EARTHSCIENCE

Earth comprises four major spheres

the biosphere, atmosphere, hydrosphere, and geosphere. These spheres interact in complex ways, fostering life and shaping environmental conditions.

Biosphere

is the global sum of all ecosystems and living organisms, ranging from microscopic bacteria to massive mammals. plays a critical role in nutrient cycling and ecological balance .

Lithosphere

Earth's crust where terrestrial life exists.

Hydrosphere

All forms of water, including oceans, rivers, and groundwater.

Atmosphere

The layer of gases surrounding Earth, vital for life and weather phenomena.

Hydrosphere

encompasses all water on Earth, found in oceans, rivers, lakes, glaciers, groundwater, and atmospheric water vapor.

Water Cycle Steps

The water cycle outlines how water moves through evaporation, transpiration, condensation, precipitation

Geosphere

consists of the solid parts of Earth: the crust, mantle, and core. This layer supports ecosystems and provides vital nutrients through soil and minerals, undergoing continuous change through tectonic activity, which leads to earthquakes and volcanic events.

Earth's Structure

Crust, Mantle, Core

Crust

The outermost layer, divided into oceanic and continental crust.

Mantle

The thickest layer, where convection currents cause movement and geological activity.

Core

Composed of heavy metals like iron and nickel, divided into the outer core (liquid) and inner core (solid).

Atmosphere

acts as a shield, absorbing harmful solar radiation, regulating temperature differences, and housing gasses necessary for life.

Troposphere

Where weather occurs, containing 75% of the atmosphere's mass.

Stratosphere

Contains the ozone layer, stabilizes air, and is where jets fly.

Mesosphere

The coldest layer, where meteors burn up.

Thermosphere

Experiences high temperatures and is home to the ionosphere.

Exosphere

The outermost layer, gradually transitioning into space.

Earthquakes

result from the movement of tectonic plates, causing vibrations and significant energy release, often occurring at fault lines or tectonic boundaries.

Seismic Waves

Body Wave Surface Waves

Body Waves

Include P-waves (primary) that can travel through liquids and solids, and S-waves (secondary) that can only move through solids.

Surface Waves

Travel along the Earth's surface and can cause substantial damage during seismic events.

Volcanoes

are openings in Earth's crust for molten material to reach the surface, typically found at tectonic plate boundaries. Their eruptions can range from non-explosive to catastrophic.

Types of Eruptions

Hawaiian Strombolian Vulcanian

Hawaiian

Often peaceful, with low-viscosity lava.

Strombolian

Characterized by gas explosions.

Vulcanian

Features explosive eruptions with high-viscosity magma.

Plate Boundaries

Tectonic plate boundaries can be classified into convergent, divergent, and transform boundaries, leading to varied geological features and events.

Boundary Types

Convergent Divergent Transform

Convergent

Plates push against each other, leading to mountain building or subduction.

Divergent

Plates pull apart, creating new crust.

Transform

Plates slide past one another horizontally, causing earthquakes.

Geological Time Scale

a system that categorizes Earth's history into eons, eras, periods, and epochs based on significant geological and biological events.

Hadean

Formation of Earth and the solar system.

Archean

Early life forms emerge.

Proterozoic

Oxygen-producing cyanobacteria develop.

Phanerozoic

Significant diversification of life, leading to modern species.

Types of Rocks

igneous, sedimentary, and metamorphic.

1. Igneous Rocks

Formed from the cooling of molten rock, they vary from fine-grained (extrusive) to coarse-grained (intrusive) types.

2. Sedimentary Rocks

Comprised of sediment accumulation and often containing fossils, indicating ancient life and environments.

3. Metamorphic Rocks

Produced from existing rocks under heat and pressure, resulting in transformed mineral structures.

Weather

refers to short-term atmospheric conditions

Climate

is the long-term average of weather patterns.

Wind Patterns

Winds are classified based on their origin and influence

Local Winds

Rise from geographic features influencing temperature differentials.

Prevailing Winds

Steady winds that affect weather patterns over larger regions.

Tropical storms and cyclones

are intense weather systems originating from warm ocean waters, with unique characteristics and significant impact on surrounding areas.

Tropical Depression

Characterized by low wind speeds and favorable moisture conditions.

Tropical Storm

More intense system with higher wind velocities.

Hurricane/Typhoon

Severe storms with high winds causing significant disturbance.

The Moon

is Earth's only natural satellite, influencing tides and exhibiting phases based on its position relative to Earth and the Sun.

Eclipses

occur when one celestial body casts a shadow on another during alignment, with solar and lunar eclipses resulting from different relative positions.

Small Celestial Bodies

includes meteoroids, meteors, meteorites, comets, and asteroids, significant for their roles in astrophysics and planetary science.

Ceres

Largest identified asteroid, also classified as a dwarf planet.

Halley's Comet

A well-known periodic comet with historical significance.

Life Cycle of a Star

Stars go through various stages, from stellar nebula formation to potential supernova and the creation of stellar remnants such as neutron stars or black holes, depending on mass.

Solar Structure and Phenomena

The Sun, categorized as a G-type star, consists of layers with distinct characteristics affecting solar energy emission and solar phenomena such as flares and sunspots.

Inner core

~15,000,000°C, Site of nuclear fusion, energy releases.

Photosphere

5,500°C, Visible surface, features sunspots.

Corona

1,000,000°C, Outermost layer, visible during eclipses.

Greenhouse Effect

This natural process is essential for maintaining Earth's temperature but is exacerbated by human activities leading to climate change.

Carbon Dioxide

Resulting from fossil fuel combustion.

Methane

Emitted from farming and natural gas extraction.

Nitrous Oxide

Released during agriculture and from burning fossil fuels.

Threats to Biodiversity

Biodiversity is threatened by habitat destruction, invasive species, pollution, human population growth, and overexploitation.

Biological Magnification

This concept addresses the increase in toxin concentration as one moves up the food chain, raising significant concerns for ecosystems and human health.