Earth science
62 flashcards covering Earth science for the ACT Science section.
Earth science is the study of our planet's physical features, processes, and systems, including topics like rocks, soil, weather, oceans, and the atmosphere. It helps us understand how Earth functions as a dynamic system, from earthquakes and erosion to climate patterns and natural resources. For someone new to it, think of it as exploring the Earth's layers, cycles, and interactions with living things, which are essential for grasping environmental issues and everyday phenomena like weather forecasts.
On the ACT Science section, Earth science appears in passages that require interpreting data graphs, experimental results, or conflicting theories about topics like plate tectonics or climate change. Common question types include analyzing trends in data sets, evaluating hypotheses, and drawing conclusions from evidence, but watch out for traps like mistaking correlation for causation or overlooking subtle details in visuals. Focus on practicing quick comprehension of scientific texts and identifying key variables to boost your accuracy.
Remember to read questions carefully before examining the data.
Terms (62)
- 01
Earth's Layers
The Earth consists of four main layers: the solid inner core, liquid outer core, mostly solid mantle, and thin solid crust, which vary in composition and physical state.
- 02
Continental Drift
This theory proposes that continents have moved over geological time due to the shifting of tectonic plates, leading to changes in Earth's surface features.
- 03
Plate Boundaries
These are the edges where tectonic plates meet, categorized as divergent, convergent, or transform, and they are sites of earthquakes, volcanoes, and mountain formation.
- 04
Igneous Rocks
These rocks form from cooled and solidified magma or lava, such as granite and basalt, and are classified by their mineral composition and texture.
- 05
Sedimentary Rocks
These rocks form from the accumulation and cementation of sediments, like sandstone and limestone, often containing fossils from ancient environments.
- 06
Metamorphic Rocks
These rocks result from the alteration of existing rocks under high pressure and temperature, such as marble from limestone, changing their texture and mineral content.
- 07
Rock Cycle
This is the continuous process by which rocks are transformed through weathering, erosion, heat, pressure, and melting into igneous, sedimentary, or metamorphic forms.
- 08
Weathering
The breakdown of rocks into smaller particles through physical, chemical, or biological processes, such as freeze-thaw cycles or acid rain.
- 09
Erosion
The movement of weathered rock and soil by agents like water, wind, or ice, which shapes landscapes and transports sediments to new locations.
- 10
Deposition
The process where eroded materials are laid down in a new location, forming features like river deltas or sand dunes.
- 11
Water Cycle
The continuous movement of water on, above, and below Earth's surface, involving evaporation, condensation, precipitation, and runoff.
- 12
Evaporation
The phase change of water from liquid to vapor, driven by heat, which is a key step in the water cycle and occurs from oceans and lakes.
- 13
Condensation
The process where water vapor cools and turns into liquid droplets, forming clouds and contributing to precipitation in the atmosphere.
- 14
Precipitation
Any form of water, such as rain or snow, that falls from the atmosphere and returns to Earth's surface, influencing weather and climate.
- 15
Groundwater
Water that has infiltrated the soil and accumulated in underground aquifers, serving as a vital source for wells and natural springs.
- 16
Ocean Currents
Large-scale movements of seawater driven by wind, temperature, and salinity differences, which distribute heat and affect global climate patterns.
- 17
Tides
The rise and fall of sea levels caused by the gravitational pull of the Moon and Sun, resulting in high and low tides that follow predictable cycles.
- 18
Phases of the Moon
The changing appearances of the Moon as seen from Earth, resulting from its orbit around Earth and the varying amounts of sunlight it reflects.
- 19
Solar Eclipse
An event where the Moon passes between Earth and the Sun, blocking sunlight and casting a shadow on Earth, visible only in specific locations.
- 20
Lunar Eclipse
An occurrence when Earth passes between the Sun and the Moon, causing Earth's shadow to fall on the Moon and temporarily darken it.
- 21
Earth's Seasons
The periodic changes in weather patterns due to Earth's tilt on its axis as it orbits the Sun, leading to variations in daylight and temperature.
- 22
Greenhouse Effect
The process by which gases in the atmosphere trap heat from the Sun, warming Earth's surface and maintaining a habitable climate.
- 23
Global Warming
The long-term increase in Earth's average temperature due to human activities like burning fossil fuels, which enhances the greenhouse effect.
- 24
Ozone Layer
A region of the stratosphere containing a high concentration of ozone that absorbs most of the Sun's ultraviolet radiation, protecting life on Earth.
- 25
Fossils
The preserved remains or traces of ancient organisms, such as bones or imprints, which provide evidence of past life and environmental conditions.
- 26
Geological Time Scale
A system of chronological dating that divides Earth's history into eons, eras, periods, and epochs based on significant geological and biological events.
- 27
Radioactive Dating
A method using the decay of radioactive isotopes in rocks to determine their age, such as carbon-14 for organic materials up to about 50,000 years.
- 28
Soil Composition
The mixture of mineral particles, organic matter, water, and air that forms the top layer of Earth's surface, supporting plant growth and ecosystems.
