxygen accumulated in the oceans, it bonded with iron in the water, creating rust. This rust fell to the ocean floor, leaving evidence that scientists can study in sedimentary rock.
The axis also wobbles like a spinning toy top, toward and away from the sun, about every ______ years.
26,000
What do scientists think caused the glacial and interglacial periods?
The Milankovitch cycles
When did the most recent glacial period take place?
Between 12,000 and 11,500 years ago
What does the Vostok ice core show scientists?
The fluctuations in temperature in that period of time.
Extra info that will probably be on the test:
I have no idea what that the extra info was supposed to be ;-;
What happened during the interglacial period and how to scientists know this?
The interglacial periods resulted in the melting of glaciers and a rise in sea levels. Cold water is able to absorb more carbon dioxide, meaning carbon dioxide levels were higher during interglacial periods.
