Plate Tectonics & Earth's Interior
What rigid outer layer of Earth is divided into moving tectonic plates?
The lithosphere or crust
What process changes liquid water into water vapor (gas)?
Evaporation
What is weather?
Day-to-day conditions like rain, cloudy, snow, etc.
What object provides most of the energy that drives Earth's weather and climate?
The Sun
About how long ago did Earth form?
4.6 billion years ago
What boundary forms where two tectonic plates move apart, allowing magma to rise and create new crust?
A divergent boundary
What is the movement of water from Earth's surface into the atmosphere and back again called?
The water cycle
What causes wind?
Unequal heating creates differences in air pressure, causing air to move from areas of higher pressure toward areas of lower pressure.
Why do we observe different phases of the Moon?
As the Moon orbits Earth, the visible portion of its sunlit half changes
What was Earth's early atmosphere like, and how did it differ from today's atmosphere?
Earth's early atmosphere formed from volcanic gases and likely contained much more water vapor, carbon dioxide, and nitrogen with little or no oxygen
What type of plate boundary occurs when one tectonic plate is forced beneath another into the mantle?
A convergent boundary with subduction
How does flowing water shape valleys and canyons?
It causes weathering & erosion, carrying sediment away and cutting into the land over time
How do clouds form when moist air rises?
Rising air expands and cools. Water vapor condenses into cloud droplets or ice crystals.
What causes day and night on Earth?
Earth's rotation on its axis
How did Earth's oceans develop?
As Earth cooled, water vapor condensed into liquid water. Additional water may have been supplied by volcanic outgassing and impacts from water-rich objects
Why are active volcanoes common at areas with hotspots?
The rising mantle plume pushes through the crust to create steady volcanic activity
What does water do when it freezes & how can this affect rocks?
Water expands as it forms ice. In cracks, this expansion can break rocks apart through frost wedging.
How can ocean currents influence in the climate of coastal regions?
Warm currents can make nearby climates warmer and more humid, while cold currents can make them cooler and often drier.
How does Earth's axial tilt contribute to the seasons?
Earth's tilted axis causes the angle and duration of sunlight to change as Earth orbits the Sun, producing seasonal temperature differences
How did oxygen build up in Earth's atmosphere?
Photosynthetic organisms released oxygen
How do convection currents in the mantle help cause tectonic plate movement?
Heat from Earth's interior causes mantle material to circulate. This movement helps move the plate. (Hot rises, cold sinks)
How can removing vegetation from a hillside affect the water cycle & increase erosion?
Less vegetation reduces water uptake and interception, increasing runoff. Faster runoff can erode more soil, carry sediment into waterways, and alter local water movement.
How could increasing greenhouse gas concentrations affect Earth's climate and create risks for human communities?
More greenhouse gases means rising temperatures, causing changing precipitations patterns, sea levels, and the frequency or intensity of some hazards.
What evidence supports the idea that the universe is expanding?
Light from distant galaxies is shifted toward longer wavelengths, showing that many galaxies are moving away from us
How do the geologic time scale and fossil evidence help scientists reconstruct Earth's early history and the development of life?
Scientists use rock layers, radiometric ages, and fossils to place events in sequence and estimate their ages. Fossils reveal changes in organisms through time, while rock evidence records changes in oceans, the atmosphere, climate, and other Earth systems