- 29
Topsoil
The uppermost layer of soil, rich in organic matter and nutrients, which is essential for agriculture but vulnerable to erosion.
- 30
Subsoil
The layer beneath topsoil, containing less organic material and more minerals, which provides anchorage for plant roots and water storage.
- 31
Volcanoes
Mountains or vents in Earth's crust that release molten rock, ash, and gases, formed at plate boundaries and influencing global climate through eruptions.
- 32
Earthquakes
Sudden vibrations of the ground caused by the movement of tectonic plates along fault lines, releasing built-up energy as seismic waves.
- 33
Tsunamis
Large ocean waves triggered by underwater earthquakes or volcanic eruptions, which can travel across oceans and cause devastating coastal flooding.
- 34
Fault Lines
Fractures in Earth's crust where rocks on either side have moved, often associated with earthquakes and the release of stored stress.
- 35
Richter Scale
A logarithmic scale that measures the magnitude of earthquakes based on the amplitude of seismic waves, with each whole number increase representing a tenfold jump in energy.
- 36
Seismograph
An instrument that detects and records the ground motions produced by earthquakes, helping scientists analyze their strength and location.
- 37
Atmosphere Layers
The divisions of Earth's atmosphere, including the troposphere, stratosphere, mesosphere, thermosphere, and exosphere, each with distinct temperature and composition profiles.
- 38
Troposphere
The lowest layer of the atmosphere, where weather occurs and temperature decreases with altitude, extending from the surface up to about 12 kilometers.
- 39
Stratosphere
The layer above the troposphere, containing the ozone layer and experiencing increasing temperatures with altitude due to UV absorption.
- 40
Weather Fronts
Boundaries between air masses of different temperatures and humidity, such as cold fronts or warm fronts, which cause changes in weather patterns.
- 41
High Pressure System
An area of the atmosphere with higher pressure than surrounding areas, typically bringing clear skies and stable weather due to sinking air.
- 42
Low Pressure System
An area with lower pressure than its surroundings, often associated with stormy weather as rising air cools and forms clouds.
- 43
Coriolis Effect
The apparent deflection of moving objects, like winds and ocean currents, due to Earth's rotation, causing them to curve right in the Northern Hemisphere and left in the Southern.
- 44
Jet Stream
Fast-flowing, narrow air currents in the upper atmosphere that influence weather patterns by steering storms and affecting flight paths.
- 45
El Niño
A periodic warming of sea surface temperatures in the central and eastern Pacific Ocean, which disrupts global weather patterns and can lead to droughts or floods.
- 46
La Niña
The cooling of sea surface temperatures in the same Pacific region, opposite to El Niño, resulting in altered weather conditions worldwide.
- 47
Biomes
Large ecological areas on Earth, such as deserts or forests, characterized by distinct climate, vegetation, and animal life adapted to specific environmental conditions.
- 48
Deserts
Biomes with very low precipitation, leading to sparse vegetation and adaptations in flora and fauna for extreme heat or cold, covering about one-fifth of Earth's land.
- 49
Rainforests
Dense, wet forests with high biodiversity, receiving over 200 centimeters of rain annually, playing a crucial role in global oxygen production and carbon storage.
- 50
Tundra
A cold biome in Arctic regions with permafrost, low-growing vegetation, and short growing seasons, where the subsoil remains frozen year-round.
- 51
Watershed
A region of land that drains into a specific river, lake, or ocean, influencing water quality and flow through the management of land use and pollution.
- 52
Aquifers
Underground layers of porous rock or sediment that hold and transmit groundwater, serving as critical sources for drinking water and irrigation.
- 53
Renewable Resources
Natural resources like solar energy or wind that can be replenished naturally over short periods, providing sustainable alternatives to fossil fuels.
- 54
Non-Renewable Resources
Resources such as coal and oil that form over millions of years and cannot be quickly replaced, leading to depletion with continued use.
- 55
Carbon Cycle
The biogeochemical process by which carbon moves between the atmosphere, oceans, soil, and living organisms, regulated by processes like photosynthesis and respiration.
- 56
Nitrogen Cycle
The circulation of nitrogen through the environment via processes like fixation, ammonification, nitrification, and denitrification, essential for plant growth and ecosystems.
- 57
Acid Rain
Rainfall made acidic by atmospheric pollutants like sulfur dioxide and nitrogen oxides, which can damage forests, lakes, and buildings.
- 58
Pollution
The introduction of harmful substances or energy into the environment, such as air or water pollution, which disrupts ecosystems and human health.
- 59
Deforestation
The large-scale removal of forests, often for agriculture or urban development, leading to loss of biodiversity, soil erosion, and increased carbon emissions.
- 60
Conservation
The protection and sustainable management of natural resources, such as forests or water, to prevent depletion and maintain ecological balance.
- 61
Glaciers
Large masses of ice that form over centuries from accumulated snow, shaping landscapes through erosion and serving as indicators of climate change.
- 62
Ice Ages
Periods in Earth's history marked by extensive glacial coverage and lower global temperatures, influenced by factors like orbital variations and volcanic activity.