Earth Science: The Mantle and Hydrosphere

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Questions and Answers

What is the approximate average elevation of continents above sea level?

1.5 km

0.8 km (correct)

1.2 km

0.5 km

What distinguishes the Asthenosphere from the Lithosphere?

The Asthenosphere is characterized by weak and partially melted regions. (correct)

The Asthenosphere is significantly deeper than the Lithosphere.

The Lithosphere is solid while the Asthenosphere is molten.

The Lithosphere contains more iron than the Asthenosphere.

Which type of boundary is produced by the movement of tectonic plates?

Concentric boundary

Segregated boundary

Convergent boundary (correct)

Static boundary

What is the primary composition of Earth's core?

Iron and nickel alloy Signup and view all the answers

At what depth does the Lower Mantle begin?

From 660 km to 2890 km Signup and view all the answers

What is the role of the Outer Core?

To generate Earth's magnetic field Signup and view all the answers

What phenomenon does the Continental Drift theory propose?

Continents continually shift position. Signup and view all the answers

What is the depth of the Ocean compared to Earth's surface?

3,800 km Signup and view all the answers

What is the primary characteristic of a Shield?

Expansive flat regions of crystalline rocks Signup and view all the answers

At what altitude do Noctilucent Clouds form?

80 km Signup and view all the answers

What is the average pressure at the surface of the Earth?

1000 millibar Signup and view all the answers

Which of the following best describes the Geosphere?

The solid Earth extending up to 6380 km deep Signup and view all the answers

What is the depth of Ocean Basins relative to sea level?

3.8 km Signup and view all the answers

What defines a Continental Margin?

The portion of seafloor adjacent to major landmasses Signup and view all the answers

What is a common characteristic of Metals?

Malleable and ductile Signup and view all the answers

Which option correctly describes Diaphaneity in minerals?

Ability to transmit light Signup and view all the answers

What type of sedimentary rock is formed primarily from rounded gravel-sized particles?

Conglomerate Signup and view all the answers

Which of the following processes primarily leads to the formation of metamorphic rocks?

Increase in temperature and/or pressure Signup and view all the answers

What is the most common sedimentary rock made up of very fine-grained particles?

Shale Signup and view all the answers

Which agent of metamorphism is responsible for increasing rock compactness due to pressure?

Confining pressure Signup and view all the answers

What is a key characteristic of the sedimentary rock known as breccia?

Contains angular particles Signup and view all the answers

What is the role of thermal or contact metamorphism?

Recrystallization when magma intrudes Signup and view all the answers

What type of rock is referred to as 'Reservoir Rock'?

Porous and permeable rock Signup and view all the answers

Which metamorphic texture is associated with high-grade metamorphism?

Recrystallization and larger crystals Signup and view all the answers

What occurs at a continental-continental convergent boundary?

Mountains are formed from deformed sediments and metamorphic rocks Signup and view all the answers

What describes transform boundaries?

They allow for the sliding of plates past each other without destruction of lithosphere Signup and view all the answers

Who proposed that transform faults connect two spreading centers?

J. Tuzo Wilson Signup and view all the answers

What is a characteristic feature of active transform faults?

They lie between two offset ridge segments Signup and view all the answers

What is produced at transform boundaries that offsets segments of ridge systems?

Fracture zones Signup and view all the answers

What is an Alluvial Fan?

Sediments dropped by water moving down confined canyons. Signup and view all the answers

Which factor does NOT influence the form and size of dunes?

Proximity to rivers Signup and view all the answers

What characterizes Barchan Dunes?

They are solitary and crescent-shaped with tips pointing downwind. Signup and view all the answers

What is the role of wind in arid regions?

An insignificant erosional agent but effective in sediment transport. Signup and view all the answers

What defines a Playa?

A dry, flat lake bed often encrusted with salt. Signup and view all the answers

What does deflation refer to in the context of wind erosion?

The lifting and removal of loose material by wind. Signup and view all the answers

Which term refers to the angle maintained by a leeward slope of a dune?

