Foraminifera fossils show a low delta to the 18th power cap o before 66 million years ago and a sudden rise in delta to the 18th power cap o right after the Chicxulub asteroid impact. Over the next hundred thousand years, the delta to the 18th power cap o values gradually decreased.
Select the correct answer in each row to identify whether each inference about past environmental conditions is supported by the data or not.
Ferns and fungi often thrive in disrupted ecosystems. Scientists have observed an increase in fern and fungi fossils in the rocks directly above the Cretaceous–Paleogene boundary. What does this evidence suggest about the environmental conditions after the Chicxulub impact?
Classify each example of proxy data based on the paleoclimate condition it indicates. Drag each example to the correct box.
high atmospheric carbon dioxide concentration,tropical plant fossils|glacial deposits,narrow tree rings
Why is permafrost thawing during warming periods considered a positive feedback mechanism?
Scientists have recorded a drop in fossilized pollen and a rise in fern spores preserved in rock layers shortly after the Chicxulub impact. What can scientists infer about the effects of this catastrophic event on Earth’s systems based on this proxy data?
How did the cloud-albedo feedback loop likely contribute to climate cooling after the Chicxulub impact?
Match each type of proxy data to its definition.
The type and features of living things that indicate where and how each organism lived.|Concentrations or ratios of elements, compounds, or isotopes that provide data about the composition or temperature of air and water.|The type and structure of rock layers provide clues to the conditions where the rock was deposited.
Classify each feedback loop into the correct category based on whether it is a positive or negative feedback mechanism for causing or maintaining cold climate conditions. Drag each to the correct box.
volcanic ash eruptions,ice-albedo effect,cloud-albedo effect|permafrost thawing,water vapor as a greenhouse gas,volcanic outgassing of carbon dioxide
Arrange the events in the order they would occur in a positive feedback loop. Place the first event at the top of the list and the last event at the bottom.
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