Science - Term 1 Flashcards

Earth's moving plates and Plate Boundaries, Volcanoes, Mountains and Earthquakes AND Scientific evidence for theory of plate tectonics, Worldwide Volcanoes and Earthquakes, Earth's interconnected systems, Natural Carbon Cycle, Feedback Loops and Climate Impacts, Greenhouse gases and Energy Transfer

Crust

thin, solid outermost layer made up of continental and oceanic plates

Mantle

thick, semi-solid layer made of silicate rocks

Outer Core

liquid layer composed of molten iron and nickel

Inner Core

solid, dense centre made of iron and nickel that gets as high as 5,500C

Lithosphere

the rigid, outer most shell of planet Earth that includes the crust and uppermost mantle

How Plates Move

they float on the semi-molten mantle and are pushed by convection currents

Convection Currents

heat is generated in the core which turns into magma on the mantle, which pushes the plates around

Divergent Plate Direction

plates move away from each other

Divergent Plate Features

• mid ocean ridges

• volcanoes

• earthquakes

Convergent Plate Direction

plates move towards each other / collide

Geohazard

the risk of damage from a geological process

How Features Form at Divergent Boundaries

magma rises from the mantle to fill the gap which forms new crust

How Features Form at Convergent Boundaries

plates push together, so one plate may subduct or both crumple

How Features Form at Transform Boundaries

plates grind together; crust is neither created nor destroyed

Fossil Evidence

same species of plants or animals found on continents now separated

Geological Evidence

similar rock types and mountain ranges found different continents

Map and Satellite Evidence

shape of continents fit together like a jigsaw puzzle

Seafloor Spreading Evidence

new crust forms at mid-ocean ridges and spreads outwards

Atmosphere

the mixture of gases that surround the Earth

Biosphere

the part of the Earth's surface, waters, and atmosphere where living things are found

Hydrosphere

all the waters on Earth’s surface, such as lakes and seas, and water over the surface, such as clouds

Lithosphere

The rigid outer part of the Earth, consisting of the Earth’s crust and upper mantle

Feedback Loop

A process where the output of a system 'loops back' to either enhance or dampen the original process.

Bi-directional

Systems affect each other both ways

Photosynthesis

Plants use carbon dioxide and sunlight to make glucose.

Respiration

Living organisms release carbon dioxide as they break down food for energy.​

Combustion

Burning fuels releases carbon dioxide into the atmosphere.​

Decomposition

Dead organisms break down, releasing carbon into the soil and atmosphere.​

Weathering

Rocks break down and can remove carbon dioxide from the atmosphere over long periods.​

Volcanism

Volcanoes release carbon dioxide from Earth's interior into the atmosphere.​

Fossil Fuels

Coal, oil, and natural gas formed from ancient plants and animals.​

Carbon Dioxide

A gas in the atmosphere that contains carbon, used by plants in photosynthesis.​

Ocean Exchange

The sea absorbs and releases carbon dioxide across it surface

Atmospheric CO2

The carbon dioxide reservoir in the air that all the other parts exchange carbon with

Carbon Cycle Importance

• CO2 helps insulate the Earth, trapping heat from the sun

• Carbon compounds carry solar energy from producers to consumers to decomposers.

Human Impact on Carbon Cycle

• Burning fossil fuels, changing land use, and using limestone sends extra carbon into the atmosphere.

• Deforestation and urbanisation remove plants that would normally absorb CO2.

Positive Feedback Loop

amplifies the change (making it faster or stronger)

Negative Feedback Loop

reduces the change (bringing the system back to balance)

Ocean Acidification

When the ocean absorbs excess Co2, it reacts with water to from carbonic acid.

Carbon Flux

the movement of carbon between different reservoirs

Anthropogenic

changes caused by human activity

Ecosystem

a biological community of interacting organisms

Infrared Radiation

Energy emitted by Earth's surface as heat after absorbing sunlight

Enhanced Greenhouse Effect

The additional warming of Earth's climate caused by human-produced gases

Carbon Sink

Natural systems like forests and oceans that absorb and store CO2.

Energy Transfer Mechanics

Energy arrives as short-wave radiation from the sun, and the Earth absorbs it and re-emits it as long-wave radiation.

Short-wave Radiation

Light emitted from the Sun

Long-Wave Radiation

Heat/infrared energy from the Earth

Global Warming Potentials

a measure of how much heat a greenhouse gas traps in the atmosphere compared to carbon dioxide

GWP of Carbon Dioxide

a baseline GWP of 1

Methane

a greenhouse gas that traps 25x more heat than carbon dioxide