34 degrees Signup and view all the answers

What characterizes Transverse Dunes?

They consist of a series of ridges separated by troughs oriented at right angles to wind direction. Signup and view all the answers

Study Notes

Earth's Structure and Composition

Mercury, Venus, and Mars have respective mantle pressures of 0.3, 0.7, and 1.5 with depth; Jupiter, Saturn, Uranus, and Neptune have pressures of 5.2, 9.5, 19.2, and 30 respectively.
Upper Mantle extends from crust-mantle boundary to 660 km depth and consists of two main layers: Lithosphere (100-250 km thick, includes crust and uppermost mantle) and Asthenosphere (a weak region with slight melting, distinct from Lithosphere).
Ocean covers 71% of Earth's surface and contains 97% of Earth's water, with an average depth of 3,800 km.

Mantle and Core Characteristics

Lower Mantle ranges from 660 km to 2,890 km depth; extremely hot and capable of gradual flow.
Earth's core is composed primarily of iron-nickel alloy, with pressures reaching 11 g/cm³ at the outer core and 14 g/cm³ in the inner core.
Outer Core is liquid, 2,260 km thick, generates Earth’s magnetic field; Inner Core has a radius of 1,216 km and remains solid due to immense pressure.

Plate Tectonics and Geological Features

Continental Drift theory suggests continents are mobile rather than static.
Plate Tectonics is a comprehensive model of Earth's dynamics; lithosphere is divided into plates moving at 5 cm/yr due to uneven heat distribution.
Significant geological features include Mountain Belts (such as the Himalayas and Appalachians) and Shields (flat regions of crystalline rock).

Atmospheric and Biospheric Facts

Atmosphere is a layer of air surrounding Earth; it plays a key role in weather and climate.
Noctilucent clouds exist at 80 km altitude, with 90% of the atmosphere residing below 16 km.
The biosphere encompasses all life on Earth; geosphere includes solid Earth extending to 6,380 km deep.

Oceanic and Sedimentary Features

Ocean Basins average 3.8 km below sea level, contrasting the elevation of continental regions.
Continental Margins include the shelf (flooded extension of continents), slope (steep drop-off), and rise (gradual incline).
Deep-Ocean Basins contain Abyssal Plains (flat), Trenches (depressions), and Seamounts (submerged volcanic structures).

Sedimentary Rock Formation and Types

Conglomerates form from rounded gravel-sized particles, while Breccias consist of angular particles.
Sandstone is primarily composed of sand-sized particles; Shale is a prevalent sedimentary rock formed from fine clay minerals.
Sedimentary rocks vary in size according to energy levels during transport; gravels move swiftly, sands are carried with less force, while silts and clays settle slowly.

Metamorphic Processes and Textures

Metamorphic rocks originate from preexisting rocks altered by temperature and pressure; processes include burial and intrusion by magma.
Factors influencing metamorphism include heat, confining pressure, differential stress, and chemically active fluids.
Distinctions in metamorphic textures arise from the degree of metamorphism: low-grade formations lead to denser rocks, while high-grade formations allow for crystal growth.

Wind Erosion and Arid Landforms

Wind erosion occurs in arid regions, transporting and depositing sediments to form dunes.
Flashfloods can occur in areas with sparse vegetation and steep terrain, while dry basins may transition to Playa Lakes during excessive rainfall.
Types of dunes include Barchan Dunes (crescent-shaped) and Transverse Dunes (long ridges), with their formation influenced by sand supply and vegetation.

Plate Boundaries and Transform Faults

Transform boundaries allow tectonic plates to slide past one another without creating or destroying lithosphere, discovered by J. Tuzo Wilson in 1965.
Active transform faults can be found between offset ridge segments characterized by weak, shallow earthquakes.
Interaction between continental and oceanic plates can lead to mountain formation due to subduction and the resulting geological stress.

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Description

Explore the layers of the Earth's mantle and the dynamic nature of the hydrosphere in this quiz. Understand the characteristics of different planets and the structure from the crust to the upper mantle. Test your knowledge on the related geological processes and the measurements of planetary distances.