Earth & Oceans
Why Is Sea Water Salty?
The ocean is salty because rivers continuously wash dissolved minerals from rocks into the sea, while evaporation removes water but leaves the salt behind.
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Earth & Geology
Why Do Volcanoes Erupt?
Volcanoes erupt because molten rock from inside Earth finds a path to the surface, driven by buoyancy, pressure, and expanding gases.
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Science
How Do Earthquakes Work?
Earthquakes happen when stress inside the Earth's crust suddenly releases. Here's how tectonic plates, fault lines and seismic waves cause the ground to shake.
scienceearthquakes