Earth Science

a QuickStudy Digital Reference Guide

Frank Miskevich

• Publisher: QuickStudy Reference Guides
• Year: 2019
• ISBN:
  9781423243250
• Topic: Scienze fisiche
• Subtopic: Geologia e scienze della terra

The ultimate reference guide to the all-encompassing essential science of earth that includes geology, meteorology, oceanography and astronomy. The amount and variety of facts covered makes our expertly written and designed guide a perfect fit to increase understanding, test scores and grades for students while offering the earth-conscious and space-lovers out there handy facts about our planet systems underground, on the surface, in our sky, and into space. This digital guide with colorful illustrations, diagrams, tables and graphs pack more facts per page than you'll find anywhere for high-value quality knowledge, better grades and planet awareness at an unbeatable price.
Digital guide includes:

• Astronomy
  • Components of Study
  • The Four Spheres
• Gravity & Orbital Motion
  • The Earth
  • The Moon
  • Structures of the Earth
  • History of the Earth
  • Plate Tectonics
  • Earthquakes & Volcanoes
• Types of Rocks
  • Igneous Rocks
  • Metamorphic Rocks
  • Sedimentary Rocks
  • Minerals, Ores & Crystals
• Hydrosphere
  • Water Cycle & Moving Water
  • Energy & Discharge
  • Profile
  • Base Level
  • Work of Streams
  • Mass Wasting
  • Competence & Capacity
  • Deposition
  • Natural Levees & Stream Valleys
  • Resistant Beds, Rapids & Waterfalls
  • Meanders & Oxbow Lakes
  • Wide Valleys
  • Drainage Patterns
  • Groundwater Depletion & Contamination
  • Springs, Caves & Caverns
• Atmosphere
  • Atmospheric Composition
  • Atmospheric Layers
  • Wind
  • Clouds
  • Meteorology
• Climate

Hydrosphere

“We don't inherit the Earth from our ancestors, we borrow it from our children.” —David Brower

Oceans are large bodies of water that cover 70% of the globe and have 97% of all water on Earth.

1. Hadalpelagic zone: Deepest part of the ocean, this zone is in valleys and trenches. It is very difficult to explore.
2. Abyssal zone: Ocean floor—roughly 75% of the ocean bottom is in this range.
3. Bathypelagic zone: Deep area where sunlight does not penetrate but organisms make their own light.
4. Mesopelagic zone: Faint sunlight reaches this region starting at roughly 200 m deep.
5. Epipelagic zone: Surface regions with lots of light; most human activity takes place in this region.

• Ocean currents: Directed flows of seawater caused by winds, differences in salinity and temperature, and the Coriolis effect.
  • Currents play a significant role in determining climates as they transfer heat from the equator and move cold water from the poles.
• Salinity refers to the amount of dissolved ions found in water.
  • Oceans have roughly 35 g/L dissolved ions (mostly sodium chloride), making it undrinkable by humans.
  • “Fresh” water varies in the amount of dissolved salts (up to 0.5 g/L) and is drinkable and usable for agriculture.
  • Brackish water has 0.5 to 35 g/L dissolved ions and is found where fresh water enters the oceans.
  • Water that evaporates leaves behind the salts, slowly increasing the salinity of oceans and bodies of water without an exit (e.g., the Dead Sea and the Great Salt Lake).
• Coastal areas are regions that border oceans and seas but which cannot be precisely drawn.
  • Tides: Rise and fall of the water level of oceans caused by the gravitation of the moon.
  • Erosion can cause loss of land area into the sea.
  • Reclaimed land: Land added by humans to rise above sea level.
  • Different jurisdictions define “coast” in different ways depending upon its use and description.
  • Climate is significantly moderated due to the large amount of water present.

Water Cycle The Path Water Takes

• The Earth’s water evaporates due to the heat and energy from the Sun.
• Wind transports the evaporated water to regions where clouds form.
• Rain falls, returning the water to the Earth.
• The rainwater then makes its way back to places on the land and sea where it evaporates again, starting the process anew.

Water That Falls on Land

• Water that falls on land is either absorbed by plant life or falls to the ground.
• Water that is absorbed by plants is later released into the atmosphere through a process called transpiration.
• Water not absorbed by plants moves downward into the Earth, then laterally into lakes, streams, and oceans.

Water Cycle Dynamics

• The water cycle is a dynamic equilibrium. This means that the total amount of water contained in the atmosphere remains essentially the same at all times, whether obtained by evaporation from land or water.
• On land, precipitation exceeds evaporation. This means that in an average period of time, more rain will fall on an area than can evaporate from that area in the same amount of time.
• On water, evaporation exceeds precipitation, maintaining equilibrium.

Moving Water

• Moving water is the single most important factor in shaping the Earth’s surface.
• Water is set in motion by gravity.
• Liquid friction, the action of water constantly rubbing against rock, forms channels through the rock. The amount of liquid friction in any given spot defines the shape and roughness of the channel.
• Gradient: Vertical drop over a defined lateral distance.

Energy & Discharge

• Potential energy lies dormant while awaiting a force that will convert it to kinetic energy.
• Gravity releases the potential energy that causes water to flow.
• The steeper the gradient, the more potential energy of water is released in a smaller area.
• Shallower gradients release less potential energy but over a larger area.
• The law of conservation of energy states that energy cannot be either created or destroyed, but is conserved at all times.
• Discharge: Volume of water that passes in a given unit of time (e.g., 17,300 m3/sec.).
• Discharge is not a constant and can be affected by numerous factors (e.g., gravity, precipitation, and gradient).

Profile

• Cross-sectional view of a stream, from source to mouth
• Water usually flows faster at the head, the source of the stream, then at the mouth, the opening where the stream (or lake, river, etc.) opens into another body.
• The steeper the gradient, the smaller the discharge
• The smaller the gradient, the larger the discharge

Base Level

• The deepest level to which a stream or river can erode
• Once reached, enough potential energy has been released that there isn’t enough energy to erode more.
• Sea level is the ultimate base level since it contains no potential energy.
• Erosion is a dynamically changing process; the deeper a channel gets cut, the less energy the water has. Therefore, it moves slower and moves less silt.

EX: A lake prevents its feeder streams from eroding below its level at any point upstream from the lake.

• Any change in base level will cause a corresponding change in stream erosion activity.

Work of Streams

• Streams are any steady current of water, whether in a brook or an ocean.
• Their constant motion produces erosion, the removal of rocks and soil from a giv...