Earth's Surface and Weathering

Flashcards covering key concepts about the Earth's surface, weathering processes, and related landforms.

What natural processes modify the earth's surface?

Internal and external processes.

What are some examples of internal processes that shape the Earth's surface?

Movement of tectonic plates, volcanic eruptions, earthquakes, faulting, and folding.

What are some examples of mountains formed by internal processes?

Himalayan Mountains, Andes, Mount St. Helens, Mount Pinatubo, Sierra Nevada Mountains, and Harz Mountains.

What agents are involved in external processes?

Weather, rivers, glaciers, wind, waves, and underground water.

What is the definition of weathering?

The wearing away or breaking down of rocks by heat and moisture.

Why is weathering considered a static process?

It does not involve horizontal movement of disintegrated rocks; the weathered particles remain in the same place.

What is denudation?

The process by which external agents reduce the height of the land surface and carry away broken rock fragments.

What is erosion?

The wearing away of the earth's surface by agents like running water, moving ice, wind, and waves, involving the movement of fragmented rocks.

What is deposition (or aggradation)?

The process where rock fragments from degradation fill low-lying areas, increasing their elevation.

What is gradation?

The slow and continuous process by which external processes try to achieve a uniform level of the land surface, comprising degradation and aggradation.

What are the three main types of weathering processes?

Physical/Mechanical, Chemical, and Biological Weathering.

What is physical or mechanical weathering?

The disintegration of rocks without any change in their chemical composition.

What are the main factors responsible for physical weathering?

Temperature, water, and frost.

What is exfoliation?

A weathering process in which the outer surface of a rock flakes off in the form of leaves.

What is block disintegration?

The splitting of rocks due to the constant process of expansion and contraction, often influenced by frost action.

What is granular disintegration?

The process where rocks made up of coarse mineral grains fall apart grain by grain due to alternate heating and cooling.

What is salt crystallization?

The process where salt crystals grow in cracks, widening them and splitting the rocks apart.

What is chemical weathering?

Weathering that involves changes in the chemical composition of rocks.

What is oxidation?

The process by which minerals in rocks absorb oxygen from the air, resulting in new chemical compounds and often causing rocks to turn reddish-brown.

What is carbonation?

The absorption of carbon dioxide from the atmosphere by minerals in rocks, forming carbonic acid which can dissolve rocks like limestone.

What is hydrolysis?

The process where acidic water causes corrosion in rocks containing minerals like potassium, sodium, calcium, and silica, producing fine particles.

What is hydration?

The breakdown of rocks as they absorb water, causing them to swell and soften.

What are sinkholes?

Landforms formed when limestone or other carbonate rock below the land surface are naturally dissolved by circulating groundwater.

What are grikes and clints?

Deep narrow grooves (grikes) and flat or round topped ridges (clints) formed on the surface of rocks due to chemical weathering.

What is a stalactite?

A formation that hangs from the ceiling of caves, made of calcite.

What is a stalagmite?

A cone-shaped formation that rises from the floor of a cave, made of calcite.

What is biological weathering?

The breakdown of rocks into sediments assisted by living organisms like animals, vegetation, and humans.

How do burrowing animals contribute to weathering?

By digging into the soil and loosening materials, exposing more rocks to weathering agents.

How do plant roots contribute to weathering?

By growing in size and causing cracks in rocks, leading to their breakdown.

How do human beings contribute to weathering?

By breaking rocks for mining, quarrying, farming, and construction.

What are the main factors affecting weathering?

Climate, rock-forming minerals, particle size, and living organisms.

How does climate affect weathering?

Climatic conditions determine the variation in temperature and availability of water, influencing freeze-thaw cycles.

What is mass wasting?

The movement of rock material downslope under the influence of gravity, aided by water.

What are the three types of mass wasting?

Earth flow, mudflow, and landslide.

What is regolith?

A layer of loose fragments of rocks forming the upper surface of the earth's crust.

What is soil?

Regolith made out of fine particles added with organic substance (humus).