Seismic waves are mechanical acoustic energy that travel through Earth. They can result from earthquakes, volcanic eruptions, or man-made explosions. Seismologists record waves using seismometers, hydrophones, or accelerometers
Sedimentary rocks form from mineral or organic particles deposited at Earth's surface. Cover 73% of Earth's land surface but only 8% of crust volume. Deposited in layers forming bedding structures. Found on Mars and used for civil engineering and natural resources
Stratum is a distinct rock or sediment layer separated by bedding surfaces. Strata form parallel layers that can cover hundreds of thousands of km². Individual bands can vary in thickness from millimeters to meters
Earth's total water volume is 1.386 billion km³, with 97.5% being salt water. Freshwater accounts for nearly 1% of total water, with salinity below 0.35‰. Earth's oceans cover 70.8% of Earth's surface, making it appear blue from space
Metamorphic rocks form from existing rocks under high temperatures and pressures. They make up 12% of Earth's land surface and are found in orogenic belts. Metamorphism can occur through burial, tectonic processes, or local heating
Tectonic plates are pieces of Earth's crust and upper mantle. Plates are around 100 km thick and consist of oceanic and continental crust. Oceanic crust contains mafic basaltic rocks, continental crust felsic granitic rocks