Plate Tectonics

Key Concepts in Plate Tectonics, Earthquakes, Faults, and Volcanoes

• Plate tectonics theory explains how continents were once together and drifted apart, forming the giant continent Pangea, with tectonic plates moving on the asthenosphere.
• Convection currents are believed to cause Earth's plates to move, leading to different types of plate boundaries: divergent, convergent, and transform.
• As the seafloor spreads, magma fills the gap; subduction occurs when one plate slips under another.
• Different types of stress, including tension, compression, and shearing, affect rock and produce different types of faults: normal, reverse, and strike slip.
• Earthquakes are caused by the release of energy from the focus, below Earth's surface, and produce different types of waves: P waves, S waves, and surface waves.
• Seismographs record seismic waves, and the Mercalli, Richter, and Moment Magnitude scales are used to measure earthquakes.
• Geologists use different instruments to monitor faults, including creep meters, tiltmeters, laser-ranging devices, and GPS satellites.
• Most active volcanoes on land form near diverging plate boundaries and subduction zones, with volcanic belts forming along the boundaries of Earth's plates.
• A volcano has different parts, including a vent where lava and other substances exit and a magma chamber where magma collects.
• Volcanoes can erupt in different ways, from effusive to explosive, depending on the type of magma and the amount of gas and pressure.
• Volcanic eruptions can have different impacts, including lava flows, ash fall, pyroclastic flows, lahars, and gas emissions, affecting the environment, human health, and the economy.
• Scientists study plate tectonics, earthquakes, faults, and volcanoes to understand Earth's history and processes, and to mitigate the risks and hazards associated with natural disasters.

Key Concepts in Plate Tectonics, Earthquakes, Faults, and Volcanoes

• Plate tectonics theory explains how continents were once together and drifted apart, forming the giant continent Pangea, with tectonic plates moving on the asthenosphere.
• Convection currents are believed to cause Earth's plates to move, leading to different types of plate boundaries: divergent, convergent, and transform.
• As the seafloor spreads, magma fills the gap; subduction occurs when one plate slips under another.
• Different types of stress, including tension, compression, and shearing, affect rock and produce different types of faults: normal, reverse, and strike slip.
• Earthquakes are caused by the release of energy from the focus, below Earth's surface, and produce different types of waves: P waves, S waves, and surface waves.
• Seismographs record seismic waves, and the Mercalli, Richter, and Moment Magnitude scales are used to measure earthquakes.
• Geologists use different instruments to monitor faults, including creep meters, tiltmeters, laser-ranging devices, and GPS satellites.
• Most active volcanoes on land form near diverging plate boundaries and subduction zones, with volcanic belts forming along the boundaries of Earth's plates.
• A volcano has different parts, including a vent where lava and other substances exit and a magma chamber where magma collects.
• Volcanoes can erupt in different ways, from effusive to explosive, depending on the type of magma and the amount of gas and pressure.
• Volcanic eruptions can have different impacts, including lava flows, ash fall, pyroclastic flows, lahars, and gas emissions, affecting the environment, human health, and the economy.
• Scientists study plate tectonics, earthquakes, faults, and volcanoes to understand Earth's history and processes, and to mitigate the risks and hazards associated with natural disasters.