Landscape features
Glacial Erosion
Glaciers are incredibly powerful agents of erosion. As they move, they carve out distinctive landforms. Some common features of glacial erosion include:
- U-shaped valleys: These are broad, flat-bottomed valleys with steep sides, formed by the erosive power of glaciers.
- Cirques: These are armchair-shaped hollows carved into mountains by glaciers.
- Arêtes: These are sharp, knife-edge ridges formed when glaciers erode opposite sides of a mountain.
- Horns: These are pyramid-shaped peaks formed by the intersection of several cirques.
- Fjords: These are drowned glacial valleys, often found in coastal areas.
Glacial Deposition
As glaciers melt, they deposit the sediment they have carried. This deposition creates various landforms. Some common features of glacial deposition include:
- Moraines: These are ridges of unsorted sediment deposited by glaciers.
- Drumlins: These are elongated hills of glacial till, often found in groups.
- Eskers: These are long, winding ridges of sand and gravel deposited by meltwater streams flowing beneath glaciers.
- Outwash plains: These are flat areas formed by the deposition of sediment by meltwater streams.
- Till plains: These are gently rolling plains formed by the deposition of glacial till.
The Analogy of Water Molecules and Isotopes
Understanding the analogy:
You've correctly applied the concept of ratios to a population of people. Let's extend this to water molecules.
- H216O and H218O: These represent two different types of water molecules, distinguished by their oxygen isotopes.
- Ocean: This is similar to the lecture hall, containing a mixture of these two types of molecules.
The question:
If we were to analyze the ratio of H216O to H218O in different parts of the ocean, would we expect it to be the same everywhere? Or might there be variations due to processes like evaporation, precipitation, and ocean currents?
This is a simplified representation of how scientists study the Earth's climate history by analyzing the ratio of these isotopes in ice cores and ocean sediments.